Species Name
Preferred Formula
Image
Δf H°(0 K)
Δf H°(298.15 K)
Uncertainty
Units
Relative Molecular Mass
ATcT ID
Dihydrogen H2 (g) 0 0 exact 2.01588 ± 0.00014 1333-74-0*0 Helium He (g) 0 0 exact 4.0026020 ± 0.0000020 7440-59-7*0 Carbon C (graphite) 0 0 exact 12.01070 ± 0.00080 7440-44-0*500 Dinitrogen N2 (g) 0 0 exact 28.01348 ± 0.00014 7727-37-9*0 Dioxygen O2 (g) 0 0 exact 31.99880 ± 0.00060 7782-44-7*0 Difluorine F2 (g) 0 0 exact 37.9968064 ± 0.0000010 7782-41-4*0 Neon Ne (g) 0 0 exact 20.17970 ± 0.00060 7440-01-9*0 Silicon Si (cr,l) 0 0 exact 28.08550 ± 0.00030 7440-21-3*500 Sulfur S (cr,l) 0 0 exact 32.0660 ± 0.0060 7704-34-9*500 Dichlorine Cl2 (g) 0 0 exact 70.9054 ± 0.0018 7782-50-5*0 Argon Ar (g) 0 0 exact 39.94800 ± 0.00100 7440-37-1*0 Dibromine Br2 (cr,l) 0 0 exact 159.8080 ± 0.0020 7726-95-6*500 Krypton Kr (g) 0 0 exact 83.8000 ± 0.1000 7439-90-9*0 Diiodine I2 (cr,l) 0 0 exact 253.808940 ± 0.000060 7553-56-2*500 Xenon Xe (g) 0 0 exact 131.2900 ± 0.0200 7440-63-3*0 Platinum Pt (cr,l) 0 0 exact 195.0780 ± 0.0020 7440-06-4*500 Radon Rn (g) 0 0 exact 222.0000 ± 0.1000 10043-92-2*0 Deuterium molecule D2 (g) 0 0 exact 4.02820355600 ± 0.00000000080 7782-39-0*0 Hydrogen atom H (g) 216.034 217.998 ± 0.000 kJ/mol 1.007940 ± 0.000070 12385-13-6*0 Carbon C (g) 711.389 716.874 ± 0.040 kJ/mol 12.01070 ± 0.00080 7440-44-0*0 Oxygen atom O (g) 246.844 249.229 ± 0.0021 kJ/mol 15.99940 ± 0.00030 17778-80-2*0 Methane CH4 (g) -66.550 -74.519 ± 0.044 kJ/mol 16.04246 ± 0.00085 74-82-8*0 Nitrogen atom N (g) 470.577 472.439 ± 0.023 kJ/mol 14.006740 ± 0.000070 17778-88-0*0 Water H2O (cr,l) -286.270 -285.798 ± 0.022 kJ/mol 18.01528 ± 0.00033 7732-18-5*500 Carbon dioxide CO2 (g) -393.110 -393.476 ± 0.015 kJ/mol 44.00950 ± 0.00100 124-38-9*0 Hydron H+ (g) 1528.084 1530.047 ± 0.000 kJ/mol 1.007391 ± 0.000070 12408-02-5*0 Water H2O (g) -238.900 -241.803 ± 0.022 kJ/mol 18.01528 ± 0.00033 7732-18-5*0 Ethane CH3CH3 (g) -68.42 -84.05 ± 0.12 kJ/mol 30.0690 ± 0.0017 74-84-0*0 Chlorine atom Cl (g) 119.621 121.302 ± 0.0011 kJ/mol 35.45270 ± 0.00090 22537-15-1*0 Fluorine atom F (g) 77.254 79.360 ± 0.017 kJ/mol 18.99840320 ± 0.00000050 14762-94-8*0 Ethylene CH2CH2 (g) 60.87 52.36 ± 0.11 kJ/mol 28.0532 ± 0.0016 74-85-1*0 Methyl CH3 (g) 149.872 146.472 ± 0.050 kJ/mol 15.03452 ± 0.00083 2229-07-4*0 Methanol CH3OH (g) -190.02 -200.91 ± 0.15 kJ/mol 32.04186 ± 0.00090 67-56-1*0 Propane CH3CH2CH3 (g) -82.74 -105.03 ± 0.15 kJ/mol 44.0956 ± 0.0025 74-98-6*0 Ammonia NH3 (g) -38.565 -45.557 ± 0.029 kJ/mol 17.03056 ± 0.00022 7664-41-7*0 Bromine atom Br (g) 117.925 111.863 ± 0.055 kJ/mol 79.90400 ± 0.00100 10097-32-2*0 Hydroxyl OH (g) 37.280 37.520 ± 0.022 kJ/mol 17.00734 ± 0.00031 3352-57-6*0 Formaldehyde CH2O (g) -105.389 -109.229 ± 0.095 kJ/mol 30.02598 ± 0.00087 50-00-0*0 Acetylene HCCH (g) 228.86 228.30 ± 0.12 kJ/mol 26.0373 ± 0.0016 74-86-2*0 Carbon monoxide CO (g) -113.800 -110.520 ± 0.026 kJ/mol 28.01010 ± 0.00085 630-08-0*0 Hydrogen chloride HCl (g) -91.988 -92.172 ± 0.0062 kJ/mol 36.46064 ± 0.00090 7647-01-0*0 Ethanol CH3CH2OH (g) -217.28 -235.00 ± 0.20 kJ/mol 46.0684 ± 0.0017 64-17-5*0 Benzene C6H6 (g) 100.72 83.20 ± 0.21 kJ/mol 78.1118 ± 0.0048 71-43-2*0 Hydrogen fluoride HF (g) -272.678 -272.725 ± 0.018 kJ/mol 20.006343 ± 0.000070 7664-39-3*0 Ethyl CH3CH2 (g) 131.45 120.70 ± 0.20 kJ/mol 29.0611 ± 0.0016 2025-56-1*0 Hydrogen cyanide HCN (g) 129.672 129.288 ± 0.087 kJ/mol 27.02538 ± 0.00081 74-90-8*0 Propene CH3CHCH2 (g) 34.85 20.01 ± 0.18 kJ/mol 42.0797 ± 0.0024 115-07-1*0 Iodine I (g) 107.157 106.757 ± 0.0021 kJ/mol 126.904470 ± 0.000030 14362-44-8*0 Hydrogen bromide HBr (g) -27.52 -35.36 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*0 Nitric oxide NO (g) 90.633 91.137 ± 0.066 kJ/mol 30.00614 ± 0.00031 10102-43-9*0 Acetaldehyde CH3CHO (g) -154.95 -165.48 ± 0.22 kJ/mol 44.0526 ± 0.0017 75-07-0*0 Propyne CH3CCH (g) 192.64 185.49 ± 0.21 kJ/mol 40.0639 ± 0.0024 74-99-7*0 Chloromethane CH3Cl (g) -74.71 -82.65 ± 0.18 kJ/mol 50.4872 ± 0.0012 74-87-3*0 Acetone CH3C(O)CH3 (g) -199.99 -216.93 ± 0.26 kJ/mol 58.0791 ± 0.0025 67-64-1*0 Hydroxyde [OH]- (g) -139.061 -139.028 ± 0.022 kJ/mol 17.00789 ± 0.00031 14280-30-9*0 Dioxidanyl HOO (g) 15.07 12.16 ± 0.14 kJ/mol 33.00674 ± 0.00060 3170-83-0*0 Methylamine CH3NH2 (g) -6.54 -21.24 ± 0.22 kJ/mol 31.05714 ± 0.00088 74-89-5*0 Nitrogen dioxide ONO (g) 36.872 34.065 ± 0.066 kJ/mol 46.00554 ± 0.00060 10102-44-0*0 Vinyl CH2CH (g) 301.24 297.20 ± 0.27 kJ/mol 27.0452 ± 0.0016 2669-89-8*0 Allene CH2CCH2 (g) 197.39 189.93 ± 0.22 kJ/mol 40.0639 ± 0.0024 463-49-0*0 Fluoromethane CH3F (g) -227.42 -235.45 ± 0.23 kJ/mol 34.03292 ± 0.00083 593-53-3*0 Hydrogen iodide HI (g) 28.644 26.468 ± 0.036 kJ/mol 127.912410 ± 0.000076 10034-85-2*0 Silicon Si (g) 450.39 454.72 ± 0.59 kJ/mol 28.08550 ± 0.00030 7440-21-3*0 Hydrogen peroxide HOOH (g) -129.413 -135.399 ± 0.058 kJ/mol 34.01468 ± 0.00062 7722-84-1*0 Methylene CH2 (g, triplet) 391.063 391.609 ± 0.094 kJ/mol 14.02658 ± 0.00081 2465-56-7*1 n-Butane CH3CH2CH2CH3 (g) -98.38 -125.69 ± 0.23 kJ/mol 58.1222 ± 0.0033 106-97-8*0 Toluene C6H5CH3 (g) 73.34 50.06 ± 0.31 kJ/mol 92.1384 ± 0.0056 108-88-3*0 Silane SiH4 (g) 42.68 33.07 ± 0.65 kJ/mol 32.11726 ± 0.00041 7803-62-5*0 Ozone OOO (g) 144.407 141.744 ± 0.039 kJ/mol 47.99820 ± 0.00090 10028-15-6*0 Methylene CH2 (g, singlet) 428.72 429.13 ± 0.11 kJ/mol 14.02658 ± 0.00081 2465-56-7*2 Ammonium hydroxide NH4OH (aq, 1000 H2O) -366.37 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*839 1,3-Butadiene CH2CHCHCH2 (g) 125.51 111.03 ± 0.30 kJ/mol 54.0904 ± 0.0032 106-99-0*0 Nitrilomethyl CN (g) 436.72 440.01 ± 0.14 kJ/mol 26.01744 ± 0.00080 2074-87-5*0 Methoxy CH3O (g) 28.96 21.59 ± 0.27 kJ/mol 31.03392 ± 0.00088 2143-68-2*0 Ketene CH2CO (g) -45.35 -48.41 ± 0.11 kJ/mol 42.0367 ± 0.0016 463-51-4*0 Fluoride F- (g) -250.911 -249.126 ± 0.017 kJ/mol 18.99895178 ± 0.00000050 16984-48-8*0 Hydrogen chloride HCl (aq, 100 H2O) -165.755 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*828 Acetonitrile CH3CN (g) 81.15 74.09 ± 0.24 kJ/mol 41.0520 ± 0.0016 75-05-8*0 Bromomethane CH3Br (g) -20.53 -35.93 ± 0.20 kJ/mol 94.9385 ± 0.0013 74-83-9*0 Hydrogen iodide HI (aq, 5000 H2O) -56.643 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*844 Formic acid HC(O)OH (g, syn) -371.03 -378.35 ± 0.21 kJ/mol 46.0254 ± 0.0010 64-18-6*1 Methoxide [CH3O]- (g) -122.43 -130.16 ± 0.27 kJ/mol 31.03447 ± 0.00088 3315-60-4*0 Acetic acid CH3C(O)OH (aq, 100 H2O) -484.66 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*828 Hydrogen bromide HBr (aq, 3000 H2O) -120.26 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*842 iso-Butane CH(CH3)3 (g) -105.96 -134.56 ± 0.27 kJ/mol 58.1222 ± 0.0033 75-28-5*0 Formic acid HC(O)OH (aq, 100 H2O) -425.29 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*828 Hydrogen fluoride HF (l) -303.21 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*590 Hydroxymethyl CH2OH (g) -10.28 -16.58 ± 0.28 kJ/mol 31.03392 ± 0.00088 2597-43-5*0 Hypochlorous acid HOCl (g) -73.837 -76.777 ± 0.024 kJ/mol 52.46004 ± 0.00095 7790-92-3*0 Amidogen NH2 (g) 188.92 186.03 ± 0.11 kJ/mol 16.02262 ± 0.00016 13770-40-6*0 Formyl HCO (g) 41.381 41.755 ± 0.095 kJ/mol 29.01804 ± 0.00086 2597-44-6*0 Acetic acid CH3C(O)OH (g, syn) -418.53 -432.70 ± 0.36 kJ/mol 60.0520 ± 0.0017 64-19-7*1 Phenyl C6H5 (g) 352.13 338.78 ± 0.63 kJ/mol 77.1039 ± 0.0048 2396-01-2*0 Tetrafluoromethane CF4 (g) -927.66 -933.63 ± 0.23 kJ/mol 88.00431 ± 0.00080 75-73-0*0 Sulfur dioxide OSO (g) -294.14 -296.68 ± 0.13 kJ/mol 64.0648 ± 0.0060 7446-09-5*0 Dibromine Br2 (g) 45.70 30.90 ± 0.11 kJ/mol 159.8080 ± 0.0020 7726-95-6*0 Diiodine I2 (g) 65.497 62.417 ± 0.0041 kJ/mol 253.808940 ± 0.000060 7553-56-2*0 Ethynyl CCH (g) 563.74 567.85 ± 0.15 kJ/mol 25.0293 ± 0.0016 2122-48-7*0 Propargyl CH2CCH (g) 354.02 351.43 ± 0.32 kJ/mol 39.0559 ± 0.0024 2932-78-7*0 Cyclopropane CH2(CH2CH2) (g) 71.05 53.92 ± 0.32 kJ/mol 42.0797 ± 0.0024 75-19-4*0 Allyl CH2CHCH2 (g) 179.87 168.14 ± 0.33 kJ/mol 41.0718 ± 0.0024 1981-80-2*0 Chloroethane CH3CH2Cl (g) -96.97 -111.56 ± 0.25 kJ/mol 64.5138 ± 0.0019 75-00-3*0 Chloride Cl- (g) -228.953 -227.346 ± 0.0021 kJ/mol 35.45325 ± 0.00090 16887-00-6*0 Methanimine CH2NH (g) 96.37 88.46 ± 0.34 kJ/mol 29.04126 ± 0.00083 2053-29-4*0 Ethylamine CH3CH2NH2 (g) -28.18 -49.95 ± 0.44 kJ/mol 45.0837 ± 0.0017 75-04-7*0 Fluoroform CHF3 (g) -689.29 -696.24 ± 0.38 kJ/mol 70.01385 ± 0.00080 75-46-7*0 Oxomethylium [HCO]+ (g) 827.757 827.173 ± 0.095 kJ/mol 29.01749 ± 0.00086 17030-74-9*0 Ethenol CH2CHOH (g, syn) -113.38 -124.50 ± 0.38 kJ/mol 44.0526 ± 0.0017 557-75-5*1 Acetyl CH3CO (g) -3.67 -10.24 ± 0.29 kJ/mol 43.0446 ± 0.0016 3170-69-2*0 Trifluoromethyl CF3 (g) -464.88 -467.68 ± 0.43 kJ/mol 69.00591 ± 0.00080 2264-21-3*0 Ethylium [CH3CH2]+ (g) 915.10 903.02 ± 0.30 kJ/mol 29.0606 ± 0.0016 14936-94-8*0 n-Propyl CH3CH2CH2 (g) 118.31 100.90 ± 0.40 kJ/mol 43.0877 ± 0.0024 2143-61-5*0 Phenol C6H5OH (g) -74.68 -93.27 ± 0.63 kJ/mol 94.1112 ± 0.0048 108-95-2*0 Tetrachloromethane CCl4 (g) -89.37 -91.54 ± 0.42 kJ/mol 153.8215 ± 0.0037 56-23-5*0 Formamide CH(O)NH2 (g) -178.63 -188.99 ± 0.34 kJ/mol 45.04066 ± 0.00088 75-12-7*0 Bromide Br- (g) -206.612 -212.674 ± 0.055 kJ/mol 79.90455 ± 0.00100 24959-67-9*0 Hypobromous acid HOBr (g) -51.27 -61.74 ± 0.48 kJ/mol 96.9113 ± 0.0010 13517-11-8*0 Oxonium [H3O]+ (g) 605.89 599.14 ± 0.17 kJ/mol 19.02267 ± 0.00037 13968-08-6*0 Methyl hydroperoxide CH3OOH (g) -114.91 -127.73 ± 0.44 kJ/mol 48.0413 ± 0.0010 3031-73-0*0 iso-Propyl CH3CHCH3 (g) 105.50 88.63 ± 0.40 kJ/mol 43.0877 ± 0.0024 2025-55-0*0 Cyanoacetylene HCCCN (g) 372.17 373.92 ± 0.58 kJ/mol 51.0468 ± 0.0024 1070-71-9*0 Benzaldehyde C6H5C(O)H (g) -19.75 -37.54 ± 0.77 kJ/mol 106.1219 ± 0.0056 100-52-7*0 Chlorooxidanyl ClO (g) 101.124 101.716 ± 0.035 kJ/mol 51.45210 ± 0.00095 14989-30-1*0 Iodide I- (g) -187.995 -188.396 ± 0.0021 kJ/mol 126.905019 ± 0.000030 20461-54-5*0 Methylidyne CH (g) 592.979 596.314 ± 0.081 kJ/mol 13.01864 ± 0.00080 3315-37-5*0 Methylperoxy CH3OO (g) 22.52 13.07 ± 0.34 kJ/mol 47.0333 ± 0.0010 2143-58-0*0 Dioxymethyl CH2OO (g) 111.66 104.65 ± 0.56 kJ/mol 46.0254 ± 0.0010 56077-92-0*0 Nitric acid HON(O)O (g) -124.44 -134.16 ± 0.17 kJ/mol 63.01288 ± 0.00091 7697-37-2*0 Cyclopentadiene CH2(CHCHCHCH) (g) 151.82 134.70 ± 0.54 kJ/mol 66.1011 ± 0.0040 542-92-7*0 Hydroxyformyl HOCO (g, trans) -181.15 -184.12 ± 0.40 kJ/mol 45.0174 ± 0.0010 2564-86-5*1 Vinyl chloride CH2CHCl (g) 29.36 21.78 ± 0.27 kJ/mol 62.4979 ± 0.0018 75-01-4*0 Imidogen NH (g) 358.74 358.79 ± 0.16 kJ/mol 15.014680 ± 0.000099 13774-92-0*0 1-Hydroxyethyl CH3CHOH (g, gauche-anti) -42.82 -56.25 ± 0.46 kJ/mol 45.0605 ± 0.0017 2348-46-1*1 Vinylacetylene CH2CHCCH (g) 296.24 289.48 ± 0.56 kJ/mol 52.0746 ± 0.0032 689-97-4*0 Ethoxide [CH3CH2O]- (g) -163.84 -178.78 ± 0.44 kJ/mol 45.0610 ± 0.0017 16331-64-9*0 Methoxymethane CH3OCH3 (g) -166.51 -184.01 ± 0.37 kJ/mol 46.0684 ± 0.0017 115-10-6*0 1,3-Butadiyne HCCCCH (g) 458.30 460.03 ± 0.50 kJ/mol 50.0587 ± 0.0032 460-12-8*0 Sulfur trioxide OS(O)O (g) -389.74 -395.48 ± 0.24 kJ/mol 80.0642 ± 0.0061 7446-11-9*0 Methylium [CH3]+ (g) 1099.346 1095.402 ± 0.045 kJ/mol 15.03397 ± 0.00083 14531-53-4*0 Isocyanic acid HNCO (g) -115.94 -118.93 ± 0.28 kJ/mol 43.02478 ± 0.00086 75-13-8*0 Cyanamide NH2CN (g) 141.60 135.59 ± 0.78 kJ/mol 42.04006 ± 0.00082 420-04-2*0 Difluorophosgene CF2O (g) -603.35 -606.45 ± 0.40 kJ/mol 66.00691 ± 0.00085 353-50-4*0 Hypofluorous acid HOF (g) -84.37 -87.27 ± 0.19 kJ/mol 36.00574 ± 0.00031 14034-79-8*0 Oxygen atom anion O- (g) 105.868 108.097 ± 0.0021 kJ/mol 15.99995 ± 0.00030 14337-01-0*0 Nitric acid HON(O)O (aq, 1000 H2O) -206.22 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*839 Iodomethane CH3I (g) 24.40 14.87 ± 0.18 kJ/mol 141.93899 ± 0.00083 74-88-4*0 Isobutene CH2C(CH3)2 (g) 4.22 -16.84 ± 0.32 kJ/mol 56.1063 ± 0.0032 115-11-7*0 N-Methylenemethanamine CH3NCH2 (g) 94.49 79.57 ± 0.67 kJ/mol 43.0678 ± 0.0016 1761-67-7*0 Dichloromethane CH2Cl2 (g) -86.90 -93.75 ± 0.34 kJ/mol 84.9320 ± 0.0020 75-09-2*0 Chlorobenzene C6H5Cl (g) 67.26 52.31 ± 0.61 kJ/mol 112.5566 ± 0.0049 108-90-7*0 Hydrogen chloride HCl (aq, 600 H2O) -166.449 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*834 Isocyanomethane CH3NC (g) 183.85 177.31 ± 0.46 kJ/mol 41.0520 ± 0.0016 593-75-9*0 1,2-Butadiene CH3CHCCH2 (g) 176.02 162.52 ± 0.42 kJ/mol 54.0904 ± 0.0032 590-19-2*0 Ethynide [CCH]- (g) 277.29 280.71 ± 0.19 kJ/mol 25.0299 ± 0.0016 29075-95-4*0 Dimethylamine (CH3)2NH (g) 4.22 -17.42 ± 0.39 kJ/mol 45.0837 ± 0.0017 124-40-3*0 Trimethylsilane SiH(CH3)3 (g) -125.8 -151.9 ± 1.5 kJ/mol 74.1970 ± 0.0025 993-07-7*0 Hydride H- (g) 143.264 145.228 ± 0.000 kJ/mol 1.008489 ± 0.000070 12184-88-2*0 Oxirane O(CH2CH2) (g) -39.89 -52.43 ± 0.36 kJ/mol 44.0526 ± 0.0017 75-21-8*0 Cyanogen chloride ClCN (g) 135.13 135.83 ± 0.43 kJ/mol 61.4701 ± 0.0012 506-77-4*0 Phenide [C6H5]- (g) 244.29 230.86 ± 0.38 kJ/mol 77.1044 ± 0.0048 30922-78-2*0 Cyclopropene CH2(CHCH) (g) 292.44 283.71 ± 0.42 kJ/mol 40.0639 ± 0.0024 2781-85-3*0 2-Hydroxyethyl CH2CH2OH (g, gauche-syn) -13.01 -26.28 ± 0.49 kJ/mol 45.0605 ± 0.0017 4422-54-2*1 Trihydrogen cation [H3]+ (g) 1110.304 1106.696 ± 0.013 kJ/mol 3.02327 ± 0.00021 28132-48-1*0 Methyl formate HC(O)OCH3 (g, syn) -346.96 -360.01 ± 0.65 kJ/mol 60.0520 ± 0.0017 107-31-3*1 Acrolein CH2CHCHO (g, trans) -55.17 -65.57 ± 0.64 kJ/mol 56.0633 ± 0.0024 107-02-8*1 Sulfuric acid OS(O)(OH)2 (aq, 100 H2O) -887.45 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*828 Ammonium [NH4]+ (g) 643.03 631.71 ± 0.20 kJ/mol 18.03795 ± 0.00029 14798-03-9*0 Nitrous acid HONO (g, trans) -72.977 -79.120 ± 0.079 kJ/mol 47.01348 ± 0.00061 7782-77-6*1 Methylamidogen CH3NH (g) 187.90 177.24 ± 0.40 kJ/mol 30.04920 ± 0.00085 15622-51-2*0 Cyanide [CN]- (g) 63.968 67.254 ± 0.091 kJ/mol 26.01799 ± 0.00080 57-12-5*0 2-Butyne CH3CCCH3 (g) 159.46 146.50 ± 0.45 kJ/mol 54.0904 ± 0.0032 503-17-3*0 Difluoromethane CH2F2 (g) -443.32 -450.94 ± 0.33 kJ/mol 52.02339 ± 0.00081 75-10-5*0 Silyl SiH3 (g) 204.78 199.31 ± 0.85 kJ/mol 31.10932 ± 0.00037 13765-44-1*0 Sulfurous acid S(O)(OH)2 (aq, 2500 H2O) -617.23 ± 0.15 kJ/mol 82.0801 ± 0.0061 7782-99-2*898 Oxygen difluoride FOF (g) 26.82 24.57 ± 0.22 kJ/mol 53.99621 ± 0.00030 7783-41-7*0 Hypochlorite [ClO]- (g) -118.60 -118.33 ± 0.13 kJ/mol 51.45265 ± 0.00095 14380-61-1*0 Nitrosyl hydride HNO (g) 109.94 106.97 ± 0.11 kJ/mol 31.01408 ± 0.00032 14332-28-6*0 Propynylidene HCCCH (g, triplet) 543.68 546.68 ± 0.64 kJ/mol 38.0480 ± 0.0024 67152-18-5*1 Butatriene CH2CCCH2 (g) 328.32 322.06 ± 0.62 kJ/mol 52.0746 ± 0.0032 2873-50-9*0 Ethoxy CH3CH2O (g, X 2A") 1.29 -12.62 ± 0.42 kJ/mol 45.0605 ± 0.0017 2154-50-9*51 Acetone enol CH3C(OH)CH2 (g, syn) -151.34 -168.62 ± 0.68 kJ/mol 58.0791 ± 0.0025 29456-04-0*1 Phosgene CCl2O (g) -217.50 -219.19 ± 0.24 kJ/mol 98.9155 ± 0.0020 75-44-5*0 1-Hydroxy-2-propanone CH3C(O)CH2OH (g, syn-syn) -354.54 -373.93 ± 0.84 kJ/mol 74.0785 ± 0.0025 116-09-6*11 Cyanoamidogen HNCN (g, doublet) 322.70 320.21 ± 0.63 kJ/mol 41.03212 ± 0.00082 12347-01-2*1 Chloroform CHCl3 (g) -94.60 -99.50 ± 0.40 kJ/mol 119.3767 ± 0.0028 67-66-3*0 Tetrafluoroethylene CF2CF2 (g) -670.70 -674.10 ± 0.48 kJ/mol 100.0150 ± 0.0016 116-14-3*0 Fluoromethylidyne CF (g) 243.17 246.78 ± 0.11 kJ/mol 31.00910 ± 0.00080 3889-75-6*0 Acrylonitrile CH2CHCN (g, singlet) 193.81 187.05 ± 0.66 kJ/mol 53.0627 ± 0.0024 107-13-1*1 Silanol SiH3OH (g) -271.0 -282.7 ± 1.3 kJ/mol 48.11666 ± 0.00051 14475-38-8*0 Naphthalene C6H4(C4H4) (g) 171.21 147.73 ± 0.55 kJ/mol 128.1705 ± 0.0080 91-20-3*0 Oxygen atom cation O+ (g) 1560.786 1562.643 ± 0.0021 kJ/mol 15.99885 ± 0.00030 14581-93-2*0 1,2-Propadiene-1,3-diylidene CCC (g) 814.39 823.35 ± 0.49 kJ/mol 36.0321 ± 0.0024 12075-35-3*0 Methylidyne CH (g, quartet) 664.70 668.04 ± 0.52 kJ/mol 13.01864 ± 0.00080 3315-37-5*2 Vinyl anion [CH2CH]- (g) 236.97 232.55 ± 0.68 kJ/mol 27.0458 ± 0.0016 25012-81-1*0 Cyanogen bromide BrCN (g) 186.8 180.2 ± 1.4 kJ/mol 105.9214 ± 0.0013 506-68-3*0 n-Butyl CH3CH2CH2CH2 (g) 102.94 80.44 ± 0.61 kJ/mol 57.1143 ± 0.0033 2492-36-6*0 trans-2-Butene CH3CHCHCH3 (g, trans) 9.55 -11.02 ± 0.30 kJ/mol 56.1063 ± 0.0032 624-64-6*0 1-Butene CH2CHCH2CH3 (g) 21.12 0.17 ± 0.34 kJ/mol 56.1063 ± 0.0032 106-98-9*0 Ethyl hydroperoxide CH3CH2OOH (g) -142.74 -161.16 ± 0.72 kJ/mol 62.0678 ± 0.0018 3031-74-1*0 Ethylperoxy CH3CH2OO (g, gauche) -6.27 -22.29 ± 0.64 kJ/mol 61.0599 ± 0.0017 3170-61-4*3 Formate [HC(O)O]- (g) -463.16 -466.80 ± 0.55 kJ/mol 45.0180 ± 0.0010 71-47-6*0 Methyl acetate CH3C(O)OCH3 (g, syn) -394.18 -413.05 ± 0.57 kJ/mol 74.0785 ± 0.0025 79-20-9*1 Ethyl bromide CH3CH2Br (g) -41.03 -62.97 ± 0.24 kJ/mol 108.9651 ± 0.0019 74-96-4*0 Vinyl bromide CH2CHBr (g) 88.75 73.94 ± 0.56 kJ/mol 106.9492 ± 0.0019 593-60-2*0 Benzoyl C6H5CO (g) 138.2 124.7 ± 1.1 kJ/mol 105.1140 ± 0.0056 2652-65-5*0 Methyl nitrite CH3ONO (g, cis) -55.53 -67.31 ± 0.44 kJ/mol 61.0401 ± 0.0010 624-91-9*2 Propadienone CH2CCO (g) 132.14 130.50 ± 0.61 kJ/mol 54.0474 ± 0.0024 61244-93-7*0 Chlorine fluoride ClF (g) -55.621 -55.716 ± 0.030 kJ/mol 54.45110 ± 0.00090 7790-89-8*0 Diazynium [NNH]+ (g) 1042.57 1038.95 ± 0.67 kJ/mol 29.02087 ± 0.00016 12357-66-3*0 Nitrite [ONO]- (g) -182.62 -185.43 ± 0.46 kJ/mol 46.00609 ± 0.00060 14797-65-0*0 Hydroxylamine NH2OH (g, trans) -33.08 -43.46 ± 0.42 kJ/mol 33.02996 ± 0.00037 7803-49-8*1 Aminomethyl CH2NH2 (g) 159.36 149.52 ± 0.35 kJ/mol 30.04920 ± 0.00085 10507-29-6*0 cis-2-Butene CH3CHCHCH3 (g, cis) 14.29 -6.98 ± 0.39 kJ/mol 56.1063 ± 0.0032 590-18-1*0 1-Butyne CH3CH2CCH (g) 180.34 166.75 ± 0.55 kJ/mol 54.0904 ± 0.0032 107-00-6*0 n-Hexane CH3CH2CH2CH2CH2CH3 (g) -129.90 -166.78 ± 0.32 kJ/mol 86.1754 ± 0.0049 110-54-3*0 Methanetetraylbisamidogen NCN (g) 451.36 451.77 ± 0.41 kJ/mol 40.02418 ± 0.00081 2669-76-3*0 Tetrabromomethane CBr4 (g) 143.4 113.7 ± 1.1 kJ/mol 331.6267 ± 0.0041 558-13-4*0 Vinyl fluoride CH2CHF (g) -134.54 -142.34 ± 0.45 kJ/mol 46.0436 ± 0.0016 75-02-5*0 Phenylium [C6H5]+ (g) 1149.13 1136.35 ± 0.85 kJ/mol 77.1034 ± 0.0048 17333-73-2*0 Fluorobenzene C6H5F (g) -96.02 -111.70 ± 0.39 kJ/mol 96.1023 ± 0.0048 462-06-6*0 Nitromethane CH3N(O)O (g) -60.77 -74.67 ± 0.42 kJ/mol 61.0401 ± 0.0010 75-52-5*0 Fluorooxidanyl FO (g) 110.28 110.90 ± 0.14 kJ/mol 34.99780 ± 0.00030 12061-70-0*0 Hypoiodous acid HOI (g) -54.1 -58.9 ± 3.1 kJ/mol 143.91181 ± 0.00031 14332-21-9*0 Nitrous oxide NNO (g) 86.023 82.594 ± 0.096 kJ/mol 44.01288 ± 0.00033 10024-97-2*0 Azanide [NH2]- (g) 114.65 111.77 ± 0.29 kJ/mol 16.02317 ± 0.00016 17655-31-1*0 Methanium [CH5]+ (g) 921.99 911.74 ± 0.44 kJ/mol 17.04985 ± 0.00087 15135-49-6*0 Peroxynitrous acid HOONO (g, cis, cis) -5.73 -14.17 ± 0.35 kJ/mol 63.01288 ± 0.00091 14691-52-2*3 Ethylidene CH3CH (g, triplet) 361.26 354.25 ± 0.48 kJ/mol 28.0532 ± 0.0016 4218-50-2*1 Cyanomethyl CH2CN (g) 262.84 259.96 ± 0.53 kJ/mol 40.0440 ± 0.0016 2932-82-3*0 Cyanic fluoride FCN (g) 8.52 8.85 ± 0.70 kJ/mol 45.01584 ± 0.00080 1495-50-7*0 n-Pentane CH3CH2CH2CH2CH3 (g) -114.18 -146.06 ± 0.29 kJ/mol 72.1488 ± 0.0041 109-66-0*0 Methanediol CH2(OH)2 (g, C2 gauche) -378.60 -392.55 ± 0.71 kJ/mol 48.0413 ± 0.0010 463-57-0*1 Formic acid HC(O)OH (g, anti) -354.70 -361.81 ± 0.37 kJ/mol 46.0254 ± 0.0010 64-18-6*2 Cyanooxidanyl NCO (g) 126.95 127.43 ± 0.33 kJ/mol 42.01684 ± 0.00086 22400-26-6*0 Ethenamine CH2CHNH2 (g) 69.29 54.73 ± 0.66 kJ/mol 43.0678 ± 0.0016 593-67-9*0 Aziridine NH(CH2CH2) (g) 143.27 126.74 ± 0.88 kJ/mol 43.0678 ± 0.0016 151-56-4*0 Fluoroethane CH3CH2F (g) -257.25 -272.11 ± 0.36 kJ/mol 48.0595 ± 0.0016 353-36-6*0 Chlorotrifluoromethane CF3Cl (g) -704.30 -709.41 ± 0.56 kJ/mol 104.4586 ± 0.0012 75-72-9*0 Pyridine N(CHCHCHCHCH) (g) 157.34 140.54 ± 0.40 kJ/mol 79.0999 ± 0.0040 110-86-1*0 Acrylonitrile CH2CHCN (g) 193.81 187.05 ± 0.66 kJ/mol 53.0627 ± 0.0024 107-13-1*0 1,2,3-Butatrien-1-yl CH2CCCH (g) 497.40 497.42 ± 0.69 kJ/mol 51.0666 ± 0.0032 22112-56-7*0 Disilane SiH3SiH3 (g) 92.1 76.0 ± 1.3 kJ/mol 62.21864 ± 0.00073 1590-87-0*0 2,4-Hexadiyne CH3CCCCCH3 (g) 380.21 370.19 ± 0.85 kJ/mol 78.1118 ± 0.0048 2809-69-0*0 Hydrogen sulfide H2S (g) -17.32 -20.24 ± 0.19 kJ/mol 34.0819 ± 0.0060 7783-06-4*0 Bromooxidanyl BrO (g) 131.21 123.68 ± 0.28 kJ/mol 95.9034 ± 0.0010 15656-19-6*0 Dioxygen cation [O2]+ (g) 1164.585 1165.221 ± 0.0092 kJ/mol 31.99825 ± 0.00060 12185-07-8*0 Ethynylene C2 (g) 819.977 828.443 ± 0.085 kJ/mol 24.0214 ± 0.0016 12070-15-4*0 Ethanide [CH3CH2]- (g) 155.41 144.33 ± 0.87 kJ/mol 29.0616 ± 0.0016 25013-41-6*0 Vinylium [CH2CH]+ (g) 1119.11 1115.67 ± 0.55 kJ/mol 27.0447 ± 0.0016 14604-48-9*0 Vinylidene CCH2 (g) 411.21 412.12 ± 0.30 kJ/mol 26.0373 ± 0.0016 2143-69-3*0 Hydroxymethylium [CH2OH]+ (g) 717.68 709.74 ± 0.18 kJ/mol 31.03337 ± 0.00088 18682-95-6*0 Hydroxymethylene HCOH (g, trans) 112.68 108.91 ± 0.27 kJ/mol 30.02598 ± 0.00087 19710-56-6*1 Peroxyformic acid HC(O)OOH (g, cis) -279.25 -288.60 ± 0.63 kJ/mol 62.0248 ± 0.0012 107-32-4*1 1,2-Propadienyl anion [CH2CCH]- (g) 266.02 262.96 ± 0.63 kJ/mol 39.0565 ± 0.0024 64066-06-4*0 Propadienylidene CH2CC (g) 554.42 555.56 ± 0.40 kJ/mol 38.0480 ± 0.0024 60731-10-4*0 Cyclopentane CH2(CH2CH2CH2CH2) (g) -43.37 -75.94 ± 0.38 kJ/mol 70.1329 ± 0.0041 287-92-3*0 Vinoxy CH2CHO (g) 22.98 16.18 ± 0.57 kJ/mol 43.0446 ± 0.0016 6912-06-7*0 Propionaldehyde CH3CH2CHO (g) -171.22 -186.62 ± 0.24 kJ/mol 58.0791 ± 0.0025 123-38-6*0 Phenolate [C6H5O]- (g) -146.44 -161.91 ± 0.84 kJ/mol 93.1038 ± 0.0048 3229-70-7*0 (1E)-Ethanimine CH3CHNH (g, trans) 55.71 39.50 ± 0.72 kJ/mol 43.0678 ± 0.0016 56003-81-7*0 Diazomethyl HCNN (g, doublet) 467.84 465.28 ± 0.68 kJ/mol 41.03212 ± 0.00082 20813-32-5*1 Bromotrifluoromethane CF3Br (g) -638.67 -650.79 ± 0.40 kJ/mol 148.9099 ± 0.0013 75-63-8*0 Bromoform CHBr3 (g) 80.4 54.3 ± 1.1 kJ/mol 252.7306 ± 0.0031 75-25-2*0 Cyclopentadienyl CH(CHCHCHCH) (g) 275.27 262.15 ± 0.91 kJ/mol 65.0932 ± 0.0040 2143-53-5*0 Carbamoyl NH2CO (g) -7.78 -14.19 ± 0.74 kJ/mol 44.03272 ± 0.00087 2858-51-7*0 Tetrahedrane CH(CH(CHCH)) (g) 547.66 539.25 ± 0.91 kJ/mol 52.0746 ± 0.0032 157-39-1*0 Silylene SiH2 (g, singlet) 271.42 269.76 ± 0.86 kJ/mol 30.10138 ± 0.00033 13825-90-6*2 Chlorine dioxide OClO (g) 101.41 98.94 ± 0.29 kJ/mol 67.4515 ± 0.0011 10049-04-4*0 (E)-Diazene HNNH (g, trans) 207.11 199.97 ± 0.41 kJ/mol 30.02936 ± 0.00020 15626-43-4*0 Ethylidene CH3CH (g, singlet) 373.60 366.37 ± 0.57 kJ/mol 28.0532 ± 0.0016 4218-50-2*2 (E)-Iminomethyl HCNH (g, trans) 275.79 272.17 ± 0.56 kJ/mol 28.03332 ± 0.00082 54980-10-8*0 Cyanogen NCCN (g) 308.16 310.11 ± 0.41 kJ/mol 52.0349 ± 0.0016 460-19-5*0 Water H2O (l) -285.798 ± 0.022 kJ/mol 18.01528 ± 0.00033 7732-18-5*590 Peroxyformyl HC(O)OO (g, syn) -100.43 -105.73 ± 0.67 kJ/mol 61.0168 ± 0.0012 56240-83-6*1 1-Methylethenyl CH3CCH2 (g) 262.98 252.58 ± 0.61 kJ/mol 41.0718 ± 0.0024 15552-77-9*0 neo-Pentane C(CH3)4 (g) -134.26 -167.14 ± 0.38 kJ/mol 72.1488 ± 0.0041 463-82-1*0 Cyclopentene CH2(CH2CHCHCH2) (g) 59.94 35.67 ± 0.43 kJ/mol 68.1170 ± 0.0040 142-29-0*0 Trimethylamine (CH3)3N (g) 2.24 -26.62 ± 0.75 kJ/mol 59.1103 ± 0.0025 75-50-3*0 Diazomethane CH2NN (g) 273.61 267.34 ± 0.86 kJ/mol 42.04006 ± 0.00082 334-88-3*0 Dichloromethylene CCl2 (g, singlet) 229.86 231.04 ± 0.64 kJ/mol 82.9161 ± 0.0020 1605-72-7*2 Trifluoromethylium [CF3]+ (g) 409.75 406.54 ± 0.42 kJ/mol 69.00536 ± 0.00080 18851-76-8*0 Trioxidane HOOOH (g, trans) -81.72 -90.56 ± 0.41 kJ/mol 50.01408 ± 0.00091 14699-99-1*1 Ethyl nitrite CH3CH2ONO (g, trans-cis) -81.26 -99.99 ± 0.87 kJ/mol 75.0666 ± 0.0017 109-95-5*1 Methylketene CH3CHCO (g) -54.16 -63.63 ± 0.63 kJ/mol 56.0633 ± 0.0024 6004-44-0*0 Hypobromite [BrO]- (g) -96.02 -103.50 ± 0.54 kJ/mol 95.9039 ± 0.0010 14380-62-2*0 Azido radical NNN (g) 452.29 449.70 ± 0.60 kJ/mol 42.02022 ± 0.00021 12596-60-0*0 Hydroxyoxomethylium [HOCO]+ (g) 600.69 597.60 ± 0.43 kJ/mol 45.0169 ± 0.0010 638-71-1*0 Aminooxy NH2O (g) 70.63 64.02 ± 0.62 kJ/mol 32.02202 ± 0.00034 13408-29-2*0 Hydroxyamidogen HNOH (g, trans) 101.28 94.45 ± 0.87 kJ/mol 32.02202 ± 0.00034 13940-32-4*1 Hydrazoic acid HNNN (g) 297.94 291.64 ± 0.49 kJ/mol 43.02816 ± 0.00022 7782-79-8*0 Acetylium [CH3CO]+ (g) 666.65 659.36 ± 0.42 kJ/mol 43.0441 ± 0.0016 15762-07-9*0 Aminomethylium [CH2NH2]+ (g) 763.52 751.55 ± 0.52 kJ/mol 30.04865 ± 0.00085 488821-23-4*0 Difluorodioxidane FOOF (g) 35.34 31.61 ± 0.40 kJ/mol 69.99561 ± 0.00060 7783-44-0*0 Hydrogen isocyanide HNC (g) 192.05 192.43 ± 0.31 kJ/mol 27.02538 ± 0.00081 6914-07-4*0 Chloroacetylene HCCCl (g) 229.28 230.14 ± 0.45 kJ/mol 60.4820 ± 0.0018 593-63-5*0 Fluoroacetylene HCCF (g) 104.97 105.68 ± 0.40 kJ/mol 44.0277 ± 0.0016 2713-09-9*0 1-Propenyl CH3CHCH (g, cis) 278.15 267.31 ± 0.63 kJ/mol 41.0718 ± 0.0024 6067-68-1*2 1-Hydroxyethylium [CH3CHOH]+ (g, anti) 608.80 594.37 ± 0.38 kJ/mol 45.0600 ± 0.0017 18682-96-7*1 Ketenyl HCCO (g) 177.10 178.20 ± 0.54 kJ/mol 41.0287 ± 0.0016 51095-15-9*0 Formic acid HC(O)OH (g) -371.03 -378.32 ± 0.21 kJ/mol 46.0254 ± 0.0010 64-18-6*0 Ozonide [OOO]- (g) -58.47 -60.83 ± 0.21 kJ/mol 47.99875 ± 0.00090 12596-80-4*0 Acetic acid CH3C(O)OH (g, anti) -397.72 -412.13 ± 0.52 kJ/mol 60.0520 ± 0.0017 64-19-7*2 Glycolaldehyde HC(O)CH2OH (g, syn-syn) -304.43 -317.70 ± 0.89 kJ/mol 60.0520 ± 0.0017 141-46-8*11 Methyl formate HC(O)OCH3 (g, anti) -326.6 -339.1 ± 1.1 kJ/mol 60.0520 ± 0.0017 107-31-3*2 Glyoxal OCHCHO (g, trans) -207.79 -213.43 ± 0.55 kJ/mol 58.0361 ± 0.0017 107-22-2*1 (Methylamino)methyl CH3NHCH2 (g) 168.51 152.06 ± 0.69 kJ/mol 44.0758 ± 0.0017 31277-24-4*0 Diazirinyl HC(NN) (g, 2A2) 491.06 487.67 ± 0.96 kJ/mol 41.03212 ± 0.00082 69967-71-1*1 Diazirine CH2(NN) (g) 320.7 313.0 ± 1.1 kJ/mol 42.04006 ± 0.00082 157-22-2*0 Trichloromethyl CCl3 (g) 73.73 73.25 ± 0.84 kJ/mol 118.3688 ± 0.0028 3170-80-7*0 1,1-Dichloroethane CH3CHCl2 (g) -120.19 -132.97 ± 0.43 kJ/mol 98.9586 ± 0.0024 75-34-3*0 Bromobenzene C6H5Br (g) 127.0 104.9 ± 1.3 kJ/mol 157.0079 ± 0.0049 108-86-1*0 Phenylethene C6H5CHCH2 (g) 169.92 148.59 ± 0.51 kJ/mol 104.1491 ± 0.0064 100-42-5*0 Phenylacetylene C6H5CCH (g) 332.81 317.65 ± 0.69 kJ/mol 102.1332 ± 0.0064 536-74-3*0 Dioxidanide [HOO]- (g) -88.92 -91.58 ± 0.34 kJ/mol 33.00729 ± 0.00060 14691-59-9*0 Acetophenone C6H5C(O)CH3 (g) -61.4 -84.6 ± 1.0 kJ/mol 120.1485 ± 0.0064 98-86-2*0 Nitrosomethane CH3NO (g) 80.77 70.86 ± 0.91 kJ/mol 45.04066 ± 0.00088 865-40-7*0 Isocyanoacetylene HCCNC (g) 484.75 486.97 ± 0.99 kJ/mol 51.0468 ± 0.0024 66723-45-3*0 Cyclobutadiene CH(CHCHCH) (g) 436.62 428.17 ± 0.69 kJ/mol 52.0746 ± 0.0032 1120-53-2*0 Fulvene CH2C(CHCHCHCH) (g) 232.1 216.0 ± 1.1 kJ/mol 78.1118 ± 0.0048 497-20-1*0 Silanone SiH2O (g) -93.7 -99.1 ± 1.0 kJ/mol 46.10078 ± 0.00045 22755-01-7*0 Silyloxy SiH3O (g) 8.6 0.6 ± 1.4 kJ/mol 47.10872 ± 0.00047 81429-20-1*0 Sulfur S (g) 276.89 279.14 ± 0.14 kJ/mol 32.0660 ± 0.0060 7704-34-9*0 Chlorous acid HOClO (g) 25.76 20.71 ± 0.63 kJ/mol 68.4594 ± 0.0011 13898-47-0*0 Iodooxidanyl IO (g) 127.00 125.07 ± 0.82 kJ/mol 142.90387 ± 0.00030 14696-98-1*0 Carbon monoxide cation [CO]+ (g) 1238.309 1241.589 ± 0.026 kJ/mol 28.00955 ± 0.00085 12144-04-6*0 Hydrazine NH2NH2 (g) 111.71 97.56 ± 0.44 kJ/mol 32.04524 ± 0.00031 302-01-2*0 Nitrate [ON(O)O]- (g) -299.72 -306.27 ± 0.22 kJ/mol 62.00549 ± 0.00090 14797-55-8*0 Methanide [CH3]- (g) 141.15 137.71 ± 0.24 kJ/mol 15.03507 ± 0.00083 15194-58-8*0 Methyleneamidogen CH2N (g) 242.07 238.42 ± 0.55 kJ/mol 28.03332 ± 0.00082 15845-29-1*0 Hypofluorite [FO]- (g) -108.84 -108.67 ± 0.48 kJ/mol 34.99835 ± 0.00030 12763-66-5*0 Cyanogen iodide ICN (g) 222.5 222.0 ± 1.7 kJ/mol 152.92191 ± 0.00080 506-78-5*0 Formyl anion [HCO]- (g) 11.59 11.98 ± 0.44 kJ/mol 29.01859 ± 0.00086 57340-31-5*0 Cyclopropyl CH(CH2CH2) (g) 303.87 291.24 ± 0.48 kJ/mol 41.0718 ± 0.0024 2417-82-5*0 2-Propynylidyne CCCH (g) 718.75 723.11 ± 0.71 kJ/mol 37.0400 ± 0.0024 53590-28-6*0 Fluorodioxidanyl FOO (g) 26.87 25.16 ± 0.26 kJ/mol 50.99720 ± 0.00060 15499-23-7*0 iso-Pentane CH3CH2CH(CH3)2 (g) -118.94 -152.98 ± 0.39 kJ/mol 72.1488 ± 0.0041 78-78-4*0 1-Hydroxyethylidene CH3COH (g, anti singlet) 57.37 47.00 ± 0.77 kJ/mol 44.0526 ± 0.0017 30967-49-8*21 Dicarbon monoxide CCO (g, triplet) 377.12 381.16 ± 0.83 kJ/mol 40.0208 ± 0.0016 12071-23-7*1 1-Propanol CH3CH2CH2OH (g) -231.26 -255.10 ± 0.24 kJ/mol 60.0950 ± 0.0025 71-23-8*0 Acetic acid CH3C(O)OH (g) -418.53 -432.69 ± 0.36 kJ/mol 60.0520 ± 0.0017 64-19-7*0 Dimethylamidogen (CH3)2N (g) 174.77 157.43 ± 0.91 kJ/mol 44.0758 ± 0.0017 15337-44-7*0 2-Iminoethyl CH2CHNH (g, anti) 219.27 207.90 ± 0.86 kJ/mol 42.0599 ± 0.0016 73843-90-0*2 Isocyanoamidogen HNNC (g, doublet) 489.7 487.7 ± 1.2 kJ/mol 41.03212 ± 0.00082 947408-73-3*1 Chloromethylene CHCl (g, singlet) 320.35 320.64 ± 0.89 kJ/mol 48.4713 ± 0.0012 2108-20-5*2 Dibromomethane CH2Br2 (g) 27.4 6.0 ± 1.1 kJ/mol 173.8346 ± 0.0022 74-95-3*0 1,1-Difluoroethene CH2CF2 (g) -343.48 -350.54 ± 0.76 kJ/mol 64.0341 ± 0.0016 75-38-7*0 o-Tolualdehyde CH3C6H4C(O)H (g, ortho) -44.7 -66.9 ± 1.1 kJ/mol 120.1485 ± 0.0064 529-20-4*0 Acetonyl CH3C(O)CH2 (g) -18.47 -32.07 ± 0.68 kJ/mol 57.0712 ± 0.0024 3122-07-4*0 3-Buten-2-one CH3C(O)CHCH2 (g, trans) -95.39 -111.63 ± 0.85 kJ/mol 70.0898 ± 0.0032 78-94-4*1 Urea NH2C(O)NH2 (g) -218.18 -234.58 ± 0.42 kJ/mol 60.05534 ± 0.00091 57-13-6*0 Oxomethaniminium [NH2CO]+ (g) 695.32 688.76 ± 0.89 kJ/mol 44.03217 ± 0.00087 59348-22-0*0 Acetamide CH3C(O)NH2 (g) -219.62 -237.13 ± 0.56 kJ/mol 59.0672 ± 0.0017 60-35-5*0 1-Cyanovinyl CH2CCN (g) 419.0 418.8 ± 1.1 kJ/mol 52.0547 ± 0.0024 15091-87-9*0 Disilanyl SiH3SiH2 (g) 242.6 230.6 ± 1.6 kJ/mol 61.21070 ± 0.00069 73151-72-1*0 Disilene SiH2SiH2 (g, singlet) 288.6 280.0 ± 1.9 kJ/mol 60.20276 ± 0.00066 15435-77-5*2 1,3-Hexadiyne HCCCCCH2CH3 (g) 405.12 393.42 ± 0.96 kJ/mol 78.1118 ± 0.0048 4447-21-6*0 (E)-1-Methylallyl CH3CHCHCH2 (g, trans) 152.54 135.23 ± 0.79 kJ/mol 55.0984 ± 0.0032 17787-86-9*0 Sulfuric acid OS(O)(OH)2 (aq, 1000 H2O) -892.16 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*839 Chlorine trifluoride FCl(F)F (g) -158.63 -162.73 ± 0.86 kJ/mol 92.44791 ± 0.00090 7790-91-2*0 Chlorine atom cation Cl+ (g) 1370.807 1372.603 ± 0.0021 kJ/mol 35.45215 ± 0.00090 24203-47-2*0 Iodine monochloride ICl (g) 19.024 17.391 ± 0.013 kJ/mol 162.35717 ± 0.00090 7790-99-0*0 Iodotrifluoromethane CF3I (g) -583.26 -589.14 ± 0.45 kJ/mol 195.91038 ± 0.00080 2314-97-8*0 Trinitrogen cation [NNN]+ (g) 1519.45 1516.81 ± 0.89 kJ/mol 42.01967 ± 0.00021 12185-03-4*0 Oxonitrate anion [NO]- (g) 88.11 88.14 ± 0.25 kJ/mol 30.00669 ± 0.00031 14967-78-3*0 Nitrosyl ion [NO]+ (g) 984.501 984.496 ± 0.066 kJ/mol 30.00559 ± 0.00031 14452-93-8*0 Nitrogen sesquioxide ONN(O)O (g) 90.75 86.18 ± 0.15 kJ/mol 76.01168 ± 0.00091 10544-73-7*0 Dioxygen anion [O2]- (g) -43.36 -42.72 ± 0.17 kJ/mol 31.99935 ± 0.00060 11062-77-4*0 Methyliumyl [CH2]+ (g) 1393.20 1394.06 ± 0.10 kJ/mol 14.02603 ± 0.00081 15091-72-2*0 Methylene anion [CH2]- (g) 328.17 328.60 ± 0.18 kJ/mol 14.02713 ± 0.00081 50928-07-9*0 Methylidyne anion [CH]- (g) 475.77 479.09 ± 0.21 kJ/mol 13.01919 ± 0.00080 28604-54-8*0 Ethanium [C2H7]+ (g, bridged C2) 874.35 858.08 ± 0.61 kJ/mol 31.0764 ± 0.0017 24669-33-8*1 Tetrafluorosilane SiF4 (g) -1608.79 -1614.30 ± 0.53 kJ/mol 104.07911 ± 0.00030 7783-61-1*0 iso-Propylium [CH3CHCH3]+ (g) 822.93 805.84 ± 0.23 kJ/mol 43.0871 ± 0.0024 19252-53-0*0 Carbonic acid C(O)(OH)2 (g, cis-cis) -602.32 -612.49 ± 0.58 kJ/mol 62.0248 ± 0.0012 463-79-6*1 Methylperoxy anion [CH3OO]- (g) -89.69 -99.84 ± 0.45 kJ/mol 47.0339 ± 0.0010 35683-44-4*0 Cyclobutane CH2(CH2CH2CH2) (g) 52.23 27.69 ± 0.36 kJ/mol 56.1063 ± 0.0032 287-23-0*0 2-Butynyl CH3CCCH2 (g) 318.08 310.71 ± 0.67 kJ/mol 53.0825 ± 0.0032 82252-88-8*0 1,2-Butadienyl CH3CHCCH (g) 328.90 320.18 ± 0.63 kJ/mol 53.0825 ± 0.0032 4777-46-2*0 Isoprene CH2C(CH3)CHCH2 (g) 96.24 75.72 ± 0.66 kJ/mol 68.1170 ± 0.0040 78-79-5*0 Ethynol HCCOH (g, singlet) 95.31 92.82 ± 0.73 kJ/mol 42.0367 ± 0.0016 32038-79-2*2 Hydroxymethoxy CH2(OH)O (g, gauche) -159.64 -169.60 ± 0.87 kJ/mol 47.0333 ± 0.0010 72144-78-6*3 Formyloxidanyl HC(O)O (g, 2A1) -125.82 -127.48 ± 0.55 kJ/mol 45.0174 ± 0.0010 16499-21-1*1 Methoxyethane CH3CH2OCH3 (g) -194.79 -217.68 ± 0.55 kJ/mol 60.0950 ± 0.0025 540-67-0*0 Acetate [CH3C(O)O]- (g) -496.01 -505.14 ± 0.80 kJ/mol 59.0446 ± 0.0017 71-50-1*0 Cyanoamidogen anion [HNCN]- (g, singlet) 69.72 66.72 ± 0.72 kJ/mol 41.03267 ± 0.00082 67131-47-9*2 Chloronium [HClH]+ (g) 881.5 878.4 ± 1.1 kJ/mol 37.46803 ± 0.00091 36658-55-6*0 1,1,1-Trichloroethane CH3CCl3 (g) -134.01 -144.59 ± 0.51 kJ/mol 133.4033 ± 0.0031 71-55-6*0 Tetrachloroethene CCl2CCl2 (g) -20.58 -21.45 ± 0.99 kJ/mol 165.8322 ± 0.0039 127-18-4*0 Chlorodifluoromethane CHClF2 (g) -475.59 -481.79 ± 0.99 kJ/mol 86.4681 ± 0.0012 75-45-6*0 Fluoromethylene CHF (g, singlet) 148.40 148.68 ± 0.43 kJ/mol 32.01704 ± 0.00080 13453-52-6*2 Fluoroformyl FCO (g) -176.62 -176.04 ± 0.37 kJ/mol 47.00850 ± 0.00085 1871-24-5*0 2-Bromoethanol BrCH2CH2OH (g) -196.03 -220.09 ± 0.52 kJ/mol 124.9645 ± 0.0019 540-51-2*0 Carbon suboxide OCCCO (g) -94.5 -92.4 ± 1.0 kJ/mol 68.0309 ± 0.0025 504-64-3*0 Benzyl C6H5CH2 (g) 230.28 211.46 ± 0.55 kJ/mol 91.1305 ± 0.0056 2154-56-5*0 Ethylbenzene C6H5CH2CH3 (g) 58.45 29.98 ± 0.52 kJ/mol 106.1650 ± 0.0064 100-41-4*0 Phenoxy C6H5O (g) 71.02 55.73 ± 0.84 kJ/mol 93.1033 ± 0.0048 2122-46-5*0 m-Tolualdehyde CH3C6H4C(O)H (g, meta) -49.1 -71.9 ± 1.2 kJ/mol 120.1485 ± 0.0064 620-23-5*0 3-Oxo-1-propenyl CHCHCHO (g, anti-trans) 190.93 184.91 ± 0.91 kJ/mol 55.0553 ± 0.0024 206255-29-0*11 2-Propynal CHCCHO (g) 135.44 133.27 ± 0.88 kJ/mol 54.0474 ± 0.0024 624-67-9*0 Cyanomethylene HCCN (g, triplet) 479.7 483.0 ± 1.1 kJ/mol 39.0361 ± 0.0016 2612-62-6*1 3-Methylenecyclopropene CH2C(CHCH) (g) 395.96 388.03 ± 0.83 kJ/mol 52.0746 ± 0.0032 4095-06-1*0 Phenylperoxy C6H5OO (g) 153.5 136.5 ± 1.4 kJ/mol 109.1027 ± 0.0049 91422-02-5*0 Bromosilane SiH3Br (g) -59.0 -75.4 ± 1.4 kJ/mol 111.0133 ± 0.0011 13465-73-1*0 Bromotrimethylsilane SiBr(CH3)3 (g) -259.5 -290.2 ± 2.0 kJ/mol 153.0931 ± 0.0027 2857-97-8*0 Trimethylsilylium [Si(CH3)3]+ (g) 655.3 634.7 ± 2.0 kJ/mol 73.1885 ± 0.0025 28927-31-3*0 1-Methyl-1-propenyl CH3CCHCH3 (g, trans) 240.00 223.82 ± 0.66 kJ/mol 55.0984 ± 0.0032 71790-71-1*1 1-Butenyl CH3CH2CHCH (g, cis) 263.36 246.02 ± 0.68 kJ/mol 55.0984 ± 0.0032 2669-61-6*2 Sulfur monoxide SO (g) 6.02 6.06 ± 0.13 kJ/mol 48.0654 ± 0.0060 13827-32-2*0 Oxygen atom O (g, triplet) 246.844 249.229 ± 0.0021 kJ/mol 15.99940 ± 0.00030 17778-80-2*1 Ammonium [NH4]+ (aq) -133.076 ± 0.056 kJ/mol 18.03795 ± 0.00029 14798-03-9*800 Methylidyne CH (g, doublet) 592.979 596.314 ± 0.081 kJ/mol 13.01864 ± 0.00080 3315-37-5*1 Ethylidyne CH3C (g, quartet) 640.8 636.3 ± 1.1 kJ/mol 27.0452 ± 0.0016 67624-57-1*2 Hydroxyde [OH]- (aq) -229.754 ± 0.023 kJ/mol 17.00789 ± 0.00031 14280-30-9*800 Isocyanomethanide [CH2NC]- (g) 254.05 251.01 ± 0.89 kJ/mol 40.0446 ± 0.0016 81704-80-5*0 Trioxidanide [HOOO]- (g, gauche) -120.0 -123.1 ± 1.6 kJ/mol 49.00669 ± 0.00090 89965-38-8*2 Peroxyformate [HC(O)OO]- (g, syn) -340.95 -346.41 ± 0.80 kJ/mol 61.0174 ± 0.0012 104960-05-6*1 n-Propylium [CH3CH2CH2]+ (g) 856.77 838.49 ± 0.79 kJ/mol 43.0871 ± 0.0024 19252-52-9*0 1-Methylethylidene CH3CCH3 (g, singlet) 316.00 302.10 ± 0.97 kJ/mol 42.0797 ± 0.0024 40852-89-9*2 Propylidene CH3CH2CH (g, triplet gauche) 349.47 335.78 ± 0.92 kJ/mol 42.0797 ± 0.0024 6700-78-3*11 Hydrogen peroxide cation [HOOH]+ (g, trans) 897.29 890.31 ± 0.51 kJ/mol 34.01413 ± 0.00062 12325-10-9*1 Cycloprop-2-enylium [CH(CHCH)]+ (g) 1080.4 1075.3 ± 1.0 kJ/mol 39.0554 ± 0.0024 26810-74-2*0 t-Butyl (CH3)3C (g) 75.23 49.93 ± 0.69 kJ/mol 57.1143 ± 0.0033 1605-73-8*0 Cyclobutene CH2(CH2CHCH) (g) 177.98 160.93 ± 0.60 kJ/mol 54.0904 ± 0.0032 822-35-5*0 1,3-Butadienyl CH2CHCHCH (g, trans-trans) 372.19 361.71 ± 0.87 kJ/mol 53.0825 ± 0.0032 86181-68-2*11 Cyclohexane CH2(CH2CH2CH2CH2CH2) (g) -83.19 -122.75 ± 0.29 kJ/mol 84.1595 ± 0.0049 110-82-7*0 Protonated oxirane [(CH2CH2)OH]+ (g) 725.68 709.51 ± 0.61 kJ/mol 45.0600 ± 0.0017 *38607-31-7*0 Methoxymethylene CH3OCH (g, anti singlet) 129.15 118.62 ± 0.78 kJ/mol 44.0526 ± 0.0017 19527-10-7*21 Oxirene O(CHCH) (g, t-triplet) 387.9 383.7 ± 1.3 kJ/mol 42.0367 ± 0.0016 157-18-6*11 Cyanic acid HOCN (g) -12.32 -15.04 ± 0.43 kJ/mol 43.02478 ± 0.00086 420-05-3*0 Fulminic acid HCNO (g) 170.72 169.26 ± 0.44 kJ/mol 43.02478 ± 0.00086 51060-05-0*0 Isofulminic acid HONC (g) 235.24 233.54 ± 0.43 kJ/mol 43.02478 ± 0.00086 506-85-4*0 Nitrosomethylidyne CNO (g) 389.3 390.7 ± 1.1 kJ/mol 42.01684 ± 0.00086 82267-15-0*0 Acetyl chloride CH3C(O)Cl (g) -232.53 -241.52 ± 0.39 kJ/mol 78.4973 ± 0.0019 75-36-5*0 Dioxoethyl OCHCO (g) -63.23 -64.65 ± 0.86 kJ/mol 57.0281 ± 0.0017 702699-38-5*0 Chlorohydroxymethyl CH(Cl)OH (g, syn-gauche) -54.8 -60.8 ± 1.1 kJ/mol 65.4787 ± 0.0012 147139-06-8*1 1,1-Dichloroethene CH2CCl2 (g) 9.27 3.28 ± 0.50 kJ/mol 96.9427 ± 0.0024 75-35-4*0 Dichlorodifluoromethane CF2Cl2 (g) -488.92 -493.11 ± 0.45 kJ/mol 120.9129 ± 0.0020 75-71-8*0 Fluorodichloromethane CHFCl2 (g) -277.66 -283.12 ± 0.90 kJ/mol 102.9224 ± 0.0020 75-43-4*0 Difluoromethylene CF2 (g, singlet) -193.87 -193.39 ± 0.35 kJ/mol 50.00751 ± 0.00080 2154-59-8*2 Fluoromethylene CHF (g, triplet) 210.38 210.71 ± 0.65 kJ/mol 32.01704 ± 0.00080 13453-52-6*1 Formyl fluoride CHFO (g) -378.64 -382.23 ± 0.31 kJ/mol 48.01644 ± 0.00086 1493-02-3*0 p-Tolualdehyde CH3C6H4C(O)H (g, para) -49.8 -72.8 ± 1.2 kJ/mol 120.1485 ± 0.0064 104-87-0*0 o-Toluoyl CH3C6H4CO (g, ortho) 109.7 91.3 ± 1.4 kJ/mol 119.1406 ± 0.0064 104680-89-9*0 1-Propen-2-ol-1-yl CH3C(OH)CH (g, trans-cis) 101.58 89.36 ± 0.87 kJ/mol 57.0712 ± 0.0024 1976041-84-5*11 Propyl nitrite CH3CH2CH2ONO (g, gauche-trans-cis) -95.9 -120.8 ± 1.8 kJ/mol 89.0932 ± 0.0025 543-67-9*1 1-Formylethenyl CH2CCHO (g) 177.58 172.05 ± 0.80 kJ/mol 55.0553 ± 0.0024 191018-90-3*0 2-Cyanovinyl CHCHCN (g, syn) 447.76 445.28 ± 0.99 kJ/mol 52.0547 ± 0.0024 189141-20-6*2 1,2,3-Butatrien-1-ylium [CH2CCCH]+ (g, singlet) 1271.7 1269.9 ± 1.1 kJ/mol 51.0661 ± 0.0032 81932-79-8*2 1-Buten-3-yn-1-yl HCCCHCH (g, trans) 547.23 544.56 ± 0.86 kJ/mol 51.0666 ± 0.0032 2810-61-9*1 3-Buten-1-ynyl CH2CHCC (g) 628.5 626.3 ± 1.0 kJ/mol 51.0666 ± 0.0032 108179-98-2*0 Fluorosilane SiH3F (g) -346.19 -355.58 ± 0.73 kJ/mol 50.10772 ± 0.00037 13537-33-2*0 Chlorosilane SiH3Cl (g) -126.5 -135.5 ± 1.4 kJ/mol 66.56202 ± 0.00097 13465-78-6*0 Tetramethylsilane Si(CH3)4 (g) -185.9 -216.4 ± 2.0 kJ/mol 88.2236 ± 0.0033 75-76-3*0 Hydroxysilyl SiH2OH (g) -104.1 -112.0 ± 1.5 kJ/mol 47.10872 ± 0.00047 113648-09-2*0 Trimethylsilanol (CH3)3SiOH (g) -465.3 -491.6 ± 1.9 kJ/mol 90.1964 ± 0.0025 1066-40-6*0 2-Aminoethyl CH2CH2NH2 (g) 174.24 157.78 ± 0.82 kJ/mol 44.0758 ± 0.0017 4422-53-1*0 2-Propanamine CH3CH(CH3)NH2 (g) -56.67 -83.47 ± 0.52 kJ/mol 59.1103 ± 0.0025 75-31-0*0 Hydroperoxonium [H2OOH]+ (g, trans) 738.2 727.9 ± 1.2 kJ/mol 35.02207 ± 0.00064 70850-26-9*1 Hypoiodite [IO]- (g) -102.44 -104.25 ± 0.88 kJ/mol 142.90442 ± 0.00030 15065-65-3*0 Dinitrogen cation [N2]+ (g) 1503.311 1503.312 ± 0.000 kJ/mol 28.01293 ± 0.00014 13966-04-6*0 Nitrogen atom cation N+ (g) 1872.905 1875.686 ± 0.023 kJ/mol 14.006191 ± 0.000070 14158-23-7*0 Nitrogen atom N (g, quartet) 470.577 472.439 ± 0.023 kJ/mol 14.006740 ± 0.000070 17778-88-0*1 Carbon dioxide cation [CO2]+ (g) 936.090 936.925 ± 0.017 kJ/mol 44.00895 ± 0.00100 12181-61-2*0 Chlorine pentafluoride FCl(F)(F)(F)F (g) -226.0 -234.1 ± 1.3 kJ/mol 130.44472 ± 0.00090 13637-63-3*0 Nitroxyl ON(O)O (g) 79.38 74.13 ± 0.19 kJ/mol 62.00494 ± 0.00090 12033-49-7*0 Hydrazino NH2NH (g) 234.76 224.24 ± 0.69 kJ/mol 31.03730 ± 0.00025 13598-46-4*0 Carbon anion C- (g) 589.613 594.759 ± 0.040 kJ/mol 12.01125 ± 0.00080 14337-00-9*0 Hydrogen isocyanide cation [HNC]+ (g) 1351.52 1351.48 ± 0.83 kJ/mol 27.02483 ± 0.00081 74158-11-5*0 Cyanomethanide [CH2CN]- (g) 113.69 110.87 ± 0.53 kJ/mol 40.0446 ± 0.0016 21438-99-3*0 Methyloxonium [CH3OH2]+ (g) 589.1 574.9 ± 1.1 kJ/mol 33.04925 ± 0.00092 17836-08-7*0 n-Propylide [CH3CH2CH2]- (g) 123.1 105.4 ± 1.2 kJ/mol 43.0882 ± 0.0024 59513-13-2*0 Allyl anion [CH2CHCH2]- (g) 133.96 122.95 ± 0.21 kJ/mol 41.0723 ± 0.0024 1724-46-5*0 Propargylenide [HCCCH]- (g, transoid 2B) 434.4 437.0 ± 1.1 kJ/mol 38.0485 ± 0.0024 82906-05-6*1 Oxoniumyl ion [H2O]+ (g) 978.498 975.595 ± 0.024 kJ/mol 18.01473 ± 0.00033 56583-62-1*0 2-Butyn-1-yl anion [CH3CCCH2]- (g) 253.7 244.8 ± 1.1 kJ/mol 53.0830 ± 0.0032 65114-66-1*0 Ethoxy CH3CH2O (g, A 2A') 5.56 -8.88 ± 0.43 kJ/mol 45.0605 ± 0.0017 2154-50-9*52 Ethenol CH2CHOH (g, anti) -108.95 -119.66 ± 0.50 kJ/mol 44.0526 ± 0.0017 557-75-5*2 Hydroperoxymethyl CH2OOH (g) 73.17 65.88 ± 0.97 kJ/mol 47.0333 ± 0.0010 74087-87-9*0 Oxiranyl CH2(CHO) (g) 172.78 164.50 ± 0.98 kJ/mol 43.0446 ± 0.0016 31586-84-2*0 Ketene CH2CO (g, triplet) 182.0 179.0 ± 1.1 kJ/mol 42.0367 ± 0.0016 463-51-4*1 Oxoethylidene HCC(O)H (g, syn-triplet) 261.1 257.6 ± 1.1 kJ/mol 42.0367 ± 0.0016 39920-84-8*12 Dihydroxymethyl CH(OH)2 (g, syn-anti) -197.1 -206.5 ± 1.2 kJ/mol 47.0333 ± 0.0010 14840-85-8*1 Dioxirane CH2(OO) (g) 9.39 1.72 ± 0.53 kJ/mol 46.0254 ± 0.0010 157-26-6*0 Methoxyethene CH2CHOCH3 (g, cis) -89.5 -107.4 ± 1.1 kJ/mol 58.0791 ± 0.0025 107-25-5*2 2-Propanol CH3CH(OH)CH3 (g) -248.66 -272.76 ± 0.26 kJ/mol 60.0950 ± 0.0025 67-63-0*0 Methyl acetate CH3C(O)OCH3 (g, anti) -363.3 -382.1 ± 1.2 kJ/mol 74.0785 ± 0.0025 79-20-9*2 Carboxymethyl CH2C(O)OH (g, syn) -226.7 -236.5 ± 1.1 kJ/mol 59.0440 ± 0.0017 2887-46-9*1 1-Iminoethyl CH3CNH (g, anti) 233.0 222.9 ± 1.1 kJ/mol 42.0599 ± 0.0016 128365-64-0*2 1-Aminoethenyl CH2CNH2 (g) 294.63 286.00 ± 0.92 kJ/mol 42.0599 ± 0.0016 180385-92-6*0 Nitrilomethylimidogen NCHN (g, quartet) 581.6 578.4 ± 1.5 kJ/mol 41.03212 ± 0.00082 324529-58-0*2 Cyanoacetylide [CCCN]- (g) 300.3 305.6 ± 1.1 kJ/mol 50.0394 ± 0.0024 12373-53-4*0 Chloromethylidyne CCl (g) 430.62 434.38 ± 0.67 kJ/mol 47.4634 ± 0.0012 3889-76-7*0 Chloromethanol CH2(Cl)OH (g) -232.4 -242.6 ± 1.2 kJ/mol 66.4866 ± 0.0013 15454-33-8*0 Chloromethoxy CH2(Cl)O (g) -12.0 -18.8 ± 1.1 kJ/mol 65.4787 ± 0.0012 114282-89-2*0 Fluorotrichloromethane CCl3F (g) -283.29 -286.44 ± 0.76 kJ/mol 137.3672 ± 0.0028 75-69-4*0 Hexafluoroethane CF3CF3 (g) -1334.04 -1342.34 ± 0.82 kJ/mol 138.0118 ± 0.0016 76-16-4*0 Chloro hypochlorite ClOCl (g) 79.79 77.98 ± 0.36 kJ/mol 86.9048 ± 0.0018 7791-21-1*0 Formyl chloride CHClO (g) -179.87 -183.08 ± 0.67 kJ/mol 64.4707 ± 0.0012 2565-30-2*0 2-Chloroethanol ClCH2CH2OH (g) -249.81 -266.52 ± 0.59 kJ/mol 80.5132 ± 0.0019 107-07-3*0 Butadiynyl CCCCH (g) 801.82 808.42 ± 0.96 kJ/mol 49.0507 ± 0.0032 53561-65-2*0 o-Benzyne C6H4 (g, singlet) 468.14 459.22 ± 0.86 kJ/mol 76.0960 ± 0.0048 462-80-6*2 Tropyl CH(CHCHCHCHCHCH) (g) 296.5 279.1 ± 1.1 kJ/mol 91.1305 ± 0.0056 3551-27-7*0 Indane C6H4(CH2CH2CH2) (g) 91.04 60.01 ± 0.77 kJ/mol 118.1757 ± 0.0072 496-11-7*0 Indene C6H4(CHCHCH2) (g) 183.91 160.02 ± 0.75 kJ/mol 116.1598 ± 0.0072 95-13-6*0 m-Toluoyl CH3C6H4CO (g, meta) 108.7 90.1 ± 1.5 kJ/mol 119.1406 ± 0.0064 67958-04-7*0 Sulfur dioxide anion [OSO]- (g) -401.09 -403.35 ± 0.74 kJ/mol 64.0653 ± 0.0060 12143-17-8*0 Iodobenzene C6H5I (g) 178.43 162.45 ± 0.99 kJ/mol 204.0084 ± 0.0048 591-50-4*0 1-Hydroxy-1-methylethyl CH3C(OH)CH3 (g) -78.30 -96.54 ± 0.79 kJ/mol 59.0871 ± 0.0025 5131-95-3*0 Trifluoroethene CF2CHF (g) -493.0 -498.0 ± 1.6 kJ/mol 82.0245 ± 0.0016 359-11-5*0 Dichloride [Cl2]- (g) -231.91 -230.85 ± 0.34 kJ/mol 70.9059 ± 0.0018 12595-89-0*0 Chlorooxy hypochlorite ClOOCl (g) 134.58 131.34 ± 0.56 kJ/mol 102.9042 ± 0.0019 12292-23-8*0 Isocyanoethene CH2CHNC (g) 285.17 278.67 ± 0.94 kJ/mol 53.0627 ± 0.0024 14668-82-7*0 1-Isocyanoethylidene CH3CNC (g, singlet) 527.9 523.1 ± 1.1 kJ/mol 53.0627 ± 0.0024 *498544-34-6*2 2-Cyanovinyl CHCHCN (g, anti) 448.18 445.72 ± 0.97 kJ/mol 52.0547 ± 0.0024 189141-20-6*1 3-Methylene-1-cyclopropen-1-yl CH2C(CHC) (g) 628.2 625.6 ± 1.1 kJ/mol 51.0666 ± 0.0032 127611-24-9*0 Oxosilylene SiO (g) -98.35 -97.19 ± 0.54 kJ/mol 44.08490 ± 0.00042 10097-28-6*0 Silyloxy anion [SiH3O]- (g) -311.7 -321.0 ± 1.6 kJ/mol 47.10927 ± 0.00047 43336-62-5*0 Cyclobutyl CH(CH2CH2CH2) (g) 246.47 227.57 ± 0.72 kJ/mol 55.0984 ± 0.0032 4548-06-5*0 Peroxyhypochlorous acid HOOCl (g) 3.98 -1.29 ± 0.95 kJ/mol 68.4594 ± 0.0011 67952-07-2*0 1-Propanamine CH3CH2CH2NH2 (g) -42.23 -69.97 ± 0.42 kJ/mol 59.1103 ± 0.0025 107-10-8*0 Disulfur S2 (g) 127.48 127.79 ± 0.27 kJ/mol 64.1320 ± 0.0120 23550-45-0*0 Sulfuric acid OS(O)(OH)2 (g) -715.0 -729.2 ± 1.2 kJ/mol 98.0795 ± 0.0061 7664-93-9*0 Sulfurous acid S(O)(OH)2 (g, cis) -511.18 -521.39 ± 0.89 kJ/mol 82.0801 ± 0.0061 7782-99-2*2 Sulfo OS(OH)O (g) -366.7 -374.6 ± 1.1 kJ/mol 81.0721 ± 0.0061 32750-86-0*0 Dioxodiazoxane ONONO (g, t, t) 93.0 87.9 ± 1.3 kJ/mol 76.01168 ± 0.00091 122413-35-8*1 Nitric acid HON(O)O (aq) -206.54 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*800 Isodiazene NNH2 (g) 307.53 300.45 ± 0.63 kJ/mol 30.02936 ± 0.00020 28647-38-3*0 Oxoammoniumyl [HNO]+ (g) 1092.47 1089.55 ± 0.67 kJ/mol 31.01353 ± 0.00032 63559-87-5*0 Peroxynitrous acid HOONO (g, trans, perp) 7.84 0.76 ± 0.41 kJ/mol 63.01288 ± 0.00091 14691-52-2*1 Peroxynitric acid HOON(O)O (g) -41.45 -51.76 ± 0.32 kJ/mol 79.0123 ± 0.0012 26404-66-0*0 Carbon cation C+ (g) 1797.842 1803.440 ± 0.040 kJ/mol 12.01015 ± 0.00080 14067-05-1*0 Ethylidyne CH3C (g) 508.61 504.91 ± 0.80 kJ/mol 27.0452 ± 0.0016 67624-57-1*0 Ethynylium [CCH]+ (g) 1687.61 1690.95 ± 0.15 kJ/mol 25.0288 ± 0.0016 16456-59-0*0 Methylamidogen anion [CH3NH]- (g) 145.32 134.49 ± 0.64 kJ/mol 30.04975 ± 0.00085 54448-39-4*0 Methylimidogen CH3N (g) 323.0 315.3 ± 1.0 kJ/mol 29.04126 ± 0.00083 27770-42-9*0 Iminomethylium [HCNH]+ (g) 953.3 949.3 ± 1.4 kJ/mol 28.03277 ± 0.00082 196216-36-1*0 2-Hydrotrioxy OO(H)O (g) 299.7 293.9 ± 1.2 kJ/mol 49.00614 ± 0.00090 *12500-78-6*0 Hydrogen carbonate [HOC(O)O]- (g) -719.3 -725.6 ± 1.5 kJ/mol 61.0174 ± 0.0012 71-52-3*0 Chloric acid HOCl(O)O (g) 0.6 -6.5 ± 1.1 kJ/mol 84.4588 ± 0.0013 7790-93-4*0 Cyclopropylide [CH(CH2CH2)]- (g) 265.3 252.5 ± 1.1 kJ/mol 41.0723 ± 0.0024 1724-45-4*0 Propylidyne CH3CH2C (g, doublet) 492.6 483.0 ± 1.2 kJ/mol 41.0718 ± 0.0024 85056-54-8*1 Cyclopropylidene C(CH2CH2) (g, singlet) 474.96 466.93 ± 0.84 kJ/mol 40.0639 ± 0.0024 2143-70-6*1 Propargylium [CH2CCH]+ (g) 1193.49 1190.68 ± 0.32 kJ/mol 39.0554 ± 0.0024 21540-27-2*0 Cycloprop-1-enyl CH2(CHC) (g) 527.43 523.04 ± 0.58 kJ/mol 39.0559 ± 0.0024 19528-44-0*0 Cyclopropenylidene C(CHCH) (g) 497.05 496.08 ± 0.45 kJ/mol 38.0480 ± 0.0024 16165-40-5*0 Propargylenide [HCCCH]- (g, cisoid 2A) 436.9 439.5 ± 1.1 kJ/mol 38.0485 ± 0.0024 82906-05-6*2 2-Propyn-1-ylium-1-ylidene [CCCH]+ (g) 1598.46 1602.84 ± 0.90 kJ/mol 37.0395 ± 0.0024 75104-46-0*0 sec-Butyl CH3CH2CHCH3 (g) 91.17 66.40 ± 0.72 kJ/mol 57.1143 ± 0.0033 2348-55-2*0 1-Methylene-2-propenyl CH2CHCCH2 (g) 327.09 317.09 ± 0.75 kJ/mol 53.0825 ± 0.0032 1204515-52-5*0 Perchloryl OCl(O)O (g) 191.76 186.09 ± 0.62 kJ/mol 83.4509 ± 0.0013 13932-10-0*0 n-Heptane CH3(CH2)5CH3 (g) -145.38 -187.26 ± 0.45 kJ/mol 100.2019 ± 0.0057 142-82-5*0 n-Octane CH3(CH2)6CH3 (g) -161.01 -207.84 ± 0.53 kJ/mol 114.2285 ± 0.0065 111-65-9*0 Methoxymethyl CH3OCH2 (g) 13.22 0.65 ± 0.91 kJ/mol 45.0605 ± 0.0017 16520-04-0*0 Oxoethanide [CH3CO]- (g) -44.0 -49.5 ± 1.3 kJ/mol 43.0452 ± 0.0016 78944-68-0*0 Oxirene O(CHCH) (g, singlet) 273.17 271.01 ± 0.92 kJ/mol 42.0367 ± 0.0016 157-18-6*2 Chlorate [OCl(O)O]- (g) -208.2 -213.7 ± 1.5 kJ/mol 83.4514 ± 0.0013 14866-68-3*0 2-Hydroperoxyethyl CH2CH2OOH (g, gauche-syn) 64.5 50.2 ± 1.3 kJ/mol 61.0599 ± 0.0017 126898-97-3*32 Methoxyoxomethyl CH3OCO (g, anti-staggered) -152.8 -160.8 ± 1.2 kJ/mol 59.0440 ± 0.0017 16481-04-2*1 Hydroxyformyl HOCO (g, cis) -174.34 -177.37 ± 0.48 kJ/mol 45.0174 ± 0.0010 2564-86-5*2 Hydroxyformyl anion [HOCO]- (g, cis) -319.54 -322.12 ± 0.56 kJ/mol 45.0180 ± 0.0010 78944-70-4*2 Ethoxyethane CH3CH2OCH2CH3 (g) -223.72 -251.14 ± 0.60 kJ/mol 74.1216 ± 0.0033 60-29-7*0 Fluoronium [HFH]+ (g, singlet) 774.04 771.10 ± 0.91 kJ/mol 21.01373 ± 0.00014 12206-67-6*2 Water dimer (H2O)2 (g) -491.021 -499.060 ± 0.044 kJ/mol 36.03056 ± 0.00066 25655-83-8*0 Bromanylium Br+ (g) 1257.786 1251.723 ± 0.056 kJ/mol 79.90345 ± 0.00100 22541-56-6*0 Ethyl formate HC(O)OCH2CH3 (g, syn) -375.1 -393.9 ± 1.0 kJ/mol 74.0785 ± 0.0025 109-94-4*1 Propionic acid CH3CH2C(O)OH (g, syn) -435.93 -453.83 ± 0.59 kJ/mol 74.0785 ± 0.0025 79-09-4*1 (Methylimino)methyl CH3NCH (g, trans) 277.9 267.8 ± 1.1 kJ/mol 42.0599 ± 0.0016 117928-23-1*1 1-Aziridinyl N(CH2CH2) (g) 313.7 301.5 ± 1.4 kJ/mol 42.0599 ± 0.0016 23838-09-7*0 (Dimethylamino)methyl (CH3)2NCH2 (g) 166.1 143.0 ± 1.3 kJ/mol 58.1024 ± 0.0025 30208-47-0*0 Cyanoamidogen HNCN (g, t-quartet) 652.4 649.6 ± 1.2 kJ/mol 41.03212 ± 0.00082 12347-01-2*21 Diazomethyl HCNN (g, c-quartet) 652.7 649.7 ± 1.3 kJ/mol 41.03212 ± 0.00082 20813-32-5*22 Diazomethanide [HCNN]- (g, singlet) 305.17 302.08 ± 0.76 kJ/mol 41.03267 ± 0.00082 100840-43-5*2 Isocyanoamidogen HNNC (g, c-quartet) 828.2 825.4 ± 1.3 kJ/mol 41.03212 ± 0.00082 947408-73-3*22 Ethylamidogen anion [CH3CH2NH]- (g) 106.38 88.73 ± 0.80 kJ/mol 44.0763 ± 0.0017 54448-40-7*0 Chloromethide [CH2Cl]- (g) 56.3 53.0 ± 2.0 kJ/mol 49.4798 ± 0.0012 60291-29-4*0 Hexachloroethane CCl3CCl3 (g) -144.2 -146.6 ± 1.3 kJ/mol 236.7376 ± 0.0056 67-72-1*0 cis-1,2-Dichloroethene CHClCHCl (g, cis) 3.79 -2.21 ± 0.55 kJ/mol 96.9427 ± 0.0024 156-59-2*0 Dichloroacetylene ClCCCl (g) 232.69 236.00 ± 0.74 kJ/mol 94.9268 ± 0.0024 7572-29-4*0 Difluoromethylene CF2 (g) -193.87 -193.39 ± 0.35 kJ/mol 50.00751 ± 0.00080 2154-59-8*0 1,1-Difluoroethane CH3CHF2 (g) -488.99 -502.72 ± 0.53 kJ/mol 66.0500 ± 0.0016 75-37-6*0 2-Fluoroethanol FCH2CH2OH (g) -405.67 -422.91 ± 0.99 kJ/mol 64.0589 ± 0.0017 371-62-0*0 1,3,5-Hexatriyne HCCCCCCH (g) 682.0 686.9 ± 1.2 kJ/mol 74.0801 ± 0.0048 3161-99-7*0 Benzylide [C6H5CH2]- (g) 142.03 123.12 ± 0.40 kJ/mol 91.1310 ± 0.0056 18860-15-6*0 Cycloheptatriene CH2(CHCHCHCHCHCH) (g) 207.64 184.22 ± 0.94 kJ/mol 92.1384 ± 0.0056 544-25-2*0 Benzonitrile C6H5CN (g) 230.03 215.84 ± 0.92 kJ/mol 103.1213 ± 0.0056 100-47-0*0 p-Toluoyl CH3C6H4CO (g, para) 107.7 89.1 ± 1.5 kJ/mol 119.1406 ± 0.0064 67958-03-6*0 Acetonate [CH3C(O)CH2]- (g) -187.57 -201.13 ± 0.92 kJ/mol 57.0717 ± 0.0024 24262-31-5*0 Methyl nitrite CH3ONO (g) -55.53 -66.20 ± 0.44 kJ/mol 61.0401 ± 0.0010 624-91-9*0 Difluoride [F2]- (g) -291.6 -290.7 ± 1.4 kJ/mol 37.9973550 ± 0.0000010 12184-85-9*0 Acryloyl CH2CHCO (g, 2A") 102.76 97.17 ± 0.98 kJ/mol 55.0553 ± 0.0024 72241-20-4*2 3-Oxo-1,2-propadien-1-yl HCCCO (g) 290.27 292.79 ± 0.95 kJ/mol 53.0394 ± 0.0024 1198096-74-0*0 1-Cyanoethylidene CH3CCN (g, singlet) 475.7 470.5 ± 1.1 kJ/mol 53.0627 ± 0.0024 498544-34-6*2 3-Imino-2-propen-1-ylidene CHCHCNH (g, syn-singlet) 530.6 525.8 ± 1.2 kJ/mol 53.0627 ± 0.0024 916765-05-4*11 2-(Methylidyneamino)ethenyl CHCHNCH (g, anti-singlet) 600.7 595.6 ± 1.2 kJ/mol 53.0627 ± 0.0024 123416-74-0*11 1-Cyanovinyl anion [CH2CCN]- (g) 224.2 221.4 ± 1.2 kJ/mol 52.0553 ± 0.0024 36259-97-9*0 1,2,3-Butatrien-1-yl anion [CH2CCCH]- (g) 388.4 386.5 ± 1.1 kJ/mol 51.0672 ± 0.0032 102275-54-7*0 Silylene SiH2 (g, triplet) 362.0 360.4 ± 1.1 kJ/mol 30.10138 ± 0.00033 13825-90-6*1 Di-mu-hydrodihydrodisilicon HSi(HSiHH) (g, trans-singlet) 374.5 364.2 ± 2.4 kJ/mol 60.20276 ± 0.00066 129970-82-7*12 Methylsilane CH3SiH3 (g) -9.74 -25.91 ± 0.92 kJ/mol 46.14384 ± 0.00095 992-94-9*0 Trimethylsiloxy (CH3)3SiO (g) -188.1 -211.1 ± 1.9 kJ/mol 89.1885 ± 0.0025 54572-10-0*0 1,5-Hexadiyne HCCCH2CH2CCH (g) 431.6 421.1 ± 1.2 kJ/mol 78.1118 ± 0.0048 628-16-0*0 2-Methylallyl CH3C(CH2)CH2 (g) 155.84 138.73 ± 0.77 kJ/mol 55.0984 ± 0.0032 15157-95-6*0 3-Butenyl CH2CHCH2CH2 (g) 223.11 206.60 ± 0.91 kJ/mol 55.0984 ± 0.0032 2154-62-3*0 2-Methyl-1-propenyl CH3C(CH3)CH (g) 251.15 234.13 ± 0.72 kJ/mol 55.0984 ± 0.0032 33825-33-1*0 N-Methylethanamine CH3CH2NHCH3 (g) -17.7 -45.8 ± 1.1 kJ/mol 59.1103 ± 0.0025 624-78-2*0 Phenanthrene C6H4(C2H2(CC(C4H4))) (g) 232.03 203.22 ± 0.75 kJ/mol 178.2292 ± 0.0112 85-01-8*0 Trioxidane HOOOH (g, cis) -72.59 -81.08 ± 0.79 kJ/mol 50.01408 ± 0.00091 14699-99-1*2 Disulfene oxide SSO (g) -50.49 -52.51 ± 0.43 kJ/mol 80.1314 ± 0.0120 20901-21-7*0 Sulfur hydroxide oxide OHS(O)(O)O (g, staggered) -474.0 -483.5 ± 1.7 kJ/mol 97.0715 ± 0.0061 12337-07-4*1 Dinitrogen tetraoxide O2NNO2 (g) 20.18 10.89 ± 0.14 kJ/mol 92.0111 ± 0.0012 10544-72-6*0 Azanylium [NH3]+ (g) 944.272 937.318 ± 0.029 kJ/mol 17.03001 ± 0.00022 19496-55-0*0 Oxidanylium [OH]+ (g) 1293.362 1293.391 ± 0.025 kJ/mol 17.00679 ± 0.00031 12259-29-9*0 Nitryl hydride HN(O)O (g) -36.74 -43.71 ± 0.93 kJ/mol 47.01348 ± 0.00061 90266-90-3*0 Oxygen atom O (g, singlet) 436.665 438.523 ± 0.0021 kJ/mol 15.99940 ± 0.00030 17778-80-2*2 Methyliumylidene [CH]+ (g) 1619.746 1623.090 ± 0.041 kJ/mol 13.01809 ± 0.00080 24361-82-8*0 Ethylidyne CH3C (g, doublet) 508.61 504.91 ± 0.80 kJ/mol 27.0452 ± 0.0016 67624-57-1*1 Vinylidene anion [CCH2]- (g) 364.25 364.06 ± 0.31 kJ/mol 26.0378 ± 0.0016 66295-36-1*0 Methanol cation [CH3OH]+ (g) 856.83 846.51 ± 0.32 kJ/mol 32.04131 ± 0.00090 12538-91-9*0 Hydroxymethylene HCOH (g, gauche triplet) 219.3 216.4 ± 1.1 kJ/mol 30.02598 ± 0.00087 19710-56-6*3 Aquacarbon H2OC (g, triplet) 442.7 441.1 ± 1.3 kJ/mol 30.02598 ± 0.00087 81434-73-3*1 Carbonic acid C(O)(OH)2 (g, cis-trans) -596.50 -606.61 ± 0.74 kJ/mol 62.0248 ± 0.0012 463-79-6*2 Carbonic acid C(O)(OH)2 (g, trans-trans) -561.31 -570.15 ± 0.91 kJ/mol 62.0248 ± 0.0012 463-79-6*3 Hydroperoxycarbonyl HOOCO (g) -73.25 -77.11 ± 0.97 kJ/mol 61.0168 ± 0.0012 153751-35-0*0 Hypochloroperoxoous acid, hydroxy ester HOOOCl (g, syn) 48.4 41.5 ± 1.8 kJ/mol 84.4588 ± 0.0013 928652-99-7*1 Allylium [CH2CHCH2]+ (g) 964.42 952.86 ± 0.33 kJ/mol 41.0713 ± 0.0024 1724-44-3*0 Propylidyne CH3CH2C (g, quartet) 624.8 613.3 ± 1.3 kJ/mol 41.0718 ± 0.0024 85056-54-8*2 1-Propynyl CH3CC (g) 528.50 526.33 ± 0.65 kJ/mol 39.0559 ± 0.0024 89342-91-6*0 1-Propynylide [CH3CC]- (g) 264.56 260.97 ± 0.66 kJ/mol 39.0565 ± 0.0024 36147-87-2*0 1-Propen-1-yl-3-ylidene CHCHCH (g, c-c quartet) 656.7 653.3 ± 1.1 kJ/mol 39.0559 ± 0.0024 84654-90-0*11 t-Butyl anion [(CH3)3C]- (g) 76.8 52.0 ± 1.3 kJ/mol 57.1148 ± 0.0033 65114-21-8*0 Trioxygen difluoride FOOOF (g, trans) 112.5 106.7 ± 1.1 kJ/mol 85.99501 ± 0.00090 16829-28-0*1 2-Hydroxyethenyl CHCHOH (g, trans-cis) 137.93 131.19 ± 0.72 kJ/mol 43.0446 ± 0.0016 108665-16-3*21 Oxiranylidene CH2(CO) (g, singlet) 213.5 209.2 ± 1.4 kJ/mol 42.0367 ± 0.0016 50983-85-2*2 1-Hydroperoxyethylium [CH3CHOOH]+ (g, trans singlet) 690.5 674.8 ± 1.5 kJ/mol 61.0594 ± 0.0017 *126898-98-4*21 Iodine monobromide IBr (g) 49.727 40.780 ± 0.066 kJ/mol 206.8085 ± 0.0010 7789-33-5*0 Hydroxyformyl anion [HOCO]- (g, trans) -313.65 -315.45 ± 0.56 kJ/mol 45.0180 ± 0.0010 78944-70-4*1 Ethoxyethene CH2CHOCH2CH3 (g, cis-trans) -118.0 -141.7 ± 1.5 kJ/mol 72.1057 ± 0.0033 109-92-2*2 1,1-Ethenediol CH2C(OH)2 (g, syn-anti Cs) -307.65 -320.60 ± 0.83 kJ/mol 60.0520 ± 0.0017 10375-04-9*1 1,2-Ethenediol HOCHCHOH (g, cis) -272.79 -285.12 ± 0.90 kJ/mol 60.0520 ± 0.0017 1571-60-4*1 Hydrogen fluoride HF (aq, 5500 H2O) -324.57 ± 0.13 kJ/mol 20.006343 ± 0.000070 7664-39-3*955 (Formyloxy)methyl HC(O)OCH2 (g, syn) -151.4 -159.5 ± 1.1 kJ/mol 59.0440 ± 0.0017 3122-12-1*1 Ethylene glycol (CH2OH)2 (g) -369.66 -389.28 ± 0.40 kJ/mol 62.0678 ± 0.0018 107-21-1*0 Oxalic acid (C(O)OH)2 (g) -721.0 -731.6 ± 1.2 kJ/mol 90.0349 ± 0.0020 144-62-7*0 Tetroxidane HOOOOH (g, C1) -33.29 -43.95 ± 0.44 kJ/mol 66.0135 ± 0.0012 29683-94-1*21 (Methylamino)methyl cation [CH3NHCH2]+ (g) 729.23 710.61 ± 0.95 kJ/mol 44.0752 ± 0.0017 *31277-24-4*0 (Methyleneamino)methyl anion [CH2NCH2]- (g) 186.9 176.5 ± 1.6 kJ/mol 42.0604 ± 0.0016 73859-26-4*0 2-Aminoethenyl CHCHNH2 (g, anti) 319.7 309.6 ± 1.3 kJ/mol 42.0599 ± 0.0016 176964-54-8*2 Bromochlorane BrCl (g) 21.891 14.447 ± 0.059 kJ/mol 115.3567 ± 0.0013 13863-41-7*0 Bromotrichloromethane CCl3Br (g) -29.92 -39.07 ± 0.54 kJ/mol 198.2728 ± 0.0030 75-62-7*0 Trioxidanyl HOOO (g, trans) 25.36 23.38 ± 0.13 kJ/mol 49.00614 ± 0.00090 12500-78-6*1 Dichloromethyl CHCl2 (g) 92.87 90.95 ± 0.88 kJ/mol 83.9240 ± 0.0020 3474-12-2*0 Chloromethyl CH2Cl (g) 118.44 115.37 ± 0.87 kJ/mol 49.4793 ± 0.0012 6806-86-6*0 Methyl hypochlorite CH3OCl (g) -53.1 -63.0 ± 1.4 kJ/mol 66.4866 ± 0.0013 593-78-2*0 1,2-Dichloroethane CH2ClCH2Cl (g) -118.53 -130.47 ± 0.53 kJ/mol 98.9586 ± 0.0024 107-06-2*0 Tetraiodomethane CI4 (g) 320.8 315.7 ± 2.0 kJ/mol 519.62858 ± 0.00081 507-25-5*0 Chlorofluoromethane CH2FCl (g) -256.45 -263.65 ± 0.85 kJ/mol 68.4777 ± 0.0012 593-70-4*0 Difluoromethyliumyl [CF2]+ (g) 908.27 908.70 ± 0.77 kJ/mol 50.00696 ± 0.00080 54250-40-7*0 Fluoromethyliumylidene [CF]+ (g) 1123.11 1126.33 ± 0.45 kJ/mol 31.00855 ± 0.00080 33412-11-2*0 1,2-Difluoroacetylene FCCF (g) 2.87 5.70 ± 0.64 kJ/mol 62.0182 ± 0.0016 689-99-6*0 Chloroformyl ClCO (g) -21.92 -20.53 ± 0.49 kJ/mol 63.4628 ± 0.0012 2602-42-8*0 o-Benzyne anion [C6H4]- (g) 413.74 404.64 ± 0.95 kJ/mol 76.0965 ± 0.0048 100569-88-8*0 Cycloheptene CH2(CHCHCH2CH2CH2CH2) (g) 28.53 -8.69 ± 0.75 kJ/mol 96.1702 ± 0.0057 628-92-2*0 Benzoylium [C6H5CO]+ (g) 763.5 749.4 ± 1.3 kJ/mol 105.1135 ± 0.0056 19270-10-1*0 Benzoyl fluoride C6H5C(O)F (g) -288.5 -304.9 ± 1.3 kJ/mol 124.1124 ± 0.0056 455-32-3*0 Iodine I (g, 2P3/2) 107.157 106.757 ± 0.0021 kJ/mol 126.904470 ± 0.000030 14362-44-8*1 Fluorobenzene cation [C6H5F]+ (g) 791.95 776.93 ± 0.39 kJ/mol 96.1018 ± 0.0048 34468-25-2*0 Nitrosobenzene C6H5NO (g) 216.7 199.7 ± 1.2 kJ/mol 107.1100 ± 0.0048 586-96-9*0 1-Methylethoxy CH3CH(O)CH3 (g) -25.12 -43.89 ± 0.74 kJ/mol 59.0871 ± 0.0025 3958-66-5*0 Nitromethyl CH2N(O)O (g) 139.6 130.2 ± 1.1 kJ/mol 60.0321 ± 0.0010 16787-85-2*0 2-Butanone CH3CH2C(O)CH3 (g) -216.88 -238.33 ± 0.79 kJ/mol 72.1057 ± 0.0033 78-93-3*0 Acryloyl CH2CHCO (g, 2A', trans) 101.1 95.1 ± 1.4 kJ/mol 55.0553 ± 0.0024 72241-20-4*11 Formaldoxime CH2NOH (g, trans) 30.5 19.9 ± 1.3 kJ/mol 45.04066 ± 0.00088 75-17-2*1 1,3-Cyclobutadien-1-yl C(CHCHCH) (g) 653.7 649.2 ± 1.1 kJ/mol 51.0666 ± 0.0032 127611-22-7*0 Silylsilylene SiH3SiH (g, singlet) 317.1 309.3 ± 2.0 kJ/mol 60.20276 ± 0.00066 50420-90-1*2 Fluorotrimethylsilane SiF(CH3)3 (g) -547.2 -570.8 ± 2.1 kJ/mol 92.1875 ± 0.0025 420-56-4*0 Chlorotrimethylsilane SiCl(CH3)3 (g) -326.4 -349.5 ± 2.3 kJ/mol 108.6418 ± 0.0027 75-77-4*0 Trimethylsiloxide [(CH3)3SiO]- (g) -486.6 -510.4 ± 2.1 kJ/mol 89.1890 ± 0.0025 41866-81-3*0 1,3-Pentadiyne HCCCCCH3 (g) 417.99 413.77 ± 0.81 kJ/mol 64.0853 ± 0.0040 4911-55-1*0 1,4-Hexadiyne HCCCH2CCCH3 (g) 424.7 414.7 ± 1.3 kJ/mol 78.1118 ± 0.0048 10420-91-4*0 Biallenyl CH2CCHCHCCH2 (g, trans) 410.6 398.9 ± 1.5 kJ/mol 78.1118 ± 0.0048 29776-96-3*1 1,2,3,4-Hexatetraene CH2CCCCHCH3 (g) 429.8 420.1 ± 1.6 kJ/mol 78.1118 ± 0.0048 177856-38-1*0 Dioxaziridinyl N(OO) (g) 355.1 352.6 ± 1.4 kJ/mol 46.00554 ± 0.00060 66252-29-7*0 1-Aminoethyl CH3CHNH2 (g) 133.11 116.33 ± 0.93 kJ/mol 44.0758 ± 0.0017 30208-36-7*0 Ethylamidogen CH3CH2NH (g) 166.51 150.39 ± 0.94 kJ/mol 44.0758 ± 0.0017 41084-92-8*0 2-Naphthyl anion [C6H4(CHCCHCH)]- (g) 288.8 269.3 ± 1.2 kJ/mol 127.1631 ± 0.0080 88760-89-8*0 1-Naphthyl anion [C6H4(CCHCHCH)]- (g) 283.6 264.2 ± 1.2 kJ/mol 127.1631 ± 0.0080 125254-29-7*0 Nitrosamine NH2NO (g) 84.98 76.10 ± 0.96 kJ/mol 46.02876 ± 0.00036 35576-91-1*0 Sulfanyl SH (g) 142.86 143.31 ± 0.19 kJ/mol 33.0739 ± 0.0060 13940-21-1*0 Diazenyl NNH (g) 252.14 249.23 ± 0.45 kJ/mol 29.02142 ± 0.00016 36882-13-0*0 Nitrosyl chloride ClNO (g) 54.467 52.566 ± 0.068 kJ/mol 65.45884 ± 0.00095 2696-92-6*0 Carbide [C2]- (g) 504.39 510.96 ± 0.31 kJ/mol 24.0219 ± 0.0016 12595-78-7*0 Carbon dioxide CO2 (g, triplet) 49.8 50.6 ± 1.1 kJ/mol 44.00950 ± 0.00100 124-38-9*1 Bifluoride [(HF)(F)]- (g, singlet) -481.8 -480.6 ± 1.9 kJ/mol 39.005295 ± 0.000070 *18130-74-0*2 Bicyclo[1.1.0]buta-1,3-diene-2,4-diyl C(CC)C (g) 1047.12 1054.72 ± 0.68 kJ/mol 48.0428 ± 0.0032 12184-80-4*0 Methane cation [CH4]+ (g) 1150.679 1144.297 ± 0.057 kJ/mol 16.04191 ± 0.00085 20741-88-2*0 Ethanium [C2H7]+ (g) 874.35 858.11 ± 0.61 kJ/mol 31.0764 ± 0.0017 24669-33-8*0 Acetylene cation [HCCH]+ (g) 1328.87 1328.20 ± 0.12 kJ/mol 26.0367 ± 0.0016 25641-79-6*0 Water anion [(H)(OH)]- (g, vdW ?) 31.3 29.8 ± 3.1 kJ/mol 18.01583 ± 0.00033 12259-30-2*100 1-Ethylium-1-ylidene [CH3C]+ (g) 1329.7 1328.3 ± 1.2 kJ/mol 27.0447 ± 0.0016 78949-84-5*0 Ethylidyne anion [CH3C]- (g) 457.1 453.1 ± 1.2 kJ/mol 27.0458 ± 0.0016 117768-70-4*0 Isocyanomethyl CH2NC (g) 363.3 360.9 ± 1.1 kJ/mol 40.0440 ± 0.0016 70971-59-4*0 Methyloxoniumylidene [CH3O]+ (g) 1062.69 1054.88 ± 0.57 kJ/mol 31.03337 ± 0.00088 58157-09-8*0 Hydroxymethanide [CH2OH]- (g) 9.9 3.3 ± 1.5 kJ/mol 31.03447 ± 0.00088 55830-71-2*0 Hydroxymethylene HCOH (g, cis) 131.10 127.36 ± 0.29 kJ/mol 30.02598 ± 0.00087 19710-56-6*2 Hydroxymethylene cation [HCOH]+ (g, trans) 971.9 968.2 ± 1.4 kJ/mol 30.02543 ± 0.00087 135395-06-1*1 Chloryl hydride HCl(O)O (g) 197.7 191.2 ± 1.6 kJ/mol 68.4594 ± 0.0011 174365-32-3*0 Isoformyl COH (g) 217.24 217.63 ± 0.69 kJ/mol 29.01804 ± 0.00086 71080-92-7*0 Hydroxyoxomethoxy HOC(O)O (g) -360.37 -366.45 ± 0.93 kJ/mol 61.0168 ± 0.0012 38330-85-7*0 3-Dioxiranone OC(OO) (g) -159.9 -162.7 ± 1.5 kJ/mol 60.0089 ± 0.0012 94660-13-6*0 Carbonylbis(oxy) anion [OC(O)O]- (g) -550.4 -552.4 ± 1.4 kJ/mol 60.0094 ± 0.0012 16518-46-0*0 1-Methylethylidene CH3CCH3 (g, triplet) 326.8 313.7 ± 1.2 kJ/mol 42.0797 ± 0.0024 40852-89-9*1 1-Propenyl CH3CHCH (g, trans) 280.22 269.39 ± 0.76 kJ/mol 41.0718 ± 0.0024 6067-68-1*1 Iodide I- (aq) -56.827 ± 0.090 kJ/mol 126.905019 ± 0.000030 20461-54-5*800 Cyclopropynyl CH(CC) (g) 711.25 715.37 ± 0.71 kJ/mol 37.0400 ± 0.0024 119178-99-3*0 n-Butyl anion [CH3CH2CH2CH2]- (g) 106.1 81.1 ± 1.3 kJ/mol 57.1148 ± 0.0033 79431-01-9*0 sec-Butyl anion [CH3CH2CHCH3]- (g) 103.2 78.7 ± 1.3 kJ/mol 57.1148 ± 0.0033 79431-00-8*0 iso-Butyl (CH3)2CHCH2 (g) 97.24 73.25 ± 0.82 kJ/mol 57.1143 ± 0.0033 4630-45-9*0 1,2-Butadienyl anion [CH3CHCCH]- (g) 255.7 246.1 ± 1.1 kJ/mol 53.0830 ± 0.0032 65114-67-2*0 n-Hexane CH3CH2CH2CH2CH2CH3 (cr,l) -179.84 -198.49 ± 0.32 kJ/mol 86.1754 ± 0.0049 110-54-3*500 1-Hydroxyethylium [CH3CHOH]+ (g, syn) 610.9 596.4 ± 1.1 kJ/mol 45.0600 ± 0.0017 18682-96-7*2 2-Hydroxyethyl CH2CH2OH (g, gauche-anti) -10.96 -23.59 ± 0.93 kJ/mol 45.0605 ± 0.0017 4422-54-2*2 Vinyl alcohol cation [CH2CHOH]+ (g, anti) 778.6 767.3 ± 1.3 kJ/mol 44.0520 ± 0.0017 57239-63-1*2 1-Hydroxyethylidene CH3COH (g, syn singlet) 69.99 59.48 ± 0.86 kJ/mol 44.0526 ± 0.0017 30967-49-8*22 Hydrogen bromide HBr (aq) -120.51 ± 0.13 kJ/mol 80.9119 ± 0.0010 10035-10-6*800 Oxiranylium [CH2(CHO)]+ (g, singlet) 901.3 893.3 ± 1.4 kJ/mol 43.0441 ± 0.0016 57789-76-1*2 C=O=C COC (g, triplet) 653.0 657.3 ± 1.5 kJ/mol 40.0208 ± 0.0016 *12071-23-7*1 C=O=C COC (g, singlet) 721.9 726.2 ± 1.6 kJ/mol 40.0208 ± 0.0016 *12071-23-7*2 Oxoethylidene HCC(O)H (g, singlet) 275.4 272.6 ± 1.7 kJ/mol 42.0367 ± 0.0016 39920-84-8*2 Dihydroxymethanide [CH(OH)2]- (g, syn-syn) -194.3 -203.3 ± 1.8 kJ/mol 47.0339 ± 0.0010 61192-32-3*2 1-Hydroperoxyethyl CH3CHOOH (g) 39.5 25.9 ± 1.3 kJ/mol 61.0599 ± 0.0017 126898-98-4*0 Formic acid cation [HC(O)OH]+ (g, syn) 721.95 714.86 ± 0.25 kJ/mol 46.0248 ± 0.0010 50614-05-6*1 Formyloxidanyl HC(O)O (g, 2B2) -122.01 -125.36 ± 0.55 kJ/mol 45.0174 ± 0.0010 16499-21-1*2 1-Methoxyethenol CH2C(OH)OCH3 (g, anti-syn) -284.3 -303.7 ± 1.2 kJ/mol 74.0785 ± 0.0025 4453-91-2*1 1-Propene-1,2-diol CH3C(OH)CHOH (g, cis) -311.4 -329.8 ± 1.2 kJ/mol 74.0785 ± 0.0025 7333-03-1*1 1-Propene-1,2-diol CH3C(OH)CHOH (g, trans) -293.2 -309.8 ± 1.3 kJ/mol 74.0785 ± 0.0025 7333-03-1*2 (Formyloxy)methyl HC(O)OCH2 (g, anti) -135.8 -144.0 ± 1.3 kJ/mol 59.0440 ± 0.0017 3122-12-1*2 Bromonium [HBrH]+ (g) 924.4 913.6 ± 3.0 kJ/mol 81.9193 ± 0.0010 36658-54-5*0 Carboxymethyl CH2C(O)OH (g, anti) -206.1 -215.4 ± 1.2 kJ/mol 59.0440 ± 0.0017 2887-46-9*2 Dimethylamide [(CH3)2N]- (g) 122.9 104.5 ± 1.4 kJ/mol 44.0763 ± 0.0017 34285-60-4*0 Ethylideneamidogen CH3CHN (g) 209.7 199.2 ± 1.1 kJ/mol 42.0599 ± 0.0016 28445-33-2*0 (Methyleneamino)methyl CH2NCH2 (g) 244.1 233.5 ± 1.3 kJ/mol 42.0599 ± 0.0016 56391-78-7*0 Dinitrogen pentoxide O2NONO2 (g) 24.33 14.76 ± 0.29 kJ/mol 108.0105 ± 0.0015 10102-03-1*0 2-Aminoethenyl CHCHNH2 (g, syn) 325.5 315.3 ± 1.3 kJ/mol 42.0599 ± 0.0016 176964-54-8*1 2-Aziridinyl NH(CHCH2) (g, syn) 360.6 348.5 ± 1.7 kJ/mol 42.0599 ± 0.0016 *23838-09-7*1 Diazirenide [HC(NN)]- (g, singlet) 454.9 452.2 ± 1.5 kJ/mol 41.03267 ± 0.00082 130614-84-5*2 1H-Diazirin-3-yl HN(NC) (g, doublet) 618.7 615.8 ± 1.6 kJ/mol 41.03212 ± 0.00082 324529-57-9*1 Dioxidenium [HOO]+ (g) 1110.87 1107.98 ± 0.11 kJ/mol 33.00619 ± 0.00060 12207-52-2*0 1H-Diazirene CH(NHN) (g) 405.1 398.0 ± 1.4 kJ/mol 42.04006 ± 0.00082 157-23-3*0 Trioxidanylium [HOOO]+ (g, trans) 1070.4 1064.1 ± 1.4 kJ/mol 49.00559 ± 0.00090 74241-49-9*1 1,1,2-Trichloroethane CH2ClCHCl2 (g) -135.7 -147.3 ± 1.1 kJ/mol 133.4033 ± 0.0031 79-00-5*0 1,1,1,2-Tetrachloroethane CH2ClCCl3 (g) -144.4 -152.9 ± 1.3 kJ/mol 167.8481 ± 0.0039 630-20-6*0 Pentachloroethyl CCl3CCl2 (g) 28.9 27.0 ± 1.3 kJ/mol 201.2849 ± 0.0048 7094-17-9*0 Iodomethane CH3I (l) -12.28 ± 0.20 kJ/mol 141.93899 ± 0.00083 74-88-4*590 Bromo hypobromite BrOBr (g) 121.1 104.6 ± 1.2 kJ/mol 175.8074 ± 0.0020 21308-80-5*0 Bromide Br- (aq) -120.51 ± 0.13 kJ/mol 79.90455 ± 0.00100 24959-67-9*800 Difluoromethylene CF2 (g, triplet) 43.32 44.04 ± 0.35 kJ/mol 50.00751 ± 0.00080 2154-59-8*1 Ethyl iodide CH3CH2I (l) -9.39 -39.26 ± 0.48 kJ/mol 155.9656 ± 0.0016 75-03-6*500 cis-1,2-Difluoroethene CHFCHF (g, cis) -302.83 -309.59 ± 0.89 kJ/mol 64.0341 ± 0.0016 1630-77-9*0 Fluoroethynyl CCF (g) 445.3 449.8 ± 1.6 kJ/mol 43.0198 ± 0.0016 22533-50-2*0 Fluoro(fluorooxy)methylene FCOF (g, cis) -134.8 -136.0 ± 1.3 kJ/mol 66.00691 ± 0.00085 479587-30-9*2 Dibromophosgene CBr2O (g) -97.93 -113.86 ± 0.37 kJ/mol 187.8181 ± 0.0022 593-95-3*0 1,3,5-Hexatriynyl CCCCCCH (g) 1003.0 1010.5 ± 2.3 kJ/mol 73.0721 ± 0.0048 88053-50-3*0 Benzene C6H6 (cr,l) 50.81 49.27 ± 0.21 kJ/mol 78.1118 ± 0.0048 71-43-2*500 o-Benzyne C6H4 (g) 468.14 459.22 ± 0.86 kJ/mol 76.0960 ± 0.0048 462-80-6*0 m-Benzyne C6H4 (g, singlet) 527.0 518.5 ± 1.2 kJ/mol 76.0960 ± 0.0048 1828-89-3*2 p-Benzyne C6H4 (g, singlet) 587.0 577.5 ± 1.2 kJ/mol 76.0960 ± 0.0048 3355-34-8*2 Cycloheptane CH2(CH2CH2CH2CH2CH2CH2) (g) -72.43 -117.92 ± 0.52 kJ/mol 98.1861 ± 0.0057 291-64-5*0 Azide [NNN]- (g) 193.56 190.06 ± 0.91 kJ/mol 42.02077 ± 0.00021 14343-69-2*0 Iodine cation I+ (g) 1115.549 1115.149 ± 0.0062 kJ/mol 126.903921 ± 0.000030 22541-93-1*0 Propyn-1-ol CH3CCOH (g) 65.6 57.4 ± 1.1 kJ/mol 56.0633 ± 0.0024 6175-54-8*0 1H-Triazirin-1-yl N(NN) (g) 585.9 584.2 ± 2.0 kJ/mol 42.02022 ± 0.00021 912535-95-6*0 Formylethynyl CCCHO (g) 468.4 470.4 ± 1.3 kJ/mol 53.0394 ± 0.0024 277743-00-7*0 2-Cyclopropen-1-one OC(CHCH) (g) 163.8 159.9 ± 1.1 kJ/mol 54.0474 ± 0.0024 2961-80-0*0 Cyanovinylidene CCHCN (g) 581.7 584.2 ± 1.2 kJ/mol 51.0468 ± 0.0024 70277-81-5*0 Isocyanovinylidene CCHNC (g) 697.0 700.4 ± 1.4 kJ/mol 51.0468 ± 0.0024 737788-76-0*0 Hydrogen difluoride (F)(HF) (g, lin) -198.5 -198.4 ± 1.2 kJ/mol 39.004746 ± 0.000070 12528-21-1*1 Isocyanoethene CH2CHNC (g, singlet) 285.17 278.67 ± 0.94 kJ/mol 53.0627 ± 0.0024 14668-82-7*1 1-Cyanoethylidene CH3CCN (g, triplet) 437.5 433.7 ± 1.5 kJ/mol 53.0627 ± 0.0024 498544-34-6*1 Isocyanomethylene HCNC (g, singlet) 582.2 583.4 ± 1.7 kJ/mol 39.0361 ± 0.0016 78694-65-2*1 2-Methyl-2-cyclopropen-1-ylidene CH3C(CHC) (g, singlet) 448.0 441.8 ± 1.2 kJ/mol 52.0746 ± 0.0032 185841-59-2*2 1,2,3-Butatrien-1-ylium [CH2CCCH]+ (g, triplet) 1425.8 1426.1 ± 1.3 kJ/mol 51.0661 ± 0.0032 81932-79-8*1 But-1-en-3-yn-1-ide [HCCCHCH]- (g, cis) 419.7 418.5 ± 1.2 kJ/mol 51.0672 ± 0.0032 119611-65-3*2 But-3-en-1-yn-1-ide [CH2CHCC]- (g, singlet) 326.6 323.5 ± 1.4 kJ/mol 51.0672 ± 0.0032 58870-47-6*2 Cyclobutenyl CH2(CHCHCH) (g) 337.2 324.7 ± 1.2 kJ/mol 53.0825 ± 0.0032 24669-29-2*0 Propargyl chloride HCCCH2Cl (g) 186.6 180.7 ± 1.3 kJ/mol 74.5086 ± 0.0026 624-65-7*0 Dioxosilane SiO2 (g) -277.9 -279.2 ± 2.0 kJ/mol 60.08430 ± 0.00067 7631-86-9*0 Silylidyne SiH (g) 371.30 373.10 ± 0.76 kJ/mol 29.09344 ± 0.00031 13774-94-2*0 Trimethylsilyl Si(CH3)3 (g) 47.5 25.4 ± 2.0 kJ/mol 73.1891 ± 0.0025 16571-41-8*0 Benzvalene ((CHCH)(CH(CHCH)CH)) (g) 404.4 386.6 ± 1.2 kJ/mol 78.1118 ± 0.0048 659-85-8*0 Chlorine difluoride FClF (g) -47.0 -48.2 ± 1.3 kJ/mol 73.44951 ± 0.00090 24801-48-7*0 2-Naphthalenyl C6H4(CHCCHCH) (g) 416.8 397.2 ± 1.3 kJ/mol 127.1626 ± 0.0080 10237-50-0*0 1-Naphthalenyl C6H4(CCHCHCH) (g) 418.1 398.5 ± 1.3 kJ/mol 127.1626 ± 0.0080 2510-51-2*0 Aniline C6H5NH2 (g) 108.82 86.81 ± 0.72 kJ/mol 93.1265 ± 0.0048 62-53-3*0 Pyruvic acid CH3C(O)C(O)OH (g) -521.1 -535.5 ± 1.1 kJ/mol 88.0621 ± 0.0026 127-17-3*0 Thiodioxy SOO (g) 199.3 197.1 ± 1.3 kJ/mol 64.0648 ± 0.0060 164034-62-2*0 Sulfuric acid OS(O)(OH)2 (cr,l) -811.81 -813.80 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*500 Dioxyamidogen HNOO (g, cis) 240.5 233.8 ± 1.8 kJ/mol 47.01348 ± 0.00061 71843-95-3*2 Peroxynitrous acid HOONO (g, cis, perp) -0.11 -7.16 ± 0.53 kJ/mol 63.01288 ± 0.00091 14691-52-2*2 Dioxiranylidene C(OO) (g) 190.3 191.1 ± 1.4 kJ/mol 44.00950 ± 0.00100 138832-57-2*0 Bifluoride [FFH]- (g, triplet) -68.0 -67.6 ± 1.6 kJ/mol 39.005295 ± 0.000070 *18130-74-0*1 Oxofluoronium [FO]+ (g) 1342.66 1342.61 ± 0.80 kJ/mol 34.99725 ± 0.00030 12763-67-6*0 Methylammonium [CH3NH3]+ (g) 628.30 609.38 ± 0.97 kJ/mol 32.06453 ± 0.00091 17000-00-9*0 Aminomethylene CHNH2 (g) 245.9 238.1 ± 1.5 kJ/mol 29.04126 ± 0.00083 35430-17-2*0 Methyleneamidogen anion [CH2N]- (g) 192.83 189.08 ± 0.88 kJ/mol 28.03387 ± 0.00082 28892-56-0*0 (Z)-Iminomethyl HCNH (g, cis) 294.51 291.03 ± 0.89 kJ/mol 28.03332 ± 0.00082 54980-11-9*0 Aminomethylidyne CNH2 (g) 371.9 368.4 ± 1.1 kJ/mol 28.03332 ± 0.00082 84654-89-7*0 Ethynylamidogen HCCNH (g) 395.26 393.23 ± 0.96 kJ/mol 40.0440 ± 0.0016 73456-14-1*0 Methyleneoxonium CH2OH2 (g) 152.47 144.16 ± 0.49 kJ/mol 32.04186 ± 0.00090 177788-17-9*0 Hydroxymethylene anion [HCOH]- (g, trans) 147.1 144.1 ± 1.6 kJ/mol 30.02653 ± 0.00087 207914-87-2*1 Hydroxymethyliumylidene [COH]+ (g) 986.01 987.65 ± 0.83 kJ/mol 29.01749 ± 0.00086 60528-75-8*0 Isoformyl anion [(CO)(H)]- (g, vdW singlet ?) 55.7 58.4 ± 1.8 kJ/mol 29.01859 ± 0.00086 81747-63-9*1 Carbonic acid C(O)(OH)2 (g) -602.32 -611.63 ± 0.58 kJ/mol 62.0248 ± 0.0012 463-79-6*0 Peroxyformic acid HC(O)OOH (g, trans) -265.3 -273.2 ± 1.5 kJ/mol 62.0248 ± 0.0012 107-32-4*2 Oxywater (H2O)O (g) 64.8 58.3 ± 1.3 kJ/mol 34.01468 ± 0.00062 171363-09-0*0 1,3-Propanediyl CH2CH2CH2 (g, triplet Cs) 319.2 307.0 ± 1.3 kJ/mol 42.0797 ± 0.0024 32458-33-6*11 Propan-1-yl-3-ylidene CH2CH2CH (g, quartet) 554.3 545.6 ± 1.3 kJ/mol 41.0718 ± 0.0024 *50457-59-5*2 1-Propenylidene CH3CHC (g, singlet) 392.4 388.0 ± 1.1 kJ/mol 40.0639 ± 0.0024 70277-78-0*1 Cycloprop-2-enyl CH(CHCH) (g) 490.26 485.71 ± 0.58 kJ/mol 39.0559 ± 0.0024 28933-84-8*0 2-Propen-1-yl-3-ylidene CH2CHC (g) 556.61 554.35 ± 0.89 kJ/mol 39.0559 ± 0.0024 202744-74-9*0 2-Propynylidyne anion [CCCH]- (g) 540.77 545.54 ± 0.75 kJ/mol 37.0406 ± 0.0024 82893-67-2*0 Peroxychlorous acid HOOClO (g, syn) 95.4 89.4 ± 2.0 kJ/mol 84.4588 ± 0.0013 177778-92-6*1 t-Butylium [(CH3)3C]+ (g) 733.92 710.64 ± 0.98 kJ/mol 57.1137 ± 0.0033 14804-25-2*0 Methylcyclopropane CH3CH(CH2CH2) (g) 47.8 24.5 ± 1.3 kJ/mol 56.1063 ± 0.0032 594-11-6*0 2-Hydrotrioxy cation [OO(H)O]+ (g) 1298.2 1291.5 ± 1.5 kJ/mol 49.00559 ± 0.00090 *74241-49-9*0 1,2-Butadienylium [CH3CHCCH]+ (g, singlet) 1099.2 1089.8 ± 1.2 kJ/mol 53.0820 ± 0.0032 *65114-67-2*2 Dioxosilane SiO2 (cr, quartz) -906.74 -911.72 ± 0.63 kJ/mol 60.08430 ± 0.00067 7631-86-9*505 Triiodide [I3]- (aq) -51.49 ± 0.80 kJ/mol 380.713959 ± 0.000090 14900-04-0*800 2-Hydrotrioxy anion [OO(H)O]- (g) 27.5 21.8 ± 1.4 kJ/mol 49.00669 ± 0.00090 *89965-38-8*0 2,2-Dimethylbutane CH3CH2C(CH3)3 (g) -145.29 -185.72 ± 0.75 kJ/mol 86.1754 ± 0.0049 75-83-2*0 n-Nonane CH3(CH2)7CH3 (g) -176.18 -227.97 ± 0.49 kJ/mol 128.2551 ± 0.0073 111-84-2*0 Ethanol CH3CH2OH (cr,l) -269.70 -277.46 ± 0.20 kJ/mol 46.0684 ± 0.0017 64-17-5*500 Vinyl alcohol cation [CH2CHOH]+ (g, syn) 786.57 775.34 ± 0.80 kJ/mol 44.0520 ± 0.0017 57239-63-1*1 Perchloric acid HOCl(O)(O)O (g) 11.7 0.2 ± 1.3 kJ/mol 100.4582 ± 0.0015 7601-90-3*0 Vinoxy cation [CH2CHO]+ (g, triplet) 1020.2 1013.2 ± 1.5 kJ/mol 43.0441 ± 0.0016 *35731-40-9*1 Vinoxide [CH2CHO]- (g) -153.02 -160.08 ± 0.57 kJ/mol 43.0452 ± 0.0016 35731-40-9*0 Oxiranyl anion [CH2(CHO)]- (g, singlet) 121.3 113.2 ± 1.5 kJ/mol 43.0452 ± 0.0016 72722-59-9*2 Ketene CH2CO (g, singlet) -45.35 -48.41 ± 0.11 kJ/mol 42.0367 ± 0.0016 463-51-4*2 COC vdW (CO)(C) (g, triplet) 589.7 598.4 ± 1.5 kJ/mol 40.0208 ± 0.0016 *12071-24-8*1 Oxirene O(CHCH) (g, c-triplet) 389.9 385.7 ± 1.4 kJ/mol 42.0367 ± 0.0016 157-18-6*12 Nitrosodioxaziridine ONN(OO) (g, trans) 413.7 407.6 ± 1.8 kJ/mol 76.01168 ± 0.00091 132871-99-9*1 1,2,3-Trioxolane O(OCH2CH2O) (g) -9.5 -27.2 ± 1.8 kJ/mol 76.0514 ± 0.0019 6669-36-9*0 Methanediol CH2(OH)2 (g, Cs gauche) -368.99 -381.93 ± 0.79 kJ/mol 48.0413 ± 0.0010 463-57-0*2 Hydroxymethoxy anion [CH2(OH)O]- (g, syn) -373.88 -383.82 ± 0.89 kJ/mol 47.0339 ± 0.0010 67899-36-9*2 Ethoxyoxoniumylidene [CH3CH2OO]+ (g, triplet) 923.7 911.4 ± 1.5 kJ/mol 61.0594 ± 0.0017 268728-77-4*1 Ethaneperoxolate [CH3CH2OO]- (g, gauche) -120.50 -137.12 ± 0.72 kJ/mol 61.0604 ± 0.0017 268728-75-2*3 Formyloxoniumylidene [HC(O)O]+ (g) 1017.4 1014.0 ± 1.4 kJ/mol 45.0169 ± 0.0010 54375-27-8*0 Dioxymethylene HCOO (g, trans) 364.0 361.7 ± 2.4 kJ/mol 45.0174 ± 0.0010 438586-67-5*1 Trioxidaniumyl [HOOOH]+ (g, t, t) 925.6 916.4 ± 1.5 kJ/mol 50.01353 ± 0.00091 161321-37-5*2 Cyanate [NCO]- (g) -221.17 -221.39 ± 0.53 kJ/mol 42.01739 ± 0.00086 661-20-1*0 Oxazirinyl C(NO) (g) 450.1 450.9 ± 1.5 kJ/mol 42.01684 ± 0.00086 228850-18-8*0 Hydrogen fluoride HF (aq) -334.70 ± 0.15 kJ/mol 20.006343 ± 0.000070 7664-39-3*800 2-Propene-1,2-diol CH2C(OH)CH2OH (g, anti-gauche-gauche) -295.5 -315.0 ± 1.2 kJ/mol 74.0785 ± 0.0025 44169-27-9*11 2-Methoxy-2-oxoethyl CH2C(O)OCH3 (g, syn) -203.0 -218.2 ± 1.5 kJ/mol 73.0706 ± 0.0025 54668-31-4*1 (Acetyloxy)methyl CH3C(O)OCH2 (g, syn) -200.2 -213.9 ± 1.5 kJ/mol 73.0706 ± 0.0025 2887-49-2*1 Glyoxal OCHCHO (g) -207.79 -213.35 ± 0.55 kJ/mol 58.0361 ± 0.0017 107-22-2*0 Oxygen anion monohydrate [(HOH)O]- (g) -239.0 -244.3 ± 3.0 kJ/mol 34.01523 ± 0.00062 31748-17-1*0 Dimethylmethyleneammonium [(CH3)2NCH2]+ (g) 696.7 671.6 ± 1.3 kJ/mol 58.1018 ± 0.0025 28149-27-1*0 Fluoride F- (aq) -334.70 ± 0.15 kJ/mol 18.99895178 ± 0.00000050 16984-48-8*800 2-Methanidylidynehydrazin-2-ium-1-ide [HNNC]- (g, singlet) 281.8 279.1 ± 1.4 kJ/mol 41.03267 ± 0.00082 *947408-74-4*2 2-Methanidylidynehydrazin-2-ium-1-ide [HNNC]- (g, c-triplet) 518.6 516.1 ± 1.6 kJ/mol 41.03267 ± 0.00082 *947408-74-4*12 (E)-Diazene cation [HNNH]+ (g, trans) 1132.48 1125.54 ± 0.64 kJ/mol 30.02881 ± 0.00020 59952-06-6*0 (Z)-Diazene HNNH (g, cis) 228.82 221.69 ± 0.63 kJ/mol 30.02936 ± 0.00020 15626-42-3*0 Isocyanamide NH2NC (g) 328.5 322.6 ± 1.5 kJ/mol 42.04006 ± 0.00082 4702-38-9*0 Trichloromethide [CCl3]- (g) -123.2 -122.7 ± 2.0 kJ/mol 118.3693 ± 0.0028 14478-07-0*0 1,1,2,2-Tetrachloroethane CHCl2CHCl2 (g) -146.7 -156.1 ± 1.5 kJ/mol 167.8481 ± 0.0039 79-34-5*0 1,1,2,2-Tetrachloroethane CHCl2CHCl2 (cr,l) -172.9 -201.8 ± 1.5 kJ/mol 167.8481 ± 0.0039 79-34-5*500 Pentachloroethane CHCl2CCl3 (cr,l) -201.9 ± 2.5 kJ/mol 202.2928 ± 0.0048 76-01-7*500 Trichloroethene CHClCCl2 (l) -48.8 ± 1.5 kJ/mol 131.3874 ± 0.0031 79-01-6*590 Tetrachloroethene CCl2CCl2 (l) -61.17 ± 0.99 kJ/mol 165.8322 ± 0.0039 127-18-4*500 Trichloroethene CHClCCl2 (g) -10.9 -14.2 ± 1.5 kJ/mol 131.3874 ± 0.0031 79-01-6*0 Bromodichloromethane CHCl2Br (g) -34.9 -46.6 ± 1.2 kJ/mol 163.8280 ± 0.0022 75-27-4*0 Difluorodibromomethane CF2Br2 (g) -360.2 -378.2 ± 1.3 kJ/mol 209.8155 ± 0.0022 75-61-6*0 Dichlorodibromomethane CCl2Br2 (g) 27.7 11.8 ± 1.3 kJ/mol 242.7241 ± 0.0028 594-18-3*0 Difluorobromomethane CHF2Br (g) -411.40 -424.59 ± 0.46 kJ/mol 130.9194 ± 0.0013 1511-62-2*0 1,2-Difluoroethane CH2FCH2F (g) -434.39 -447.81 ± 0.80 kJ/mol 66.0500 ± 0.0016 624-72-6*0 Fluoro(fluorooxy)methylene FCOF (g, trans) -37.5 -39.1 ± 1.4 kJ/mol 66.00691 ± 0.00085 479587-30-9*1 Benzenium [CH2(CHCHCHCHCH)]+ (g) 887.7 867.6 ± 1.1 kJ/mol 79.1192 ± 0.0048 26812-57-7*0 Phenylium [C6H5]+ (g, triplet) 1251.2 1238.1 ± 1.6 kJ/mol 77.1034 ± 0.0048 17333-73-2*1 Benzylium [C6H5CH2]+ (g) 929.70 910.20 ± 0.55 kJ/mol 91.1299 ± 0.0056 6711-19-9*0 Pentalene CH(CHC(CHCHCH)CCH) (g) 389.8 373.6 ± 1.4 kJ/mol 102.1332 ± 0.0064 250-25-9*0 Benzoyl chloride C6H5C(O)Cl (cr,l) -157.09 ± 0.26 kJ/mol 140.5667 ± 0.0057 98-88-4*500 Benzoyl chloride C6H5C(O)Cl (g) -90.1 -105.4 ± 1.3 kJ/mol 140.5667 ± 0.0057 98-88-4*0 Hexafluorobenzene C6F6 (g) -942.58 -947.58 ± 0.87 kJ/mol 186.0546 ± 0.0048 392-56-3*0 Chlorobenzene cation [C6H5Cl]+ (g) 942.59 928.67 ± 0.61 kJ/mol 112.5561 ± 0.0049 55450-32-3*0 Chlorobenzene C6H5Cl (cr,l) 11.34 ± 0.59 kJ/mol 112.5566 ± 0.0049 108-90-7*500 m-Chlorophenyl C6H4Cl (g) 321.3 310.5 ± 1.6 kJ/mol 111.5487 ± 0.0049 3474-40-6*0 p-Chlorophenyl C6H4Cl (g) 324.2 313.4 ± 1.6 kJ/mol 111.5487 ± 0.0049 2396-00-1*0 o-Chlorophenyl C6H4Cl (g) 328.5 317.8 ± 1.6 kJ/mol 111.5487 ± 0.0049 3474-42-8*0 Bromobenzene cation [C6H5Br]+ (g) 995.1 973.5 ± 1.3 kJ/mol 157.0074 ± 0.0049 55450-33-4*0 Iodobenzene C6H5I (cr,l) 113.5 113.6 ± 1.1 kJ/mol 204.0084 ± 0.0048 591-50-4*500 Nitrobenzene C6H5N(O)O (g) 82.1 62.1 ± 1.4 kJ/mol 123.1094 ± 0.0049 98-95-3*0 Dihydrogen fluoride anion [HFH]- (g, triplet) 133.2 131.9 ± 1.6 kJ/mol 21.01483 ± 0.00014 117339-92-1*1 3-Methylenecyclopropene cation [CH2C(CHCH)]+ (g) 1181.7 1174.6 ± 1.2 kJ/mol 52.0740 ± 0.0032 79105-72-9*0 1-Hydroxy-1-methylethyl cation [CH3C(OH)CH3]+ (g) 521.3 501.0 ± 1.2 kJ/mol 59.0865 ± 0.0025 *5131-95-3*0 1-Hydroxypropyl CH3CH2CHOH (g) -55.4 -73.1 ± 1.1 kJ/mol 59.0871 ± 0.0025 5723-77-3*0 1,3-Butadien-2-ol CH2C(OH)CHCH2 (g, s-trans, syn) -53.4 -70.4 ± 1.5 kJ/mol 70.0898 ± 0.0032 59120-04-6*11 Cyclopropanone OC(CH2CH2) (g) 30.61 19.19 ± 0.96 kJ/mol 56.0633 ± 0.0024 5009-27-8*0 Hydroxyaminiumyl [NOH]+ (g) 1161.2 1158.2 ± 1.4 kJ/mol 31.01353 ± 0.00032 63559-88-6*0 Xenon cation Xe+ (g) 1170.354 1170.354 ± 0.0062 kJ/mol 131.2895 ± 0.0200 24203-25-6*0 2-Formylethen-1-ide [CHCHCHO]- (g, anti-trans) 27.3 20.5 ± 2.5 kJ/mol 55.0559 ± 0.0024 135924-69-5*11 Ethenedione OCCO (g) 14.5 17.0 ± 1.2 kJ/mol 56.0202 ± 0.0017 4363-38-6*0 Chlorine fluoride cation [ClF]+ (g) 1165.52 1165.70 ± 0.49 kJ/mol 54.45055 ± 0.00090 12432-44-9*0 Oxygen cation monohydrate [(HOH)O]+ (g) 1153.3 1147.8 ± 3.3 kJ/mol 34.01413 ± 0.00062 *31748-17-1*0 Formaldonitrone CH2NHO (g) 78.3 67.1 ± 1.4 kJ/mol 45.04066 ± 0.00088 67353-84-8*0 2-Cyclopropen-1-imine (CHCH)CNH (g) 401.8 394.1 ± 1.4 kJ/mol 53.0627 ± 0.0024 31589-17-0*0 1-Isocyanovinyl CH2CNC (g) 519.0 517.3 ± 1.4 kJ/mol 52.0547 ± 0.0024 321850-14-0*0 Chlorine chlorite ClOClO (g, gauche) 168.6 166.2 ± 1.3 kJ/mol 102.9042 ± 0.0019 105206-44-8*3 Hydroxyamidogen HNOH (g, cis) 123.3 116.7 ± 1.7 kJ/mol 32.02202 ± 0.00034 13940-32-4*2 Hydroxyaminylium [HNOH]+ (g, trans) 1019.5 1012.3 ± 2.5 kJ/mol 32.02147 ± 0.00034 66097-71-0*1 Vinylvinylidene CH2CHCHC (g, singlet) 494.1 488.8 ± 1.7 kJ/mol 52.0746 ± 0.0032 148759-16-4*2 But-1-en-3-yn-1-ide [HCCCHCH]- (g, trans) 422.3 420.9 ± 1.3 kJ/mol 51.0672 ± 0.0032 119611-65-3*1 Tetrahedryl anion [C(CH(CHCH))]- (g) 634.5 630.7 ± 1.6 kJ/mol 51.0672 ± 0.0032 138805-00-2*0 Deuterium atom D (g) 219.804 221.717 ± 0.000 kJ/mol 2.01410177800 ± 0.00000000040 16873-17-9*0 Silicon carbide SiC (g) 740.4 745.3 ± 2.4 kJ/mol 40.09620 ± 0.00085 409-21-2*0 Silicon carbide SiC (cr, alpha-hex) -70.6 -71.6 ± 1.5 kJ/mol 40.09620 ± 0.00085 409-21-2*501 Silanide [SiH3]- (g) 69.3 63.7 ± 1.4 kJ/mol 31.10987 ± 0.00037 15807-96-2*0 Fluorohydrochlorine cation [FClH]+ (g) 975.3 972.3 ± 2.0 kJ/mol 55.45849 ± 0.00090 70110-64-4*0 Dimethylsilanone CH3Si(O)CH3 (g) -237.3 -252.8 ± 2.3 kJ/mol 74.1539 ± 0.0017 47956-45-6*0 Dimethylsilane CH3SiH2CH3 (g) -66.7 -88.2 ± 1.1 kJ/mol 60.1704 ± 0.0017 1111-74-6*0 Chlorosyl hydride HClO (g) 141.9 139.0 ± 1.7 kJ/mol 52.46004 ± 0.00095 71572-35-5*0 Hydroxysilyl anion [SiH2OH]- (g, syn) -219.2 -227.2 ± 2.1 kJ/mol 47.10927 ± 0.00047 78450-47-2*1 Triprismane ((CHCH)((CHCH)(CHCH))) (g) 576.0 556.6 ± 1.3 kJ/mol 78.1118 ± 0.0048 650-42-0*0 Propargylallene CH2CCHCH2CCH (g, gauche) 431.4 419.8 ± 1.4 kJ/mol 78.1118 ± 0.0048 33142-15-3*3 Aquachlorine cation [ClOH2]+ (g) 822.0 815.1 ± 1.8 kJ/mol 53.46743 ± 0.00096 142599-65-3*0 Biphenyl C6H5C6H5 (g) 207.0 178.8 ± 1.1 kJ/mol 154.2078 ± 0.0096 92-52-4*0 Diacetylide [CCCCH]- (g) 460.91 465.94 ± 0.97 kJ/mol 49.0513 ± 0.0032 59012-21-4*0 Hydrogen difluoride cation [FFH]+ (g) 1174.3 1171.3 ± 1.5 kJ/mol 39.004198 ± 0.000070 *126950-54-7*0 Sulfur trioxide anion [OS(O)O]- (g) -604.4 -610.0 ± 2.8 kJ/mol 80.0647 ± 0.0061 12210-38-7*0 Chlorine difluoride cation [FClF]+ (g) 998.9 996.7 ± 1.7 kJ/mol 73.44896 ± 0.00090 32629-46-2*0 Bisulfite cation [OS(OH)O]+ (g) 554.0 545.3 ± 1.3 kJ/mol 81.0716 ± 0.0061 43637-78-1*0 Hydrogen atom H (ad, 1 Pt(111) atop) -18.9 -21.4 ± 4.3 kJ/mol 1.007940 ± 0.000070 12385-13-6*1002001 Hydrogen atom H (ad, 4 Pt(111) atop) -30.3 -32.7 ± 5.3 kJ/mol 1.007940 ± 0.000070 12385-13-6*1002004 NON NON (g) 545.5 542.6 ± 1.7 kJ/mol 44.01288 ± 0.00033 227934-46-5*0 Vinylidene CCH2 (g, triplet) 610.62 610.33 ± 0.39 kJ/mol 26.0373 ± 0.0016 2143-69-3*1 Iminomethide [HCNH]- (g, trans) 237.3 233.5 ± 1.8 kJ/mol 28.03387 ± 0.00082 90623-30-6*1 Hydroxydioxonitrate [HON(O)O]- (g) -193.2 -197.5 ± 2.4 kJ/mol 63.01343 ± 0.00091 58875-09-5*0 Cyanogen iodide anion [ICN]- (g) 86.5 88.8 ± 8.1 kJ/mol 152.92246 ± 0.00080 1356929-44-6*0 Methanol CH3OH (cr,l) -235.27 -238.60 ± 0.15 kJ/mol 32.04186 ± 0.00090 67-56-1*500 Formaldehyde cation [CH2O]+ (g) 944.853 941.232 ± 0.096 kJ/mol 30.02543 ± 0.00087 54288-05-0*0 Isoformyl anion [COH]- (g, triplet) 267.4 268.0 ± 1.6 kJ/mol 29.01859 ± 0.00086 81747-63-9*2 Trihydrogen dioxide anion [HOHOH]- (g) -487.4 -495.7 ± 1.1 kJ/mol 35.02317 ± 0.00064 12501-19-8*0 1,3-Propanediyl CH2CH2CH2 (g, singlet Cs TS) 358.6 343.6 ± 1.4 kJ/mol 42.0797 ± 0.0024 32458-33-6*22 Allene cation [CH2CCH2]+ (g) 1132.18 1125.03 ± 0.22 kJ/mol 40.0633 ± 0.0024 65812-77-3*0 2-Propenylidene CHCHCH2 (g, triplet anti) 417.5 409.9 ± 1.5 kJ/mol 40.0639 ± 0.0024 19527-08-3*11 2-Propenylidene CHCHCH2 (g, singlet) 452.64 445.51 ± 0.90 kJ/mol 40.0639 ± 0.0024 19527-08-3*2 Cycloprop-1-enylide [CH2(CHC)]- (g) 373.6 369.2 ± 1.7 kJ/mol 39.0565 ± 0.0024 80251-77-0*0 2-Cyclopropen-1-ylium-1-yl [C(CHCH)]+ (g) 1381.8 1380.8 ± 1.1 kJ/mol 38.0474 ± 0.0024 85398-75-0*0 Propynylidene HCCCH (g, cis singlet) 597.8 599.5 ± 1.3 kJ/mol 38.0480 ± 0.0024 67152-18-5*3 Propenediylidene CHCHC (g) 796.3 797.5 ± 1.4 kJ/mol 38.0480 ± 0.0024 60731-11-5*0 n-Butylium [CH3CH2CH2CH2]+ (g) 827.4 803.1 ± 1.1 kJ/mol 57.1137 ± 0.0033 25453-90-1*0 Hydrogen fluoride HF (aq, 30 H2O) -321.90 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*820 2-Butynylium [CH3CCCH2]+ (g, singlet) 1085.8 1077.6 ± 1.3 kJ/mol 53.0820 ± 0.0032 64235-83-2*2 1-Methylene-2-propenyl anion [CH2CHCCH2]- (g) 256.3 246.5 ± 1.3 kJ/mol 53.0830 ± 0.0032 64480-63-3*0 1,3-Butadienyl anion [CH2CHCHCH]- (g) 265.3 254.9 ± 1.5 kJ/mol 53.0830 ± 0.0032 65114-68-3*0 n-Decane CH3(CH2)8CH3 (g) -192.10 -248.85 ± 0.79 kJ/mol 142.2817 ± 0.0081 124-18-5*0 Ethyloxoniumyl [CH3CH2OH]+ (g) 783.3 766.4 ± 1.7 kJ/mol 46.0679 ± 0.0017 34480-55-2*0 1-Hydroxyethyl CH3CHOH (g, gauche-syn) -41.45 -54.92 ± 0.92 kJ/mol 45.0605 ± 0.0017 2348-46-1*2 1-Hydroxyethylium [CH3CHOH]+ (g) 608.80 594.37 ± 0.38 kJ/mol 45.0600 ± 0.0017 18682-96-7*0 2-Hydroxyethylium [CH2CH2OH]+ (g, staggered-anti) 1019.2 1006.4 ± 1.5 kJ/mol 45.0600 ± 0.0017 38607-31-7*3 Ethyloxoniumylidene [CH3CH2O]+ (g) 988.7 975.0 ± 1.5 kJ/mol 45.0600 ± 0.0017 54387-07-4*0 Triiodide [I3]- (g) -254.3 -257.5 ± 3.4 kJ/mol 380.713959 ± 0.000090 14900-04-0*0 Acetaldehyde cation [CH3CHO]+ (g) 832.04 822.06 ± 0.23 kJ/mol 44.0520 ± 0.0017 36505-03-0*0 1-Hydroxyethylidene CH3COH (g, gauche triplet) 184.9 175.5 ± 1.4 kJ/mol 44.0526 ± 0.0017 30967-49-8*1 Methoxymethylene CH3OCH (g, gauche triplet) 245.3 235.8 ± 1.4 kJ/mol 44.0526 ± 0.0017 19527-10-7*1 1-Hydroxyethenyl CH2COH (g) 121.25 114.87 ± 0.87 kJ/mol 43.0446 ± 0.0016 81847-74-7*0 Oxiranylium [CH2(CHO)]+ (g, triplet) 1233.6 1226.6 ± 1.6 kJ/mol 43.0441 ± 0.0016 57789-76-1*1 Oxiranyl anion [CH2(CHO)]- (g, triplet) 141.0 135.0 ± 1.6 kJ/mol 43.0452 ± 0.0016 72722-59-9*1 Acetic acid CH3C(O)OH (aq) -485.10 ± 0.27 kJ/mol 60.0520 ± 0.0017 64-19-7*800 Ketenyl anion [HCCO]- (g) -48.44 -47.51 ± 0.82 kJ/mol 41.0293 ± 0.0016 64066-01-9*0 Dicarbon monoxide anion [CCO]- (g) 154.17 157.82 ± 0.83 kJ/mol 40.0213 ± 0.0016 87191-88-6*0 Dicarbon monoxide CCO (g, singlet) 440.21 444.55 ± 0.83 kJ/mol 40.0208 ± 0.0016 12071-23-7*2 COC vdW (CO)(C) (g, singlet) 726.2 734.6 ± 1.7 kJ/mol 40.0208 ± 0.0016 *12071-24-8*2 C=O-C cation [COC]+ (g, doublet) 1585.8 1592.9 ± 2.7 kJ/mol 40.0203 ± 0.0016 83483-98-1*1 C=O=C anion [COC]- (g) 550.3 554.0 ± 1.7 kJ/mol 40.0213 ± 0.0016 *87191-88-6*0 Oxirene cation [O(CHCH)]+ (g) 1106.3 1102.6 ± 1.9 kJ/mol 42.0361 ± 0.0016 94664-69-4*0 Ethynol HCCOH (g) 95.31 92.82 ± 0.73 kJ/mol 42.0367 ± 0.0016 32038-79-2*0 Ethynol HCCOH (g, gauche triplet) 400.0 397.6 ± 1.9 kJ/mol 42.0367 ± 0.0016 32038-79-2*11 Oxoethylidene HCC(O)H (g, anti-triplet) 265.9 262.6 ± 1.6 kJ/mol 42.0367 ± 0.0016 39920-84-8*11 1-Hydroperoxyethylium [CH3CHOOH]+ (g, trans triplet) 841.3 829.3 ± 1.7 kJ/mol 61.0594 ± 0.0017 *126898-98-4*11 Ethenyldioxy CH2CHOO (g, anti) 118.7 109.2 ± 1.3 kJ/mol 59.0440 ± 0.0017 88181-72-0*1 Formic acid cation [HC(O)OH]+ (g, anti) 723.8 716.7 ± 1.2 kJ/mol 46.0248 ± 0.0010 50614-05-6*2 Formic acid anion [HC(O)OH]- (g, syn) -256.2 -262.3 ± 1.8 kJ/mol 46.0259 ± 0.0010 19066-82-1*1 Peroxychlorite [OClOO]- (g) -34.4 -34.4 ± 2.0 kJ/mol 83.4514 ± 0.0013 852472-63-0*0 Isocyanic acid cation [HNCO]+ (g) 1003.00 1000.34 ± 0.49 kJ/mol 43.02423 ± 0.00086 444010-28-0*0 Fulminic acid cation [HCNO]+ (g) 1215.7 1212.9 ± 1.3 kJ/mol 43.02423 ± 0.00086 114766-65-3*0 Dibromide [Br2]- (g) -197.0 -211.1 ± 2.3 kJ/mol 159.8085 ± 0.0020 12595-70-9*0 Fluorosyl fluoride FFO (g, triplet) 192.8 193.3 ± 2.3 kJ/mol 53.99621 ± 0.00030 86825-57-2*1 1,2-Ethenediol HOCHCHOH (g, trans) -254.0 -266.4 ± 1.3 kJ/mol 60.0520 ± 0.0017 1571-60-4*2 Acetyl chloride CH3C(O)Cl (l) -272.09 ± 0.39 kJ/mol 78.4973 ± 0.0019 75-36-5*500 Methyl formate HC(O)OCH3 (l) -388.59 ± 0.67 kJ/mol 60.0520 ± 0.0017 107-31-3*500 Ethyl formate HC(O)OCH2CH3 (g, anti) -355.4 -374.6 ± 1.4 kJ/mol 74.0785 ± 0.0025 109-94-4*2 Dioxygen O2 (g, singlet) 94.410 94.383 ± 0.000 kJ/mol 31.99880 ± 0.00060 7782-44-7*2 Acetoxy CH3C(O)O (g, 2A") -182.16 -190.98 ± 0.80 kJ/mol 59.0440 ± 0.0017 13799-69-4*1 1-Chloro ozone ClOOO (g, cis vdW) 226.3 223.0 ± 2.3 kJ/mol 83.4509 ± 0.0013 141801-66-3*101 2-Methoxy-2-oxoethyl CH2C(O)OCH3 (g, anti) -172.9 -188.1 ± 1.7 kJ/mol 73.0706 ± 0.0025 54668-31-4*2 (Acetyloxy)methyl CH3C(O)OCH2 (g, anti) -173.9 -186.9 ± 1.7 kJ/mol 73.0706 ± 0.0025 2887-49-2*2 Hydroxyoxoethenyl HOCCO (g) 24.5 22.8 ± 1.7 kJ/mol 57.0281 ± 0.0017 702699-39-6*0 Fluoronium [(HF)(H)]+ (g, triplet) 1490.1 1491.4 ± 1.9 kJ/mol 21.01373 ± 0.00014 12206-67-6*1 Isocyanomethylidyne CNC (g) 672.1 676.5 ± 1.7 kJ/mol 38.0281 ± 0.0016 53590-27-5*0 Cyanomethylidyne CCN (g) 684.7 689.1 ± 2.1 kJ/mol 38.0281 ± 0.0016 4120-02-9*0 Cyanoaminylium [HNCN]+ (g, triplet) 1363.1 1360.8 ± 1.3 kJ/mol 41.03157 ± 0.00082 205443-18-1*1 Cyanoamidogen anion [HNCN]- (g) 69.72 66.72 ± 0.72 kJ/mol 41.03267 ± 0.00082 67131-47-9*0 Diazomethylium [HCNN]+ (g, triplet) 1395.7 1394.1 ± 1.3 kJ/mol 41.03157 ± 0.00082 271249-81-1*1 Diazomethanide [HCNN]- (g) 305.17 302.08 ± 0.76 kJ/mol 41.03267 ± 0.00082 100840-43-5*0 2-Methyliumylidynehydrazin-2-ium-1-ide [HNNC]+ (g, singlet) 1544.1 1542.4 ± 1.7 kJ/mol 41.03157 ± 0.00082 *947408-73-3*2 2-Methyliumylidynehydrazin-2-ium-1-ide [HNNC]+ (g, triplet) 1563.1 1561.5 ± 1.5 kJ/mol 41.03157 ± 0.00082 *947408-73-3*1 Nitrilomethylimidogen NCHN (g, doublet) 728.7 725.6 ± 2.4 kJ/mol 41.03212 ± 0.00082 324529-58-0*1 Methanediimine HNCNH (g) 153.1 146.4 ± 1.3 kJ/mol 42.04006 ± 0.00082 151-51-9*0 Tetrachloromethane CCl4 (l) -104.63 -124.04 ± 0.42 kJ/mol 153.8215 ± 0.0037 56-23-5*500 Hydrogen chloride HCl (aq) -166.989 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*800 Dichloromethylene anion [CCl2]- (g) 75.96 78.24 ± 0.77 kJ/mol 82.9166 ± 0.0020 118364-73-1*0 Dichloromethylium [CHCl2]+ (g) 895.4 892.2 ± 1.2 kJ/mol 83.9235 ± 0.0020 56932-33-3*0 Dichloromethide [CHCl2]- (g) -40.8 -42.5 ± 2.0 kJ/mol 83.9246 ± 0.0020 32180-91-9*0 Chloromethylium [CH2Cl]+ (g) 962.4 958.5 ± 1.2 kJ/mol 49.4787 ± 0.0012 59000-00-9*0 Chloromethylene CHCl (g, triplet) 346.23 346.53 ± 0.89 kJ/mol 48.4713 ± 0.0012 2108-20-5*1 Dihydrogen fluoride anion [(F)(HH)]- (g, singlet) -257.0 -260.1 ± 1.9 kJ/mol 21.01483 ± 0.00014 *117339-92-1*2 1,2-Dichloroethane CH2ClCH2Cl (cr,l) -165.68 ± 0.56 kJ/mol 98.9586 ± 0.0024 107-06-2*500 Chloride Cl- (aq) -166.989 ± 0.023 kJ/mol 35.45325 ± 0.00090 16887-00-6*800 1,1-Dichloroethane CH3CHCl2 (cr,l) -163.77 ± 0.48 kJ/mol 98.9586 ± 0.0024 75-34-3*500 1,1,2-Trichloroethane CH2ClCHCl2 (l) -187.6 ± 1.1 kJ/mol 133.4033 ± 0.0031 79-00-5*500 Pentachloroethane CHCl2CCl3 (g) -150.5 -156.5 ± 1.9 kJ/mol 202.2928 ± 0.0048 76-01-7*0 Dioxymethylidyne COO (g) 299.8 301.1 ± 1.7 kJ/mol 44.00950 ± 0.00100 791121-04-5*0 Chloroform CHCl3 (l) -130.90 ± 0.43 kJ/mol 119.3767 ± 0.0028 67-66-3*590 Chlorodibromomethane CHClBr2 (g) 21.8 3.0 ± 3.5 kJ/mol 208.2793 ± 0.0023 124-48-1*0 Bromochloromethane CH2ClBr (g) -28.2 -42.3 ± 1.3 kJ/mol 129.3833 ± 0.0016 74-97-5*0 Azanylium [NH2]+ (g) 1266.56 1264.49 ± 0.11 kJ/mol 16.02207 ± 0.00016 15194-15-7*0 Fluoromethylene CHF (g) 148.40 148.68 ± 0.43 kJ/mol 32.01704 ± 0.00080 13453-52-6*0 Dioxygenyl ion monohydrate [(H2O)(O2)]+ (g) 828.7 821.6 ± 2.1 kJ/mol 50.01353 ± 0.00091 11083-61-7*0 Ethyl iodide CH3CH2I (g) 8.72 -7.15 ± 0.49 kJ/mol 155.9656 ± 0.0016 75-03-6*0 1,2-Dibromoacetylene BrCCBr (g) 333.0 322.1 ± 2.3 kJ/mol 183.8294 ± 0.0026 624-61-3*0 Diazenide [NNH]- (g, vdW) 175.6 176.7 ± 1.6 kJ/mol 29.02197 ± 0.00016 71004-29-0*100 Fluoro(fluorooxy)methylene FCOF (g, vdW triplet) -97.5 -95.7 ± 1.6 kJ/mol 66.00691 ± 0.00085 479587-30-9*101 Fluorooxomethylium [FCO]+ (g) 724.9 724.5 ± 1.2 kJ/mol 47.00795 ± 0.00085 38264-00-5*0 Fluoroisoformyl COF (g) -37.8 -32.4 ± 1.6 kJ/mol 47.00850 ± 0.00085 *1871-24-5*0 Benzene cation [C6H6]+ (g) 992.61 976.14 ± 0.21 kJ/mol 78.1113 ± 0.0048 34504-50-2*0 Diiodide [I2]- (g) -178.13 -180.72 ± 0.48 kJ/mol 253.809489 ± 0.000060 12190-71-5*0 Chlorosyl chloride ClClO (g) 134.5 133.2 ± 1.4 kJ/mol 86.9048 ± 0.0018 86825-56-1*0 Benzoic acid C6H5C(O)OH (cr,l) -367.31 -384.73 ± 0.17 kJ/mol 122.1213 ± 0.0056 65-85-0*500 Hydrogen fluoride HF (aq, 20 H2O) -321.84 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*818 2,3-Dimethylbenzaldehyde CH3C6H3(CH3)C(O)H (g, ortho-meta) -66.3 -94.3 ± 2.4 kJ/mol 134.1751 ± 0.0072 5779-93-1*0 (2,3-dimethylphenyl)oxomethyl CH3C6H3(CH3)CO (g, ortho-meta) 82.6 59.9 ± 2.6 kJ/mol 133.1672 ± 0.0072 *104680-89-9*0 2-Cyclopropyn-1-ylidene C(CC) (g, triplet) 898.4 905.3 ± 1.5 kJ/mol 36.0321 ± 0.0024 102508-15-6*1 m-Chlorophenide [C6H4Cl]- (g) 172.4 162.2 ± 1.5 kJ/mol 111.5492 ± 0.0049 77748-34-6*0 p-Chlorophenide [C6H4Cl]- (g) 179.4 169.0 ± 1.5 kJ/mol 111.5492 ± 0.0049 77748-42-6*0 o-Chlorophenide [C6H4Cl]- (g) 158.6 148.6 ± 1.5 kJ/mol 111.5492 ± 0.0049 72863-53-7*0 2-Cyclopropyn-1-ylium-1-yl [C(CC)]+ (g) 1939.2 1947.1 ± 1.3 kJ/mol 36.0316 ± 0.0024 154702-35-9*0 2-Oxopropylium [CH3C(O)CH2]+ (g) 784.7 770.9 ± 1.7 kJ/mol 57.0707 ± 0.0024 54088-52-7*0 Ammonium nitrate (NH4)NO3 (cr,l) -350.19 -365.16 ± 0.18 kJ/mol 80.04344 ± 0.00095 6484-52-2*500 Ammonia NH3 (aq, undissoc) -80.884 ± 0.053 kJ/mol 17.03056 ± 0.00022 7664-41-7*1000 2,3-Butanedione CH3C(O)C(O)CH3 (g) -310.75 -327.32 ± 0.62 kJ/mol 86.0892 ± 0.0033 431-03-8*0 1,2-Dibromoethane CH2BrCH2Br (g) -11.5 -38.3 ± 1.2 kJ/mol 187.8612 ± 0.0026 106-93-4*0 Dimethylketene CH3C(CO)CH3 (g) -73.4 -88.2 ± 1.2 kJ/mol 70.0898 ± 0.0032 598-26-5*0 2-Methyloxirene CH3C(CHO) (g, t-triplet) 344.1 334.1 ± 1.8 kJ/mol 56.0633 ± 0.0024 2835-41-8*11 1,3-Butadiyne-1,4-diyl CCCC (g) 1052.22 1062.20 ± 0.64 kJ/mol 48.0428 ± 0.0032 78015-07-3*0 3-Oxo-1-propenylium [CHCHCHO]+ (g, anti-trans-triplet) 1185.6 1179.6 ± 3.0 kJ/mol 55.0548 ± 0.0024 101705-90-2*111 (Hydroxyimino)methyl HCNOH (g, trans-trans) 250.1 243.9 ± 1.8 kJ/mol 44.03272 ± 0.00087 206442-92-4*1 Fluorochlorate [ClF]- (g) -256.03 -255.43 ± 0.81 kJ/mol 54.45165 ± 0.00090 12272-56-9*0 Hydrogen fluoride HF (aq, 10 H2O) -321.70 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*815 1-Isocyanoethylidene CH3CNC (g, triplet) 545.5 540.7 ± 1.6 kJ/mol 53.0627 ± 0.0024 *498544-34-6*1 3-Imino-2-propen-1-ylidene CHCHCNH (g, anti-triplet) 571.8 566.8 ± 1.6 kJ/mol 53.0627 ± 0.0024 916765-05-4*21 2-(Methylidyneamino)ethenyl CHCHNCH (g, anti-triplet) 634.4 629.8 ± 1.6 kJ/mol 53.0627 ± 0.0024 123416-74-0*21 Azete (CHCHCH)N (g) 469.4 461.3 ± 1.5 kJ/mol 53.0627 ± 0.0024 287-24-1*0 2-Cyanovinylium [CHCHCN]+ (g, anti triplet) 1517.2 1515.1 ± 1.8 kJ/mol 52.0542 ± 0.0024 85398-67-0*21 2-Cyanovinyl anion [CHCHCN]- (g, syn) 263.7 260.8 ± 1.8 kJ/mol 52.0553 ± 0.0024 *85398-67-0*2 2-Isocyanovinyl CHCHNC (g, anti) 543.2 541.2 ± 1.7 kJ/mol 52.0547 ± 0.0024 225798-14-1*1 3-Oxo-1,2-propadienylidene CCCO (g) 330.4 336.4 ± 1.8 kJ/mol 52.0315 ± 0.0024 11127-17-6*0 Vinylacetylene cation [CH2CHCCH]+ (g) 1221.7 1215.2 ± 1.1 kJ/mol 52.0740 ± 0.0032 59699-48-8*0 Bicyclo[1.1.0]but-2-ylium-1-yl [CH2(CCH)CH]+ (g) 1287.0 1278.0 ± 1.5 kJ/mol 52.0740 ± 0.0032 *78525-41-4*0 Oxadiazirene O(NN) (g) 351.7 349.9 ± 1.7 kJ/mol 44.01288 ± 0.00033 227934-45-4*0 Hydrogen difluoride (F)(HF) (g, perp) -187.4 -187.1 ± 1.6 kJ/mol 39.004746 ± 0.000070 12528-21-1*2 Azidonitrene NNNN (g, Cs) 692.1 687.5 ± 1.4 kJ/mol 56.02696 ± 0.00028 147363-92-6*2 3-Methylene-1-cyclopropen-1-yl anion [CH2C(CHC)]- (g) 417.2 413.5 ± 1.6 kJ/mol 51.0672 ± 0.0032 *117469-28-0*0 2-Cyclopropen-1-ylidenemethyl CHC(CHCH) (g) 635.7 632.5 ± 1.3 kJ/mol 51.0666 ± 0.0032 127611-25-0*0 5-Methyl-1,3-cyclopentadiene CH3CH(CHCHCHCH) (g) 134.0 111.0 ± 1.4 kJ/mol 80.1277 ± 0.0048 96-38-8*0 Fulvenone OCC(CHCHCHCH) (g) 117.3 107.1 ± 1.6 kJ/mol 92.0954 ± 0.0048 4727-22-4*0 Disilicon Si2 (g) 587.5 591.4 ± 1.6 kJ/mol 56.17100 ± 0.00060 12597-35-2*0 Hydroxyimidogen NOH (g) 217.91 215.03 ± 0.77 kJ/mol 31.01408 ± 0.00032 35337-59-8*0 Oxochloronium [ClO]+ (g) 1150.86 1150.70 ± 0.66 kJ/mol 51.45155 ± 0.00095 12301-79-0*0 Trifluoromethide [CF3]- (g) -637.5 -639.3 ± 1.8 kJ/mol 69.00646 ± 0.00080 54128-17-5*0 Disiloxane SiH3OSiH3 (g) -330.2 -347.3 ± 2.3 kJ/mol 78.21804 ± 0.00079 13597-73-4*0 Iodotrimethylsilane SiI(CH3)3 (g) -189.8 -214.5 ± 2.1 kJ/mol 200.0935 ± 0.0025 16029-98-4*0 Nitrous acid HONO (g, cis) -71.36 -77.72 ± 0.26 kJ/mol 47.01348 ± 0.00061 7782-77-6*2 Chlorohydrofluorine cation [ClFH]+ (g) 1000.8 998.1 ± 2.1 kJ/mol 55.45849 ± 0.00090 70110-63-3*0 1,2,3,5-Hexatetraene CH2CCCHCHCH2 (g, trans) 391.7 379.9 ± 1.6 kJ/mol 78.1118 ± 0.0048 60239-33-0*1 1,2,3-Pentatriene CH2CCCHCH3 (g) 302.6 290.3 ± 1.4 kJ/mol 66.1011 ± 0.0040 62018-46-6*0 (Z)-1-Methylallyl CH3CHCHCH2 (g, cis) 154.59 137.20 ± 0.99 kJ/mol 55.0984 ± 0.0032 98705-00-1*0 Nitronium [ONO]+ (g) 961.80 958.24 ± 0.20 kJ/mol 46.00499 ± 0.00060 14522-82-8*0 Anthracene C6H4(CH(CC(C4H4)CH)) (g) 256.04 227.02 ± 0.92 kJ/mol 178.2292 ± 0.0112 120-12-7*0 Helium hydride cation [HeH]+ (g) 1350.148 1348.258 ± 0.000 kJ/mol 5.009993 ± 0.000070 17009-49-3*0 Dihydrogen cation [H2]+ (g) 1488.364 1488.480 ± 0.000 kJ/mol 2.01533 ± 0.00014 12184-90-6*0 Peroxyimidogen NOO (g) 405.4 403.4 ± 1.9 kJ/mol 46.00554 ± 0.00060 *60488-31-5*0 Sulfuric acid OS(O)(OH)2 (aq, 2500 H2O) -895.08 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*898 Hydrogen atom H (ad, 1 Pt(111) fcc) -22.3 -25.6 ± 1.5 kJ/mol 1.007940 ± 0.000070 12385-13-6*1001001 Hydrogen atom H (ad, 4 Pt(111) fcc) -33.4 -36.7 ± 1.5 kJ/mol 1.007940 ± 0.000070 12385-13-6*1001004 Ethylene cation [CH2CH2]+ (g) 1075.19 1067.98 ± 0.11 kJ/mol 28.0526 ± 0.0016 34470-02-5*0 Trioxodinitrate anion [ONN(O)O]- (g, vdW) -104.2 -107.5 ± 1.9 kJ/mol 76.01223 ± 0.00091 194856-62-7*100 Peroxyformic acid HC(O)OOH (g, gauche) -265.2 -273.1 ± 1.4 kJ/mol 62.0248 ± 0.0012 107-32-4*3 Propylidene CH3CH2CH (g, singlet TS anti) 355.7 340.3 ± 2.0 kJ/mol 42.0797 ± 0.0024 6700-78-3*21 Cyclopropylium [CH(CH2CH2)]+ (g, TS) 1101.53 1088.72 ± 0.73 kJ/mol 41.0713 ± 0.0024 1724-43-2*200 Tetraoxidanyl (HOO)(O2) (g, vdW) 2.1 0.4 ± 2.9 kJ/mol 65.0055 ± 0.0012 69696-93-1*100 Propyne cation [CH3CCH]+ (g) 1192.60 1186.87 ± 0.38 kJ/mol 40.0633 ± 0.0024 34526-53-9*0 Cyclopropylidene C(CH2CH2) (g, triplet) 544.7 535.9 ± 1.5 kJ/mol 40.0639 ± 0.0024 2143-70-6*2 Propynylidene cation [HCCCH]+ (g) 1409.53 1412.09 ± 0.86 kJ/mol 38.0474 ± 0.0024 75123-91-0*0 Propynylidene HCCCH (g, trans singlet) 597.6 599.4 ± 1.1 kJ/mol 38.0480 ± 0.0024 67152-18-5*4 Propadienylidenide [CH2CC]- (g) 381.15 382.05 ± 0.41 kJ/mol 38.0485 ± 0.0024 109292-49-1*0 1,2-Propadien-1-ylium-1-yl [CH2CC]+ (g) 1561.5 1562.8 ± 1.4 kJ/mol 38.0474 ± 0.0024 110714-00-6*0 Trifluoride ion [F3]- (g) -349.0 -349.8 ± 2.6 kJ/mol 56.9957582 ± 0.0000015 25730-99-8*0 Oxadiazirine anion [O(NN)]- (g) 95.1 95.5 ± 2.9 kJ/mol 44.01343 ± 0.00033 350586-31-1*0 n-Pentane CH3CH2CH2CH2CH3 (cr,l) -155.83 -172.80 ± 0.30 kJ/mol 72.1488 ± 0.0041 109-66-0*500 iso-Pentane CH3CH2CH(CH3)2 (l) -178.21 ± 0.39 kJ/mol 72.1488 ± 0.0041 78-78-4*500 neo-Pentane C(CH3)4 (l) -189.53 ± 0.38 kJ/mol 72.1488 ± 0.0041 463-82-1*500 Cyclopentane CH2(CH2CH2CH2CH2) (l) -104.63 ± 0.38 kJ/mol 70.1329 ± 0.0041 287-92-3*590 2-Methylpentane CH3CH2CH2CH(CH3)2 (g) -134.46 -173.72 ± 0.73 kJ/mol 86.1754 ± 0.0049 107-83-5*0 3-Methylpentane CH3CH2CH(CH3)CH2CH3 (g) -131.92 -171.43 ± 0.76 kJ/mol 86.1754 ± 0.0049 96-14-0*0 2,3-Dimethylbutane CH3CH(CH3)CH(CH3)CH3 (g) -136.51 -177.61 ± 0.81 kJ/mol 86.1754 ± 0.0049 79-29-8*0 Cyclohexane CH2(CH2CH2CH2CH2CH2) (l) -131.77 -155.90 ± 0.28 kJ/mol 84.1595 ± 0.0049 110-82-7*500 1,5-Hexadiene CH2CHCH2CH2CHCH2 (g) 108.52 83.93 ± 0.39 kJ/mol 82.1436 ± 0.0049 592-42-7*0 Acetylene anion [HCCH]- (g, trans ?) 356.9 356.7 ± 1.9 kJ/mol 26.0378 ± 0.0016 50443-89-5*1 2-Hydroxyethyl CH2CH2OH (g, staggered-anti) -5.9 -18.3 ± 1.5 kJ/mol 45.0605 ± 0.0017 4422-54-2*3 Ethoxy CH3CH2O (g) 1.29 -12.14 ± 0.42 kJ/mol 45.0605 ± 0.0017 2154-50-9*0 Fluoroniumyl ion [HF]+ (g) 1275.557 1275.789 ± 0.022 kJ/mol 20.005795 ± 0.000070 12381-92-9*0 Trichlorine cation [Cl3]+ (g, singlet) 1056.6 1055.5 ± 1.4 kJ/mol 106.3576 ± 0.0027 33088-85-6*2 Dicarbon monoxide cation [CCO]+ (g) 1433.9 1439.0 ± 2.1 kJ/mol 40.0203 ± 0.0016 12287-08-0*0 C=O-C cation [COC]+ (g, quartet) 1816.8 1820.9 ± 2.0 kJ/mol 40.0203 ± 0.0016 83483-98-1*2 Oxirene anion [O(CHCH)]- (g) 288.3 285.3 ± 2.2 kJ/mol 42.0372 ± 0.0016 *157-18-6*0 Oxoethylidene HCC(O)H (g, triplet) 261.1 258.3 ± 1.1 kJ/mol 42.0367 ± 0.0016 39920-84-8*1 Dihydrogen fluoride (H)(HF) (g) -55.9 -54.9 ± 1.6 kJ/mol 21.01428 ± 0.00014 12592-22-2*1 Ethoxyoxoniumylidene [CH3CH2OO]+ (g, cis singlet) 962.3 945.9 ± 1.7 kJ/mol 61.0594 ± 0.0017 268728-77-4*22 2-Hydroperoxyethylium [CH2CH2OOH]+ (g, triplet) 999.8 988.8 ± 1.7 kJ/mol 61.0594 ± 0.0017 *84824-62-4*1 Formic acid anion [HC(O)OH]- (g, anti) -241.2 -246.9 ± 1.9 kJ/mol 46.0259 ± 0.0010 19066-82-1*2 Trichloride [Cl3]- (g) -328.5 -327.6 ± 1.3 kJ/mol 106.3586 ± 0.0027 18434-33-8*0 Dioxirane cation [CH2(OO)]+ (g) 1050.8 1043.1 ± 2.0 kJ/mol 46.0248 ± 0.0010 232262-10-1*0 Dioxymethyl cation [CH2OO]+ (g) 1074.8 1068.4 ± 1.7 kJ/mol 46.0248 ± 0.0010 232262-11-2*0 Chlorine oxide peroxide OClOO (g, vdW) 226.5 227.4 ± 2.5 kJ/mol 83.4509 ± 0.0013 141801-67-4*100 Nitrosyl fluoride FNO (g) -85.48 -87.84 ± 0.79 kJ/mol 49.00454 ± 0.00031 7789-25-5*0 Dioxymethylene HCOO (g, cis) 341.8 339.8 ± 3.0 kJ/mol 45.0174 ± 0.0010 438586-67-5*2 OH-CO vdW complex (OH)(CO) (g, vdW) -80.50 -76.77 ± 0.85 kJ/mol 45.0174 ± 0.0010 *2564-85-4*100 CO-HO vdW complex (CO)(HO) (g, vdW) -77.5 -73.3 ± 1.3 kJ/mol 45.0174 ± 0.0010 *2564-84-3*100 Cyanato cation [NCO]+ (g) 1261.51 1262.01 ± 0.58 kJ/mol 42.01629 ± 0.00086 17247-99-3*0 Nitrosomethyliumylidene [CNO]+ (g) 1509.8 1510.9 ± 1.7 kJ/mol 42.01629 ± 0.00086 67197-19-7*0 Fulminate [CNO]- (g) 59.5 59.8 ± 1.7 kJ/mol 42.01739 ± 0.00086 28269-67-2*0 Sulfuryl dichloride OS(O)Cl2 (g) -348.00 -354.16 ± 0.75 kJ/mol 134.9702 ± 0.0063 7791-25-5*0 Hydrofluorate ion [HF]- (g) -75.6 -75.1 ± 1.8 kJ/mol 20.006892 ± 0.000070 37249-79-9*0 Iminomethide [HCNH]- (g, cis) 252.6 248.9 ± 1.8 kJ/mol 28.03387 ± 0.00082 90623-30-6*2 Dihydrooxooxygen cation [(H2O)O]+ (g) 994.8 988.1 ± 1.6 kJ/mol 34.01413 ± 0.00062 177329-59-8*0 Glyoxal OCHCHO (g, cis) -189.35 -194.79 ± 0.71 kJ/mol 58.0361 ± 0.0017 107-22-2*2 Ethynediol HOCCOH (g) -18.3 -22.0 ± 1.6 kJ/mol 58.0361 ± 0.0017 16005-17-7*0 Nitrosyl nitrate ON(O2)NO (g, perp) 70.7 62.3 ± 1.8 kJ/mol 92.0111 ± 0.0012 *15969-55-8*0 Dimethylaminylium [(CH3)2N]+ (g) 1040.7 1025.2 ± 1.8 kJ/mol 44.0752 ± 0.0017 49784-85-2*0 Ethylimidogen CH3CH2N (g) 306.1 291.5 ± 2.0 kJ/mol 43.0678 ± 0.0016 27770-44-1*0 Diisocyanogen CNNC (g) 610.9 613.2 ± 1.7 kJ/mol 52.0349 ± 0.0016 78800-21-2*0 Hydrogen cyanide cation [HCN]+ (g) 1442.52 1442.05 ± 0.20 kJ/mol 27.02483 ± 0.00081 12601-62-6*0 1-Chloro ozone anion [ClOOO]- (g, perp) -109.0 -111.5 ± 2.2 kJ/mol 83.4514 ± 0.0013 224299-15-4*3 Cyanoamidogen anion [HNCN]- (g, c-triplet) 391.7 389.4 ± 1.8 kJ/mol 41.03267 ± 0.00082 67131-47-9*12 Diazirenide [HC(NN)]- (g) 454.9 452.2 ± 1.5 kJ/mol 41.03267 ± 0.00082 130614-84-5*0 Nitrilomethylium [CN]+ (g) 1783.12 1786.61 ± 0.48 kJ/mol 26.01689 ± 0.00080 12539-57-0*0 Trioxidaniumyl [HOOOH]+ (g, c, t) 935.3 926.3 ± 1.5 kJ/mol 50.01353 ± 0.00091 161321-37-5*3 Cyanamide cation [NH2CN]+ (g) 1158.7 1152.4 ± 1.5 kJ/mol 42.03951 ± 0.00082 148556-23-4*0 (E)-Diazene anion [HNNH]- (g, trans) 265.5 258.7 ± 2.0 kJ/mol 30.02991 ± 0.00020 *59952-06-6*0 1-Chloro ozone anion [ClOOO]- (g, cis) -66.9 -68.8 ± 2.1 kJ/mol 83.4514 ± 0.0013 224299-15-4*1 3-Diaziridinylidene C(NHNH) (g, anti) 521.8 515.0 ± 1.5 kJ/mol 42.04006 ± 0.00082 85513-79-7*1 Diazomethylene CNN (g) 577.8 578.5 ± 2.2 kJ/mol 40.02418 ± 0.00081 2468-81-7*0 Dichloromethylene CCl2 (g, triplet) 313.97 315.18 ± 0.90 kJ/mol 82.9161 ± 0.0020 1605-72-7*1 Chlorine difluoride ClFF (g) 22.5 23.9 ± 1.9 kJ/mol 73.44951 ± 0.00090 91483-78-2*0 (Z)-Diazene cation [HNNH]+ (g, cis) 1157.0 1150.1 ± 1.3 kJ/mol 30.02881 ± 0.00020 86631-37-0*0 Chloromethyliumyl [CHCl]+ (g) 1207.4 1207.7 ± 2.0 kJ/mol 48.4708 ± 0.0012 89877-51-0*0 Chloromethylene anion [CHCl]- (g) 203.53 204.34 ± 0.94 kJ/mol 48.4719 ± 0.0012 75466-08-9*0 Bromine dioxide OBrO (g) 165.6 156.0 ± 2.1 kJ/mol 111.9028 ± 0.0012 21255-83-4*0 Hydrogen peroxide cation [HOOH]+ (g, cis) 931.04 924.18 ± 0.98 kJ/mol 34.01413 ± 0.00062 12325-10-9*2 Nirous oxide cation [NNO]+ (g) 1329.70 1326.80 ± 0.12 kJ/mol 44.01233 ± 0.00033 12269-46-4*0 Chlorohydroxymethyl CH(Cl)OH (g, anti-gauche) -46.1 -51.7 ± 2.0 kJ/mol 65.4787 ± 0.0012 147139-06-8*2 1,1,1,2-Tetrachloroethane CH2ClCCl3 (cr,l) -193.5 ± 1.1 kJ/mol 167.8481 ± 0.0039 630-20-6*500 Hexachloroethane CCl3CCl3 (cr,l) -214.1 ± 2.8 kJ/mol 236.7376 ± 0.0056 67-72-1*500 3-Chloro-3-methyl-3H-diazirine (NN)CClCH3 (g) 251.4 239.6 ± 2.7 kJ/mol 90.5114 ± 0.0019 4222-21-3*0 trans-1,2-Dichloroethene CHClCHCl (g, trans) 5.62 0.20 ± 0.55 kJ/mol 96.9427 ± 0.0024 156-60-5*0 1-Hydrazinylium-1-yl [NNH2]+ (g) 1143.4 1136.4 ± 1.4 kJ/mol 30.02881 ± 0.00020 63986-30-1*0 Dihydrogen fluoride anion [(HF)(H)]- (g, singlet) -61.9 -60.5 ± 3.2 kJ/mol 21.01483 ± 0.00014 117339-92-1*2 Fluorosyl fluoride anion [FFO]- (g, doublet) -147.1 -146.8 ± 3.0 kJ/mol 53.99675 ± 0.00030 *86825-57-2*2 Perchloryloxy OCl(O)(O)O (g) 248.4 240.8 ± 1.8 kJ/mol 99.4503 ± 0.0015 12133-63-0*0 Fluorochlorobromomethane CHFClBr (g) -218.3 -230.9 ± 4.9 kJ/mol 147.3737 ± 0.0016 593-98-6*0 Perchlorate [OCl(O)(O)O]- (g) -263.9 -272.8 ± 2.1 kJ/mol 99.4508 ± 0.0015 14797-73-0*0 Fluoromethyliumyl [CHF]+ (g) 1116.6 1116.9 ± 1.7 kJ/mol 32.01649 ± 0.00080 89877-52-1*0 Fluoromethylene anion [CHF]- (g) 95.94 96.48 ± 0.61 kJ/mol 32.01759 ± 0.00080 71267-42-0*0 Polytetrafluoroethylene CF2CF2 (s) -829.99 ± 0.54 kJ/mol 100.0150 ± 0.0016 9002-84-0*591 trans-1,2-Difluoroethene CHFCHF (g, trans) -299.59 -306.03 ± 0.89 kJ/mol 64.0341 ± 0.0016 1630-78-0*0 Fluoroethynide [CCF]- (g) 133.3 137.5 ± 1.5 kJ/mol 43.0204 ± 0.0016 85905-56-2*0 Formyl fluoride cation [CHFO]+ (g) 816.6 813.3 ± 1.3 kJ/mol 48.01589 ± 0.00086 99766-68-4*0 Formyl fluoride [FCO]- (g) -405.1 -403.7 ± 1.6 kJ/mol 47.00905 ± 0.00085 62227-71-8*0 Fluoroisoformyl cation [COF]+ (g) 1347.4 1349.5 ± 1.9 kJ/mol 47.00795 ± 0.00085 *1871-25-6*0 Diazenide [NNH]- (g, triplet) 347.5 344.6 ± 1.6 kJ/mol 29.02197 ± 0.00016 71004-29-0*1 Ethynylene cation [C2]+ (g) 1964.95 1971.53 ± 0.40 kJ/mol 24.0209 ± 0.0016 12595-79-8*0 o-Benzyne cation [C6H4]+ (g) 1392.8 1384.7 ± 1.7 kJ/mol 76.0954 ± 0.0048 70220-84-7*0 Aminyliumyl [NH]+ (g) 1659.03 1659.96 ± 0.23 kJ/mol 15.014131 ± 0.000099 19067-62-0*0 Trioxidanylium [HOOO]+ (g, cis) 1085.2 1078.9 ± 1.4 kJ/mol 49.00559 ± 0.00090 74241-49-9*2 m-Benzyne cation [C6H4]+ (g) 1364.7 1356.2 ± 1.8 kJ/mol 76.0954 ± 0.0048 121058-08-0*0 Hydroxylamine NH2OH (g, cis) -15.4 -25.9 ± 1.4 kJ/mol 33.02996 ± 0.00037 7803-49-8*2 p-Benzyne C6H4 (g, triplet) 603.5 594.1 ± 1.2 kJ/mol 76.0960 ± 0.0048 3355-34-8*1 Chlorine difluoride anion [FClF]- (g) -504.9 -505.8 ± 1.9 kJ/mol 73.45005 ± 0.00090 16892-05-0*0 Hydroxylamine cation [NH2OH]+ (g) 857.7 847.9 ± 1.6 kJ/mol 33.02941 ± 0.00037 62675-55-2*0 1,3-Cycloheptadiene CH2(CHCHCHCHCH2CH2) (g, c-c) 123.65 94.54 ± 0.78 kJ/mol 94.1543 ± 0.0056 4054-38-0*1 Tropylium [CH(CHCHCHCHCHCH)]+ (g) 898.9 879.2 ± 1.1 kJ/mol 91.1299 ± 0.0056 26811-28-9*0 Deuterium atom cation D+ (g) 1532.210 1534.123 ± 0.000 kJ/mol 2.01355319809 ± 0.00000000040 14464-47-2*0 Iodine I (g, 2P1/2) 198.109 197.709 ± 0.0021 kJ/mol 126.904470 ± 0.000030 14362-44-8*2 Hexafluorobenzene C6F6 (cr,l) -997.18 -983.39 ± 0.87 kJ/mol 186.0546 ± 0.0048 392-56-3*500 cis-1,2-Dibromoethene CHBrCHBr (g, cis) 121.3 100.7 ± 2.0 kJ/mol 185.8453 ± 0.0026 590-11-4*0 1,1-Dibromoethane CH3CHBr2 (g) -4.8 -31.9 ± 1.8 kJ/mol 187.8612 ± 0.0026 557-91-5*0 Nitrogen hydride oxide NH3O (g) 71.2 60.0 ± 1.5 kJ/mol 33.02996 ± 0.00037 38544-48-8*0 Carbamoyl HNCOH (g, trans-trans) 74.1 67.7 ± 2.7 kJ/mol 44.03272 ± 0.00087 *2858-51-7*1 Formaldiminoxy CH2NO (g) 160.9 153.9 ± 1.5 kJ/mol 44.03272 ± 0.00087 2683-96-7*0 Formaldoxime CH2NOH (g, cis) 50.6 39.8 ± 1.8 kJ/mol 45.04066 ± 0.00088 75-17-2*2 Oxaziridine CH2(NHO) (g) 115.5 103.7 ± 2.1 kJ/mol 45.04066 ± 0.00088 6827-26-5*0 Aminooxy cation [NH2O]+ (g) 945.96 938.83 ± 0.76 kJ/mol 32.02147 ± 0.00034 *51375-41-8*0 Cyanoethynyl CCCN (g) 715.7 722.1 ± 1.1 kJ/mol 50.0388 ± 0.0024 62435-43-2*0 Chlorite [OClO]- (g) -105.51 -107.69 ± 0.37 kJ/mol 67.4520 ± 0.0011 14998-27-7*0 2-Methylene-2H-azirine (CHN)CCH2 (g) 404.2 396.8 ± 1.7 kJ/mol 53.0627 ± 0.0024 110027-86-6*0 Methyleneoxonium cation [CH2OH2]+ (g) 827.7 818.3 ± 1.7 kJ/mol 32.04131 ± 0.00090 *177788-17-9*0 Trioxidanyl HOOO (g, cis) 26.36 23.08 ± 0.19 kJ/mol 49.00614 ± 0.00090 12500-78-6*2 Azidonitrene NNNN (g, C2h) 660.8 657.6 ± 1.6 kJ/mol 56.02696 ± 0.00028 147363-92-6*1 2-Cyanovinylium [CHCHCN]+ (g, syn triplet) 1517.4 1515.2 ± 1.8 kJ/mol 52.0542 ± 0.0024 85398-67-0*22 2-Cyanovinyl anion [CHCHCN]- (g, anti) 266.1 263.2 ± 1.8 kJ/mol 52.0553 ± 0.0024 *85398-67-0*1 2-Isocyanovinyl CHCHNC (g, syn) 544.6 542.6 ± 1.7 kJ/mol 52.0547 ± 0.0024 225798-14-1*2 Cyanomethylene HCCN (g, singlet) 529.3 530.4 ± 1.3 kJ/mol 39.0361 ± 0.0016 2612-62-6*2 Isocyanomethylene HCNC (g, triplet) 586.1 587.2 ± 1.7 kJ/mol 39.0361 ± 0.0016 78694-65-2*2 3-Methylcycloprop-3-en-2-ylium-1-yl [CH3C(CHC)]+ (g) 1283.9 1277.4 ± 1.5 kJ/mol 52.0740 ± 0.0032 *185841-59-2*0 Formaldehyde CH2O (g, singlet) -105.389 -109.229 ± 0.095 kJ/mol 30.02598 ± 0.00087 50-00-0*2 Fluorodioxidenium [FOO]+ (g) 1221.9 1219.5 ± 2.0 kJ/mol 50.99665 ± 0.00060 139584-95-5*0 Vinylvinylidene cation [CH2CHCHC]+ (g, trans) 1429.8 1424.1 ± 2.0 kJ/mol 52.0740 ± 0.0032 161054-20-2*1 1,2-Butadien-1-ylidene CH3CHCC (g, singlet) 511.7 506.2 ± 2.0 kJ/mol 52.0746 ± 0.0032 119908-55-3*2 Hydroxyaminylium [HNOH]+ (g, cis) 1048.5 1041.3 ± 2.6 kJ/mol 32.02147 ± 0.00034 66097-71-0*2 1-Buten-3-ynylium [HCCCHCH]+ (g, trans) 1482.3 1479.8 ± 1.4 kJ/mol 51.0661 ± 0.0032 84654-85-3*1 Hydroxyamidogen anion [HNOH]- (g) 90.7 84.8 ± 2.8 kJ/mol 32.02257 ± 0.00034 *66097-71-0*0 3-Buten-1-ynylium [CH2CHCC]+ (g, triplet) 1572.6 1570.2 ± 1.7 kJ/mol 51.0661 ± 0.0032 103928-84-3*1 3-Methylene-1-cyclopropen-1-ylium [CH2C(CHC)]+ (g, singlet) 1398.7 1395.4 ± 1.7 kJ/mol 51.0661 ± 0.0032 117469-28-0*2 Butyraldehyde CH3CH2CH2CHO (g) -185.32 -205.69 ± 0.85 kJ/mol 72.1057 ± 0.0033 123-72-8*0 Chloroallene CH2CCHCl (g) 181.8 175.1 ± 1.6 kJ/mol 74.5086 ± 0.0026 3223-70-9*0 1-Chloropropyne CH3CCCl (g) 191.9 187.8 ± 1.6 kJ/mol 74.5086 ± 0.0026 7747-84-4*0 Methylcyclopentane CH3CH(CH2CH2CH2CH2) (g) -68.57 -106.09 ± 0.36 kJ/mol 84.1595 ± 0.0049 96-37-7*0 Dioxosilane SiO2 (cr,l) -906.74 -911.72 ± 0.63 kJ/mol 60.08430 ± 0.00067 7631-86-9*500 Dioxosilane SiO2 (vitr) -826.29 -902.22 ± 0.65 kJ/mol 60.08430 ± 0.00067 7631-86-9*520 Silicon carbide cation [SiC]+ (g) 1602.0 1606.7 ± 2.6 kJ/mol 40.09565 ± 0.00085 78393-58-5*0 Hydroxymethylene cation [HCOH]+ (g, cis) 986.3 982.7 ± 1.6 kJ/mol 30.02543 ± 0.00087 135395-06-1*2 Fluorodioxidanide [FOO]- (g) -256.8 -256.1 ± 1.9 kJ/mol 50.99775 ± 0.00060 23553-17-5*0 Silyliumyl [SiH2]+ (g) 1155.45 1153.83 ± 0.96 kJ/mol 30.10083 ± 0.00033 28149-31-7*0 Bifluoride [FHF]- (g) -705.22 -709.07 ± 0.35 kJ/mol 39.005295 ± 0.000070 18130-74-0*0 Hydrogen fluoride HF (aq, 22 H2O) -321.86 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*902 Disilanyl anion [SiH3SiH2]- (g) 63.4 51.1 ± 2.2 kJ/mol 61.21125 ± 0.00069 53199-49-8*0 Disilene SiH2SiH2 (g, triplet) 393.3 384.8 ± 2.3 kJ/mol 60.20276 ± 0.00066 15435-77-5*1 Ammonium hydroxide NH4OH (cr,l) -360.45 -361.53 ± 0.57 kJ/mol 35.04584 ± 0.00047 1336-21-6*500 Di-mu-hydrodihydrodisilicon HSi(HSiHH) (g, cis-singlet) 385.4 375.0 ± 2.7 kJ/mol 60.20276 ± 0.00066 129970-82-7*22 Hydroxymethylene cation [HCOH]+ (g, gauche quartet) 1482.1 1479.4 ± 1.9 kJ/mol 30.02543 ± 0.00087 135395-06-1*3 Iodosilane SiH3I (g) 6.9 -2.8 ± 2.6 kJ/mol 158.01379 ± 0.00037 13598-42-0*0 Ammonium hydroxide NH4OH (aq) -362.831 ± 0.061 kJ/mol 35.04584 ± 0.00047 1336-21-6*800 Nitric acid HON(O)O (cr,l) -178.97 -173.25 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*500 Trimethylsilanide [Si(CH3)3]- (g) -42.0 -65.5 ± 2.2 kJ/mol 73.1896 ± 0.0025 54711-92-1*0 Ethane cation [CH3CH3]+ (g) 1043.12 1029.11 ± 0.59 kJ/mol 30.0685 ± 0.0017 34488-65-8*0 Hydroxymethylene anion [HCOH]- (g, cis) 160.2 157.5 ± 1.7 kJ/mol 30.02653 ± 0.00087 207914-87-2*2 Hydroxymethylene anion [HCOH]- (g, gauche quartet) 334.0 334.8 ± 2.1 kJ/mol 30.02653 ± 0.00087 207914-87-2*3 (3E)-1,3-Hexadien-5-yne CH2CHCHCHCCH (g, trans) 358.7 346.5 ± 1.9 kJ/mol 78.1118 ± 0.0048 5222-77-5*0 Divinylacetylene CH2CHCCCHCH2 (g, cis) 361.8 350.4 ± 2.0 kJ/mol 78.1118 ± 0.0048 821-08-9*2 Dioxofluorine OFO (g) 523.9 523.2 ± 1.0 kJ/mol 50.99720 ± 0.00060 175861-93-5*0 1,2,4-Cyclohexatriene CH2(CHCHCHCCH) (g) 419.4 403.6 ± 2.0 kJ/mol 78.1118 ± 0.0048 124869-33-6*0 Pentatetraene CH2CCCCH2 (g) 452.7 448.7 ± 1.6 kJ/mol 64.0853 ± 0.0040 21986-03-8*0 Ethylammoniumyl [CH3CH2NH2]+ (g) 827.5 807.4 ± 1.6 kJ/mol 45.0832 ± 0.0017 41857-50-5*0 Dioxaziridinyl cation [N(OO)]+ (g) 1365.9 1363.3 ± 1.7 kJ/mol 46.00499 ± 0.00060 *66252-29-7*0 2-Methyl-2-propanamine (CH3)3CNH2 (g) -86.99 -120.64 ± 0.55 kJ/mol 73.1369 ± 0.0033 75-64-9*0 Aquacarbon H2OC (g, singlet vdW) 467.6 465.5 ± 1.9 kJ/mol 30.02598 ± 0.00087 81434-73-3*102 Dioxaziridinyl anion [N(OO)]- (g) 295.9 293.4 ± 1.7 kJ/mol 46.00609 ± 0.00060 66252-31-1*0 Helium He (g, triplet) 1912.302 1912.302 ± 0.000 kJ/mol 4.0026020 ± 0.0000020 7440-59-7*1 Helium cation He+ (g) 2372.322 2372.322 ± 0.000 kJ/mol 4.0020534 ± 0.0000020 14234-48-1*0 Aquacarbon cation [H2OC]+ (g) 1196.1 1193.0 ± 1.7 kJ/mol 30.02543 ± 0.00087 *81434-73-3*0 Neonium [NeH]+ (g) 1324.85 1323.04 ± 0.87 kJ/mol 21.18709 ± 0.00060 12200-65-6*0 Kryptonium [KrH]+ (g) 1106.29 1104.50 ± 0.68 kJ/mol 84.8074 ± 0.1000 37276-90-7*0 Nitrous acid HONO (g) -72.977 -78.634 ± 0.079 kJ/mol 47.01348 ± 0.00061 7782-77-6*0 Monosulfur cation S+ (g) 1276.48 1278.26 ± 0.14 kJ/mol 32.0655 ± 0.0060 14701-12-3*0 Oxosulfur [SO]+ (g) 999.33 999.93 ± 0.13 kJ/mol 48.0649 ± 0.0060 767269-11-4*0 Peroxyimidogen cation [NOO]+ (g) 1409.7 1406.8 ± 1.9 kJ/mol 46.00499 ± 0.00060 *60488-32-6*0 Hydrosulfide [SH]- (g) -80.48 -80.48 ± 0.19 kJ/mol 33.0745 ± 0.0060 15035-72-0*0 Fluorine atom cation F+ (g) 1758.302 1760.600 ± 0.017 kJ/mol 18.99785462 ± 0.00000050 14701-13-4*0 Sulfuric acid OS(O)(OH)2 (aq, 75 H2O) -887.11 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*825 Sulfuric acid OS(O)(OH)2 (aq, 7000 H2O) -899.14 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*846 Peroxyimidogen anion [NOO]- (g) 165.0 162.7 ± 1.7 kJ/mol 46.00609 ± 0.00060 60488-31-5*0 Hydrogen sulfate [OHS(O)(O)O]- (g) -942.4 -952.9 ± 1.9 kJ/mol 97.0721 ± 0.0061 14996-02-2*0 Hydrogen sulfite [OS(OH)O]- (g) -684.1 -691.4 ± 1.9 kJ/mol 81.0727 ± 0.0061 15181-46-1*0 Platinum Pt (g) 563.4 564.3 ± 1.7 kJ/mol 195.0780 ± 0.0020 7440-06-4*0 Ethylene anion [CH2CH2]- (g, anti ?) 232.0 224.4 ± 2.0 kJ/mol 28.0537 ± 0.0016 34527-91-8*1 Hydrogen chloride HCl (aq, 1000 H2O) -166.562 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*839 Cyclopentene CH2(CH2CHCHCH2) (l) 7.39 ± 0.49 kJ/mol 68.1170 ± 0.0040 142-29-0*590 Hydrogen difluoride cation [FFH]+ (g, singlet) 1174.3 1171.3 ± 1.5 kJ/mol 39.004198 ± 0.000070 *126950-54-7*2 Cyclohexene CH2(CHCHCH2CH2CH2) (g) 27.21 -4.26 ± 0.32 kJ/mol 82.1436 ± 0.0049 110-83-8*0 Cyclohexene CH2(CHCHCH2CH2CH2) (cr,l) -21.94 -37.81 ± 0.30 kJ/mol 82.1436 ± 0.0049 110-83-8*500 Acetylene anion [HCCH]- (g, cis ?) 380.1 380.3 ± 1.9 kJ/mol 26.0378 ± 0.0016 50443-89-5*2 1-Hydroxyethanide [CH3CHOH]- (g) -20.3 -33.7 ± 2.2 kJ/mol 45.0610 ± 0.0017 88032-18-2*0 Ethylene anion [CH2CH2]- (g, syn ?) 231.6 225.5 ± 2.0 kJ/mol 28.0537 ± 0.0016 34527-91-8*2 (Methylmethylene)oxonium [CH3OCH2]+ (g) 685.8 671.6 ± 2.2 kJ/mol 45.0600 ± 0.0017 23653-97-6*0 Methoxymethyl anion [CH3OCH2]- (g) 23.3 10.3 ± 2.3 kJ/mol 45.0610 ± 0.0017 61192-30-1*0 Acetaldehyde anion [CH3CHO]- (g) -62.2 -72.4 ± 2.2 kJ/mol 44.0531 ± 0.0017 60427-04-5*0 Hydrogen chloride HCl (aq, 1250 H2O) -166.603 ± 0.024 kJ/mol 36.46064 ± 0.00090 7647-01-0*954 Methylammoniumyl [CH3NH2]+ (g) 865.90 851.96 ± 0.25 kJ/mol 31.05659 ± 0.00088 34516-31-9*0 Methylamine anion [CH3NH2]- (g) 84.2 69.3 ± 2.8 kJ/mol 31.05769 ± 0.00088 81096-79-9*0 Triiodine cation [I3]+ (g) 946.1 941.0 ± 4.1 kJ/mol 380.712861 ± 0.000090 12596-32-6*0 Ketene cation [CH2CO]+ (g) 882.22 879.05 ± 0.11 kJ/mol 42.0361 ± 0.0016 64999-16-2*0 Ketene anion [CH2CO]- (g) -16.0 -19.1 ± 2.2 kJ/mol 42.0372 ± 0.0016 56391-79-8*0 Oxoethenylium [HCCO]+ (g) 1139.7 1142.4 ± 2.1 kJ/mol 41.0282 ± 0.0016 92056-63-8*0 Hydrogen chloride HCl (aq, 1500 H2O) -166.634 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*840 Aminomethyl anion [CH2NH2]- (g) 209.5 199.2 ± 2.1 kJ/mol 30.04975 ± 0.00085 74215-21-7*0 Methylaminilium [CH3NH]+ (g) 1135.2 1125.3 ± 2.1 kJ/mol 30.04865 ± 0.00085 49784-84-1*0 Chlorine difluoride cation [ClFF]+ (g) 1346.3 1344.9 ± 2.1 kJ/mol 73.44896 ± 0.00090 86825-59-4*0 Peroxychloric acid HOOCl(O)O (g) 76.6 68.4 ± 2.5 kJ/mol 100.4582 ± 0.0015 177778-91-5*0 Methyliumylamino [CH2NH]+ (g) 1056.0 1049.2 ± 1.7 kJ/mol 29.04071 ± 0.00083 65130-65-6*0 Hydrogen carbonate [HOC(O)O]- (aq) -689.860 ± 0.039 kJ/mol 61.0174 ± 0.0012 71-52-3*800 Azanidylmethyl [CH2NH]- (g) 224.4 217.1 ± 2.2 kJ/mol 29.04181 ± 0.00083 127593-73-1*0 Oxiranylidene CH2(CO) (g, triplet) 456.1 452.1 ± 2.2 kJ/mol 42.0367 ± 0.0016 50983-85-2*1 Oxiranylidene cation [CH2(CO)]+ (g) 1165.4 1161.9 ± 2.5 kJ/mol 42.0361 ± 0.0016 *50983-85-2*0 Oxiranylidene anion [CH2(CO)]- (g) 236.3 232.4 ± 2.3 kJ/mol 42.0372 ± 0.0016 *50983-86-3*0 Tribromine Br3 (g) 156.0 134.3 ± 3.2 kJ/mol 239.7120 ± 0.0030 11094-39-6*0 Aminomethyliumyl [CHNH2]+ (g) 1039.5 1031.8 ± 2.3 kJ/mol 29.04071 ± 0.00083 89302-94-3*0 Methyl hydroperoxide cation [CH3OOH]+ (g) 833.7 819.7 ± 2.0 kJ/mol 48.0407 ± 0.0010 112465-88-0*0 Dihydroxymethylium [CH(OH)2]+ (g, syn-anti) 421.3 410.0 ± 3.1 kJ/mol 47.0328 ± 0.0010 180071-68-5*1 Hydroxymethoxy cation [CH2(OH)O]+ (g, triplet gauche) 924.9 914.6 ± 3.2 kJ/mol 47.0328 ± 0.0010 180071-69-6*13 Methoxyoxoniumylidene [CH3OO]+ (g) 1012.32 1003.48 ± 0.67 kJ/mol 47.0328 ± 0.0010 86475-50-5*0 Hydrogen fluoride HF (aq, 40 H2O) -321.94 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*821 Ethylperoxy CH3CH2OO (g, trans) -5.47 -21.57 ± 0.88 kJ/mol 61.0599 ± 0.0017 3170-61-4*1 Aminomethylene anion [CHNH2]- (g) 353.0 346.1 ± 2.3 kJ/mol 29.04181 ± 0.00083 207914-86-1*0 Formic acid HC(O)OH (cr,l) -431.50 -424.66 ± 0.20 kJ/mol 46.0254 ± 0.0010 64-18-6*500 Tribromide [Br3]- (g) -287.4 -308.5 ± 1.9 kJ/mol 239.7125 ± 0.0030 14522-80-6*0 Dioxirane anion [CH2(OO)]- (g) -173.0 -179.8 ± 3.4 kJ/mol 46.0259 ± 0.0010 *157-26-6*0 Dioxymethyl anion [CH2OO]- (g) 54.8 49.7 ± 1.4 kJ/mol 46.0259 ± 0.0010 93207-29-5*0 iso-Proplylide [CH3CHCH3]- (g) 128.8 110.4 ± 1.5 kJ/mol 43.0882 ± 0.0024 25012-80-0*0 H-CO2 vdW complex (H)(OCO) (g, vdW) -178.3 -177.5 ± 2.1 kJ/mol 45.0174 ± 0.0010 *2564-83-2*100 Methylimidogen anion [CH3N]- (g) 321.0 313.4 ± 1.3 kJ/mol 29.04181 ± 0.00083 82539-34-2*0 2-Propanol CH3CH(OH)CH3 (cr,l) -305.39 -318.20 ± 0.27 kJ/mol 60.0950 ± 0.0025 67-63-0*500 1-Propanol CH3CH2CH2OH (cr,l) -290.38 -302.56 ± 0.23 kJ/mol 60.0950 ± 0.0025 71-23-8*500 Methyleneaminylium [CH2N]+ (g, triplet) 1456.7 1453.0 ± 2.1 kJ/mol 28.03277 ± 0.00082 53518-13-1*1 Oxazirinyl cation [C(NO)]+ (g) 1565.5 1566.2 ± 2.3 kJ/mol 42.01629 ± 0.00086 *228850-18-8*0 Oxazirinyl anion [C(NO)]- (g) 448.2 449.0 ± 2.4 kJ/mol 42.01739 ± 0.00086 28269-68-3*0 Acetic acid CH3C(O)OH (cr,l) -484.02 -483.60 ± 0.18 kJ/mol 60.0520 ± 0.0017 64-19-7*500 Acetic acid CH3C(O)OH (aq, 75 H2O) -484.61 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*825 Acetic acid CH3C(O)OH (aq, 1500 H2O) -484.82 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*840 Chlorine difluoride anion [ClFF]- (g) -319.0 -319.0 ± 2.2 kJ/mol 73.45005 ± 0.00090 91419-41-9*0 Nitric acid cation [HON(O)O]+ (g) 1029.19 1020.12 ± 0.69 kJ/mol 63.01233 ± 0.00091 272109-63-4*0 Ethyl formate HC(O)OCH2CH3 (cr,l) -426.0 ± 1.1 kJ/mol 74.0785 ± 0.0025 109-94-4*500 Propionic acid CH3CH2C(O)OH (g, anti) -415.5 -433.1 ± 1.3 kJ/mol 74.0785 ± 0.0025 79-09-4*2 Nitrosyl nitrate ONONO2 (g, trans) 48.3 40.4 ± 1.8 kJ/mol 92.0111 ± 0.0012 15969-55-8*1 Carbon tetracation [C]+4 (g) 14993.605 14998.752 ± 0.050 kJ/mol 12.00851 ± 0.00080 16092-62-9*0 Aminomethyliumylidene [CNH2]+ (g) 1168.3 1165.1 ± 2.2 kJ/mol 28.03277 ± 0.00082 86784-42-1*0 Chloroniumyl ion [HCl]+ (g) 1137.798 1137.732 ± 0.0051 kJ/mol 36.46009 ± 0.00090 12258-94-5*0 Trioxidanylium [HOOO]+ (g) 1070.4 1064.2 ± 1.4 kJ/mol 49.00559 ± 0.00090 74241-49-9*0 (1Z)-Ethanimine CH3CHNH (g, cis) 58.8 44.2 ± 1.4 kJ/mol 43.0678 ± 0.0016 56003-82-8*0 (E)-2-Iminoethylium [CH2CHNH]+ (g, anti-singlet) 1108.2 1097.6 ± 2.9 kJ/mol 42.0594 ± 0.0016 91127-33-2*22 2-Iminoethyl anion [CH2CHNH]- (g, syn) 104.4 93.5 ± 2.1 kJ/mol 42.0604 ± 0.0016 73843-87-5*1 Fluoronium [HFH]+ (g) 774.04 771.10 ± 0.91 kJ/mol 21.01373 ± 0.00014 12206-67-6*0 Hydrogen bromide HBr (aq, 600 H2O) -120.01 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*834 Diazenium [NH2NH]+ (g) 968.63 957.37 ± 0.73 kJ/mol 31.03675 ± 0.00025 37369-93-0*0 1,3-Propanediyl CH2CH2CH2 (g, singlet C2v TS EE) 337.6 322.9 ± 2.2 kJ/mol 42.0797 ± 0.0024 32458-33-6*21 Cyanogen cation [NCCN]+ (g) 1598.23 1600.44 ± 0.42 kJ/mol 52.0343 ± 0.0016 37354-81-7*0 Isocyanogen CNCN (g) 412.1 414.4 ± 1.3 kJ/mol 52.0349 ± 0.0016 83951-85-3*0 Diazoethenylidene NNCC (g) 658.6 661.2 ± 1.8 kJ/mol 52.0349 ± 0.0016 130760-10-0*0 Isocyanomethyliumylidene [CNC]+ (g) 1615.7 1621.2 ± 1.9 kJ/mol 38.0276 ± 0.0016 78271-45-1*0 Isocyanomethylidyne anion [CNC]- (g) 479.2 482.9 ± 2.0 kJ/mol 38.0287 ± 0.0016 *53590-27-5*0 Cyanomethyliumylidene [CCN]+ (g) 1719.8 1725.3 ± 2.1 kJ/mol 38.0276 ± 0.0016 76619-90-4*0 Cyanomethylidyne anion [CCN]- (g) 410.0 413.7 ± 2.2 kJ/mol 38.0287 ± 0.0016 12373-35-2*0 2,3-didehydro-1H-azirin-1-yl N(CC) (g) 720.3 724.3 ± 2.1 kJ/mol 38.0281 ± 0.0016 439586-06-8*0 Fluorosyl fluoride cation [FFO]+ (g, quartet) 1413.1 1413.4 ± 3.5 kJ/mol 53.99566 ± 0.00030 *86825-50-5*1 Diazirinyl HC(NN) (g, 2A') 557.1 553.9 ± 2.0 kJ/mol 41.03212 ± 0.00082 69967-71-1*2 Iminomethylimidogen anion [NCHN]- (g, singlet) 401.9 398.6 ± 2.3 kJ/mol 41.03267 ± 0.00082 150296-30-3*2 1H-Diazirin-3-ylium [HN(NC)]+ (g, singlet) 1527.2 1523.7 ± 2.0 kJ/mol 41.03157 ± 0.00082 735234-64-7*2 1H-Diazirin-3-yl HN(NC) (g, quartet) 917.7 914.3 ± 1.9 kJ/mol 41.03212 ± 0.00082 324529-57-9*2 1H-diazirin-3-ide [HN(NC)]- (g, singlet) 379.8 376.6 ± 2.0 kJ/mol 41.03267 ± 0.00082 *735234-64-7*2 Methanediimine cation [HNCNH]+ (g, cis) 1137.8 1133.1 ± 2.2 kJ/mol 42.03951 ± 0.00082 1189338-16-6*2 Diazomethane cation [CH2NN]+ (g) 1141.92 1135.65 ± 0.87 kJ/mol 42.03951 ± 0.00082 58852-13-4*0 3H-Diazirine cation [CH2(NN)]+ (g) 1327.5 1322.0 ± 1.7 kJ/mol 42.03951 ± 0.00082 796039-16-2*0 Carbon C (g, triplet) 711.389 716.874 ± 0.040 kJ/mol 12.01070 ± 0.00080 7440-44-0*1 1H-Diazirene cation [CH(NHN)]+ (g) 1333.3 1326.3 ± 1.9 kJ/mol 42.03951 ± 0.00082 *157-23-3*0 Isocyanamide cation [NH2NC]+ (g) 1321.4 1316.1 ± 1.9 kJ/mol 42.03951 ± 0.00082 160951-17-7*0 3-Diaziridinylidene cation [C(NHNH)]+ (g, anti) 1479.7 1473.7 ± 2.4 kJ/mol 42.03951 ± 0.00082 *85513-79-7*1 Carbon C (g, singlet) 833.320 838.467 ± 0.040 kJ/mol 12.01070 ± 0.00080 7440-44-0*2 Water H2O (l, eq.press.) -285.799 ± 0.022 kJ/mol 18.01528 ± 0.00033 7732-18-5*589 Trichloromethylium [CCl3]+ (g) 856.09 854.57 ± 0.93 kJ/mol 118.3683 ± 0.0028 27130-34-3*0 Dinitrogen pentoxide O2NONO2 (cr,l) -41.14 ± 0.38 kJ/mol 108.0105 ± 0.0015 10102-03-1*500 Dichloromethyliumyl [CCl2]+ (g) 1121.9 1122.9 ± 1.8 kJ/mol 82.9156 ± 0.0020 55945-51-2*0 Bromine atom Br (g, 2P3/2) 117.925 111.863 ± 0.055 kJ/mol 79.90400 ± 0.00100 10097-32-2*1 2-Chloro ozone anion [ClO(O)O]- (g) -103.6 -105.9 ± 3.2 kJ/mol 83.4514 ± 0.0013 *141801-67-4*0 1,1,1-Trichloroethane CH3CCl3 (l) -183.87 -177.23 ± 0.52 kJ/mol 133.4033 ± 0.0031 71-55-6*500 Isocyanomethylium [CH2NC]+ (g) 1272.6 1270.5 ± 2.2 kJ/mol 40.0435 ± 0.0016 78269-43-9*0 Vinyl chloride CH2CHCl (cr,l) -3.62 0.94 ± 0.91 kJ/mol 62.4979 ± 0.0018 75-01-4*500 Chloromethane cation [CH3Cl]+ (g) 1014.57 1007.80 ± 0.18 kJ/mol 50.4867 ± 0.0012 12538-71-5*0 Hypofluorous acid cation [HOF]+ (g) 1142.02 1139.01 ± 0.87 kJ/mol 36.00519 ± 0.00031 90243-22-4*0 Hydrogen chloride HCl (aq, 75 H2O) -165.554 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*825 Ammonium radical NH4 (g) 190.01 179.42 ± 0.43 kJ/mol 18.03850 ± 0.00029 92075-50-8*0 Bromofluoromethane CH2FBr (g) -197.4 -211.9 ± 4.9 kJ/mol 112.9290 ± 0.0013 373-52-4*0 Fluorodibromomethane CHFBr2 (g) -159.7 -179.3 ± 4.9 kJ/mol 191.8250 ± 0.0022 1868-53-7*0 Difluorochlorobromomethane CF2ClBr (g) -428.9 -439.9 ± 4.9 kJ/mol 165.3642 ± 0.0016 353-59-3*0 Dichlorofluorobromomethane CCl2FBr (g) -228.3 -238.3 ± 4.9 kJ/mol 181.8185 ± 0.0022 353-58-2*0 Dibromofluorochloromethane CBr2FCl (g) -169.9 -186.8 ± 4.9 kJ/mol 226.2698 ± 0.0023 353-55-9*0 Krypton cation Kr+ (g) 1350.756 1350.756 ± 0.000 kJ/mol 83.7995 ± 0.1000 16915-28-9*0 Nirous oxide anion [NNO]- (g) 99.3 96.7 ± 1.9 kJ/mol 44.01343 ± 0.00033 12274-12-3*0 Dibromine Br2 (aq) -2.25 ± 0.18 kJ/mol 159.8080 ± 0.0020 7726-95-6*800 Hydrogen fluoride HF (aq, 5 H2O) -321.33 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*809 1,2-Difluoroacetylene cation [FCCF]+ (g) 1081.7 1084.5 ± 1.3 kJ/mol 62.0177 ± 0.0016 268566-70-7*0 Difluorophosgene cation [CF2O]+ (g) 653.44 650.68 ± 0.51 kJ/mol 66.00636 ± 0.00085 73256-56-1*0 Ozone cation [OOO]+ (g) 1352.880 1350.541 ± 0.041 kJ/mol 47.99765 ± 0.00090 12596-82-6*0 1-Propenylidene CH3CHC (g, triplet) 630.4 622.9 ± 1.7 kJ/mol 40.0639 ± 0.0024 70277-78-0*2 Chloro(chlorooxy)methylene ClCOCl (g, cis) 73.5 73.7 ± 3.6 kJ/mol 98.9155 ± 0.0020 479587-31-0*2 Chlorohydroxymethylene ClCOH (g, trans) 14.0 11.1 ± 2.5 kJ/mol 64.4707 ± 0.0012 147723-60-2*1 (Chlorooxy)methylene HCOCl (g, cis) 119.2 117.9 ± 2.7 kJ/mol 64.4707 ± 0.0012 331419-80-8*2 Dibromophosgene CBr2O (l) -143.99 ± 0.95 kJ/mol 187.8181 ± 0.0022 593-95-3*590 2-Chloroethanol ClCH2CH2OH (l) -314.91 ± 0.53 kJ/mol 80.5132 ± 0.0019 107-07-3*590 2-Bromoethanol BrCH2CH2OH (l) -274.39 ± 0.46 kJ/mol 124.9645 ± 0.0019 540-51-2*590 Hypofluorous acid anion [HOF]- (g, quartet) 155.3 154.7 ± 2.6 kJ/mol 36.00629 ± 0.00031 36505-07-4*2 Phenylium [C6H5]+ (g, singlet) 1149.13 1136.35 ± 0.85 kJ/mol 77.1034 ± 0.0048 17333-73-2*2 m-Benzyne anion [C6H4]- (g) 444.1 435.2 ± 1.3 kJ/mol 76.0965 ± 0.0048 249589-31-9*0 p-Benzyne anion [C6H4]- (g) 465.0 455.4 ± 1.3 kJ/mol 76.0965 ± 0.0048 219298-17-6*0 Fluorosyl fluoride anion [FFO]- (g, quartet) -56.6 -55.7 ± 2.4 kJ/mol 53.99675 ± 0.00030 *86825-57-2*1 Cycloheptane CH2(CH2CH2CH2CH2CH2CH2) (cr,l) -126.57 -156.46 ± 0.50 kJ/mol 98.1861 ± 0.0057 291-64-5*500 Imidogen anion [NH]- (g) 322.62 322.67 ± 0.16 kJ/mol 15.015229 ± 0.000099 23841-33-0*0 Ethylbenzene C6H5CH2CH3 (cr,l) -12.28 ± 0.52 kJ/mol 106.1650 ± 0.0064 100-41-4*500 Phenylacetylene C6H5CCH (cr,l) 273.87 ± 0.71 kJ/mol 102.1332 ± 0.0064 536-74-3*500 Indane C6H4(CH2CH2CH2) (cr,l) 25.57 11.10 ± 0.77 kJ/mol 118.1757 ± 0.0072 496-11-7*500 Dioxygen O2 (g, triplet) -0.000 -0.000 ± 0.000 kJ/mol 31.99880 ± 0.00060 7782-44-7*1 Indene C6H4(CHCHCH2) (cr,l) 117.33 110.04 ± 0.86 kJ/mol 116.1598 ± 0.0072 95-13-6*500 Chlorosyl chloride cation [ClClO]+ (g) 1132.6 1130.8 ± 2.0 kJ/mol 86.9043 ± 0.0018 *86825-56-1*0 Phenyloxoniumylidene [C6H5O]+ (g) 901.5 887.1 ± 2.2 kJ/mol 93.1028 ± 0.0048 41071-17-4*0 Anisole C6H5OCH3 (g) -47.71 -72.55 ± 0.79 kJ/mol 108.1378 ± 0.0056 100-66-3*0 Hydrogen fluoride HF (aq, 60 H2O) -321.98 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*823 Imidogen NH (g, triplet) 358.74 358.79 ± 0.16 kJ/mol 15.014680 ± 0.000099 13774-92-0*1 Chlorosyl chloride anion [ClClO]- (g) -185.4 -184.7 ± 2.3 kJ/mol 86.9053 ± 0.0018 *86825-55-0*0 Ammonium chloride (NH4)Cl (cr) -311.554 -314.716 ± 0.062 kJ/mol 53.49120 ± 0.00095 12125-02-9*510 Fluorobenzene C6H5F (cr,l) -148.74 -146.33 ± 0.39 kJ/mol 96.1023 ± 0.0048 462-06-6*500 1,2-Propadien-1-yl-3-ylidene anion [CCC]- (g) 621.7 629.1 ± 1.3 kJ/mol 36.0326 ± 0.0024 109292-47-9*0 Cyanogen bromide anion [BrCN]- (g) 57.9 54.3 ± 3.8 kJ/mol 105.9220 ± 0.0013 54092-05-6*0 2-Cyclopropyn-1-ylidene C(CC) (g, singlet) 993.1 1000.0 ± 2.6 kJ/mol 36.0321 ± 0.0024 102508-15-6*2 Bromobenzene C6H5Br (cr,l) 60.2 ± 1.3 kJ/mol 157.0079 ± 0.0049 108-86-1*500 Ammonium bromide (NH4)Br (cr) -253.27 -269.85 ± 0.14 kJ/mol 97.9425 ± 0.0010 12124-97-9*510 2-Cyclopropyn-1-yl anion [C(CC)]- (g) 664.5 671.8 ± 1.6 kJ/mol 36.0326 ± 0.0024 500574-36-7*0 Pyridinium [NH(CHCHCHCHCH)]+ (g) 761.7 740.8 ± 1.3 kJ/mol 80.1073 ± 0.0040 16969-45-2*0 Acetone CH3C(O)CH3 (cr,l) -244.59 -247.71 ± 0.26 kJ/mol 58.0791 ± 0.0025 67-64-1*500 2-Hydroxy-2-propenyl CH2C(OH)CH2 (g) 4.0 -9.5 ± 1.2 kJ/mol 57.0712 ± 0.0024 742072-56-6*0 Propionaldehyde CH3CH2CHO (cr,l) -218.03 -216.57 ± 0.27 kJ/mol 58.0791 ± 0.0025 123-38-6*500 Hydrogen chloride HCl (aq, 140 H2O) -165.944 ± 0.024 kJ/mol 36.46064 ± 0.00090 7647-01-0*907 Ethyl nitrite CH3CH2ONO (g) -81.26 -98.66 ± 0.87 kJ/mol 75.0666 ± 0.0017 109-95-5*0 trans-1,2-Dibromoethene CHBrCHBr (g, trans) 121.6 101.8 ± 2.0 kJ/mol 185.8453 ± 0.0026 590-12-5*0 1,1-Dibromoethene CH2CBr2 (g) 125.5 105.1 ± 2.1 kJ/mol 185.8453 ± 0.0026 593-92-0*0 Norbornadiene (CHCH)(CHCH2CH)(CHCH) (g) 268.04 242.60 ± 0.94 kJ/mol 92.1384 ± 0.0056 121-46-0*0 Monoammonium succinate (CH2C(O)OH)2(NH3) (cr) -1067.83 ± 0.72 kJ/mol 135.1186 ± 0.0035 38457-08-8*510 Diammonium succinate (CH2COOH)2(NH3)2 (cr) -1182.34 ± 0.47 kJ/mol 152.1492 ± 0.0035 2226-88-2*510 1-Ethylium-1-yl [CH3CH]+ (g) 1182.0 1174.7 ± 3.2 kJ/mol 28.0526 ± 0.0016 85944-79-2*0 Acrolein CH2CHCHO (g, cis) -46.4 -56.7 ± 1.3 kJ/mol 56.0633 ± 0.0024 107-02-8*2 2H-Oxete O(CH2CHCH) (g) 65.7 53.3 ± 1.2 kJ/mol 56.0633 ± 0.0024 287-25-2*0 1-Formylethenylium [CH2CCHO]+ (g, singlet) 1023.5 1018.0 ± 2.3 kJ/mol 55.0548 ± 0.0024 101705-89-9*2 Chloryl chloride ClCl(O)O (g) 126.1 122.1 ± 1.7 kJ/mol 102.9042 ± 0.0019 117489-73-3*0 3-Oxo-1-propenylium [CHCHCHO]+ (g, singlet) 1005.1 1002.8 ± 2.4 kJ/mol 55.0548 ± 0.0024 101705-90-2*2 Methanol anion [CH3OH]- (g) -89.1 -99.8 ± 2.8 kJ/mol 32.04241 ± 0.00090 68474-04-4*0 Ethenedione cation [OCCO]+ (g) 909.5 912.6 ± 2.0 kJ/mol 56.0197 ± 0.0017 12541-99-0*0 2-Propenylidyne anion [CH2CHC]- (g) 464.6 460.9 ± 1.7 kJ/mol 39.0565 ± 0.0024 120126-89-8*0 Ethylidene anion [CH3CH]- (g) 325.7 318.4 ± 1.8 kJ/mol 28.0537 ± 0.0016 35829-99-3*0 Hydrogen bromide HBr (aq, 1250 H2O) -120.15 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*954 Dioxodiazoxane ONONO (g, t, c) 109.3 105.3 ± 1.8 kJ/mol 76.01168 ± 0.00091 122413-35-8*2 3-Methanetetrayl-1,2-cyclopropanediylidene CC(CC) (g) 1154.7 1164.2 ± 1.9 kJ/mol 48.0428 ± 0.0032 78015-08-4*0 2-Propen-3-yliumylidene [CHCHCH]+ (g) 1494.5 1491.5 ± 1.7 kJ/mol 39.0554 ± 0.0024 84654-86-4*0 2-Propenylidene anion [CHCHCH]- (g) 535.9 532.6 ± 1.7 kJ/mol 39.0565 ± 0.0024 98705-30-7*0 Aminooxy anion [NH2O]- (g) 47.3 40.4 ± 1.7 kJ/mol 32.02257 ± 0.00034 51375-41-8*0 Triazirinylium ion [N(NN)]+ (g) 1608.9 1606.0 ± 1.6 kJ/mol 42.01967 ± 0.00021 92220-05-8*0 Triazirine HN(NN) (g) 464.1 457.7 ± 2.6 kJ/mol 43.02816 ± 0.00022 157-29-9*0 3-Imino-2-propen-1-ylidene CHCHCNH (g, anti-singlet) 532.9 527.9 ± 1.8 kJ/mol 53.0627 ± 0.0024 916765-05-4*12 3-Imino-2-propen-1-ylidene CHCHCNH (g, syn-triplet) 572.5 567.3 ± 2.0 kJ/mol 53.0627 ± 0.0024 916765-05-4*22 2-(Methylidyneamino)ethenyl CHCHNCH (g, syn-singlet) 604.5 599.6 ± 1.9 kJ/mol 53.0627 ± 0.0024 123416-74-0*12 2-(Methylidyneamino)ethenyl CHCHNCH (g, syn-triplet) 637.1 632.3 ± 2.0 kJ/mol 53.0627 ± 0.0024 123416-74-0*22 1-Cyanovinylium [CH2CCN]+ (g) 1318.3 1317.0 ± 2.2 kJ/mol 52.0542 ± 0.0024 85399-09-3*0 2-Cyclopropyn-1-ylidenemethyl anion [CC(CC)]- (g) 800.8 809.7 ± 1.7 kJ/mol 48.0433 ± 0.0032 289679-90-9*0 Trifluorine cation [F3]+ (g) 1529.5 1527.4 ± 2.3 kJ/mol 56.9946610 ± 0.0000015 64710-22-1*0 Tetraoxygen O4 (g, C2h singlet) 145.8 142.2 ± 3.8 kJ/mol 63.9976 ± 0.0012 12596-83-7*22 Formaldehyde anion [CH2O]- (g) -26.7 -28.3 ± 2.0 kJ/mol 30.02653 ± 0.00087 27837-46-3*0 Butatriene cation [CH2CCCH2]+ (g) 1210.5 1204.6 ± 1.3 kJ/mol 52.0740 ± 0.0032 65513-85-1*0 Bicyclo[1.1.0]but-3-ene CH2(CCH)CH (g) 483.1 474.1 ± 1.6 kJ/mol 52.0746 ± 0.0032 78525-41-4*0 Nitric acid HON(O)O (aq, 3 H2O) -197.75 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*805 Propynylidene HCCCH (g) 543.68 546.68 ± 0.64 kJ/mol 38.0480 ± 0.0024 67152-18-5*0 Vinylvinylidene anion [CH2CHCHC]- (g, trans) 405.7 398.9 ± 2.0 kJ/mol 52.0751 ± 0.0032 167386-49-4*1 Tetrahedrane cation [CH(CH(CHCH))]+ (g) 1326.7 1318.5 ± 1.7 kJ/mol 52.0740 ± 0.0032 80826-01-3*0 Bicyclo[1.1.0]but-1(3)-ene CH2(CC)CH2 (g) 578.7 570.3 ± 1.9 kJ/mol 52.0746 ± 0.0032 58208-49-4*0 Bicyclo[1.1.0]but-1(3)-ene cation [CH2(CC)CH2]+ (g) 1461.6 1453.5 ± 2.1 kJ/mol 52.0740 ± 0.0032 *58208-49-4*0 Formaldehyde CH2O (g, triplet) 196.002 192.699 ± 0.095 kJ/mol 30.02598 ± 0.00087 50-00-0*1 1-Buten-3-yn-1-yl HCCCHCH (g, cis) 547.7 545.0 ± 1.2 kJ/mol 51.0666 ± 0.0032 2810-61-9*2 3-Buten-1-ynylium [CH2CHCC]+ (g, singlet) 1603.8 1602.8 ± 1.7 kJ/mol 51.0661 ± 0.0032 103928-84-3*2 1-Cyclopropene-1,2-diyl CH2(CC) (g) 791.2 790.7 ± 1.5 kJ/mol 38.0480 ± 0.0024 202744-75-0*0 3-Methylene-1-cyclopropen-1-ylium [CH2C(CHC)]+ (g, triplet) 1467.6 1463.9 ± 1.6 kJ/mol 51.0661 ± 0.0032 117469-28-0*1 2-Cyclopropen-1-ylidenemethylium [CHC(CHCH)]+ (g, singlet) 1346.4 1343.8 ± 1.8 kJ/mol 51.0661 ± 0.0032 112936-36-4*2 Nitrate [ON(O)O]- (aq) -206.54 ± 0.18 kJ/mol 62.00549 ± 0.00090 14797-55-8*800 1,3-Cyclobutadien-1-ylium [C(CHCHCH)]+ (g, singlet) 1388.2 1383.3 ± 1.8 kJ/mol 51.0661 ± 0.0032 81913-77-1*2 Cyanic azide NCNNN (g) 502.7 498.3 ± 1.9 kJ/mol 68.03766 ± 0.00085 764-05-6*0 Phenyl hydroperoxide C6H5OOH (g) 13.3 -5.7 ± 2.1 kJ/mol 110.1106 ± 0.0049 36112-26-2*0 Hydrooxonitrate [HNO]- (g) 78.62 75.70 ± 0.99 kJ/mol 31.01463 ± 0.00032 66057-02-1*0 Methylcyclopentane CH3CH(CH2CH2CH2CH2) (cr,l) -116.52 -137.87 ± 0.35 kJ/mol 84.1595 ± 0.0049 96-37-7*500 Dioxosilane SiO2 (cr, cristobalite) -904.04 -908.90 ± 0.68 kJ/mol 60.08430 ± 0.00067 7631-86-9*510 Cyclopropenyliumdiyl [CH(CC)]+ (g) 1692.3 1695.2 ± 1.8 kJ/mol 37.0395 ± 0.0024 127476-05-5*0 Deuterium hydride cation [HD]+ (g) 1490.498 1490.587 ± 0.000 kJ/mol 3.021493 ± 0.000070 12181-16-7*0 Cyclopropynyl anion [CH(CC)]- (g) 518.36 521.35 ± 0.76 kJ/mol 37.0406 ± 0.0024 136861-42-2*0 Silylene anion [SiH2]- (g) 167.1 165.5 ± 1.4 kJ/mol 30.10193 ± 0.00033 54991-62-7*0 Hydroxyimidogen anion [NOH]- (g) 229.8 227.4 ± 2.2 kJ/mol 31.01463 ± 0.00032 *35337-59-8*0 Silyliumylidene [SiH]+ (g) 1134.7 1135.9 ± 1.1 kJ/mol 29.09289 ± 0.00031 31241-66-4*0 Disilene cation [SiH2SiH2]+ (g) 1069.4 1060.4 ± 2.0 kJ/mol 60.20221 ± 0.00066 108492-63-3*0 Di-mu-hydrodihydrodisilicon cation [HSi(HSiHH)]+ (g, trans) 1180.1 1172.5 ± 3.3 kJ/mol 60.20221 ± 0.00066 *129970-82-7*1 Di-mu-hydrodihydrodisilicon anion [HSi(HSiHH)]- (g, trans) 288.3 279.7 ± 3.4 kJ/mol 60.20331 ± 0.00066 *129970-83-8*1 mu-Hydrotrihydrodisilicon Si(HSiH3) (g, triplet) 459.1 450.9 ± 2.5 kJ/mol 60.20276 ± 0.00066 497967-55-2*1 Tetranitrogen cation [NNNN]+ (g) 1392.8 1392.5 ± 1.5 kJ/mol 56.02641 ± 0.00028 12185-04-5*0 Hypochlorous acid cation [HOCl]+ (g) 998.94 995.90 ± 0.90 kJ/mol 52.45949 ± 0.00095 71606-47-8*0 Hypochlorous acid anion [HOCl]- (g) 198.7 198.4 ± 2.5 kJ/mol 52.46059 ± 0.00095 34524-94-2*0 Dewar benzene (CHCH)(CHCHCHCH) (g) 422.1 405.1 ± 1.7 kJ/mol 78.1118 ± 0.0048 5649-95-6*0 1,2-Hexadien-4-yne CH2CCHCCCH3 (g) 407.4 397.4 ± 1.7 kJ/mol 78.1118 ± 0.0048 34783-10-3*0 3-Methylene-1-penten-4-yne CH2CHC(CH2)CCH (g, trans) 362.5 349.9 ± 2.2 kJ/mol 78.1118 ± 0.0048 6929-96-0*1 3-Methyl-1,4-pentadiyne HCCCH(CH3)CCH (g) 439.0 427.6 ± 1.6 kJ/mol 78.1118 ± 0.0048 57242-04-3*0 Ethanium [C2H7]+ (g, classical Cs I) 888.7 870.3 ± 1.8 kJ/mol 31.0764 ± 0.0017 24669-33-8*2 Ethylaminylium [CH3CH2NH]+ (g, syn-triplet) 1092.2 1076.2 ± 2.4 kJ/mol 44.0752 ± 0.0017 54387-08-5*11 2-Methyl-2-propanamine (CH3)3CNH2 (cr,l) -133.09 -150.58 ± 0.53 kJ/mol 73.1369 ± 0.0033 75-64-9*500 1,2-Diphenylethane C6H5CH2CH2C6H5 (cr,l) 84.86 51.12 ± 0.75 kJ/mol 182.2610 ± 0.0112 103-29-7*500 Hydrogen fluoride HF (aq, 18 H2O) -321.83 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*901 Anthracene C6H4(CH(CC(C4H4)CH)) (cr,l) 150.67 124.86 ± 0.88 kJ/mol 178.2292 ± 0.0112 120-12-7*500 Phenanthrene C6H4(C2H2(CC(C4H4))) (cr,l) 136.32 111.04 ± 0.64 kJ/mol 178.2292 ± 0.0112 85-01-8*500 Diphenylacetylene C6H5CCC6H5 (g) 432.4 407.3 ± 1.2 kJ/mol 178.2292 ± 0.0112 501-65-5*0 Diphenylacetylene C6H5CCC6H5 (cr,l) 334.71 312.76 ± 0.93 kJ/mol 178.2292 ± 0.0112 501-65-5*500 Ethanium [C2H7]+ (g, classical Cs II) 895.1 877.3 ± 1.9 kJ/mol 31.0764 ± 0.0017 24669-33-8*3 Bicyclo[1.1.0]buta-1,1-diene-2,4-diyl C(CCH)C (g) 990.3 993.6 ± 2.0 kJ/mol 49.0507 ± 0.0032 *99417-53-5*0 Benzoic acid C6H5C(O)OH (g) -274.31 -294.11 ± 0.19 kJ/mol 122.1213 ± 0.0056 65-85-0*0 2-Butynylium [CH3CCCH2]+ (g, triplet) 1258.7 1251.4 ± 1.6 kJ/mol 53.0820 ± 0.0032 64235-83-2*1 Hydrogen bromide HBr (aq, 5000 H2O) -120.31 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*844 Argonium [ArH]+ (g) 1151.8 1150.1 ± 1.4 kJ/mol 40.9554 ± 0.0010 12254-68-1*0 Xenonium [XeH]+ (g) 1038.19 1036.42 ± 0.88 kJ/mol 132.2974 ± 0.0200 37276-91-8*0 Hydrogen chloride HCl (aq, 74 H2O) -165.544 ± 0.024 kJ/mol 36.46064 ± 0.00090 7647-01-0*953 Monosulfur anion S- (g) 76.48 78.53 ± 0.14 kJ/mol 32.0665 ± 0.0060 14337-03-2*0 Sulfur dioxide OSO (aq, undissoc) -320.63 ± 0.14 kJ/mol 64.0648 ± 0.0060 7446-09-5*1000 Hydroxyoxoammoniumyl [HONO]+ (g) 984.1 977.7 ± 1.8 kJ/mol 47.01293 ± 0.00061 80371-48-8*0 1-Methylene-2-propenylium [CH2CHCCH2]+ (g, singlet) 1059.4 1049.3 ± 1.7 kJ/mol 53.0820 ± 0.0032 62698-26-4*2 Hydroperoxyimidogen HOON (g, trans) 103.4 99.8 ± 2.4 kJ/mol 47.01348 ± 0.00061 877456-58-1*1 Sulfur oxide peroxide OSOO (g, cis) -26.0 -30.2 ± 2.3 kJ/mol 80.0642 ± 0.0061 175799-68-5*2 1-Methylene-2-propenylium [CH2CHCCH2]+ (g, triplet) 1256.3 1246.6 ± 1.7 kJ/mol 53.0820 ± 0.0032 62698-26-4*1 Sulfuric acid OS(O)(OH)2 (aq, 50 H2O) -886.59 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*822 Sulfuric acid OS(O)(OH)2 (aq, 10000 H2O) -900.57 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*850 Hydrogen atom H (ad, 1 Pt(111)) -22.3 -24.0 ± 1.5 kJ/mol 1.007940 ± 0.000070 12385-13-6*1000001 Nitric acid HON(O)O (aq, 1 H2O) -186.81 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*801 Hydrogen atom H (ad, 1 Pt(111) hcp) -17.0 -20.2 ± 5.2 kJ/mol 1.007940 ± 0.000070 12385-13-6*1003001 Hydrogen atom H (ad, 1 Pt(111) bridge) -14.1 -17.0 ± 8.5 kJ/mol 1.007940 ± 0.000070 12385-13-6*1004001 1,3-Butadienylium [CH2CHCHCH]+ (g, singlet) 1133.6 1123.6 ± 2.5 kJ/mol 53.0820 ± 0.0032 86181-69-3*2 Hydrogen atom H (ad, 4 Pt(111) hcp) -30.3 -33.4 ± 7.2 kJ/mol 1.007940 ± 0.000070 12385-13-6*1003004 Hydrogen atom H (ad, 4 Pt(111) bridge) -28.3 -31.1 ± 7.6 kJ/mol 1.007940 ± 0.000070 12385-13-6*1004004 n-Nonane CH3(CH2)7CH3 (cr,l) -247.54 -274.40 ± 0.48 kJ/mol 128.2551 ± 0.0073 111-84-2*500 n-Decane CH3(CH2)8CH3 (cr,l) -272.69 -300.24 ± 0.79 kJ/mol 142.2817 ± 0.0081 124-18-5*500 Azide [NNN]- (aq) 272.65 ± 0.48 kJ/mol 42.02077 ± 0.00021 14343-69-2*800 Formyloxidanyl HC(O)O (g) -125.82 -127.18 ± 0.55 kJ/mol 45.0174 ± 0.0010 16499-21-1*0 Dioxiranyl HC(OO) (g) 217.3 213.8 ± 2.0 kJ/mol 45.0174 ± 0.0010 120595-16-6*0 1,5-Hexadiene CH2CHCH2CH2CHCH2 (cr,l) 54.57 ± 0.31 kJ/mol 82.1436 ± 0.0049 592-42-7*500 Ethoxyethane CH3CH2OCH2CH3 (cr,l) -266.19 -278.51 ± 0.60 kJ/mol 74.1216 ± 0.0033 60-29-7*500 2,4,5-Trioxa-1,3-diazabicyclo[1.1.1]pentane N(O3)N (g) 602.5 593.3 ± 2.1 kJ/mol 76.01168 ± 0.00091 224950-18-9*0 Bromoniumyl [HBr]+ (g) 1098.16 1090.31 ± 0.12 kJ/mol 80.9114 ± 0.0010 12258-64-9*0 Nitric acid trihydrate (HON(O)O)(H2O)3 (cr,l) -1061.99 -1055.14 ± 0.20 kJ/mol 117.0587 ± 0.0019 13444-83-2*500 Hydrogen difluoride cation [(HF)(F)]+ (g, triplet) 1267.6 1265.4 ± 4.1 kJ/mol 39.004198 ± 0.000070 *126950-54-7*1 1-Methyl-1-ethylium-1-yl [CH3CCH3]+ (g) 1058.2 1045.7 ± 1.9 kJ/mol 42.0792 ± 0.0024 121408-19-3*0 Trichlorine Cl3 (g) 125.3 125.8 ± 2.0 kJ/mol 106.3581 ± 0.0027 11094-65-8*0 Isopropylidene anion [CH3CCH3]- (g) 282.4 268.3 ± 2.0 kJ/mol 42.0803 ± 0.0024 *121408-19-3*0 Glycolaldehyde HC(O)CH2OH (g, anti-anti) -292.3 -304.8 ± 1.7 kJ/mol 60.0520 ± 0.0017 141-46-8*21 Glycolaldehyde HC(O)CH2OH (g, gauche-anti) -290.6 -302.9 ± 1.7 kJ/mol 60.0520 ± 0.0017 141-46-8*31 Glycolaldehyde HC(O)CH2OH (g, anti-syn) -283.9 -296.7 ± 1.7 kJ/mol 60.0520 ± 0.0017 141-46-8*22 Tetraoxodinitrogen cation [O2NNO2]+ (g) 1030.7 1025.2 ± 2.6 kJ/mol 92.0105 ± 0.0012 64476-91-1*0 Dihydrogen H2 (g, para) -0.000 -0.058 ± 0.000 kJ/mol 2.01588 ± 0.00014 1333-74-0*2 Hydrogen fluoride HF (aq, 50 H2O) -321.96 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*822 Methyl acetate CH3C(O)OCH3 (l) -445.64 ± 0.56 kJ/mol 74.0785 ± 0.0025 79-20-9*500 Hydrogen peroxide HOOH (cr,l) -193.101 -187.283 ± 0.077 kJ/mol 34.01468 ± 0.00062 7722-84-1*500 1-Hydroxy-2-propanone CH3C(O)CH2OH (g, anti-anti) -340.6 -360.4 ± 1.7 kJ/mol 74.0785 ± 0.0025 116-09-6*21 1-Hydroxy-2-propanone CH3C(O)CH2OH (g, gauche-anti) -338.1 -356.3 ± 1.7 kJ/mol 74.0785 ± 0.0025 116-09-6*31 1-Hydroxy-2-propanone CH3C(O)CH2OH (g, anti-syn) -329.8 -349.7 ± 1.7 kJ/mol 74.0785 ± 0.0025 116-09-6*22 Methoxyoxomethyl CH3OCO (g, syn-staggered) -151.7 -160.8 ± 1.5 kJ/mol 59.0440 ± 0.0017 16481-04-2*2 Hydraziniumyl [NH2NH2]+ (g) 886.6 873.3 ± 2.0 kJ/mol 32.04469 ± 0.00031 20771-51-1*0 Carbon dication [C]+2 (g) 4150.459 4155.605 ± 0.040 kJ/mol 12.00960 ± 0.00080 16092-61-8*0 Propionic acid CH3CH2C(O)OH (cr,l) -505.36 -509.51 ± 0.17 kJ/mol 74.0785 ± 0.0025 79-09-4*500 1-Ethenylium-1-yl [CCH2]+ (g) 1507.1 1507.1 ± 2.1 kJ/mol 26.0367 ± 0.0016 80541-07-7*0 Ethylene glycol (CH2OH)2 (cr,l) -448.63 -455.15 ± 0.37 kJ/mol 62.0678 ± 0.0018 107-21-1*500 Oxalic acid (C(O)OH)2 (cr) -819.55 -829.64 ± 0.42 kJ/mol 90.0349 ± 0.0020 144-62-7*500 Dimethylamine (CH3)2NH (l) -43.31 ± 0.36 kJ/mol 45.0837 ± 0.0017 124-40-3*500 Chlorine hydride oxide HCl(O)(O)O (g) 163.9 154.0 ± 2.4 kJ/mol 84.4588 ± 0.0013 1027055-52-2*0 1,3-Propanediyl CH2CH2CH2 (g, triplet C2) 320.1 308.3 ± 1.5 kJ/mol 42.0797 ± 0.0024 32458-33-6*12 Hydrazine NH2NH2 (cr,l) 57.31 50.75 ± 0.18 kJ/mol 32.04524 ± 0.00031 302-01-2*500 Carbonate [OC(O)O]-2 (g) -225.2 -228.4 ± 2.5 kJ/mol 60.0100 ± 0.0012 3812-32-6*0 (E)-2-Iminoethylium [CH2CHNH]+ (g, anti-triplet) 1148.6 1138.8 ± 3.3 kJ/mol 42.0594 ± 0.0016 91127-33-2*12 1-Iminoethylium [CH3CNH]+ (g, singlet) 833.6 823.1 ± 3.0 kJ/mol 42.0594 ± 0.0016 *128365-64-0*2 1-Iminoethanide [CH3CNH]- (g, anti) 185.6 175.2 ± 3.2 kJ/mol 42.0604 ± 0.0016 *128365-65-1*2 1-Iminoethylium [CH3CNH]+ (g, anti-triplet) 1342.1 1333.2 ± 3.9 kJ/mol 42.0594 ± 0.0016 *128365-64-0*12 N-Methylenemethaniminium [CH2NCH2]+ (g, singlet) 904.2 893.3 ± 3.1 kJ/mol 42.0594 ± 0.0016 88333-01-1*2 (Methylimino)methanide [CH3NCH]- (g, trans) 222.9 212.1 ± 3.2 kJ/mol 42.0604 ± 0.0016 *64709-60-0*1 1,3-Butadienylium [CH2CHCHCH]+ (g, triplet) 1255.8 1246.4 ± 2.3 kJ/mol 53.0820 ± 0.0032 86181-69-3*1 2-Aminoethenylium [CHCHNH2]+ (g, anti triplet) 1110.5 1099.4 ± 2.4 kJ/mol 42.0594 ± 0.0016 64724-21-6*12 2-Aminoethenyl anion [CHCHNH2]- (g, anti) 230.1 219.2 ± 2.6 kJ/mol 42.0604 ± 0.0016 *64724-21-6*2 Aziridine NH(CH2CH2) (cr,l) 92.12 ± 0.88 kJ/mol 43.0678 ± 0.0016 151-56-4*500 2-Aziridinylium [NH(CHCH2)]+ (g, singlet) 1010.6 998.6 ± 3.3 kJ/mol 42.0594 ± 0.0016 *91127-35-4*2 2-Aziridinide [NH(CHCH2)]- (g, anti) 315.9 303.8 ± 3.5 kJ/mol 42.0604 ± 0.0016 111127-93-6*2 2-Aziridinyl NH(CHCH2) (g, anti) 364.2 352.1 ± 2.1 kJ/mol 42.0599 ± 0.0016 *23838-09-7*2 2-Aziridinylium [NH(CHCH2)]+ (g, anti-triplet) 1304.6 1292.9 ± 4.1 kJ/mol 42.0594 ± 0.0016 *91127-35-4*12 Trimethylamine (CH3)3N (l) -48.72 ± 0.86 kJ/mol 59.1103 ± 0.0025 75-50-3*500 Cyanogen anion [NCCN]- (g) 281.5 284.7 ± 2.2 kJ/mol 52.0354 ± 0.0016 11118-88-0*0 Diisocyanogen cation [CNNC]+ (g, trans) 1825.3 1828.1 ± 3.2 kJ/mol 52.0343 ± 0.0016 *78800-21-2*1 Nitric acid monohydrate (HON(O)O)(H2O) (cr,l) -479.11 -472.61 ± 0.18 kJ/mol 81.0282 ± 0.0012 13444-82-1*500 Cyanoaminyliumyl [NCN]+ (g) 1672.3 1673.7 ± 2.6 kJ/mol 40.02363 ± 0.00081 316122-03-9*0 Cyanoamidogen anion [NCN]- (g) 211.85 211.78 ± 0.60 kJ/mol 40.02473 ± 0.00081 189879-95-6*0 Cyanoaminylium [HNCN]+ (g, singlet) 1460.2 1458.0 ± 1.9 kJ/mol 41.03157 ± 0.00082 205443-18-1*2 Difluorodioxidanium [FOOF]+ (g, trans) 1283.7 1279.1 ± 2.3 kJ/mol 69.99506 ± 0.00060 *7783-44-0*1 Diazomethanide [HCNN]- (g, triplet) 479.7 478.3 ± 1.8 kJ/mol 41.03267 ± 0.00082 100840-43-5*1 Hydrochlorate ion [HCl]- (g) -25.2 -24.2 ± 2.5 kJ/mol 36.46119 ± 0.00090 63099-75-2*0 Ammonium hydroxide NH4OH (aq, 20 H2O) -366.19 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*818 1H-Diazirin-3-ylium [HN(NC)]+ (g, triplet) 1640.3 1638.0 ± 2.0 kJ/mol 41.03157 ± 0.00082 735234-64-7*1 1H-diazirin-3-ide [HN(NC)]- (g, triplet) 655.2 652.0 ± 2.1 kJ/mol 41.03267 ± 0.00082 *735234-64-7*1 1H-Diazirin-3-yl HN(NC) (g) 618.7 615.8 ± 1.6 kJ/mol 41.03212 ± 0.00082 324529-57-9*0 Cyanamide NH2CN (cr) 59.04 ± 0.52 kJ/mol 42.04006 ± 0.00082 420-04-2*500 Oxobromonium [BrO]+ (g) 1140.0 1132.2 ± 1.6 kJ/mol 95.9029 ± 0.0010 142315-39-7*0 Methoxymethylene CH3OCH (g, syn singlet) 144.7 134.3 ± 1.4 kJ/mol 44.0526 ± 0.0017 19527-10-7*22 Methylenediazeniumide HCNNH (g) 375.2 368.7 ± 1.9 kJ/mol 42.04006 ± 0.00082 24153-51-3*0 Methylidynehydrazinium-1-yl [HCNNH]+ (g) 1251.7 1245.8 ± 1.9 kJ/mol 42.03951 ± 0.00082 160951-16-6*0 (Iminomethyl)imidogen HNCHN (g, anti-triplet) 420.1 413.1 ± 2.9 kJ/mol 42.04006 ± 0.00082 87570-07-8*11 Diazomethyliumyl [CNN]+ (g) 1639.6 1640.8 ± 3.1 kJ/mol 40.02363 ± 0.00081 307495-90-5*0 Diazomethylene anion [CNN]- (g) 406.9 407.1 ± 2.4 kJ/mol 40.02473 ± 0.00081 205498-92-6*0 3H-Diazirin-3-ylidene C(NN) (g) 579.1 579.5 ± 2.7 kJ/mol 40.02418 ± 0.00081 253308-70-2*0 Hydronium radical (H2O)(H) (g, vdW) -18.5 -21.5 ± 2.1 kJ/mol 19.02322 ± 0.00037 12168-76-2*100 Acetonitrile CH3CN (cr,l) 40.64 ± 0.22 kJ/mol 41.0520 ± 0.0016 75-05-8*500 Dioxohydrazine ONNO (g, cis) 172.92 171.16 ± 0.14 kJ/mol 60.01228 ± 0.00062 16824-89-8*2 Chloromethyliumylidene [CCl]+ (g) 1282.7 1285.8 ± 2.4 kJ/mol 47.4629 ± 0.0012 69773-94-0*0 Chloromethylidyne anion [CCl]- (g) 319.8 323.6 ± 2.5 kJ/mol 47.4639 ± 0.0012 117129-77-8*0 Dioxohydrazine ONNO (g) 172.92 171.16 ± 0.14 kJ/mol 60.01228 ± 0.00062 16824-89-8*0 Dioxidanyl dimer (HOO)2 (g, triplet) -8.26 -17.83 ± 0.50 kJ/mol 66.0135 ± 0.0012 240125-82-0*1 1-Propenylium [CH3CHCH]+ (g, cis) 1231.8 1221.5 ± 1.7 kJ/mol 41.0713 ± 0.0024 50457-58-4*2 1-Propenylide [CH3CHCH]- (g, cis) 204.0 192.7 ± 1.8 kJ/mol 41.0723 ± 0.0024 65887-20-9*2 Ammonia anion [NH3]- (g) 94.3 87.2 ± 2.4 kJ/mol 17.03111 ± 0.00022 37353-00-7*0 2-Hydroxyethenyl CHCHOH (g, cis-cis) 143.78 137.22 ± 0.99 kJ/mol 43.0446 ± 0.0016 108665-16-3*11 (Z)-Diazene anion [HNNH]- (g, cis) 280.0 273.3 ± 2.0 kJ/mol 30.02991 ± 0.00020 *86631-37-0*0 Carbon dioxide anion [CO2]- (g) -340.6 -340.1 ± 2.2 kJ/mol 44.01005 ± 0.00100 14485-07-5*0 Dioxiranylidene cation [C(OO)]+ (g) 1409.1 1410.3 ± 2.6 kJ/mol 44.00895 ± 0.00100 *138832-57-2*0 Dioxiranylidene anion [C(OO)]- (g, ?) -110.2 -109.7 ± 3.0 kJ/mol 44.01005 ± 0.00100 *138832-58-3*0 2-Hydroxyethenyl CHCHOH (g, trans-trans) 147.1 140.8 ± 1.2 kJ/mol 43.0446 ± 0.0016 108665-16-3*22 2-Hydroxyethenyl CHCHOH (g, cis-trans) 150.5 144.4 ± 1.6 kJ/mol 43.0446 ± 0.0016 108665-16-3*12 Poly(vinylchloride) CH2CHCl (s, poly) -84.6 -94.0 ± 1.3 kJ/mol 62.4979 ± 0.0018 9002-86-2*500 1,1-Dichloroethene CH2CCl2 (l) -23.47 ± 0.51 kJ/mol 96.9427 ± 0.0024 75-35-4*500 Dioxymethylidyne cation [COO]+ (g, doublet) 1436.6 1439.0 ± 2.7 kJ/mol 44.00895 ± 0.00100 *791121-04-5*2 Nitrogen atom dianion [N]-2 (g) 1062.8 1064.9 ± 2.8 kJ/mol 14.007837 ± 0.000070 16727-21-2*0 Methylamine CH3NH2 (l) -45.27 ± 0.44 kJ/mol 31.05714 ± 0.00088 74-89-5*500 Isodiazene anion [NNH2]- (g) 380.9 374.1 ± 2.1 kJ/mol 30.02991 ± 0.00020 *63986-30-1*0 Dioxymethylidyne cation [(C)(OO)]+ (g, vdW quartet) 1388.2 1391.7 ± 3.2 kJ/mol 44.00895 ± 0.00100 *791121-04-5*101 Dichloromethane CH2Cl2 (l) -122.76 ± 0.37 kJ/mol 84.9320 ± 0.0020 75-09-2*590 Dihydrogen cation [H2]+ (g, para) 1488.364 1488.480 ± 0.000 kJ/mol 2.01533 ± 0.00014 12184-90-6*2 Carbon dioxide cation [CO2]+ (g, quartet) 1335.0 1335.5 ± 2.4 kJ/mol 44.00895 ± 0.00100 12181-61-2*1 Peroxynitrous acid HOONO (g) -5.73 -11.56 ± 0.35 kJ/mol 63.01288 ± 0.00091 14691-52-2*0 Ethynylaminylium [HCCNH]+ (g, triplet) 1277.8 1277.4 ± 2.6 kJ/mol 40.0435 ± 0.0016 103835-08-1*1 Carbon monoxide anion [CO]- (g) 30.0 33.7 ± 2.3 kJ/mol 28.01065 ± 0.00085 12539-63-8*0 Dioxodiazoxane ONONO (g, c, p) 125.7 120.4 ± 2.1 kJ/mol 76.01168 ± 0.00091 122413-35-8*3 Tribromofluoromethane CBr3F (g) -98.8 -122.8 ± 1.5 kJ/mol 270.7211 ± 0.0031 353-54-8*0 Tribromochloromethane CBr3Cl (g) 85.7 62.9 ± 1.5 kJ/mol 287.1754 ± 0.0032 594-15-0*0 Difluoromethylene anion [CF2]- (g) -211.14 -209.96 ± 0.58 kJ/mol 50.00805 ± 0.00080 66212-40-6*0 Fluoromethylidyne anion [CF]- (g) 200.8 204.3 ± 1.9 kJ/mol 31.00965 ± 0.00080 33412-12-3*0 Tetraoxidanyl HOOOO (g, cis) 53.0 46.0 ± 5.1 kJ/mol 65.0055 ± 0.0012 69696-93-1*2 Hydrogen fluoride HF (aq, 55 H2O) -321.97 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*905 Chloryl ion [OClO]+ (g) 1100.26 1097.60 ± 0.53 kJ/mol 67.4510 ± 0.0011 25052-55-5*0 Difluorovinylidene CCF2 (g) 129.4 130.7 ± 2.2 kJ/mol 62.0182 ± 0.0016 41895-33-4*0 Fluoroethynylium [CCF]+ (g) 1536.3 1541.0 ± 2.3 kJ/mol 43.0193 ± 0.0016 268566-69-4*0 Bromoacetylene HCCBr (g) 281.9 275.4 ± 1.6 kJ/mol 104.9333 ± 0.0019 593-61-3*0 Carbon monoxide CO (g, triplet) 465.582 469.289 ± 0.026 kJ/mol 28.01010 ± 0.00085 630-08-0*1 Bromosyl bromide BrBrO (g) 180.4 164.6 ± 2.1 kJ/mol 175.8074 ± 0.0020 68322-97-4*0 Isocyanic fluoride FNC (g) 301.0 302.9 ± 1.8 kJ/mol 45.01584 ± 0.00080 16992-26-0*0 Chloro(chlorooxy)methylene ClCOCl (g, trans singlet) 98. 101. ± 15. kJ/mol 98.9155 ± 0.0020 479587-31-0*11 Trihydrogen H(HH) (g, 2p 2A2" Ry) 756.931 754.146 ± 0.015 kJ/mol 3.02382 ± 0.00021 12184-91-7*2 Chlorooxomethylium [ClCO]+ (g) 783.7 783.8 ± 2.2 kJ/mol 63.4623 ± 0.0012 38264-03-8*0 Oxygen difluoride cation [FOF]+ (g) 1292.12 1289.59 ± 0.66 kJ/mol 53.99566 ± 0.00030 39432-25-2*0 Carbon dioxide CO2 (aq, undissoc) -412.867 ± 0.018 kJ/mol 44.00950 ± 0.00100 124-38-9*1000 Isoprene CH2C(CH3)CHCH2 (cr,l) 48.94 ± 0.69 kJ/mol 68.1170 ± 0.0040 78-79-5*500 2-Iodoethanol ICH2CH2OH (l) -207.2 ± 2.4 kJ/mol 171.9650 ± 0.0017 624-76-0*590 1,3-Butadiyne cation [HCCCCH]+ (g) 1440.16 1442.02 ± 0.57 kJ/mol 50.0581 ± 0.0032 55468-55-8*0 1,3,5-Hexatriynide [CCCCCCH]- (g) 635.5 644.0 ± 2.3 kJ/mol 73.0727 ± 0.0048 85905-65-3*0 Dihydrogen cation [H2]+ (g, ortho) 1489.060 1488.480 ± 0.000 kJ/mol 2.01533 ± 0.00014 12184-90-6*1 Carbon suboxide cation [OCCCO]+ (g) 928.7 932.2 ± 1.1 kJ/mol 68.0304 ± 0.0025 151528-67-5*0 Carbon suboxide anion [OCCCO]- (g) -131.2 -127.7 ± 2.5 kJ/mol 68.0314 ± 0.0025 109362-94-9*0 Benzene anion [C6H6]- (g) 209.2 197.3 ± 1.2 kJ/mol 78.1124 ± 0.0048 34562-85-1*0 o-Benzyne C6H4 (g, triplet) 625.6 616.3 ± 1.1 kJ/mol 76.0960 ± 0.0048 462-80-6*1 Oxygen atom hexacation [O]+6 (g) 42035.28 42037.14 ± 0.12 kJ/mol 15.99611 ± 0.00030 14158-22-6*0 m-Benzyne C6H4 (g) 527.0 518.5 ± 1.2 kJ/mol 76.0960 ± 0.0048 1828-89-3*0 Oxygen difluoride anion [FOF]- (g) -202.0 -201.9 ± 2.7 kJ/mol 53.99675 ± 0.00030 *7783-41-7*0 p-Benzyne cation [C6H4]+ (g) 1424.9 1417.7 ± 2.1 kJ/mol 76.0954 ± 0.0048 121058-09-1*0 p-Benzyne C6H4 (g) 587.0 577.6 ± 1.2 kJ/mol 76.0960 ± 0.0048 3355-34-8*0 Deuterium hydride HD (g) 0.328 0.319 ± 0.000 kJ/mol 3.022042 ± 0.000070 13983-20-5*0 Toluene C6H5CH3 (l) 19.78 12.02 ± 0.31 kJ/mol 92.1384 ± 0.0056 108-88-3*500 Ammonium hydroxide NH4OH (aq, 5000 H2O) -366.30 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*844 Cyclopentadienylium [CH(CHCHCHCH)]+ (g) 1088.36 1075.49 ± 0.91 kJ/mol 65.0927 ± 0.0040 29661-18-5*0 Nitrosyl nitrite anion [ONONO]- (g, t, t) -103.0 -106.2 ± 2.8 kJ/mol 76.01223 ± 0.00091 *122413-35-8*1 Cycloheptene CH2(CHCHCH2CH2CH2CH2) (cr,l) -25.1 -46.2 ± 1.7 kJ/mol 96.1702 ± 0.0057 628-92-2*500 1-Propynylium [CH3CC]+ (g) 1547.0 1545.1 ± 3.1 kJ/mol 39.0554 ± 0.0024 24858-94-4*0 Cycloheptatriene CH2(CHCHCHCHCHCH) (cr,l) 154.28 145.50 ± 0.96 kJ/mol 92.1384 ± 0.0056 544-25-2*500 Hydrogen chloride HCl (aq, 2439 H2O) -166.711 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*951 Phenylethene C6H5CHCH2 (cr,l) 104.50 ± 0.47 kJ/mol 104.1491 ± 0.0064 100-42-5*500 Benzonitrile C6H5CN (cr,l) 161.21 163.57 ± 0.90 kJ/mol 103.1213 ± 0.0056 100-47-0*500 Isocyanobenzene C6H5NC (g) 321.0 307.2 ± 1.7 kJ/mol 103.1213 ± 0.0056 931-54-4*0 Phenol C6H5OH (cr,l) -146.43 -162.28 ± 0.65 kJ/mol 94.1112 ± 0.0048 108-95-2*500 Hydrazoic acid cation [HNNN]+ (g) 1333.69 1328.01 ± 0.83 kJ/mol 43.02761 ± 0.00022 58852-14-5*0 Anisole C6H5OCH3 (l) -119.48 ± 0.77 kJ/mol 108.1378 ± 0.0056 100-66-3*500 Benzaldehyde C6H5C(O)H (cr,l) -86.11 -87.18 ± 0.95 kJ/mol 106.1219 ± 0.0056 100-52-7*500 Ethynylene C2 (g, triplet) 827.200 833.906 ± 0.085 kJ/mol 24.0214 ± 0.0016 12070-15-4*1 Isocyanogen chloride ClNC (g) 314.7 316.3 ± 2.4 kJ/mol 61.4701 ± 0.0012 75754-69-7*0 Acetophenone C6H5C(O)CH3 (cr,l) -140.0 ± 1.1 kJ/mol 120.1485 ± 0.0064 98-86-2*500 1-Phenylethenol C6H5C(OH)CH2 (g) -9.4 -33.2 ± 2.1 kJ/mol 120.1485 ± 0.0064 4383-15-7*0 p-Tolualdehyde CH3C6H4C(O)H (cr, l, para) -126.4 ± 1.3 kJ/mol 120.1485 ± 0.0064 104-87-0*500 Perchloryl cation [OCl(O)O]+ (g) 1252.1 1246.4 ± 2.5 kJ/mol 83.4504 ± 0.0013 23594-88-9*0 o-Tolualdehyde CH3C6H4C(O)H (cr, l, ortho) -119.4 ± 1.1 kJ/mol 120.1485 ± 0.0064 529-20-4*500 Hydrogen fluoride HF (aq, 23 H2O) -321.86 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*903 Fluorobenzene anion [C6H5F]- (g) -15.3 -27.1 ± 1.6 kJ/mol 96.1029 ± 0.0048 34561-55-2*0 Hexafluorobenzene anion [C6F6]- (g) -992.6 -995.0 ± 3.5 kJ/mol 186.0552 ± 0.0048 37551-90-9*0 Cycloprop-1-enylium [CH2(CHC)]+ (g) 1502.2 1497.9 ± 2.2 kJ/mol 39.0554 ± 0.0024 117067-78-4*0 Ammonium hydroxide NH4OH (aq, 100 H2O) -366.36 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*828 1,2-Propadien-1-ylium-1-yl-3-ylidene [CCC]+ (g, lin) 1957.16 1965.03 ± 0.82 kJ/mol 36.0316 ± 0.0024 118090-85-0*1 m-Chlorophenylium [C6H4Cl]+ (g) 1161.3 1151.2 ± 2.6 kJ/mol 111.5481 ± 0.0049 127983-85-1*0 p-Chlorophenylium [C6H4Cl]+ (g) 1148.6 1139.1 ± 2.5 kJ/mol 111.5481 ± 0.0049 42766-43-8*0 o-Chlorophenylium [C6H4Cl]+ (g) 1167.9 1158.6 ± 2.5 kJ/mol 111.5481 ± 0.0049 137963-70-3*0 Isocyanogen bromide BrNC (g) 341.2 335.5 ± 3.5 kJ/mol 105.9214 ± 0.0013 65997-98-0*0 Iodobenzene cation [C6H5I]+ (g) 1023.43 1008.00 ± 0.99 kJ/mol 204.0078 ± 0.0048 38406-85-8*0 Nitrobenzene C6H5N(O)O (cr,l) 7.1 ± 1.4 kJ/mol 123.1094 ± 0.0049 98-95-3*500 Pyridine N(CHCHCHCHCH) (cr,l) 102.24 100.21 ± 0.38 kJ/mol 79.0999 ± 0.0040 110-86-1*500 Hydrazoic acid anion [HNNN]- (g, trans) 309.0 302.7 ± 2.3 kJ/mol 43.02871 ± 0.00022 203264-98-6*1 Hydrogen iodide HI (aq) -56.827 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*800 Bicyclo[1.1.0]buta-1,3-dien-4-ylium-2-yl [C(CC)C]+ (g) 2087.6 2097.5 ± 2.3 kJ/mol 48.0423 ± 0.0032 289679-91-0*0 Nitromethane CH3N(O)O (cr,l) -114.11 -112.93 ± 0.41 kJ/mol 61.0401 ± 0.0010 75-52-5*500 2,2,4-Trimethylpentane (CH3)2CHCH2C(CH3)3 (cr,l) -224.2 -258.6 ± 1.5 kJ/mol 114.2285 ± 0.0065 540-84-1*500 cis-1,2-Diiodoethene CHICHI (g, cis) 217.43 209.15 ± 0.35 kJ/mol 279.8462 ± 0.0016 590-26-1*0 trans-1,2-Diiodoethene CHICHI (g, trans) 215.09 207.70 ± 0.35 kJ/mol 279.8462 ± 0.0016 590-27-2*0 2-Oxo-1-ethylium-1-yl [HCC(O)H]+ (g, anti-quartet) 1289.4 1286.0 ± 2.5 kJ/mol 42.0361 ± 0.0016 214464-96-7*11 Norbornadiene (CHCH)(CHCH2CH)(CHCH) (l) 209.3 ± 1.1 kJ/mol 92.1384 ± 0.0056 121-46-0*500 2,3-Butanedione CH3C(O)C(O)CH3 (cr,l) -365.57 ± 0.53 kJ/mol 86.0892 ± 0.0033 431-03-8*500 Succinic acid (CH2C(O)OH)2 (g) -801.4 -823.6 ± 2.7 kJ/mol 118.0880 ± 0.0034 110-15-6*0 Oxoethylidene anion [HCC(O)H]- (g, anti-gauche) 86.9 83.6 ± 2.1 kJ/mol 42.0372 ± 0.0016 106543-38-8*1 Cycloprop-2-enylide [CH(CHCH)]- (g) 514.8 511.8 ± 2.2 kJ/mol 39.0565 ± 0.0024 20829-57-6*0 1,2-Diiodoethane CH2ICH2I (g) 87.85 73.19 ± 0.90 kJ/mol 281.8621 ± 0.0016 624-73-7*0 1,2-Diiodoethane CH2ICH2I (cr,l) 9.32 ± 0.60 kJ/mol 281.8621 ± 0.0016 624-73-7*500 2-Butanone CH3CH2C(O)CH3 (cr,l) -267.76 -273.25 ± 0.79 kJ/mol 72.1057 ± 0.0033 78-93-3*500 Bicyclo[1.1.0]buta-1,3-dien-2-yl anion [C(CC)C]- (g) 803.1 810.7 ± 1.8 kJ/mol 48.0433 ± 0.0032 289679-89-6*0 Isocyanogen iodide INC (g) 341.7 341.9 ± 4.9 kJ/mol 152.92191 ± 0.00080 66004-32-8*0 Acrolein cation [CH2CHCHO]+ (g, trans) 919.96 909.82 ± 0.79 kJ/mol 56.0627 ± 0.0024 84005-05-0*1 Acrolein anion [CH2CHCHO]- (g, cis) -71.8 -81.9 ± 3.1 kJ/mol 56.0638 ± 0.0024 23555-87-5*2 Acrolein CH2CHCHO (cr,l) -95.63 ± 0.96 kJ/mol 56.0633 ± 0.0024 107-02-8*500 Isocyanogen iodide anion [INC]- (g) 123.0 125.1 ± 9.3 kJ/mol 152.92246 ± 0.00080 *66004-32-8*0 NON cation [NON]+ (g) 1444.0 1444.2 ± 2.8 kJ/mol 44.01233 ± 0.00033 *227934-46-5*0 1-Oxo-2-propenylium [CH2CHCO]+ (g, singlet) 772.8 765.9 ± 3.0 kJ/mol 55.0548 ± 0.0024 35335-83-2*2 1-Oxo-2-propenide [CH2CHCO]- (g, I, trans) 50.7 46.0 ± 2.6 kJ/mol 55.0559 ± 0.0024 78944-75-9*1 Peroxyhypochlorous acid anion [HOOCl]- (g, cis quartet) -32.1 -33.9 ± 2.6 kJ/mol 68.4600 ± 0.0011 *67952-08-3*2 3-Oxo-1-propenylium [CHCHCHO]+ (g, anti-cis-triplet) 1197.7 1192.0 ± 3.4 kJ/mol 55.0548 ± 0.0024 101705-90-2*121 Hydroxylamine NH2OH (aq, undissoc) -97.1 ± 2.2 kJ/mol 33.02996 ± 0.00037 7803-49-8*1000 Ethenedione anion [OCCO]- (g) -149.7 -147.1 ± 1.7 kJ/mol 56.0207 ± 0.0017 77783-15-4*0 1,3-Butadiynyl anion [CCCC]- (g) 677.2 686.3 ± 1.1 kJ/mol 48.0433 ± 0.0032 59158-53-1*0 Urea NH2C(O)NH2 (cr,l) -317.73 -333.32 ± 0.12 kJ/mol 60.05534 ± 0.00091 57-13-6*500 Formamide CH(O)NH2 (cr,l) -251.04 ± 0.28 kJ/mol 45.04066 ± 0.00088 75-12-7*500 Acetamide CH3C(O)NH2 (cr,l) -315.89 ± 0.53 kJ/mol 59.0672 ± 0.0017 60-35-5*500 Dihydrogen H2 (g, ortho) 1.417 0.019 ± 0.000 kJ/mol 2.01588 ± 0.00014 1333-74-0*1 Acrylonitrile CH2CHCN (g, triplet) 446.4 440.9 ± 1.7 kJ/mol 53.0627 ± 0.0024 107-13-1*2 Acrylonitrile CH2CHCN (cr,l) 146.32 153.98 ± 0.77 kJ/mol 53.0627 ± 0.0024 107-13-1*500 Trifluorine F3 (g) 80.6 81.8 ± 2.6 kJ/mol 56.9952096 ± 0.0000015 73455-86-4*0 Isocyanoethene CH2CHNC (g, triplet) 544.1 539.2 ± 1.8 kJ/mol 53.0627 ± 0.0024 14668-82-7*2 1-Isocyanoethylidene CH3CNC (g) 527.9 523.2 ± 1.1 kJ/mol 53.0627 ± 0.0024 *498544-34-6*0 Iodine monochloride ICl (cr) -36.511 -35.537 ± 0.063 kJ/mol 162.35717 ± 0.00090 7790-99-0*510 Methanol dimer (CH3OH)2 (g) -398.5 -419.1 ± 1.4 kJ/mol 64.0837 ± 0.0018 42845-44-3*0 2-Cyclopropyn-1-ylidenemethyliumyl [CC(CC)]+ (g) 2239.7 2247.6 ± 2.3 kJ/mol 48.0423 ± 0.0032 289679-92-1*0 Trioxirane O(OO) (g) 272.7 270.1 ± 1.3 kJ/mol 47.99820 ± 0.00090 153851-84-4*0 Cyclopropenylidene anion [C(CHCH)]- (g) 544.2 543.8 ± 2.2 kJ/mol 38.0485 ± 0.0024 *16165-40-5*0 Ammonium hydroxide NH4OH (aq, 500 H2O) -366.38 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*833 Ammonium hydroxide NH4OH (aq, 50 H2O) -366.32 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*822 Tetraoxygen O4 (g, C2h triplet) 104.4 102.4 ± 3.5 kJ/mol 63.9976 ± 0.0012 12596-83-7*11 Vinylacetylene CH2CHCCH (cr,l) 266.3 ± 2.1 kJ/mol 52.0746 ± 0.0032 689-97-4*500 Hydroxymethoxy CH2(OH)O (g) -159.64 -169.50 ± 0.87 kJ/mol 47.0333 ± 0.0010 72144-78-6*0 Chlorine chlorite ClOClO (g, cis) 177.4 175.1 ± 2.2 kJ/mol 102.9042 ± 0.0019 105206-44-8*2 Vinylvinylidene CH2CHCHC (g, triplet, trans) 690.4 684.3 ± 2.7 kJ/mol 52.0746 ± 0.0032 148759-16-4*11 Hydroxymethyleneoxonium [CH2OOH]+ (g) 792.88 782.74 ± 0.64 kJ/mol 47.0328 ± 0.0010 77144-12-8*0 1-Buten-3-ynylium [HCCCHCH]+ (g, cis) 1483.0 1480.5 ± 1.7 kJ/mol 51.0661 ± 0.0032 84654-85-3*2 Ethyl hydroperoxide CH3CH2OOH (cr,l) -210. ± 20. kJ/mol 62.0678 ± 0.0018 3031-74-1*500 n-Heptane CH3(CH2)5CH3 (cr,l) -201.45 -223.91 ± 0.45 kJ/mol 100.2019 ± 0.0057 142-82-5*500 Paraformaldehyde CH2O (cr, paraformaldehyde) -179.2 ± 1.6 kJ/mol 30.02598 ± 0.00087 30525-89-4*500 Propane cation [CH3CH2CH3]+ (g) 974.6 954.6 ± 1.7 kJ/mol 44.0951 ± 0.0025 34479-70-4*0 2-Cyclopropen-1-ylidenemethylium [CHC(CHCH)]+ (g, triplet) 1433.1 1429.3 ± 1.9 kJ/mol 51.0661 ± 0.0032 112936-36-4*1 1,3-Cyclobutadien-1-ylium [C(CHCHCH)]+ (g, triplet) 1472.9 1468.4 ± 1.9 kJ/mol 51.0661 ± 0.0032 81913-77-1*1 1,3-Cyclobutadien-1-yl anion [C(CHCHCH)]- (g) 616.3 611.7 ± 2.1 kJ/mol 51.0672 ± 0.0032 154675-37-3*0 Cyclobutenylium [CH2(CHCHCH)]+ (g) 1038.6 1025.5 ± 2.8 kJ/mol 53.0820 ± 0.0032 12316-90-4*0 Triiodine I3 (g) 153.4 149.4 ± 3.6 kJ/mol 380.713410 ± 0.000090 12596-31-5*0 Butyraldehyde CH3CH2CH2CHO (cr,l) -235.85 -239.37 ± 0.84 kJ/mol 72.1057 ± 0.0033 123-72-8*500 2-Propen-3-ylium-1-ylidyne [CHCHC]+ (g) 1791.2 1792.8 ± 2.6 kJ/mol 38.0474 ± 0.0024 161054-36-0*0 Propenediylidene anion [CHCHC]- (g) 588.8 590.0 ± 2.3 kJ/mol 38.0485 ± 0.0024 *161054-36-0*0 Disilicon cation [Si2]+ (g) 1349.9 1353.5 ± 2.7 kJ/mol 56.17045 ± 0.00060 12597-36-3*0 NON anion [NON]- (g) 495.3 492.8 ± 2.5 kJ/mol 44.01343 ± 0.00033 *227934-47-6*0 Dioxosilane cation [SiO2]+ (g) 946.3 946.2 ± 2.8 kJ/mol 60.08375 ± 0.00067 59458-81-0*0 Silicate [SiO2]- (g) -477.4 -478.2 ± 2.6 kJ/mol 60.08485 ± 0.00067 53095-83-3*0 Oxosilicate [SiO]- (g) -106.0 -104.8 ± 2.6 kJ/mol 44.08545 ± 0.00042 12503-59-2*0 Silicon carbide SiC (cr, beta-cubic) -72.0 -73.0 ± 1.5 kJ/mol 40.09620 ± 0.00085 409-21-2*502 Silane cation [SiH4]+ (g) 1104.7 1097.5 ± 1.6 kJ/mol 32.11671 ± 0.00041 34826-51-2*0 Silylium [SiH3]+ (g) 989.74 984.16 ± 0.94 kJ/mol 31.10877 ± 0.00037 41753-67-7*0 Tetrazete N(NNN) (g, D2h) 764.9 759.0 ± 1.8 kJ/mol 56.02696 ± 0.00028 42851-09-2*0 n-Octane CH3(CH2)6CH3 (cr,l) -226.25 -249.37 ± 0.53 kJ/mol 114.2285 ± 0.0065 111-65-9*500 Silylidyne anion [SiH]- (g) 250.0 251.2 ± 1.1 kJ/mol 29.09399 ± 0.00031 68865-96-3*0 Disilanylium [SiH3SiH2]+ (g) 981.7 970.4 ± 2.6 kJ/mol 61.21015 ± 0.00069 86860-82-4*0 Ammonium hydroxide NH4OH (aq, 10000 H2O) -366.24 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*850 1-Disilanylium-1-yl [SiH3SiH]+ (g) 1124.0 1116.4 ± 2.3 kJ/mol 60.20221 ± 0.00066 108492-64-4*0 Tetraazatetrahedrane N(N(N)N) (g, Td) 763.7 757.2 ± 1.7 kJ/mol 56.02696 ± 0.00028 12596-63-3*0 Di-mu-hydrodihydrodisilicon cation [HSi(HSiHH)]+ (g, cis) 1194.2 1184.5 ± 3.5 kJ/mol 60.20221 ± 0.00066 *129970-82-7*2 Di-mu-hydrodihydrodisilicon anion [HSi(HSiHH)]- (g, cis) 296.4 288.9 ± 3.5 kJ/mol 60.20331 ± 0.00066 *129970-83-8*2 Oxadiazirine cation [O(NN)]+ (g) 1509.9 1507.2 ± 2.4 kJ/mol 44.01233 ± 0.00033 *227934-45-4*0 Dioxygen difluoride OOF2 (g) 75.1 71.6 ± 3.6 kJ/mol 69.99561 ± 0.00060 183051-89-0*0 Ammonium hydroxide NH4OH (aq, 50000 H2O) -366.02 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*855 Ammonium hydroxide NH4OH (aq, 1 H2O) -363.82 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*801 Hydrogen difluoride cation [FHF]+ (g, triplet ?) 1241. 1238. ± 17. kJ/mol 39.004198 ± 0.000070 126950-54-7*1 2,4-Hexadiyne CH3CCCCCH3 (cr,l) 319.04 312.68 ± 0.98 kJ/mol 78.1118 ± 0.0048 2809-69-0*500 Ammonium hydroxide NH4OH (aq, 2 H2O) -364.67 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*803 Trimethylenecyclopropane (C3)(CH2)3 (g) 454.2 441.3 ± 1.8 kJ/mol 78.1118 ± 0.0048 3227-90-5*0 3,4-Bis(methylene)cyclobutene CH2(CCHCHC)CH2 (g) 355.5 340.9 ± 1.8 kJ/mol 78.1118 ± 0.0048 5291-90-7*0 Peroxyhypochlorite [ClOO]- (g) -252.78 -251.75 ± 0.34 kJ/mol 67.4520 ± 0.0011 224299-14-3*0 Cyclobutane CH2(CH2CH2CH2) (l) 3.88 ± 0.39 kJ/mol 56.1063 ± 0.0032 287-23-0*590 1-Ethynylcyclobutene HCCC(CHCH2CH2) (g) 402.2 387.9 ± 1.8 kJ/mol 78.1118 ± 0.0048 813466-25-0*0 3-Methyl-1,2-pentadien-4-yne CH2CC(CH3)CCH (g) 414.6 403.4 ± 2.3 kJ/mol 78.1118 ± 0.0048 813466-14-7*0 Ammonium hydroxide NH4OH (aq, 3 H2O) -365.13 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*805 Methylcyclopropane CH3CH(CH2CH2) (l) 1.95 ± 0.59 kJ/mol 56.1063 ± 0.0032 594-11-6*590 Hydroxyoxoammoniumyl [HONO]+ (g, trans) 984.1 977.7 ± 1.8 kJ/mol 47.01293 ± 0.00061 80371-48-8*1 1,3-Pentadiyne HCCCCCH3 (cr,l) 384.9 ± 5.0 kJ/mol 64.0853 ± 0.0040 4911-55-1*500 Ammonium hydroxide NH4OH (aq, 4 H2O) -365.43 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*807 1-Aminoethylium [CH3CHNH2]+ (g) 683.2 664.5 ± 2.3 kJ/mol 44.0752 ± 0.0017 *30208-36-7*0 1-Propanamine CH3CH2CH2NH2 (cr,l) -93.79 -101.40 ± 0.40 kJ/mol 59.1103 ± 0.0025 107-10-8*500 2-Propanamine CH3CH(CH3)NH2 (cr,l) -101.56 -112.17 ± 0.52 kJ/mol 59.1103 ± 0.0025 75-31-0*500 Dihydrogen fluoride (HF)(H) (g) -56.5 -54.2 ± 1.7 kJ/mol 21.01428 ± 0.00014 12592-22-2*2 Naphthalene C6H4(C4H4) (cr,l) 94.75 75.17 ± 0.55 kJ/mol 128.1705 ± 0.0080 91-20-3*500 Biphenyl C6H5C6H5 (cr,l) 121.6 97.1 ± 1.1 kJ/mol 154.2078 ± 0.0096 92-52-4*500 Biphenyl C6H5C6H5 (cr) 121.6 97.1 ± 1.1 kJ/mol 154.2078 ± 0.0096 92-52-4*520 Nitrous acid anion [HONO]- (g, cis) -105.83 -110.45 ± 0.78 kJ/mol 47.01403 ± 0.00061 256393-36-9*2 Aniline C6H5NH2 (cr,l) 37.29 31.03 ± 0.63 kJ/mol 93.1265 ± 0.0048 62-53-3*500 Chlorodioxidanyl ClOO (g) 100.36 99.27 ± 0.34 kJ/mol 67.4515 ± 0.0011 17376-09-9*0 Dihelium He2 (g, triplet) 1733.310 1729.576 ± 0.018 kJ/mol 8.0052040 ± 0.0000040 12184-98-4*1 Dihydrohelium cation [HeHH]+ (g) 1467.27 1461.99 ± 0.44 kJ/mol 6.01793 ± 0.00014 12500-88-8*0 Neon cation Ne+ (g) 2080.662 2080.769 ± 0.000 kJ/mol 20.17915 ± 0.00060 14782-23-1*0 Formic acid HC(O)OH (aq) -425.47 ± 0.45 kJ/mol 46.0254 ± 0.0010 64-18-6*800 Pyruvic acid CH3C(O)C(O)OH (cr,l) -588.52 ± 0.74 kJ/mol 88.0621 ± 0.0026 127-17-3*500 Peroxyhypochlorous acid cation [HOOCl]+ (g, trans) 1030.4 1024.6 ± 2.5 kJ/mol 68.4589 ± 0.0011 *67952-07-2*1 Sulfur trioxide OS(O)O (l) -440.84 ± 0.30 kJ/mol 80.0642 ± 0.0061 7446-11-9*590 Ammonium hydroxide NH4OH (aq, 10 H2O) -366.00 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*815 Sulfanylium [SH]+ (g) 1148.41 1148.41 ± 0.19 kJ/mol 33.0734 ± 0.0060 12273-42-6*0 Sulfuric acid OS(O)(OH)2 (aq, 70 H2O) -887.02 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*824 1,2-Butadienylium [CH3CHCCH]+ (g, triplet) 1315.5 1307.4 ± 1.7 kJ/mol 53.0820 ± 0.0032 *65114-67-2*1 Sulfur hydroxide oxide cation [OHS(O)(O)O]+ (g, eclipsed) 659.0 648.2 ± 3.5 kJ/mol 97.0710 ± 0.0061 *12337-07-4*2 Ammonium hydroxide NH4OH (aq, 100000 H2O) -365.85 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*861 Sulfurous acid S(O)(OH)2 (g) -511.18 -520.68 ± 0.89 kJ/mol 82.0801 ± 0.0061 7782-99-2*0 Sulfurous acid S(O)(OH)2 (aq, undissoc) -606.43 ± 0.14 kJ/mol 82.0801 ± 0.0061 7782-99-2*1000 Hydrogen sulfite [OS(OH)O]- (aq, undissoc) -631.77 ± 0.15 kJ/mol 81.0727 ± 0.0061 15181-46-1*1000 Sulfur dioxide - hydroxyl complex (OH)(OSO) (g, vdW) -265.9 -268.0 ± 2.2 kJ/mol 81.0721 ± 0.0061 *32750-86-0*100 Peroxychlorous acid HOOClO (g, anti) 102.7 96.9 ± 2.4 kJ/mol 84.4588 ± 0.0013 177778-92-6*2 Platinum dimer Pt2 (g) 823.5 822.5 ± 3.9 kJ/mol 390.1560 ± 0.0040 12596-95-1*0 Platinum hydride PtH (g) 457.1 456.2 ± 9.2 kJ/mol 196.0859 ± 0.0020 13966-55-7*0 Hydrogen atom H (ad, Pt(111)) -37.0 -38.7 ± 1.1 kJ/mol 1.007940 ± 0.000070 12385-13-6*1000000 Hydrogen atom H (ad, 4 Pt(111)) -33.4 -35.1 ± 1.5 kJ/mol 1.007940 ± 0.000070 12385-13-6*1000004 Trioxidanyl HOOO (g) 25.36 23.27 ± 0.13 kJ/mol 49.00614 ± 0.00090 12500-78-6*0 Diisocyanogen cation [CNNC]+ (g, cis) 1838.6 1842.5 ± 3.1 kJ/mol 52.0343 ± 0.0016 *78800-21-2*2 Acetaldehyde CH3CHO (cr,l) -186.98 -191.69 ± 0.29 kJ/mol 44.0526 ± 0.0017 75-07-0*500 Hydrogen peroxide cation [HOOH]+ (g, cis, para) 931.04 924.18 ± 0.98 kJ/mol 34.01413 ± 0.00062 12325-10-9*22 Ammonia NH3 (aq, 2 H2O) -78.02 ± 0.41 kJ/mol 17.03056 ± 0.00022 7664-41-7*803 Cyanoamidogen HNCN (g, c-quartet) 657.4 654.6 ± 2.0 kJ/mol 41.03212 ± 0.00082 12347-01-2*22 Nitrogen atom anion N- (g) 488.2 490.5 ± 2.3 kJ/mol 14.007289 ± 0.000070 17778-87-9*0 Nitrogen atom dication [N]+2 (g) 4728.992 4731.820 ± 0.024 kJ/mol 14.005643 ± 0.000070 17439-59-7*0 Diazomethylium [HCNN]+ (g, singlet) 1458.9 1456.8 ± 2.2 kJ/mol 41.03157 ± 0.00082 271249-81-1*2 Nitrogen atom trication [N]+3 (g) 9306.68 9308.54 ± 0.23 kJ/mol 14.005094 ± 0.000070 18396-22-0*0 Oxoniumyl ion [H2O]+ (g, ortho) 978.498 975.595 ± 0.024 kJ/mol 18.01473 ± 0.00033 56583-62-1*1 Carbide [C]-4 (g) 2709.5 2714.7 ± 2.7 kJ/mol 12.01289 ± 0.00080 12385-15-8*0 Peroxyformate [HC(O)OO]- (g, anti) -320.7 -326.5 ± 1.7 kJ/mol 61.0174 ± 0.0012 104960-05-6*2 Diazirinylium [HC(NN)]+ (g, singlet) 1384.8 1381.2 ± 2.1 kJ/mol 41.03157 ± 0.00082 77116-26-8*2 Dioxofluorine cation [OFO]+ (g) 1667.0 1664.8 ± 2.8 kJ/mol 50.99665 ± 0.00060 223566-05-0*0 Propylidene CH3CH2CH (g, triplet) 349.47 335.71 ± 0.92 kJ/mol 42.0797 ± 0.0024 6700-78-3*1 Iminomethylimidogen cation [NCHN]+ (g, triplet) 1677.6 1676.4 ± 2.3 kJ/mol 41.03157 ± 0.00082 *150296-30-3*1 Iminomethylimidogen anion [NCHN]- (g, triplet) 405.3 402.0 ± 2.5 kJ/mol 41.03267 ± 0.00082 150296-30-3*1 1-Hydroxyethyl CH3CHOH (g) -42.82 -56.25 ± 0.46 kJ/mol 45.0605 ± 0.0017 2348-46-1*0 Ammonia NH3 (aq, 3 H2O) -78.87 ± 0.41 kJ/mol 17.03056 ± 0.00022 7664-41-7*805 Fluorine atom pentacation [F]+5 (g) 30617.6 30619.4 ± 1.8 kJ/mol 18.99566030 ± 0.00000050 14701-05-4*0 Trioxygen difluoride FOOOF (g) 112.5 107.3 ± 1.1 kJ/mol 85.99501 ± 0.00090 16829-28-0*0 Nitrogen atom tetracation [N]+4 (g) 16781.74 16783.60 ± 0.23 kJ/mol 14.004546 ± 0.000070 14452-70-1*0 Ammonia NH3 (aq, 4 H2O) -79.33 ± 0.41 kJ/mol 17.03056 ± 0.00022 7664-41-7*807 (Iminomethyl)imidogen HNCHN (g, triplet) 420.1 413.2 ± 2.9 kJ/mol 42.04006 ± 0.00082 87570-07-8*1 Formylimidogen HC(O)N (g, singlet) 245.3 242.1 ± 3.3 kJ/mol 43.02478 ± 0.00086 42288-92-6*2 Peroxyformyl HC(O)OO (g, anti) -90.4 -95.9 ± 1.7 kJ/mol 61.0168 ± 0.0012 56240-83-6*2 Hydrogen fluoride HF (aq, undissoc) -321.39 ± 0.17 kJ/mol 20.006343 ± 0.000070 7664-39-3*1000 1-Methylethenylium [CH3CCH2]+ (g) 995.1 986.0 ± 1.9 kJ/mol 41.0713 ± 0.0024 50457-57-3*0 Oxygen atom dication [O]+2 (g) 4949.458 4953.000 ± 0.013 kJ/mol 15.99830 ± 0.00030 14127-63-0*0 Fluorine atom hexacation [F]+6 (g) 45781.5 45783.3 ± 1.8 kJ/mol 18.99511172 ± 0.00000050 14701-04-3*0 1-Methylethenyl anion [CH3CCH2]- (g) 199.3 188.1 ± 2.0 kJ/mol 41.0723 ± 0.0024 65887-19-6*0 Nitrogen atom pentacation [N]+5 (g) 26226.69 26228.56 ± 0.23 kJ/mol 14.003997 ± 0.000070 20508-99-0*0 Acetylene HCCH (g, cis-triplet) 599.1 599.0 ± 1.5 kJ/mol 26.0373 ± 0.0016 74-86-2*11 1-Propenylium [CH3CHCH]+ (g, trans) 1233.7 1223.3 ± 2.0 kJ/mol 41.0713 ± 0.0024 50457-58-4*1 1-Propenylide [CH3CHCH]- (g, trans) 210.4 199.3 ± 2.0 kJ/mol 41.0723 ± 0.0024 65887-20-9*1 Bromodioxy BrOO (g) 116.7 107.7 ± 3.8 kJ/mol 111.9028 ± 0.0012 67177-47-3*0 Oxonium [H3O]+ (g, para) 605.89 599.14 ± 0.17 kJ/mol 19.02267 ± 0.00037 13968-08-6*2 Nitrogen atom hexacation [N]+6 (g) 79493.09 79494.96 ± 0.23 kJ/mol 14.003449 ± 0.000070 15721-56-9*0 2-Chloro ozone ClO(O)O (g) 265.7 265.1 ± 3.7 kJ/mol 83.4509 ± 0.0013 *141801-66-3*0 Dihydrogen anion [H2]- (g) 253.8 254.7 ± 1.2 kJ/mol 2.01643 ± 0.00014 12184-89-3*0 Trihydrogen H(HH) (g, 2s 2A1' Ry) 745.878 743.094 ± 0.062 kJ/mol 3.02382 ± 0.00021 12184-91-7*1 Hydrogen fluoride HF (aq, 3 H2O) -320.70 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*805 Tetrabromomethane CBr4 (cr, monoclinic) 59.2 ± 1.3 kJ/mol 331.6267 ± 0.0041 558-13-4*500 Fluorine atom dication [F]+2 (g) 5132.472 5134.257 ± 0.021 kJ/mol 18.99730604 ± 0.00000050 14701-07-6*0 Tetraiodomethane CI4 (cr, monoclinic) 392.5 ± 8.0 kJ/mol 519.62858 ± 0.00081 507-25-5*500 Bromomethane CH3Br (l) -56.25 -59.26 ± 0.21 kJ/mol 94.9385 ± 0.0013 74-83-9*590 Trioxirane cation [O(OO)]+ (g) 1444.5 1442.3 ± 2.2 kJ/mol 47.99765 ± 0.00090 *153851-84-4*0 Ammonia NH3 (aq, 5 H2O) -79.63 ± 0.41 kJ/mol 17.03056 ± 0.00022 7664-41-7*809 Fluorine atom heptacation [F]+7 (g) 63649.3 63651.1 ± 1.8 kJ/mol 18.99456314 ± 0.00000050 14700-77-7*0 Trihydrogen cation [H3]+ (g, para) 1110.304 1106.697 ± 0.013 kJ/mol 3.02327 ± 0.00021 28132-48-1*2 Chlorine atom tetracation [Cl]+4 (g) 12615.5 12617.1 ± 4.6 kJ/mol 35.45051 ± 0.00090 22541-74-8*0 Nitride [N]-3 (g) 1879.1 1881.0 ± 4.4 kJ/mol 14.008386 ± 0.000070 18851-77-9*0 Ethynylaminylium [HCCNH]+ (g, singlet) 1350.6 1348.7 ± 2.5 kJ/mol 40.0435 ± 0.0016 103835-08-1*2 Hypochloroperoxoous acid, hydroxy ester HOOOCl (g, anti) 48.7 41.8 ± 2.5 kJ/mol 84.4588 ± 0.0013 928652-99-7*2 Hydrogen bromide HBr (aq, 2570 H2O) -120.24 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*952 Carbon monoxide CO (g, singlet) -113.800 -110.520 ± 0.026 kJ/mol 28.01010 ± 0.00085 630-08-0*2 Ethyl bromide CH3CH2Br (l) -55.43 -90.96 ± 0.25 kJ/mol 108.9651 ± 0.0019 74-96-4*500 Ammonia NH3 (aq) -77.033 ± 0.056 kJ/mol 17.03056 ± 0.00022 7664-41-7*800 Vinyl iodide CH2CHI (g) 139.7 130.8 ± 1.2 kJ/mol 153.9497 ± 0.0016 593-66-8*0 Ketene CH2CO (g, para singlet) -45.35 -48.41 ± 0.11 kJ/mol 42.0367 ± 0.0016 463-51-4*21 Difluorovinylidene cation [CCF2]+ (g) 1181.6 1183.1 ± 2.3 kJ/mol 62.0177 ± 0.0016 268566-71-8*0 Chlorine atom Cl (g, 2P3/2) 119.621 121.228 ± 0.0011 kJ/mol 35.45270 ± 0.00090 22537-15-1*1 Cyclopentadiene CH2(CHCHCHCH) (l) 110.39 ± 0.57 kJ/mol 66.1011 ± 0.0040 542-92-7*590 Chloro(chlorooxy)methylene ClCOCl (g, trans triplet) 101.1 104.7 ± 4.8 kJ/mol 98.9155 ± 0.0020 479587-31-0*12 Chlorine atom pentacation [Cl]+5 (g) 19147. 19149. ± 11. kJ/mol 35.44996 ± 0.00090 20337-89-7*0 Water trimer (H2O)3 (g) -762.64 -776.74 ± 0.20 kJ/mol 54.04584 ± 0.00099 31014-12-7*0 mu-Oxodichlorine cation [ClOCl]+ (g) 1130.45 1126.84 ± 0.63 kJ/mol 86.9043 ± 0.0018 51174-96-0*0 Chlorine atom trication [Cl]+3 (g) 7487.2 7490.2 ± 3.3 kJ/mol 35.45105 ± 0.00090 16547-50-5*0 Hydrogen peroxide HOOH (g, para) -129.413 -135.399 ± 0.058 kJ/mol 34.01468 ± 0.00062 7722-84-1*2 1,3,5-Hexatriynylium [CCCCCCH]+ (g, singlet) 1952.4 1961.3 ± 7.6 kJ/mol 73.0716 ± 0.0048 81932-75-4*2 mu-Oxodichlorate anion [ClOCl]- (g) -147.8 -147.7 ± 2.5 kJ/mol 86.9053 ± 0.0018 365546-30-1*0 Carbon suboxide OCCCO (cr,l) -131.2 -116.2 ± 1.1 kJ/mol 68.0309 ± 0.0025 504-64-3*500 Fluorine atom tetracation [F]+4 (g) 19594.3 19596.6 ± 1.7 kJ/mol 18.99620888 ± 0.00000050 14700-79-9*0 Difluorine cation [F2]+ (g) 1514.301 1514.475 ± 0.013 kJ/mol 37.9962578 ± 0.0000010 12184-86-0*0 Water H2O (cr) -286.270 -292.711 ± 0.022 kJ/mol 18.01528 ± 0.00033 7732-18-5*510 m-Benzyne C6H4 (g, triplet) 614.6 605.2 ± 1.4 kJ/mol 76.0960 ± 0.0048 1828-89-3*1 Ammonia NH3 (aq, 10 H2O) -80.16 ± 0.41 kJ/mol 17.03056 ± 0.00022 7664-41-7*815 Ammonia NH3 (aq, 20 H2O) -80.38 ± 0.41 kJ/mol 17.03056 ± 0.00022 7664-41-7*818 Dioxaziridine HN(OO) (g) 277.5 270.8 ± 1.9 kJ/mol 47.01348 ± 0.00061 67394-35-8*0 Carbonic acid C(O)(OH)2 (aq, undissoc) -698.665 ± 0.028 kJ/mol 62.0248 ± 0.0012 463-79-6*1000 Methyl acetate CH3C(O)OCH3 (g) -394.18 -413.05 ± 0.57 kJ/mol 74.0785 ± 0.0025 79-20-9*0 Hydroxylamine NH2OH (g) -33.08 -43.45 ± 0.42 kJ/mol 33.02996 ± 0.00037 7803-49-8*0 Nitrosyl nitrite anion [ONONO]- (g, t, c) -100.2 -103.4 ± 2.9 kJ/mol 76.01223 ± 0.00091 *122413-35-8*2 Tropylide [CH(CHCHCHCHCHCH)]- (g) 261.5 245.2 ± 2.0 kJ/mol 91.1310 ± 0.0056 34464-18-1*0 Tetraoxodinitrate anion [O2NNO2]- (g) -184.6 -187.8 ± 2.4 kJ/mol 92.0116 ± 0.0012 63552-02-3*0 Ammonia NH3 (aq, 10000 H2O) -80.45 ± 0.41 kJ/mol 17.03056 ± 0.00022 7664-41-7*850 Ethynylene C2 (g, singlet) 819.977 826.550 ± 0.085 kJ/mol 24.0214 ± 0.0016 12070-15-4*2 Ammonium oxide (NH4)2O (cr,l) -428.46 -430.45 ± 0.61 kJ/mol 52.07640 ± 0.00065 12161-77-2*500 Trihydrogen (H)(HH) (g, vdW) 215.9 218.3 ± 1.1 kJ/mol 3.02382 ± 0.00021 12184-91-7*100 2-Methylpentane CH3CH2CH2CH(CH3)2 (cr,l) -180.16 -203.82 ± 0.73 kJ/mol 86.1754 ± 0.0049 107-83-5*500 Chlorine atom hexacation [Cl]+6 (g) 28501. 28503. ± 11. kJ/mol 35.44941 ± 0.00090 22541-73-7*0 Methyl formate HC(O)OCH3 (g) -346.96 -360.00 ± 0.65 kJ/mol 60.0520 ± 0.0017 107-31-3*0 Ethyl formate HC(O)OCH2CH3 (g) -375.1 -393.9 ± 1.0 kJ/mol 74.0785 ± 0.0025 109-94-4*0 Ammonia NH3 (aq, 1 H2O) -75.73 ± 0.57 kJ/mol 17.03056 ± 0.00022 7664-41-7*801 1,2-Propadien-1-ylium-1-yl-3-ylidene [CCC]+ (g) 1939.2 1947.1 ± 1.3 kJ/mol 36.0316 ± 0.0024 118090-85-0*0 3-Methylpentane CH3CH2CH(CH3)CH2CH3 (cr,l) -177.63 -201.89 ± 0.76 kJ/mol 86.1754 ± 0.0049 96-14-0*500 Oxygen atom tetracation [O]+4 (g) 17719.207 17721.064 ± 0.025 kJ/mol 15.99721 ± 0.00030 14127-65-2*0 Ammonia NH3 (aq, 50000 H2O) -80.22 ± 0.41 kJ/mol 17.03056 ± 0.00022 7664-41-7*855 Ammonia NH3 (aq, 100000 H2O) -80.06 ± 0.41 kJ/mol 17.03056 ± 0.00022 7664-41-7*861 Difluorodioxidanium [FOOF]+ (g, cis) 1287.2 1283.0 ± 2.3 kJ/mol 69.99506 ± 0.00060 *7783-44-0*2 Hydrogen peroxide cation [HOOH]+ (g, trans, ortho) 897.29 890.31 ± 0.51 kJ/mol 34.01413 ± 0.00062 12325-10-9*11 Isocyanogen bromide anion [BrNC]- (g) 105.0 101.9 ± 4.6 kJ/mol 105.9220 ± 0.0013 *238754-53-5*0 Chlorine trifluoride cation [FCl(F)F]+ (g) 1053.5 1049.2 ± 2.3 kJ/mol 92.44736 ± 0.00090 478167-77-0*0 2,3-Dimethylbutane CH3CH(CH3)CH(CH3)CH3 (cr,l) -182.43 -206.94 ± 0.81 kJ/mol 86.1754 ± 0.0049 79-29-8*500 Oxygen atom trication [O]+3 (g) 10249.929 10252.880 ± 0.018 kJ/mol 15.99775 ± 0.00030 14127-64-1*0 2,2-Dimethylbutane CH3CH2C(CH3)3 (cr,l) -187.93 -213.64 ± 0.75 kJ/mol 86.1754 ± 0.0049 75-83-2*500 Ammonia NH3 (aq, 50 H2O) -80.52 ± 0.41 kJ/mol 17.03056 ± 0.00022 7664-41-7*822 Hydrogen iodide HI (aq, 5130 H2O) -56.645 ± 0.089 kJ/mol 127.912410 ± 0.000076 10034-85-2*958 Acetoxy CH3C(O)O (g) -182.16 -190.87 ± 0.80 kJ/mol 59.0440 ± 0.0017 13799-69-4*0 Fluorosyl fluoride FFO (g, singlet) 227. 225. ± 21. kJ/mol 53.99621 ± 0.00030 86825-57-2*2 Succinic acid (CH2C(O)OH)2 (cr,l) -918.47 -940.20 ± 0.12 kJ/mol 118.0880 ± 0.0034 110-15-6*500 2-Oxo-1-ethylium-1-yl [HCC(O)H]+ (g, syn-quartet) 1292.0 1288.7 ± 2.4 kJ/mol 42.0361 ± 0.0016 214464-96-7*12 Oxoethylidene anion [HCC(O)H]- (g, syn-gauche) 92.3 89.0 ± 2.3 kJ/mol 42.0372 ± 0.0016 106543-38-8*2 1,2-Dibromoethane CH2BrCH2Br (cr,l) -80.1 ± 1.2 kJ/mol 187.8612 ± 0.0026 106-93-4*500 Acetylene anion [HCCH]- (g) 356.9 356.7 ± 1.9 kJ/mol 26.0378 ± 0.0016 50443-89-5*0 Ammonium hydroxide NH4OH (aq, undissoc) -366.682 ± 0.059 kJ/mol 35.04584 ± 0.00047 1336-21-6*1000 1,3-Butadien-2-ol CH2C(OH)CHCH2 (g, s-cis, syn) -42.7 -59.2 ± 2.3 kJ/mol 70.0898 ± 0.0032 59120-04-6*21 1,3-Butadien-2-ol CH2C(OH)CHCH2 (g, s-trans) -53.4 -68.7 ± 1.5 kJ/mol 70.0898 ± 0.0032 59120-04-6*1 Carbon trication [C]+3 (g) 8770.927 8776.073 ± 0.047 kJ/mol 12.00905 ± 0.00080 14067-06-2*0 Acrolein CH2CHCHO (g) -55.17 -65.26 ± 0.64 kJ/mol 56.0633 ± 0.0024 107-02-8*0 Dioxofluorine anion [OFO]- (g) 155.9 154.4 ± 2.5 kJ/mol 50.99775 ± 0.00060 *175861-93-5*0 Bicyclo[1.1.0]buta-1,3-diene-2,4-diyl C(CC)C (g, singlet) 1047.12 1054.72 ± 0.68 kJ/mol 48.0428 ± 0.0032 12184-80-4*2 Propionic acid CH3CH2C(O)OH (g) -435.93 -453.82 ± 0.59 kJ/mol 74.0785 ± 0.0025 79-09-4*0 1-Oxo-2-propenide [CH2CHCO]- (g, II) 83.6 78.6 ± 2.5 kJ/mol 55.0559 ± 0.0024 78944-75-9*2 Propadien-1-olate [CH2CCHO]- (g) 1.4 -4.4 ± 2.5 kJ/mol 55.0559 ± 0.0024 109686-13-7*0 1-Formylethenylium [CH2CCHO]+ (g, triplet) 1158.8 1154.2 ± 3.0 kJ/mol 55.0548 ± 0.0024 101705-89-9*1 1,3-Butadiyn-4-ylium-1-yl [CCCC]+ (g) 2109.8 2120.5 ± 2.8 kJ/mol 48.0423 ± 0.0032 124708-46-9*0 3-Oxo-1-propenyl CHCHCHO (g, trans) 190.93 184.95 ± 0.91 kJ/mol 55.0553 ± 0.0024 206255-29-0*1 3-Oxo-1-propenyl CHCHCHO (g, anti-cis) 191.7 185.7 ± 2.1 kJ/mol 55.0553 ± 0.0024 206255-29-0*21 Hydrazoic acid anion [HNNN]- (g, cis) 316.2 310.1 ± 2.3 kJ/mol 43.02871 ± 0.00022 203264-98-6*2 2-Formylethen-1-ide [CHCHCHO]- (g, anti-cis) 30.5 23.7 ± 3.1 kJ/mol 55.0559 ± 0.0024 135924-69-5*21 1,2-Propadien-1-one cation [CH2CCO]+ (g) 1012.7 1011.3 ± 1.8 kJ/mol 54.0468 ± 0.0024 87612-93-9*0 2-Propynal cation [CHCCHO]+ (g) 1168.3 1167.1 ± 1.3 kJ/mol 54.0468 ± 0.0024 100815-70-1*0 Hydroxylamine NH2OH (cr,l) -107.47 ± 0.60 kJ/mol 33.02996 ± 0.00037 7803-49-8*500 Formylethynyl cation [CC(CHO)]+ (g, singlet) 1539.9 1541.8 ± 2.7 kJ/mol 53.0389 ± 0.0024 *85905-64-2*2 Formylethynyl cation [CCCHO]+ (g, triplet) 1540.6 1542.8 ± 2.8 kJ/mol 53.0389 ± 0.0024 *85905-64-2*1 2-Hydroxyethylium [CH2CH2OH]+ (g, gauche) 1024.7 1012.1 ± 2.0 kJ/mol 45.0600 ± 0.0017 38607-31-7*1 Carbon pentacation [C]+5 (g) 52824.589 52829.735 ± 0.050 kJ/mol 12.00796 ± 0.00080 14280-11-6*0 1,3-Butadiyne-1,4-diyl CCCC (g, triplet) 1052.22 1062.20 ± 0.64 kJ/mol 48.0428 ± 0.0032 78015-07-3*1 2-Propen-1-ylium-1-ylidene [CH2CHC]+ (g) 1373.2 1369.6 ± 2.0 kJ/mol 39.0554 ± 0.0024 88000-25-3*0 (Hydroxyimino)methyl HCNOH (g, trans-cis) 258.8 252.7 ± 2.0 kJ/mol 44.03272 ± 0.00087 206442-92-4*2 Oxygen atom heptacation [O]+7 (g) 113369.48 113371.34 ± 0.12 kJ/mol 15.99556 ± 0.00030 14274-89-6*0 Tribromine cation [Br3]+ (g) 1036.3 1013.6 ± 2.5 kJ/mol 239.7115 ± 0.0030 33105-86-1*0 Cyanoacetylene cation [HCCCN]+ (g) 1495.51 1497.81 ± 0.58 kJ/mol 51.0462 ± 0.0024 85398-68-1*0 Isocyanoacetylene cation [HCCNC]+ (g) 1567.8 1570.3 ± 1.3 kJ/mol 51.0462 ± 0.0024 145076-03-5*0 Ammonia NH3 (aq, 100 H2O) -80.56 ± 0.41 kJ/mol 17.03056 ± 0.00022 7664-41-7*828 Cyanoethynylium [CCCN]+ (g) 1867.6 1874.3 ± 3.2 kJ/mol 50.0383 ± 0.0024 104233-69-4*0 Nitrosyl nitrate ONONO2 (g, cis-perp) 60.4 52.5 ± 1.9 kJ/mol 92.0111 ± 0.0012 15969-55-8*2 Chlorine atom dication [Cl]+2 (g) 3668.474 3670.081 ± 0.013 kJ/mol 35.45160 ± 0.00090 15723-23-6*0 1-Propen-1-yl-3-ylidene CHCHCH (g, quartet) 656.7 653.3 ± 1.1 kJ/mol 39.0559 ± 0.0024 84654-90-0*1 3-Imino-2-propen-1-ylidene CHCHCNH (g, singlet) 530.6 526.3 ± 1.2 kJ/mol 53.0627 ± 0.0024 916765-05-4*1 Dinitrogen dimer (N2)2 (g) -0.88 0.84 ± 0.67 kJ/mol 56.02696 ± 0.00028 154680-01-0*0 2-(Methylidyneamino)ethenyl CHCHNCH (g, singlet) 600.7 596.3 ± 1.2 kJ/mol 53.0627 ± 0.0024 123416-74-0*1 Trioxodinitrate anion [ONN(O)O]- (g, non-vdW) -87.3 -93.0 ± 2.2 kJ/mol 76.01223 ± 0.00091 194856-62-7*1 Tetraoxygen O4 (g, D2h singlet) 69.8 65.1 ± 4.4 kJ/mol 63.9976 ± 0.0012 12596-83-7*21 Tetraoxygen O4 (g, D2d singlet) 399.0 393.4 ± 3.9 kJ/mol 63.9976 ± 0.0012 12596-83-7*23 Tetraoxygen O4 (g, D3h singlet) 465.6 459.6 ± 4.2 kJ/mol 63.9976 ± 0.0012 12596-83-7*24 Oxygen atom pentacation [O]+5 (g) 28708.788 28710.645 ± 0.053 kJ/mol 15.99666 ± 0.00030 14127-66-3*0 Ammonia NH3 (aq, 5000 H2O) -80.50 ± 0.41 kJ/mol 17.03056 ± 0.00022 7664-41-7*844 Formaldehyde CH2O (g, para singlet) -105.389 -109.229 ± 0.095 kJ/mol 30.02598 ± 0.00087 50-00-0*21 Hydrazine monohydrate (NH2NH2)(H2O) (l) -242.57 ± 0.19 kJ/mol 50.06052 ± 0.00053 7803-57-8*500 1,2-Butadien-1-ylium-1-yl [CH3CHCC]+ (g) 1466.9 1461.7 ± 3.1 kJ/mol 52.0740 ± 0.0032 161054-21-3*0 Bicyclo[1.1.0]butan-3-id-1-yl [CH2(CC)CH2]- (g) 524.6 515.9 ± 2.6 kJ/mol 52.0751 ± 0.0032 131273-95-5*0 1,2-Cyclobutadiene C(CHCH2CH) (g) 586.0 579.3 ± 2.2 kJ/mol 52.0746 ± 0.0032 50682-90-1*0 But-3-en-1-yn-1-ide [CH2CHCC]- (g, triplet) 559.0 558.3 ± 2.2 kJ/mol 51.0672 ± 0.0032 58870-47-6*1 Hydrazoic acid HNNN (aq, undissoc) 257.67 ± 0.48 kJ/mol 43.02816 ± 0.00022 7782-79-8*1000 Polyoxymethylene CH2O (cr, polyoxymethylene) -170.85 ± 0.21 kJ/mol 30.02598 ± 0.00087 9002-81-7*500 2-Iminoethyl CH2CHNH (g, syn) 221.6 210.3 ± 1.8 kJ/mol 42.0599 ± 0.0016 73843-90-0*1 2-Iminoethyl anion [CH2CHNH]- (g, anti) 110.6 100.1 ± 2.3 kJ/mol 42.0604 ± 0.0016 73843-87-5*2 Hydrazoic acid HNNN (aq) 272.65 ± 0.48 kJ/mol 43.02816 ± 0.00022 7782-79-8*800 Water H2O (g, para) -238.900 -241.803 ± 0.022 kJ/mol 18.01528 ± 0.00033 7732-18-5*2 2-Iminoethylium [CH2CHNH]+ (g, singlet) 1108.2 1097.6 ± 2.9 kJ/mol 42.0594 ± 0.0016 73843-91-1*2 (E)-2-Iminoethylium [CH2CHNH]+ (g, anti) 1108.2 1094.8 ± 2.9 kJ/mol 42.0594 ± 0.0016 91127-33-2*0 Formaldehyde CH2O (aq) -171.20 ± 0.59 kJ/mol 30.02598 ± 0.00087 50-00-0*800 Fluorine atom F (g, 2P3/2) 77.254 79.039 ± 0.017 kJ/mol 18.99840320 ± 0.00000050 14762-94-8*1 Silicon cation Si+ (g) 1236.90 1241.03 ± 0.59 kJ/mol 28.08495 ± 0.00030 14067-07-3*0 Silicon atom dication [Si]+2 (g) 2814.04 2817.02 ± 0.59 kJ/mol 28.08440 ± 0.00030 14175-55-4*0 Silicon atom trication [Si]+3 (g) 6045.62 6048.60 ± 0.59 kJ/mol 28.08385 ± 0.00030 14175-56-5*0 (Z)-2-Iminoethylium [CH2CHNH]+ (g, syn) 1151.7 1143.0 ± 3.3 kJ/mol 42.0594 ± 0.0016 91127-34-3*0 (Z)-2-Iminoethylium [CH2CHNH]+ (g, syn-triplet) 1151.7 1143.0 ± 3.3 kJ/mol 42.0594 ± 0.0016 91127-34-3*11 Peroxyhypochlorous acid cation [HOOCl]+ (g, cis) 1050.8 1045.2 ± 2.5 kJ/mol 68.4589 ± 0.0011 *67952-07-2*2 Dioxosilane SiO2 (cr, tridymite) -901.5 -906.3 ± 1.4 kJ/mol 60.08430 ± 0.00067 7631-86-9*515 Oxosilyliumyl [SiO]+ (g) 1022.0 1023.2 ± 2.9 kJ/mol 44.08435 ± 0.00042 12359-18-1*0 Methylene CH2 (g) 391.063 391.609 ± 0.094 kJ/mol 14.02658 ± 0.00081 2465-56-7*0 Ammonia NH3 (aq, 500 H2O) -80.58 ± 0.41 kJ/mol 17.03056 ± 0.00022 7664-41-7*833 Fluorine atom octacation [F]+8 (g) 155686.5 155688.3 ± 1.8 kJ/mol 18.99401456 ± 0.00000050 15721-58-1*0 Deuteride D- (g) 146.991 148.904 ± 0.0021 kJ/mol 2.01465035791 ± 0.00000000040 14452-69-8*0 1-Hydroperoxyethylium [CH3CHOOH]+ (g, singlet) 690.5 675.6 ± 1.5 kJ/mol 61.0594 ± 0.0017 *126898-98-4*2 mu-Hydrotetrahydrodisilicon cation [SiH2(HSiH2)]+ (g) 981.8 969.1 ± 2.8 kJ/mol 61.21015 ± 0.00069 160896-65-1*0 Di-mu-hydrotrihydrodisilicon cation [SiH2(HSiHH)]+ (g) 1033.9 1020.5 ± 2.8 kJ/mol 61.21015 ± 0.00069 *160896-65-1*0 Disilene anion [SiH2SiH2]- (g) 178.4 170.0 ± 3.1 kJ/mol 60.20331 ± 0.00066 157379-08-3*0 sec-Butylium [CH3CH2CHCH3]+ (g) 792.6 769.0 ± 1.5 kJ/mol 57.1137 ± 0.0033 16548-59-7*0 Silylsilylene anion [SiH3SiH]- (g) 160.1 151.4 ± 3.1 kJ/mol 60.20331 ± 0.00066 286949-98-2*0 Silylsilylene SiH3SiH (g, triplet) 381.2 372.4 ± 2.7 kJ/mol 60.20276 ± 0.00066 50420-90-1*1 mu-Hydrotrihydrodisilicon SiH2(HSiH) (g) 317.7 307.6 ± 2.2 kJ/mol 60.20276 ± 0.00066 497967-56-3*0 Propylene cation [CH3CHCH2]+ (g) 975.14 961.61 ± 0.18 kJ/mol 42.0792 ± 0.0024 34504-10-4*0 mu-Hydrotrihydrodisilicon cation [Si(HSiH3)]+ (g) 1160.0 1152.0 ± 2.6 kJ/mol 60.20221 ± 0.00066 *497967-55-2*0 Fluorine atom trication [F]+3 (g) 11182.872 11186.697 ± 0.032 kJ/mol 18.99675746 ± 0.00000050 14700-88-0*0 Peroxyhypochlorous acid anion [HOOCl]- (g, trans quartet) -2.8 -3.3 ± 2.6 kJ/mol 68.4600 ± 0.0011 *67952-08-3*1 Silyloxoniumylidene [SiH3O]+ (g, triplet) 1096.3 1090.0 ± 2.9 kJ/mol 47.10817 ± 0.00047 152720-17-7*1 Hydroxysilylium [SiH2OH]+ (g) 600.3 591.6 ± 2.9 kJ/mol 47.10817 ± 0.00047 66639-72-3*0 Oxygen atom octacation [O]+8 (g) 197447.75 197449.60 ± 0.12 kJ/mol 15.99501 ± 0.00030 21450-98-6*0 1,5-Hexadiyne HCCCH2CH2CCH (cr,l) 385.9 ± 1.9 kJ/mol 78.1118 ± 0.0048 628-16-0*500 2-Hydroperoxyethyl CH2CH2OOH (g, anti-anti) 65.0 51.2 ± 2.2 kJ/mol 61.0599 ± 0.0017 126898-97-3*11 Hydroxymethylene HCOH (g) 112.68 108.92 ± 0.27 kJ/mol 30.02598 ± 0.00087 19710-56-6*0 Bicyclo[3.1.0]hexa-1,3-diene CH2((CCH)(CHCHCH)) (g) 406.5 390.9 ± 2.2 kJ/mol 78.1118 ± 0.0048 28425-23-2*0 3-Ethenylidenecyclobutene CH2CC(CHCHCH2) (g) 406.5 392.4 ± 2.3 kJ/mol 78.1118 ± 0.0048 813466-23-8*0 3,4-Hexadien-1-yne HCCCHCCHCH3 (g) 418.6 407.4 ± 2.6 kJ/mol 78.1118 ± 0.0048 194024-51-6*0 3-Ethynylcyclobutene HCCCH(CHCHCH2) (g) 421.7 407.3 ± 2.4 kJ/mol 78.1118 ± 0.0048 175090-90-1*0 Deuterium molecule cation [D2]+ (g) 1492.286 1492.361 ± 0.000 kJ/mol 4.02765497609 ± 0.00000000080 12184-84-8*0 2-Aminoethenylium [CHCHNH2]+ (g, syn triplet) 1117.9 1106.7 ± 2.4 kJ/mol 42.0594 ± 0.0016 64724-21-6*11 Cyclopropane cation [CH2(CH2CH2)]+ (g) 1021.8 1006.3 ± 1.5 kJ/mol 42.0792 ± 0.0024 34496-93-0*0 2-Aminoethylium [CH2CH2NH2]+ (g, triplet) 1042.4 1025.9 ± 2.4 kJ/mol 44.0752 ± 0.0017 54088-54-9*1 2-Aminoethyl anion [CH2CH2NH2]- (g) 148.8 131.7 ± 2.1 kJ/mol 44.0763 ± 0.0017 71857-14-2*0 2-Aminoethenyl anion [CHCHNH2]- (g, syn) 241.9 231.2 ± 2.6 kJ/mol 42.0604 ± 0.0016 *64724-21-6*1 1,2-Diphenylethane C6H5CH2CH2C6H5 (g) 180.76 142.28 ± 0.76 kJ/mol 182.2610 ± 0.0112 103-29-7*0 Iodine monochloride ICl (l) -24.048 ± 0.063 kJ/mol 162.35717 ± 0.00090 7790-99-0*590 Hydroxyoxoammoniumyl [HONO]+ (g, cis) 1014.8 1008.4 ± 2.0 kJ/mol 47.01293 ± 0.00061 80371-48-8*2 2-Naphthalenylium [C6H4(CHCCHCH)]+ (g) 1195.6 1177.7 ± 3.5 kJ/mol 127.1620 ± 0.0080 79319-69-0*0 Nitrous acid anion [HONO]- (g, trans) -105.4 -109.4 ± 1.8 kJ/mol 47.01403 ± 0.00061 256393-36-9*1 1-Naphthalenylium [C6H4(CCHCHCH)]+ (g) 1192.7 1174.7 ± 3.4 kJ/mol 127.1620 ± 0.0080 79319-68-9*0 Ammonia NH3 (aq, 1000 H2O) -80.57 ± 0.41 kJ/mol 17.03056 ± 0.00022 7664-41-7*839 Methylaminyliumyl [CH3N]+ (g, doublet ?) 1388.2 1381.9 ± 2.2 kJ/mol 29.04071 ± 0.00083 56924-51-7*1 Biphenyl C6H5C6H5 (l) 113.7 ± 1.1 kJ/mol 154.2078 ± 0.0096 92-52-4*590 Buckminsterfullerene C60 (g) 2523.3 2518.7 ± 6.4 kJ/mol 720.6420 ± 0.0480 99685-96-8*0 Buckminsterfullerene C60 (cr,l) 2328.2 2337.7 ± 6.4 kJ/mol 720.6420 ± 0.0480 99685-96-8*500 Cyclobutatrienyl CH(CCC) (g) 962.0 965.5 ± 2.4 kJ/mol 49.0507 ± 0.0032 *99417-52-4*0 Helium anion He- (g, 1s.2s.2p 4P) 1904.822 1904.822 ± 0.000 kJ/mol 4.0031506 ± 0.0000020 14452-58-5*3 Helium anion He- (g, 2p3 4S3/2) 5724.96 5724.96 ± 0.32 kJ/mol 4.0031506 ± 0.0000020 14452-58-5*4 Dihelium cation [He2]+ (g) 2143.643 2139.915 ± 0.018 kJ/mol 8.0046554 ± 0.0000040 12184-99-5*0 Dihelium anion [He2]- (g, quartet 4Pig) 1714.9 1711.2 ± 1.9 kJ/mol 8.0057526 ± 0.0000040 90188-47-9*1 Helium dihydride HeHH (g) -0.05 0.87 ± 0.42 kJ/mol 6.01848 ± 0.00014 33309-42-1*0 Helium dihydride HHeH (g) 614.5 608.9 ± 2.6 kJ/mol 6.01848 ± 0.00014 *33309-42-1*0 Dihydrohelium cation [HHeH]+ (g) 1572.2 1568.9 ± 2.4 kJ/mol 6.01793 ± 0.00014 *12500-88-8*0 Neon dication [Ne]+2 (g) 6032.988 6033.214 ± 0.0041 kJ/mol 20.17860 ± 0.00060 14041-55-5*0 Neon trication [Ne]+3 (g) 12152.403 12152.403 ± 0.032 kJ/mol 20.17805 ± 0.00060 14158-25-9*0 Neon tetracation [Ne]+4 (g) 21529.82 21531.45 ± 0.25 kJ/mol 20.17751 ± 0.00060 14041-56-6*0 Neon pentacation [Ne]+5 (g) 33711.1 33711.1 ± 1.2 kJ/mol 20.17696 ± 0.00060 14175-48-5*0 Neon hexacation [Ne]+6 (g) 48949.3 48949.3 ± 1.3 kJ/mol 20.17641 ± 0.00060 14041-57-7*0 Neon heptacation [Ne]+7 (g) 68948.7 68948.7 ± 1.4 kJ/mol 20.17586 ± 0.00060 14175-50-9*0 Neon octacation [Ne]+8 (g) 92018.2 92018.2 ± 1.4 kJ/mol 20.17531 ± 0.00060 14782-26-4*0 Neon nonacation [Ne]+9 (g) 207396.1 207396.1 ± 1.4 kJ/mol 20.17476 ± 0.00060 15721-59-2*0 Formic acid HC(O)OH (aq, undissoc) -425.37 ± 0.45 kJ/mol 46.0254 ± 0.0010 64-18-6*1000 Sulfur atom dication [S]+2 (g) 3528.24 3531.93 ± 0.14 kJ/mol 32.0649 ± 0.0060 14127-58-3*0 Sulfur atom trication [S]+3 (g) 6890.9 6892.9 ± 3.2 kJ/mol 32.0644 ± 0.0060 22541-72-6*0 Sulfur atom tetracation [S]+4 (g) 11447.1 11448.9 ± 3.4 kJ/mol 32.0638 ± 0.0060 20681-10-1*0 Sulfur atom pentacation [S]+5 (g) 18451.4 18453.2 ± 3.4 kJ/mol 32.0633 ± 0.0060 14127-59-4*0 Dioxathiirane S(OO) (g) 166.2 163.8 ± 2.2 kJ/mol 64.0648 ± 0.0060 191663-73-7*0 Sulfur trioxide OS(O)O (cr,l) -454.29 ± 0.37 kJ/mol 80.0642 ± 0.0061 7446-11-9*500 3-Oxidedioxathiirane OS(OO) (g) -127.8 -132.8 ± 2.2 kJ/mol 80.0642 ± 0.0061 2243010-16-2*0 Trioxathietane S(OOO) (g) 263.7 258.6 ± 2.3 kJ/mol 80.0642 ± 0.0061 *2243010-16-2*0 Oxadithiirane O(SS) (g) 136.5 134.4 ± 2.5 kJ/mol 80.1314 ± 0.0120 488092-02-0*0 Sulfanylideneoxidaniumthiolate SOS (g) 220.9 219.1 ± 2.0 kJ/mol 80.1314 ± 0.0120 401811-43-6*0 Sulfuric acid OS(O)(OH)2 (aq, 115 H2O) -887.62 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*893 Sulfuric acid OS(O)(OH)2 (aq) -878.84 -909.08 ± 0.14 kJ/mol 98.0795 ± 0.0061 7664-93-9*800 Sulfuric acid OS(O)(OH)2 (aq, 40 H2O) -886.27 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*821 Chlorodioxidenium [ClOO]+ (g) 1215.1 1212.9 ± 6.3 kJ/mol 67.4510 ± 0.0011 64710-10-7*0 Sulfuric acid OS(O)(OH)2 (aq, 700 H2O) -891.17 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*835 Sulfuric acid OS(O)(OH)2 (aq, 800 H2O) -891.54 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*837 Sulfuric acid OS(O)(OH)2 (aq, 1500 H2O) -893.34 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*840 Sulfuric acid OS(O)(OH)2 (aq, 2000 H2O) -894.29 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*841 Sulfuric acid OS(O)(OH)2 (aq, 3000 H2O) -895.75 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*842 Sulfuric acid OS(O)(OH)2 (aq, 5000 H2O) -897.78 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*844 Sulfuric acid OS(O)(OH)2 (aq, 45 H2O) -886.44 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*906 Sulfuric acid OS(O)(OH)2 (aq, 60 H2O) -886.83 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*823 Sulfuric acid OS(O)(OH)2 (aq, 80 H2O) -887.18 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*826 Sulfuric acid OS(O)(OH)2 (aq, 90 H2O) -887.32 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*827 Sulfuric acid OS(O)(OH)2 (aq, 750 H2O) -891.36 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*836 Sulfuric acid OS(O)(OH)2 (aq, 1250 H2O) -892.79 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*954 Sulfuric acid OS(O)(OH)2 (aq, 6000 H2O) -898.51 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*845 Sulfuric acid OS(O)(OH)2 (aq, 7500 H2O) -899.43 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*847 Sulfuric acid OS(O)(OH)2 (aq, 8000 H2O) -899.69 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*848 Sulfuric acid OS(O)(OH)2 (aq, 9000 H2O) -900.15 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*849 Sulfuric acid monohydrate (OS(O)(OH)2)(H2O) (cr,l) -1126.25 -1127.40 ± 0.14 kJ/mol 116.0948 ± 0.0062 10193-30-3*500 Sulfuric acid dihydrate (OS(O)(OH)2)(H2O)2 (cr,l) -1422.06 -1426.85 ± 0.15 kJ/mol 134.1100 ± 0.0063 13451-10-0*500 Sulfuric acid trihydrate (OS(O)(OH)2)(H2O)3 (cr,l) -1716.00 -1720.12 ± 0.16 kJ/mol 152.1253 ± 0.0064 40835-65-2*500 Sulfuric acid tetrahydrate (OS(O)(OH)2)(H2O)4 (cr,l) -2006.85 -2010.88 ± 0.17 kJ/mol 170.1406 ± 0.0065 37006-20-5*500 Tribromide [Br3]- (aq) -129.18 ± 0.22 kJ/mol 239.7125 ± 0.0030 14522-80-6*800 Carbon hexacation [C]+6 (g) 100101.743 100106.890 ± 0.050 kJ/mol 12.00741 ± 0.00080 16249-02-8*0 Isocyanogen cation [CNCN]+ (g) 1654.1 1656.5 ± 1.4 kJ/mol 52.0343 ± 0.0016 133415-63-1*0 Isocyanic fluoride cation [FNC]+ (g) 1618.1 1618.7 ± 4.0 kJ/mol 45.01529 ± 0.00080 *16992-26-0*0 Hydrogen iodide HI (aq, 1500 H2O) -56.522 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*840 Phosgene cation [CCl2O]+ (g) 897.0 896.0 ± 1.7 kJ/mol 98.9150 ± 0.0020 73249-38-4*0 Phosgene CCl2O (cr, l, I+liquid) -242.79 ± 0.25 kJ/mol 98.9155 ± 0.0020 75-44-5*501 Phosgene CCl2O (cr, l, II+liquid) -255.49 -242.79 ± 0.25 kJ/mol 98.9155 ± 0.0020 75-44-5*502 Hydrogen fluoride HF (aq, 400 H2O) -322.27 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*832 Chloro(chlorooxy)methylene ClCOCl (g) 73.5 73.9 ± 3.6 kJ/mol 98.9155 ± 0.0020 479587-31-0*0 Chloro(chlorooxy)methylene ClCOCl (g, trans) 98. 105. ± 15. kJ/mol 98.9155 ± 0.0020 479587-31-0*1 Acetic acid CH3C(O)OH (aq, 600 H2O) -484.80 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*834 Chlorine pentafluoride cation [FCl(F)(F)(F)F]+ (g) 1005.9 996.9 ± 3.2 kJ/mol 130.44417 ± 0.00090 478167-78-1*0 Hypobromous acid cation [HOBr]+ (g) 975.25 964.63 ± 0.54 kJ/mol 96.9108 ± 0.0010 154804-02-1*0 Propylidene CH3CH2CH (g, triplet anti) 349.7 335.9 ± 2.0 kJ/mol 42.0797 ± 0.0024 6700-78-3*12 Chlorohydroxymethylene ClCOH (g, cis) 14.4 11.5 ± 3.2 kJ/mol 64.4707 ± 0.0012 147723-60-2*2 Chlorohydroxymethylene ClCOH (g) 14.0 11.3 ± 2.5 kJ/mol 64.4707 ± 0.0012 147723-60-2*0 Hydrogen iodide HI (aq, 50000 H2O) -56.764 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*855 (Chlorooxy)methylene HCOCl (g, trans) 155.5 155.3 ± 3.7 kJ/mol 64.4707 ± 0.0012 331419-80-8*1 (Chlorooxy)methylene HCOCl (g) 119.2 117.9 ± 2.7 kJ/mol 64.4707 ± 0.0012 331419-80-8*0 Acetic acid CH3C(O)OH (aq, 700 H2O) -484.80 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*835 Acetic acid CH3C(O)OH (aq, 800 H2O) -484.80 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*837 Chloroformyl anion [ClCO]- (g) -356.5 -352.9 ± 3.3 kJ/mol 63.4633 ± 0.0012 41976-93-6*0 Acetic acid CH3C(O)OH (aq, 900 H2O) -484.81 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*838 Acetic acid CH3C(O)OH (aq, 1000 H2O) -484.81 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*839 Nitrogen atom N (g, doublet) 700.553 702.456 ± 0.023 kJ/mol 14.006740 ± 0.000070 17778-88-0*2 Ethenol CH2CHOH (g) -113.38 -123.72 ± 0.38 kJ/mol 44.0526 ± 0.0017 557-75-5*0 1,3-Butadienylium [CH2CHCHCH]+ (g) 1133.6 1123.6 ± 2.5 kJ/mol 53.0820 ± 0.0032 86181-69-3*0 Hydrogen iodide HI (aq, 400 H2O) -56.321 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*832 Dicarbon monoxide CCO (g) 377.12 381.16 ± 0.83 kJ/mol 40.0208 ± 0.0016 12071-23-7*0 Acetic acid CH3C(O)OH (aq, 2000 H2O) -484.82 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*841 2-Iodoethanol ICH2CH2OH (g) -131.9 -150.1 ± 2.5 kJ/mol 171.9650 ± 0.0017 624-76-0*0 Hydrogen fluoride HF (aq, 800 H2O) -322.58 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*837 Acetic acid CH3C(O)OH (aq, 5000 H2O) -484.70 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*844 Nitrilomethylimidogen NCHN (g) 581.6 578.4 ± 1.5 kJ/mol 41.03212 ± 0.00082 324529-58-0*0 1,3,5-Hexatriyne cation [HCCCCCCH]+ (g) 1600.8 1605.4 ± 2.8 kJ/mol 74.0795 ± 0.0048 61866-06-6*0 Diazenide [NNH]- (g) 175.6 176.7 ± 1.6 kJ/mol 29.02197 ± 0.00016 71004-29-0*0 Iminomethylimidogen anion [NCHN]- (g) 401.9 400.0 ± 2.3 kJ/mol 41.03267 ± 0.00082 150296-30-3*0 Acetic acid CH3C(O)OH (aq, 10000 H2O) -484.84 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*850 Acetic acid CH3C(O)OH (aq, 20000 H2O) -484.85 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*852 1,3,5-Hexatriynylium [CCCCCCH]+ (g, triplet) 1924.3 1933.4 ± 8.4 kJ/mol 73.0716 ± 0.0048 81932-75-4*1 Ethoxyethene CH2CHOCH2CH3 (g, cis-perp) -111.5 -135.4 ± 2.3 kJ/mol 72.1057 ± 0.0033 109-92-2*21 Acetic acid CH3C(O)OH (aq, 50000 H2O) -484.86 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*855 Acetic acid CH3C(O)OH (aq, 100000 H2O) -484.87 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*861 1-Hydroxyethylidene CH3COH (g, singlet) 57.37 47.06 ± 0.77 kJ/mol 44.0526 ± 0.0017 30967-49-8*2 Isocyanic fluoride anion [FNC]- (g) 74.1 75.7 ± 5.7 kJ/mol 45.01639 ± 0.00080 357426-78-9*0 Hydrogen fluoride HF (aq, 7500 H2O) -325.00 ± 0.17 kJ/mol 20.006343 ± 0.000070 7664-39-3*847 Ammonium hydroxide NH4OH (aq, 30 H2O) -366.26 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*820 Oxonium [H3O]+ (g, ortho) 605.95 599.14 ± 0.17 kJ/mol 19.02267 ± 0.00037 13968-08-6*1 Hydrogen fluoride HF (aq, 2000 H2O) -323.40 ± 0.12 kJ/mol 20.006343 ± 0.000070 7664-39-3*841 1-Hydroxyethylidene CH3COH (g) 57.37 47.06 ± 0.77 kJ/mol 44.0526 ± 0.0017 30967-49-8*0 Hydroperoxyimidogen HOON (g, cis) 111.9 109.0 ± 2.8 kJ/mol 47.01348 ± 0.00061 877456-58-1*2 Diiodine cation [I2]+ (g) 963.523 960.408 ± 0.018 kJ/mol 253.808391 ± 0.000060 28712-14-3*0 2-Propenylidene CHCHCH2 (g, triplet) 417.5 410.5 ± 1.5 kJ/mol 40.0639 ± 0.0024 19527-08-3*1 2-Propenylidene CHCHCH2 (g) 417.5 410.5 ± 1.5 kJ/mol 40.0639 ± 0.0024 19527-08-3*0 Ammonium hydroxide NH4OH (aq, 15 H2O) -366.13 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*817 Hydrogen fluoride HF (aq, 20000 H2O) -326.67 ± 0.17 kJ/mol 20.006343 ± 0.000070 7664-39-3*852 2-Propenylidene CHCHCH2 (g, triplet syn) 419.1 411.5 ± 2.3 kJ/mol 40.0639 ± 0.0024 19527-08-3*12 Ethoxyethene CH2CHOCH2CH3 (g, trans-trans) -111.0 -133.2 ± 2.6 kJ/mol 72.1057 ± 0.0033 109-92-2*1 Hydrogen fluoride HF (aq, 300 H2O) -322.18 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*831 1,1-Ethenediol CH2C(OH)2 (g) -307.65 -320.19 ± 0.83 kJ/mol 60.0520 ± 0.0017 10375-04-9*0 COC vdW (CO)(C) (g) 589.7 598.4 ± 1.5 kJ/mol 40.0208 ± 0.0016 *12071-24-8*0 Methylaminyliumyl [CH3N]+ (g ?) 1388.2 1381.9 ± 2.2 kJ/mol 29.04071 ± 0.00083 56924-51-7*0 1,1-Ethenediol CH2C(OH)2 (g, syn-syn C2v) -302.4 -315.8 ± 1.9 kJ/mol 60.0520 ± 0.0017 10375-04-9*2 Hydrogen iodide HI (aq, 2000 H2O) -56.555 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*841 1,1-Ethenediol CH2C(OH)2 (g, gauche-gauche C2) -296.1 -309.3 ± 1.9 kJ/mol 60.0520 ± 0.0017 10375-04-9*3 Glycolaldehyde HC(O)CH2OH (g) -304.43 -317.47 ± 0.89 kJ/mol 60.0520 ± 0.0017 141-46-8*0 Isocyanic acid anion [HNCO]- (g) -54.2 -57.4 ± 3.0 kJ/mol 43.02533 ± 0.00086 *444010-28-0*0 Formic acid HC(O)OH (aq, 600 H2O) -425.35 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*834 Formic acid HC(O)OH (aq, 700 H2O) -425.35 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*835 Formic acid HC(O)OH (aq, 800 H2O) -425.35 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*837 O--HH Complex (H2)(O) (g, vdW C2v ?) 247.2 248.2 ± 2.0 kJ/mol 18.01528 ± 0.00033 *7732-18-5*102 Acetylide [C2]-2 (g) 843.0 849.5 ± 3.2 kJ/mol 24.0225 ± 0.0016 34846-56-5*0 Formic acid HC(O)OH (aq, 900 H2O) -425.35 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*838 1H-Diazirin-3-ylium [HN(NC)]+ (g) 1527.2 1523.7 ± 2.0 kJ/mol 41.03157 ± 0.00082 735234-64-7*0 1H-diazirin-3-ide [HN(NC)]- (g) 379.8 376.6 ± 2.0 kJ/mol 41.03267 ± 0.00082 *735234-64-7*0 Cyclopentadienide [CH(CHCHCHCH)]- (g) 100.8 87.9 ± 1.1 kJ/mol 65.0937 ± 0.0040 12127-83-2*0 Formic acid HC(O)OH (aq, 1000 H2O) -425.36 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*839 Hydrogen fluoride HF (aq, 700 H2O) -322.51 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*835 Propylidene CH3CH2CH (g, singlet TS) 355.7 340.7 ± 2.0 kJ/mol 42.0797 ± 0.0024 6700-78-3*2 Formic acid HC(O)OH (aq, 2000 H2O) -425.36 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*841 trans-Cycloheptene CH2(CHCHCH2CH2CH2CH2) (g) 141.9 103.9 ± 1.9 kJ/mol 96.1702 ± 0.0057 45509-99-7*0 Oxide [O]-2 (g) 651. 653. ± 15. kJ/mol 16.00050 ± 0.00030 16833-27-5*0 Perchloric acid cation [HOCl(O)(O)O]+ (g) 1190.2 1180.6 ± 3.3 kJ/mol 100.4577 ± 0.0015 91712-47-9*0 Formic acid HC(O)OH (aq, 5000 H2O) -425.37 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*844 Cyanogen chloride cation [ClCN]+ (g) 1326.21 1327.54 ± 0.95 kJ/mol 61.4696 ± 0.0012 37612-72-9*0 Cyanic acid cation [HOCN]+ (g) 1135.7 1133.2 ± 2.9 kJ/mol 43.02423 ± 0.00086 59780-31-3*0 Propylidene CH3CH2CH (g, singlet TS syn) 362.8 347.4 ± 2.8 kJ/mol 42.0797 ± 0.0024 6700-78-3*22 Cyanogen chloride anion [ClCN]- (g) 46.8 51.2 ± 3.1 kJ/mol 61.4707 ± 0.0012 12281-43-5*0 Hydrogen iodide HI (aq, 500 H2O) -56.358 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*833 Hydrobromate ion [HBr]- (g) -5.5 -12.0 ± 4.3 kJ/mol 80.9125 ± 0.0010 85532-97-4*0 Carbon dianion [C]-2 (g) 1027.5 1033.0 ± 4.9 kJ/mol 12.01180 ± 0.00080 50802-47-6*0 Hydrogen chloride HCl (aq, 10 H2O) -161.148 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*815 C=O-C cation [COC]+ (g) 1585.8 1592.9 ± 2.7 kJ/mol 40.0203 ± 0.0016 83483-98-1*0 Hydrogen bromide HBr (aq, 500 H2O) -119.98 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*833 Formic acid HC(O)OH (aq, 10000 H2O) -425.37 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*850 Methoxymethylene CH3OCH (g, singlet) 129.15 118.64 ± 0.78 kJ/mol 44.0526 ± 0.0017 19527-10-7*2 Methanediimine cation [HNCNH]+ (g) 1137.8 1135.6 ± 2.2 kJ/mol 42.03951 ± 0.00082 1189338-16-6*0 Oxirane O(CH2CH2) (cr,l) -77.27 -77.94 ± 0.62 kJ/mol 44.0526 ± 0.0017 75-21-8*500 Methanediimine cation [HNCNH]+ (g, trans) 1139.0 1136.2 ± 3.2 kJ/mol 42.03951 ± 0.00082 1189338-16-6*1 Hydrogen iodide HI (aq, 100 H2O) -56.045 ± 0.097 kJ/mol 127.912410 ± 0.000076 10034-85-2*828 Peroxyformyl HC(O)OO (g) -100.43 -105.53 ± 0.67 kJ/mol 61.0168 ± 0.0012 56240-83-6*0 Phenol cation [C6H5OH]+ (g) 746.17 727.37 ± 0.64 kJ/mol 94.1107 ± 0.0048 40932-22-7*0 Phenol anion [C6H5OH]- (g) 22.8 7.8 ± 4.9 kJ/mol 94.1118 ± 0.0048 38752-11-3*0 Hydrogen chloride HCl (aq, 500 H2O) -166.403 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*833 Ammonium hydroxide NH4OH (aq, 3000 H2O) -366.34 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*842 Hydrogen fluoride HF (aq, 50000 H2O) -328.59 ± 0.17 kJ/mol 20.006343 ± 0.000070 7664-39-3*855 Peroxyformate [HC(O)OO]- (g) -340.95 -346.40 ± 0.80 kJ/mol 61.0174 ± 0.0012 104960-05-6*0 1-Methoxyethenol CH2C(OH)OCH3 (g) -284.3 -302.8 ± 1.2 kJ/mol 74.0785 ± 0.0025 4453-91-2*0 Hydrogen chloride HCl (aq, 12 H2O) -162.010 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*816 Benzaldehyde cation [C6H5C(O)H]+ (g) 896.4 879.7 ± 1.8 kJ/mol 106.1214 ± 0.0056 80226-59-1*0 Benzaldehyde anion [C6H5C(O)H]- (g) -55.6 -73.3 ± 2.7 kJ/mol 106.1225 ± 0.0056 34473-57-9*0 2-Hydroxyethyl CH2CH2OH (g) -13.01 -26.28 ± 0.49 kJ/mol 45.0605 ± 0.0017 4422-54-2*0 Oxirene O(CHCH) (g) 273.17 271.01 ± 0.92 kJ/mol 42.0367 ± 0.0016 157-18-6*0 Oxirene O(CHCH) (g, triplet) 387.9 384.5 ± 1.3 kJ/mol 42.0367 ± 0.0016 157-18-6*1 Benzoyl anion [C6H5CO]- (g) 69.6 57.0 ± 4.0 kJ/mol 105.1145 ± 0.0056 78944-74-8*0 Hydrogen iodide HI (aq, 2500 H2O) -56.580 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*898 Trihydrogen H(HH) (g, TS) 477.4 474.7 ± 2.3 kJ/mol 3.02382 ± 0.00021 12184-91-7*201 Hypochloroperoxoous acid, hydroxy ester HOOOCl (g) 48.4 41.6 ± 1.8 kJ/mol 84.4588 ± 0.0013 928652-99-7*0 Isocyanogen chloride cation [ClNC]+ (g) 1481.0 1482.2 ± 3.9 kJ/mol 61.4696 ± 0.0012 956475-91-5*0 Hydrogen chloride HCl (aq, 15 H2O) -162.855 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*817 Methoxymethylene CH3OCH (g) 129.15 118.64 ± 0.78 kJ/mol 44.0526 ± 0.0017 19527-10-7*0 Tetraoxidanyl HOOOO (g, trans) 76.7 69.5 ± 6.1 kJ/mol 65.0055 ± 0.0012 69696-93-1*1 Hydrogen bromide HBr (aq, 2640 H2O) -120.25 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*957 Hydrogen bromide HBr (aq, 300 H2O) -119.87 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*831 Hydrogen fluoride HF (aq, 18.5 H2O) -321.83 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*887 Formic acid HC(O)OH (aq, 20000 H2O) -425.38 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*852 m-Tolualdehyde CH3C6H4C(O)H (cr, l, meta) -125.6 ± 1.3 kJ/mol 120.1485 ± 0.0064 620-23-5*500 Imidogen NH (g, singlet) 509.34 509.39 ± 0.17 kJ/mol 15.014680 ± 0.000099 13774-92-0*2 Hydrogen chloride HCl (aq, 20000 H2O) -166.885 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*852 Hydrogen iodide HI (aq, 600 H2O) -56.392 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*834 Hydrogen bromide HBr (aq, 1 H2O) -71.67 ± 0.13 kJ/mol 80.9119 ± 0.0010 10035-10-6*801 Isocyanogen chloride anion [ClNC]- (g) 102.9 107.4 ± 3.9 kJ/mol 61.4707 ± 0.0012 923019-39-0*0 Hydrogen fluoride HF (aq, 100000 H2O) -330.14 ± 0.17 kJ/mol 20.006343 ± 0.000070 7664-39-3*861 Hydrogen fluoride HF (aq, 3000 H2O) -323.84 ± 0.12 kJ/mol 20.006343 ± 0.000070 7664-39-3*842 Ethynol cation [HCCOH]+ (g) 1063.8 1061.2 ± 2.9 kJ/mol 42.0361 ± 0.0016 84005-02-7*0 Hydrogen peroxide cation [HOOH]+ (g) 897.29 890.31 ± 0.51 kJ/mol 34.01413 ± 0.00062 12325-10-9*0 Ethynol anion [HCCOH]- (g) 163.5 165.0 ± 3.3 kJ/mol 42.0372 ± 0.0016 864971-50-6*0 Cyanic acid anion [HOCN]- (g) -9.2 -9.6 ± 3.1 kJ/mol 43.02533 ± 0.00086 58199-47-6*0 Hexafluorobenzene cation [C6F6]+ (g) 13.67 9.88 ± 0.87 kJ/mol 186.0541 ± 0.0048 34528-23-9*0 1-Hydroxy-2-propanone CH3C(O)CH2OH (g) -354.54 -373.87 ± 0.84 kJ/mol 74.0785 ± 0.0025 116-09-6*0 Hydrogen iodide HI (aq, 200 H2O) -56.195 ± 0.097 kJ/mol 127.912410 ± 0.000076 10034-85-2*830 Formic acid HC(O)OH (aq, 50000 H2O) -425.39 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*855 Formic acid HC(O)OH (aq, 100000 H2O) -425.42 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*861 Nitric acid HON(O)O (aq, 2000 H2O) -206.29 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*841 Trioxodinitrate anion [ONN(O)O]- (g) -104.2 -107.5 ± 1.9 kJ/mol 76.01223 ± 0.00091 194856-62-7*0 Formic acid HC(O)OH (aq, 20 H2O) -425.19 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*818 Trihydrogen H(HH) (g, Ry) 745.878 743.199 ± 0.062 kJ/mol 3.02382 ± 0.00021 12184-91-7*0 Hydrogen iodide HI (aq, 50 H2O) -55.806 ± 0.096 kJ/mol 127.912410 ± 0.000076 10034-85-2*822 Cyanogen bromide cation [BrCN]+ (g) 1331.3 1325.0 ± 1.4 kJ/mol 105.9209 ± 0.0013 34749-77-4*0 Hydrodioxonitrogen cation [HN(O)O]+ (g) 1130.0 1123.4 ± 3.0 kJ/mol 47.01293 ± 0.00061 252986-76-8*0 Dioxyamidogen HNOO (g, trans) 251.2 244.6 ± 2.5 kJ/mol 47.01348 ± 0.00061 71843-95-3*1 3-Diaziridinylidene C(NHNH) (g) 521.8 515.0 ± 1.5 kJ/mol 42.04006 ± 0.00082 85513-79-7*0 2-Propene-1,2-diol CH2C(OH)CH2OH (g) -295.5 -314.5 ± 1.2 kJ/mol 74.0785 ± 0.0025 44169-27-9*0 Ethynol HCCOH (g, t-c triplet) 406.4 403.2 ± 3.2 kJ/mol 42.0367 ± 0.0016 32038-79-2*12 Ethynol HCCOH (g, t-t triplet) 409.4 406.3 ± 3.2 kJ/mol 42.0367 ± 0.0016 32038-79-2*13 Trihydrogen cation [H3]+ (g, ortho) 1110.577 1106.695 ± 0.013 kJ/mol 3.02327 ± 0.00021 28132-48-1*1 Hydrogen bromide HBr (aq, 800 H2O) -120.07 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*837 Isocyanogen bromide cation [BrNC]+ (g) 1470.0 1464.2 ± 5.9 kJ/mol 105.9209 ± 0.0013 238754-53-5*0 Ethynol HCCOH (g, c-t triplet) 455.5 452.2 ± 3.2 kJ/mol 42.0367 ± 0.0016 32038-79-2*14 Ethynol HCCOH (g, c-c triplet) 464.2 460.9 ± 3.2 kJ/mol 42.0367 ± 0.0016 32038-79-2*15 Hydrogen fluoride HF (aq, 4000 H2O) -324.15 ± 0.14 kJ/mol 20.006343 ± 0.000070 7664-39-3*843 Carbonylmethyloxonium [CH3OCO]+ (g) 561.2 552.9 ± 3.0 kJ/mol 59.0435 ± 0.0017 24434-00-2*0 2-Cyclopropyn-1-ylidene C(CC) (g) 898.4 905.3 ± 1.5 kJ/mol 36.0321 ± 0.0024 102508-15-6*0 Pyridiniumyl [N(CHCHCHCHCH)]+ (g) 1051.33 1035.38 ± 0.61 kJ/mol 79.0994 ± 0.0040 16399-94-3*0 Pyridine anion [N(CHCHCHCHCH)]- (g) 214.4 200.9 ± 3.2 kJ/mol 79.1005 ± 0.0040 12169-63-0*0 1,2-Propadien-1-yl-3-ylidene anion [CCC]- (g, lin) 621.7 629.1 ± 1.3 kJ/mol 36.0326 ± 0.0024 109292-47-9*1 Hydrogen bromide HBr (aq, 1500 H2O) -120.17 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*840 Methoxyoxomethyl CH3OCO (g) -152.8 -160.5 ± 1.2 kJ/mol 59.0440 ± 0.0017 16481-04-2*0 3-Diaziridinylidene C(NHNH) (g, syn) 537.0 530.3 ± 2.0 kJ/mol 42.04006 ± 0.00082 85513-79-7*2 Acetone enol CH3C(OH)CH2 (g) -151.34 -168.15 ± 0.68 kJ/mol 58.0791 ± 0.0025 29456-04-0*0 Acetone enol CH3C(OH)CH2 (g, anti) -145.3 -162.6 ± 1.9 kJ/mol 58.0791 ± 0.0025 29456-04-0*2 Hydrogen chloride HCl (aq, 50000 H2O) -166.922 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*855 3-Diaziridinylidene cation [C(NHNH)]+ (g) 1479.7 1473.7 ± 2.4 kJ/mol 42.03951 ± 0.00082 *85513-79-7*0 3-Diaziridinylidene cation [C(NHNH)]+ (g, syn) 1497.2 1491.7 ± 3.1 kJ/mol 42.03951 ± 0.00082 *85513-79-7*2 Hydrogen bromide HBr (aq, 2 H2O) -92.67 ± 0.13 kJ/mol 80.9119 ± 0.0010 10035-10-6*803 1-Propen-2-ol-1-yl CH3C(OH)CH (g) 101.58 90.22 ± 0.87 kJ/mol 57.0712 ± 0.0024 1976041-84-5*0 1-Propen-2-ol-1-yl CH3C(OH)CH (g, cis-cis) 106.5 94.5 ± 1.9 kJ/mol 57.0712 ± 0.0024 1976041-84-5*12 1-Propen-2-ol-1-yl CH3C(OH)CH (g, trans-trans) 114.0 102.8 ± 1.9 kJ/mol 57.0712 ± 0.0024 1976041-84-5*21 1-Propen-2-ol-1-yl CH3C(OH)CH (g, cis-trans) 115.1 104.3 ± 1.9 kJ/mol 57.0712 ± 0.0024 1976041-84-5*22 Hydrogen iodide HI (aq, 111 H2O) -56.074 ± 0.096 kJ/mol 127.912410 ± 0.000076 10034-85-2*892 Methoxyoxomethyl CH3OCO (g, anti-eclipsed) -151.9 -160.0 ± 2.1 kJ/mol 59.0440 ± 0.0017 16481-04-2*3 Ammonium hydroxide NH4OH (aq, 40 H2O) -366.31 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*821 Hydrogen chloride HCl (aq, 555.1 H2O) -166.430 ± 0.024 kJ/mol 36.46064 ± 0.00090 7647-01-0*895 1-Methylethylidene CH3CCH3 (g) 316.00 303.10 ± 0.97 kJ/mol 42.0797 ± 0.0024 40852-89-9*0 Nitric acid HON(O)O (aq, 10000 H2O) -206.41 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*850 Acetyloxoniumylidene [CH3C(O)O]+ (g, triplet) 892.3 883.8 ± 2.9 kJ/mol 59.0435 ± 0.0017 67057-47-0*1 Water dimer cation [(H2O)2]+ (g) 556.9 546.4 ± 3.0 kJ/mol 36.03001 ± 0.00066 158061-35-9*0 Hydrogen fluoride HF (aq, 75 H2O) -322.00 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*825 Oxiranylidene CH2(CO) (g) 213.5 209.2 ± 1.4 kJ/mol 42.0367 ± 0.0016 50983-85-2*0 Methyl nitrite CH3ONO (g, trans) -52.41 -64.37 ± 0.89 kJ/mol 61.0401 ± 0.0010 624-91-9*1 Methyl nitrite CH3ONO (cr,l) -88.76 ± 0.55 kJ/mol 61.0401 ± 0.0010 624-91-9*500 Dichlorine cation [Cl2]+ (g) 1108.307 1108.286 ± 0.0062 kJ/mol 70.9049 ± 0.0018 12595-90-3*0 Hydrogen chloride HCl (aq, 400 H2O) -166.336 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*832 Ethyl nitrite CH3CH2ONO (g, gauche-trans) -80.2 -98.4 ± 1.9 kJ/mol 75.0666 ± 0.0017 109-95-5*2 Ethyl nitrite CH3CH2ONO (g, gauche-cis) -78.1 -97.1 ± 1.9 kJ/mol 75.0666 ± 0.0017 109-95-5*3 Hydrogen bromide HBr (aq, 3 H2O) -102.21 ± 0.13 kJ/mol 80.9119 ± 0.0010 10035-10-6*805 Propyl nitrite CH3CH2CH2ONO (g) -95.9 -119.7 ± 1.8 kJ/mol 89.0932 ± 0.0025 543-67-9*0 Propyl nitrite CH3CH2CH2ONO (g, trans-trans-cis) -95.5 -120.2 ± 2.5 kJ/mol 89.0932 ± 0.0025 543-67-9*2 Propyl nitrite CH3CH2CH2ONO (g, gauche-gauche-trans) -95.7 -120.2 ± 2.5 kJ/mol 89.0932 ± 0.0025 543-67-9*3 Propyl nitrite CH3CH2CH2ONO (g, gauche-gauche-trans II) -94.9 -119.5 ± 2.5 kJ/mol 89.0932 ± 0.0025 543-67-9*4 Propyl nitrite CH3CH2CH2ONO (g, trans-gauche-trans) -94.8 -119.1 ± 2.5 kJ/mol 89.0932 ± 0.0025 543-67-9*5 Propyl nitrite CH3CH2CH2ONO (g, trans-gauche-cis) -93.0 -117.9 ± 2.5 kJ/mol 89.0932 ± 0.0025 543-67-9*6 Propyl nitrite CH3CH2CH2ONO (g, gauche-gauche-cis) -92.7 -117.8 ± 2.5 kJ/mol 89.0932 ± 0.0025 543-67-9*7 Propyl nitrite CH3CH2CH2ONO (g, gauche-gauche-cis II) -91.3 -116.2 ± 2.8 kJ/mol 89.0932 ± 0.0025 543-67-9*8 1,2-Dibromoethene CHBrCHBr (g) 121.3 101.1 ± 2.0 kJ/mol 185.8453 ± 0.0026 540-49-8*0 Nitric acid HON(O)O (aq, 15 H2O) -205.69 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*817 Peroxychlorous acid HOOClO (g, perp ?) 101.5 95.4 ± 3.6 kJ/mol 84.4588 ± 0.0013 177778-92-6*3 Diatomic bromine cation [Br2]+ (g) 1060.34 1045.39 ± 0.23 kJ/mol 159.8075 ± 0.0020 12595-71-0*0 Iminomethyl HCNH (g) 275.79 272.19 ± 0.56 kJ/mol 28.03332 ± 0.00082 15691-95-9*0 2,2,4-Trimethylpentane (CH3)2CHCH2C(CH3)3 (g) -171.0 -223.5 ± 1.5 kJ/mol 114.2285 ± 0.0065 540-84-1*0 Propylidene CH3CH2CH (g) 349.47 335.79 ± 0.92 kJ/mol 42.0797 ± 0.0024 6700-78-3*0 (Iminomethyl)imidogen HNCHN (g) 420.1 413.2 ± 2.9 kJ/mol 42.04006 ± 0.00082 87570-07-8*0 1,3-Propanediyl CH2CH2CH2 (g) 319.2 307.8 ± 1.3 kJ/mol 42.0797 ± 0.0024 32458-33-6*0 (Iminomethyl)imidogen HNCHN (g, syn-triplet) 430.4 423.5 ± 3.3 kJ/mol 42.04006 ± 0.00082 87570-07-8*12 Acetate [CH3C(O)O]- (aq) -485.10 ± 0.27 kJ/mol 59.0446 ± 0.0017 71-50-1*800 Dinitrogen tetraoxide O2NNO2 (cr,l) -37.84 -26.99 ± 0.19 kJ/mol 92.0111 ± 0.0012 10544-72-6*500 Cyanogen iodide cation [ICN]+ (g) 1271.3 1271.1 ± 1.7 kJ/mol 152.92136 ± 0.00080 34749-78-5*0 Hydrogen chloride HCl (aq, 150 H2O) -165.977 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*829 Hydrogen bromide HBr (aq, 2000 H2O) -120.21 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*841 Isofulminic acid cation [HONC]+ (g) 1376.9 1374.9 ± 2.9 kJ/mol 43.02423 ± 0.00086 117800-60-9*0 (Formyloxy)methyl HC(O)OCH2 (g) -151.4 -159.5 ± 1.1 kJ/mol 59.0440 ± 0.0017 3122-12-1*0 Diisocyanogen cation [CNNC]+ (g) 1825.3 1828.5 ± 3.2 kJ/mol 52.0343 ± 0.0016 *78800-21-2*0 Formylimidogen HC(O)N (g, triplet) 245.2 242.1 ± 4.6 kJ/mol 43.02478 ± 0.00086 42288-92-6*1 Carboxymethyl CH2C(O)OH (g) -226.7 -236.5 ± 1.1 kJ/mol 59.0440 ± 0.0017 2887-46-9*0 1,1-Dibromoethane CH3CHBr2 (cr,l) -67.1 ± 1.3 kJ/mol 187.8612 ± 0.0026 557-91-5*500 Oxoiodonium [IO]+ (g) 1066.1 1064.1 ± 1.9 kJ/mol 142.90332 ± 0.00030 81182-81-2*0 Hydrazine anion [NH2NH2]- (g) 232.3 217.9 ± 4.1 kJ/mol 32.04579 ± 0.00031 65391-88-0*0 Trihydrogen HHH (g, TS) 254.5 250.7 ± 1.2 kJ/mol 3.02382 ± 0.00021 12184-91-7*200 2-Methoxy-2-oxoethyl CH2C(O)OCH3 (g) -203.0 -218.2 ± 1.5 kJ/mol 73.0706 ± 0.0025 54668-31-4*0 3-Buten-2-one CH3C(O)CHCH2 (g) -95.39 -110.93 ± 0.85 kJ/mol 70.0898 ± 0.0032 78-94-4*0 Hydrogen chloride HCl (aq, 100000 H2O) -166.947 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*861 3-Buten-2-one CH3C(O)CHCH2 (g, cis) -93.8 -109.9 ± 1.6 kJ/mol 70.0898 ± 0.0032 78-94-4*2 Hydrogen fluoride HF (aq, 5000 H2O) -324.44 ± 0.14 kJ/mol 20.006343 ± 0.000070 7664-39-3*844 1,3-Butadien-2-ol CH2C(OH)CHCH2 (g, s-trans, anti) -48.1 -64.3 ± 2.3 kJ/mol 70.0898 ± 0.0032 59120-04-6*12 Cyanoamidogen HNCN (g) 322.70 320.21 ± 0.63 kJ/mol 41.03212 ± 0.00082 12347-01-2*0 1,3-Butadien-2-ol CH2C(OH)CHCH2 (g, s-cis, anti) -37.9 -54.3 ± 2.3 kJ/mol 70.0898 ± 0.0032 59120-04-6*22 Cyclopropane CH2(CH2CH2) (l) 41.49 35.80 ± 0.47 kJ/mol 42.0797 ± 0.0024 75-19-4*500 1,3-Butadien-2-ol CH2C(OH)CHCH2 (g, s-cis) -42.7 -58.7 ± 2.3 kJ/mol 70.0898 ± 0.0032 59120-04-6*2 1,3-Butadien-2-ol CH2C(OH)CHCH2 (g) -53.4 -68.3 ± 1.5 kJ/mol 70.0898 ± 0.0032 59120-04-6*0 Iminomethide [HCNH]- (g) 237.3 233.6 ± 1.8 kJ/mol 28.03387 ± 0.00082 90623-30-6*0 Water H2O (cr, l, eq.press.) -286.272 -285.799 ± 0.022 kJ/mol 18.01528 ± 0.00033 7732-18-5*499 Hydrogen fluoride HF (aq, 100 H2O) -322.02 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*828 Chlorine trifluoride anion [FCl(F)F]- (g) -480.4 -481.9 ± 3.5 kJ/mol 92.44846 ± 0.00090 184289-50-7*0 (Acetyloxy)methyl CH3C(O)OCH2 (g) -200.2 -213.9 ± 1.5 kJ/mol 73.0706 ± 0.0025 2887-49-2*0 Carbonate [OC(O)O]-2 (aq) -675.158 ± 0.053 kJ/mol 60.0100 ± 0.0012 3812-32-6*800 Carbon C (g, quintuplet) 1114.952 1120.099 ± 0.040 kJ/mol 12.01070 ± 0.00080 7440-44-0*3 Acrolein cation [CH2CHCHO]+ (g) 919.96 910.00 ± 0.79 kJ/mol 56.0627 ± 0.0024 84005-05-0*0 Acrolein cation [CH2CHCHO]+ (g, cis) 930.8 920.9 ± 1.9 kJ/mol 56.0627 ± 0.0024 84005-05-0*2 Acrolein anion [CH2CHCHO]- (g) -71.8 -81.3 ± 3.1 kJ/mol 56.0638 ± 0.0024 23555-87-5*0 Acrolein anion [CH2CHCHO]- (g, trans) -68.0 -78.0 ± 3.5 kJ/mol 56.0638 ± 0.0024 23555-87-5*1 Hydrogen bromide HBr (aq, 20000 H2O) -120.40 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*852 Cyanoamidogen HNCN (g, quartet) 652.4 650.3 ± 1.2 kJ/mol 41.03212 ± 0.00082 12347-01-2*2 Oxoethylidene HCC(O)H (g) 261.1 258.3 ± 1.1 kJ/mol 42.0367 ± 0.0016 39920-84-8*0 Bicyclo[1.1.0]buta-1,3-diene-2,4-diyl C(CC)C (g, triplet) 1133.1 1140.9 ± 2.7 kJ/mol 48.0428 ± 0.0032 12184-80-4*1 Propyn-1-ol cation [CH3CCOH]+ (g) 959.9 951.7 ± 3.0 kJ/mol 56.0627 ± 0.0024 84005-04-9*0 Formic acid HC(O)OH (aq, 400 H2O) -425.34 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*832 2-Methyloxirene CH3C(CHO) (g, triplet) 344.1 334.8 ± 1.8 kJ/mol 56.0633 ± 0.0024 2835-41-8*1 2-Methyloxirene CH3C(CHO) (g, c-triplet) 346.7 336.8 ± 2.5 kJ/mol 56.0633 ± 0.0024 2835-41-8*12 Oxooxoniumylmethoxy [OC(O)O]+ (g) 1178.0 1177.3 ± 5.7 kJ/mol 60.0084 ± 0.0012 952586-28-6*0 Formic acid HC(O)OH (aq, 25 H2O) -425.20 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*819 Trichlorine cation [Cl3]+ (g) 1056.6 1055.5 ± 1.4 kJ/mol 106.3576 ± 0.0027 33088-85-6*0 Nitrosodioxaziridine ONN(OO) (g, gauche) 415.3 409.5 ± 2.8 kJ/mol 76.01168 ± 0.00091 132871-99-9*3 Difluorodioxidanium [FOOF]+ (g) 1283.7 1280.1 ± 2.3 kJ/mol 69.99506 ± 0.00060 *7783-44-0*0 Acryloyl CH2CHCO (g) 101.1 96.3 ± 1.4 kJ/mol 55.0553 ± 0.0024 72241-20-4*0 Acryloyl CH2CHCO (g, 2A') 101.1 95.9 ± 1.4 kJ/mol 55.0553 ± 0.0024 72241-20-4*1 Acryloyl CH2CHCO (g, 2A', cis, TS?) 109.5 103.8 ± 5.7 kJ/mol 55.0553 ± 0.0024 72241-20-4*12 1-Oxo-2-propenylium [CH2CHCO]+ (g) 772.8 765.9 ± 3.0 kJ/mol 55.0548 ± 0.0024 35335-83-2*0 1-Oxo-2-propenylium [CH2CHCO]+ (g, triplet) 1036.1 1030.7 ± 3.9 kJ/mol 55.0548 ± 0.0024 35335-83-2*1 1-Oxo-2-propenide [CH2CHCO]- (g) 50.7 46.0 ± 2.6 kJ/mol 55.0559 ± 0.0024 78944-75-9*0 Hydrogen bromide HBr (aq, 5 H2O) -110.69 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*809 2-Oxo-1-ethylium-1-yl [HCC(O)H]+ (g, quartet) 1289.4 1286.7 ± 2.5 kJ/mol 42.0361 ± 0.0016 214464-96-7*1 Nitrosyl nitrite anion [ONONO]- (g) -103.0 -106.1 ± 2.8 kJ/mol 76.01223 ± 0.00091 *122413-35-8*0 1-Formylethenylium [CH2CCHO]+ (g) 1023.5 1018.0 ± 2.3 kJ/mol 55.0548 ± 0.0024 101705-89-9*0 Oxoethylidene anion [HCC(O)H]- (g) 86.9 84.2 ± 2.1 kJ/mol 42.0372 ± 0.0016 106543-38-8*0 1,2,4-Trioxolane O(CH2OOCH2) (g) -209.7 -227.9 ± 3.1 kJ/mol 76.0514 ± 0.0019 289-14-5*0 Dichloromethylene CCl2 (g) 229.86 231.04 ± 0.64 kJ/mol 82.9161 ± 0.0020 1605-72-7*0 3-Oxo-1-propenyl CHCHCHO (g) 190.93 185.39 ± 0.91 kJ/mol 55.0553 ± 0.0024 206255-29-0*0 Cyanoaminylium [HNCN]+ (g) 1363.1 1360.8 ± 1.3 kJ/mol 41.03157 ± 0.00082 205443-18-1*0 3-Oxo-1-propenyl CHCHCHO (g, cis) 191.7 185.9 ± 2.1 kJ/mol 55.0553 ± 0.0024 206255-29-0*2 Ethoxyethene CH2CHOCH2CH3 (g, trans-perp) -108.9 -132.1 ± 2.3 kJ/mol 72.1057 ± 0.0033 109-92-2*11 3-Oxo-1-propenyl CHCHCHO (g, syn-cis) 201.3 195.5 ± 2.0 kJ/mol 55.0553 ± 0.0024 206255-29-0*22 3-Oxo-1-propenyl CHCHCHO (g, syn-trans) 206.0 200.2 ± 2.0 kJ/mol 55.0553 ± 0.0024 206255-29-0*12 3-Oxo-1-propenylium [CHCHCHO]+ (g) 1005.1 1002.8 ± 2.4 kJ/mol 55.0548 ± 0.0024 101705-90-2*0 3-Oxo-1-propenylium [CHCHCHO]+ (g, triplet) 1185.6 1179.9 ± 3.0 kJ/mol 55.0548 ± 0.0024 101705-90-2*1 Hydrogen iodide HI (aq, 900 H2O) -56.450 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*838 3-Oxo-1-propenylium [CHCHCHO]+ (g, trans-triplet) 1185.6 1179.8 ± 3.0 kJ/mol 55.0548 ± 0.0024 101705-90-2*11 3-Oxo-1-propenylium [CHCHCHO]+ (g, cis-triplet) 1197.7 1192.4 ± 3.4 kJ/mol 55.0548 ± 0.0024 101705-90-2*12 Ozone OOO (aq, undissoc) 118.20 ± 0.75 kJ/mol 47.99820 ± 0.00090 10028-15-6*1000 3-Oxo-1-propenylium [CHCHCHO]+ (g, syn-trans-triplet) 1195.7 1189.8 ± 3.4 kJ/mol 55.0548 ± 0.0024 101705-90-2*112 3-Oxo-1-propenylium [CHCHCHO]+ (g, syn-cis-triplet) 1205.7 1200.2 ± 3.8 kJ/mol 55.0548 ± 0.0024 101705-90-2*122 2-Formylethen-1-ide [CHCHCHO]- (g) 27.3 21.3 ± 2.5 kJ/mol 55.0559 ± 0.0024 135924-69-5*0 2-Formylethen-1-ide [CHCHCHO]- (g, trans) 27.3 20.5 ± 2.5 kJ/mol 55.0559 ± 0.0024 135924-69-5*1 2-Formylethen-1-ide [CHCHCHO]- (g, cis) 30.5 23.7 ± 3.1 kJ/mol 55.0559 ± 0.0024 135924-69-5*2 Dioxohydrazine ONNO (g, trans) 192.3 188.7 ± 1.8 kJ/mol 60.01228 ± 0.00062 16824-89-8*1 2-Formylethen-1-ide [CHCHCHO]- (g, syn-cis) 54.6 47.9 ± 3.1 kJ/mol 55.0559 ± 0.0024 135924-69-5*22 2-Formylethen-1-ide [CHCHCHO]- (g, syn-trans) 65.0 58.4 ± 3.1 kJ/mol 55.0559 ± 0.0024 135924-69-5*12 Formic acid HC(O)OH (aq, 200 H2O) -425.33 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*830 1,2-Propadien-1-one anion [CH2CCO]- (g) 49.7 48.5 ± 3.1 kJ/mol 54.0479 ± 0.0024 159171-62-7*0 Hydrogen iodide HI (aq, 3 H2O) -36.91 ± 0.56 kJ/mol 127.912410 ± 0.000076 10034-85-2*805 Chlorine atom dianion [Cl]-2 (g) 406.6 408.2 ± 4.8 kJ/mol 35.45380 ± 0.00090 33944-49-9*0 Cyanoamidogen anion [HNCN]- (g, triplet) 391.7 389.9 ± 1.8 kJ/mol 41.03267 ± 0.00082 67131-47-9*1 1-Oxo-2-propyn-1-ylium [HCCCO]+ (g) 1001.7 1003.1 ± 3.0 kJ/mol 53.0389 ± 0.0024 53474-99-0*0 3-Oxo-1,2-propadien-1-yl anion [HCCCO]- (g) 179.4 182.0 ± 3.2 kJ/mol 53.0400 ± 0.0024 557113-97-0*0 Nitric acid HON(O)O (aq, 5 H2O) -201.94 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*809 Formic acid HC(O)OH (aq, 500 H2O) -425.34 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*833 Carbon C (diamond) 2.390 1.862 ± 0.043 kJ/mol 12.01070 ± 0.00080 7440-44-0*501 Formylethynyl anion [CCCHO]- (g) 100.5 101.8 ± 3.4 kJ/mol 53.0400 ± 0.0024 85905-64-2*0 Nitric acid HON(O)O (aq, 20 H2O) -205.92 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*818 2-Cyclopropen-1-one cation [OC(CHCH)]+ (g) 1078.7 1075.6 ± 2.0 kJ/mol 54.0468 ± 0.0024 100815-68-7*0 Cyanoamidogen anion [HNCN]- (g, t-triplet) 392.3 390.4 ± 6.2 kJ/mol 41.03267 ± 0.00082 67131-47-9*11 1,3-Propanediyl CH2CH2CH2 (g, triplet) 319.2 307.8 ± 1.3 kJ/mol 42.0797 ± 0.0024 32458-33-6*1 Water H2O (cr, eq.press.) -286.272 -292.712 ± 0.022 kJ/mol 18.01528 ± 0.00033 7732-18-5*509 Hydrogen fluoride HF (aq, 200 H2O) -322.09 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*830 Hydrogen chloride HCl (aq, 5000 H2O) -166.793 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*844 Isourea NHC(OH)NH2 (g) -156.2 -172.8 ± 2.6 kJ/mol 60.05534 ± 0.00091 4744-36-9*0 Fluorosyl fluoride anion [FFO]- (g) -147.1 -146.8 ± 3.0 kJ/mol 53.99675 ± 0.00030 *86825-57-2*0 Hydrogen iodide HI (aq, 700 H2O) -56.413 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*835 Carbamoyl anion [NH2CO]- (g) -81.9 -87.8 ± 3.1 kJ/mol 44.03327 ± 0.00087 78944-69-1*0 Chlorine atom Cl (g, 2P1/2) 130.176 131.783 ± 0.0011 kJ/mol 35.45270 ± 0.00090 22537-15-1*2 Carbamoyl HNCOH (g) 74.1 68.3 ± 2.7 kJ/mol 44.03272 ± 0.00087 *2858-51-7*0 Carbamoyl HNCOH (g, trans-cis) 76.4 69.9 ± 3.2 kJ/mol 44.03272 ± 0.00087 *2858-51-7*2 Carbamoyl HNCOH (g, cis-trans) 96.3 90.1 ± 3.2 kJ/mol 44.03272 ± 0.00087 *2858-51-7*3 Carbamoyl HNCOH (g, cis-cis) 110.9 104.8 ± 3.2 kJ/mol 44.03272 ± 0.00087 *2858-51-7*4 1,3-Butadienyl CH2CHCHCH (g) 372.19 362.97 ± 0.87 kJ/mol 53.0825 ± 0.0032 86181-68-2*0 Hydrogen chloride HCl (aq, 20 H2O) -163.675 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*818 (Hydroxyimino)methyl HCNOH (g) 250.1 244.3 ± 1.8 kJ/mol 44.03272 ± 0.00087 206442-92-4*0 Methanediol CH2(OH)2 (g) -378.60 -391.69 ± 0.71 kJ/mol 48.0413 ± 0.0010 463-57-0*0 1,3-Butadienyl CH2CHCHCH (g, gauche-cis) 385.5 375.3 ± 1.9 kJ/mol 53.0825 ± 0.0032 86181-68-2*22 (Hydroxyimino)methyl HCNOH (g, cis-trans) 262.5 257.1 ± 2.5 kJ/mol 44.03272 ± 0.00087 206442-92-4*3 (Hydroxyimino)methyl HCNOH (g, cis-cis) 281.4 275.9 ± 2.5 kJ/mol 44.03272 ± 0.00087 206442-92-4*4 1,3-Butadiyne-1,4-diyl CCCC (g, singlet) 1083.96 1093.77 ± 0.83 kJ/mol 48.0428 ± 0.0032 78015-07-3*2 Dioxoethylium [OCHCO]+ (g) 688.6 689.9 ± 2.9 kJ/mol 57.0276 ± 0.0017 *1994332-01-2*0 Chloromethylene CHCl (g) 320.35 320.64 ± 0.89 kJ/mol 48.4713 ± 0.0012 2108-20-5*0 Ethanedial anion [OCHCO]- (g) -188.7 -190.3 ± 3.1 kJ/mol 57.0287 ± 0.0017 1994332-01-2*0 Hydrogen iodide HI (aq, 55.51 H2O) -55.856 ± 0.096 kJ/mol 127.912410 ± 0.000076 10034-85-2*891 Hydrazoic acid anion [HNNN]- (g) 309.0 303.2 ± 2.3 kJ/mol 43.02871 ± 0.00022 203264-98-6*0 Formaldoxime CH2NOH (g) 30.5 19.9 ± 1.3 kJ/mol 45.04066 ± 0.00088 75-17-2*0 Vinyl alcohol cation [CH2CHOH]+ (g) 778.6 767.6 ± 1.3 kJ/mol 44.0520 ± 0.0017 57239-63-1*0 1,3-Butadienyl CH2CHCHCH (g, trans-cis) 374.8 364.4 ± 1.9 kJ/mol 53.0825 ± 0.0032 86181-68-2*12 Ammonium hydroxide NH4OH (aq, 4000 H2O) -366.32 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*843 Hydrogen chloride HCl (aq, 25 H2O) -164.169 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*819 Chlorine atom heptacation [Cl]+7 (g) 39520. 39522. ± 11. kJ/mol 35.44886 ± 0.00090 22537-27-5*0 Hydrogen peroxide cation [HOOH]+ (g, cis, ortho) 931.06 924.18 ± 0.98 kJ/mol 34.01413 ± 0.00062 12325-10-9*21 1-Propen-1-yl-3-ylidene CHCHCH (g) 656.7 653.3 ± 1.1 kJ/mol 39.0559 ± 0.0024 84654-90-0*0 Ethoxyethene CH2CHOCH2CH3 (g) -118.0 -136.5 ± 1.5 kJ/mol 72.1057 ± 0.0033 109-92-2*0 Dihydroxymethyl CH(OH)2 (g) -197.1 -205.4 ± 1.2 kJ/mol 47.0333 ± 0.0010 14840-85-8*0 2-Hydroxyethylium [CH2CH2OH]+ (g) 1019.2 1007.1 ± 1.5 kJ/mol 45.0600 ± 0.0017 38607-31-7*0 Hydroxyoxoethenylium [HOCCO]+ (g) 866.4 865.2 ± 3.5 kJ/mol 57.0276 ± 0.0017 *1994332-00-1*0 Ethynediolide [HOCCO]- (g) -132.9 -134.0 ± 3.5 kJ/mol 57.0287 ± 0.0017 1994332-00-1*0 Hydrogen iodide HI (aq, 4 H2O) -44.15 ± 0.30 kJ/mol 127.912410 ± 0.000076 10034-85-2*807 Chlorohydroxymethyl CH(Cl)OH (g) -54.8 -60.6 ± 1.1 kJ/mol 65.4787 ± 0.0012 147139-06-8*0 Hydrogen chloride HCl (aq, 111 H2O) -165.819 ± 0.024 kJ/mol 36.46064 ± 0.00090 7647-01-0*892 Diazoethenylidene cation [NNCC]+ (g) 1771.1 1773.1 ± 3.5 kJ/mol 52.0343 ± 0.0016 *130760-10-0*0 Dihydroxymethyl CH(OH)2 (g, syn-syn) -190.8 -199.5 ± 2.3 kJ/mol 47.0333 ± 0.0010 14840-85-8*2 1-Cyanoethylidene CH3CCN (g) 437.5 433.7 ± 1.5 kJ/mol 53.0627 ± 0.0024 498544-34-6*0 Hydrogen iodide HI (aq, 5 H2O) -47.73 ± 0.32 kJ/mol 127.912410 ± 0.000076 10034-85-2*809 Isocyanomethane CH3NC (cr,l) 146.5 ± 2.2 kJ/mol 41.0520 ± 0.0016 593-75-9*500 Nitrosyl nitrate ONONO2 (g) 48.3 40.4 ± 1.8 kJ/mol 92.0111 ± 0.0012 15969-55-8*0 Dihydroxymethyl CH(OH)2 (g, anti-anti) -188.0 -196.9 ± 2.1 kJ/mol 47.0333 ± 0.0010 14840-85-8*3 Nitrosodioxaziridine ONN(OO) (g) 413.7 408.2 ± 1.8 kJ/mol 76.01168 ± 0.00091 132871-99-9*0 Hydroxyformyl HOCO (g) -181.15 -183.70 ± 0.40 kJ/mol 45.0174 ± 0.0010 2564-86-5*0 Dihydroxymethylium [CH(OH)2]+ (g) 421.3 410.2 ± 3.1 kJ/mol 47.0328 ± 0.0010 180071-68-5*0 3-Imino-2-propen-1-ylidene CHCHCNH (g) 530.6 526.3 ± 1.2 kJ/mol 53.0627 ± 0.0024 916765-05-4*0 Chloroethane CH3CH2Cl (cr,l) -134.36 -135.98 ± 0.25 kJ/mol 64.5138 ± 0.0019 75-00-3*500 3-Imino-2-propen-1-ylidene CHCHCNH (g, triplet) 571.8 567.0 ± 1.6 kJ/mol 53.0627 ± 0.0024 916765-05-4*2 Hydrogen chloride HCl (aq, 2000 H2O) -166.680 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*841 Dihydroxymethylium [CH(OH)2]+ (g, anti-anti) 428.3 417.1 ± 3.5 kJ/mol 47.0328 ± 0.0010 180071-68-5*3 Hydrogen chloride HCl (aq, 200 H2O) -166.102 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*830 Dihydroxymethylium [CH(OH)2]+ (g, syn-syn) 439.2 428.1 ± 3.5 kJ/mol 47.0328 ± 0.0010 180071-68-5*2 2-(Methylidyneamino)ethenyl CHCHNCH (g) 600.7 596.3 ± 1.2 kJ/mol 53.0627 ± 0.0024 123416-74-0*0 Hydrogen fluoride HF (aq, 500000 H2O) -333.06 ± 0.17 kJ/mol 20.006343 ± 0.000070 7664-39-3*866 2-(Methylidyneamino)ethenyl CHCHNCH (g, triplet) 634.4 630.4 ± 1.6 kJ/mol 53.0627 ± 0.0024 123416-74-0*2 Hydroxyformyl anion [HOCO]- (g) -319.54 -321.40 ± 0.56 kJ/mol 45.0180 ± 0.0010 78944-70-4*0 1-Propen-1-yl-3-ylidene CHCHCH (g, c-t quartet) 656.7 653.2 ± 2.0 kJ/mol 39.0559 ± 0.0024 84654-90-0*12 1-Propen-1-yl-3-ylidene CHCHCH (g, t-t quartet) 665.7 662.2 ± 2.0 kJ/mol 39.0559 ± 0.0024 84654-90-0*13 1-Propen-1-yl-3-ylidene CHCHCH (g, doublet) 699.2 696.3 ± 3.4 kJ/mol 39.0559 ± 0.0024 84654-90-0*2 Dihydroxymethanide [CH(OH)2]- (g) -194.3 -202.5 ± 1.8 kJ/mol 47.0339 ± 0.0010 61192-32-3*0 Hydrogen iodide HI (aq, 3000 H2O) -56.601 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*842 Dihydroxymethanide [CH(OH)2]- (g, syn-anti) -192.1 -201.4 ± 2.5 kJ/mol 47.0339 ± 0.0010 61192-32-3*1 Hydrogen iodide HI (aq, 6 H2O) -49.965 ± 0.096 kJ/mol 127.912410 ± 0.000076 10034-85-2*811 Hydrogen bromide HBr (aq, 10 H2O) -115.91 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*815 Oxoniumyl ion [H2O]+ (g, para) 978.748 975.597 ± 0.024 kJ/mol 18.01473 ± 0.00033 56583-62-1*2 (Methylamino)methyl anion [CH3NHCH2]- (g) 201.8 184.9 ± 3.1 kJ/mol 44.0763 ± 0.0017 *31277-25-5*0 Hydrogen chloride HCl (aq, 3000 H2O) -166.738 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*842 1,3-Propanediyl CH2CH2CH2 (g, singlet TS) 337.6 322.9 ± 2.2 kJ/mol 42.0797 ± 0.0024 32458-33-6*2 2-Cyanovinyl CHCHCN (g) 447.76 445.36 ± 0.99 kJ/mol 52.0547 ± 0.0024 189141-20-6*0 2-Cyanovinylium [CHCHCN]+ (g, triplet) 1517.2 1515.2 ± 1.8 kJ/mol 52.0542 ± 0.0024 85398-67-0*2 2-Cyanovinyl anion [CHCHCN]- (g) 263.7 261.4 ± 1.8 kJ/mol 52.0553 ± 0.0024 *85398-67-0*0 Ammonium hydroxide NH4OH (aq, 555.1 H2O) -366.38 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*895 Dihydroxymethanide [CH(OH)2]- (g, anti-anti) -177.7 -187.6 ± 2.5 kJ/mol 47.0339 ± 0.0010 61192-32-3*3 2-Isocyanovinyl CHCHNC (g) 543.2 541.8 ± 1.7 kJ/mol 52.0547 ± 0.0024 225798-14-1*0 Cyanomethylium [CH2CN]+ (g) 1256.23 1253.59 ± 0.61 kJ/mol 40.0435 ± 0.0016 34430-18-7*0 Hydroperoxonium [H2OOH]+ (g, cis) 762.5 752.7 ± 2.0 kJ/mol 35.02207 ± 0.00064 70850-26-9*2 Cyanomethyliumyl [HCCN]+ (g) 1506.5 1508.0 ± 2.3 kJ/mol 39.0355 ± 0.0016 34447-38-6*0 Cyanomethylene anion [HCCN]- (g) 286.3 286.8 ± 1.5 kJ/mol 39.0366 ± 0.0016 12373-24-9*0 Cyanomethylene HCCN (g) 479.7 483.0 ± 1.1 kJ/mol 39.0361 ± 0.0016 2612-62-6*0 Methane anion [CH4]- (g) 27.3 19.4 ± 5.1 kJ/mol 16.04301 ± 0.00085 27680-53-1*0 Hydrogen bromide HBr (aq, 2500 H2O) -120.24 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*898 Isocyanomethyliumyl [HCNC]+ (g) 1505.8 1507.6 ± 3.3 kJ/mol 39.0355 ± 0.0016 99045-54-2*0 Isocyanomethylene anion [HCNC]- (g) 400.4 401.1 ± 2.1 kJ/mol 39.0366 ± 0.0016 144141-01-5*0 Isocyanomethylene HCNC (g) 582.2 584.4 ± 1.7 kJ/mol 39.0361 ± 0.0016 78694-65-2*0 Ethylidene CH3CH (g) 361.26 354.27 ± 0.48 kJ/mol 28.0532 ± 0.0016 4218-50-2*0 3-Oxo-1,2-propadien-1-ylium-1-yl [CCCO]+ (g) 1380.3 1385.6 ± 3.8 kJ/mol 52.0310 ± 0.0024 151455-13-9*0 3-Oxo-1,2-propadienylidene anion [CCCO]- (g) 224.4 230.2 ± 3.5 kJ/mol 52.0320 ± 0.0024 109292-50-4*0 Hydrogen bromide HBr (aq, 1000 H2O) -120.11 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*839 Ammonium hydroxide NH4OH (aq, 2000 H2O) -366.35 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*841 1,3-Butadienyl CH2CHCHCH (g, cis-trans) 384.0 374.4 ± 1.9 kJ/mol 53.0825 ± 0.0032 86181-68-2*21 2-Hydroxyethenyl CHCHOH (g) 137.93 132.11 ± 0.72 kJ/mol 43.0446 ± 0.0016 108665-16-3*0 Diazomethyl HCNN (g) 467.84 465.28 ± 0.68 kJ/mol 41.03212 ± 0.00082 20813-32-5*0 Trichlorine cation [Cl3]+ (g, triplet) 1196.6 1197.2 ± 3.2 kJ/mol 106.3576 ± 0.0027 33088-85-6*1 Hydrazoic acid HNNN (cr,l) 261.52 ± 0.65 kJ/mol 43.02816 ± 0.00022 7782-79-8*500 Fluorosyl fluoride FFO (g) 192.8 193.3 ± 2.3 kJ/mol 53.99621 ± 0.00030 86825-57-2*0 Ethanimine CH3CHNH (g) 55.71 41.07 ± 0.72 kJ/mol 43.0678 ± 0.0016 20729-41-3*0 Hydrogen chloride HCl (aq, 2400 H2O) -166.708 ± 0.024 kJ/mol 36.46064 ± 0.00090 7647-01-0*896 Hydrogen chloride HCl (aq, 30 H2O) -164.500 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*820 1,3-Cyclobutadiene cation [CH(CHCHCH)]+ (g) 1215.6 1207.3 ± 3.0 kJ/mol 52.0740 ± 0.0032 34531-09-4*0 Hydrogen peroxide HOOH (aq) -190.69 ± 0.30 kJ/mol 34.01468 ± 0.00062 7722-84-1*800 Hydrogen iodide HI (aq, 4000 H2O) -56.626 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*843 2-Methyl-2-cyclopropen-1-ylidene CH3C(CHC) (g) 448.0 441.8 ± 1.2 kJ/mol 52.0746 ± 0.0032 185841-59-2*0 2-Methyl-2-cyclopropen-1-ylidene CH3C(CHC) (g, triplet) 670.6 664.6 ± 2.8 kJ/mol 52.0746 ± 0.0032 185841-59-2*1 Hydroxymethoxy CH2(OH)O (g, anti) -150.0 -159.8 ± 1.9 kJ/mol 47.0333 ± 0.0010 72144-78-6*1 Hydroxymethoxy cation [CH2(OH)O]+ (g, triplet) 924.9 915.2 ± 3.2 kJ/mol 47.0328 ± 0.0010 180071-69-6*1 Trioxidaniumyl [HOOOH]+ (g) 925.6 916.7 ± 1.5 kJ/mol 50.01353 ± 0.00091 161321-37-5*0 Peroxyhypochlorous acid anion [HOOCl]- (g, quartet) -32.1 -33.9 ± 2.6 kJ/mol 68.4600 ± 0.0011 *67952-08-3*0 Hydroxymethoxy cation [CH2(OH)O]+ (g, triplet syn) 930.8 921.3 ± 3.7 kJ/mol 47.0328 ± 0.0010 180071-69-6*12 Hydroxymethoxy cation [CH2(OH)O]+ (g, triplet anti) 933.4 923.7 ± 3.7 kJ/mol 47.0328 ± 0.0010 180071-69-6*11 Vinylvinylidene CH2CHCHC (g) 494.1 488.8 ± 1.7 kJ/mol 52.0746 ± 0.0032 148759-16-4*0 Vinylvinylidene CH2CHCHC (g, triplet) 690.4 684.6 ± 2.7 kJ/mol 52.0746 ± 0.0032 148759-16-4*1 Formic acid HC(O)OH (aq, 555.1 H2O) -425.34 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*895 Vinylvinylidene CH2CHCHC (g, triplet, cis) 695.4 689.0 ± 3.3 kJ/mol 52.0746 ± 0.0032 148759-16-4*12 Vinylvinylidene cation [CH2CHCHC]+ (g) 1429.8 1424.5 ± 2.0 kJ/mol 52.0740 ± 0.0032 161054-20-2*0 Vinylvinylidene cation [CH2CHCHC]+ (g, cis) 1437.8 1432.1 ± 2.7 kJ/mol 52.0740 ± 0.0032 161054-20-2*2 Vinylvinylidene anion [CH2CHCHC]- (g) 405.7 399.0 ± 2.0 kJ/mol 52.0751 ± 0.0032 167386-49-4*0 Vinylvinylidene anion [CH2CHCHC]- (g, cis) 423.2 416.6 ± 2.7 kJ/mol 52.0751 ± 0.0032 167386-49-4*2 Hydrogen chloride HCl (aq, 800 H2O) -166.516 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*837 Hydrodioxonitrate [HN(O)O]- (g) -62.0 -68.4 ± 3.2 kJ/mol 47.01403 ± 0.00061 61508-71-2*0 1,2-Butadien-1-ylidene CH3CHCC (g) 511.7 506.2 ± 2.0 kJ/mol 52.0746 ± 0.0032 119908-55-3*0 1,2-Butadien-1-ylidene CH3CHCC (g, triplet) 651.7 646.2 ± 3.7 kJ/mol 52.0746 ± 0.0032 119908-55-3*1 Hydroxymethoxy anion [CH2(OH)O]- (g) -373.88 -383.82 ± 0.89 kJ/mol 47.0339 ± 0.0010 67899-36-9*0 Hydroxymethoxy anion [CH2(OH)O]- (g, anti) -349.2 -358.8 ± 2.0 kJ/mol 47.0339 ± 0.0010 67899-36-9*1 Hydrogen iodide HI (aq, 100000 H2O) -56.781 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*861 Diazene HNNH (g, trans-cis-iso equilib) 207.11 199.98 ± 0.41 kJ/mol 30.02936 ± 0.00020 3618-05-1*0 Hydrogen chloride HCl (aq, 700 H2O) -166.487 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*835 Formaldehyde CH2O (g, ortho singlet) -105.263 -109.229 ± 0.095 kJ/mol 30.02598 ± 0.00087 50-00-0*22 Hydrogen bromide HBr (aq, 12 H2O) -116.68 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*816 Propynylidene HCCCH (g, singlet) 597.8 599.6 ± 1.3 kJ/mol 38.0480 ± 0.0024 67152-18-5*2 Ethylideneammoniumylidene [CH3CHN]+ (g, triplet) 1309.9 1300.3 ± 3.0 kJ/mol 42.0594 ± 0.0016 91127-36-5*1 1,2,3-Butatrien-1-ylium [CH2CCCH]+ (g) 1271.7 1269.9 ± 1.1 kJ/mol 51.0661 ± 0.0032 81932-79-8*0 Hydrogen bromide HBr (aq, 15 H2O) -117.39 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*817 Propargylenide [HCCCH]- (g) 434.4 437.6 ± 1.1 kJ/mol 38.0485 ± 0.0024 82906-05-6*0 Hydrogen fluoride HF (aq, 37 H2O) -321.93 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*890 Ethylideneazanide [CH3CHN]- (g) 147.7 137.5 ± 3.2 kJ/mol 42.0604 ± 0.0016 144810-43-5*0 Isoformyl anion [COH]- (g) 55.7 58.4 ± 1.8 kJ/mol 29.01859 ± 0.00086 81747-63-9*0 Hydrogen chloride HCl (aq, 300 H2O) -166.253 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*831 1-Buten-3-yn-1-yl HCCCHCH (g) 547.23 544.71 ± 0.86 kJ/mol 51.0666 ± 0.0032 2810-61-9*0 1-Buten-3-ynylium [HCCCHCH]+ (g) 1482.3 1480.2 ± 1.4 kJ/mol 51.0661 ± 0.0032 84654-85-3*0 But-1-en-3-yn-1-ide [HCCCHCH]- (g) 419.7 419.1 ± 1.2 kJ/mol 51.0672 ± 0.0032 119611-65-3*0 Hydrogen bromide HBr (aq, 20 H2O) -118.03 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*818 Peroxyformic acid HC(O)OOH (g) -279.25 -288.39 ± 0.63 kJ/mol 62.0248 ± 0.0012 107-32-4*0 Hydrogen chloride HCl (aq, 3500 H2O) -166.752 ± 0.024 kJ/mol 36.46064 ± 0.00090 7647-01-0*899 Hydroxyamidogen HNOH (g) 101.28 94.45 ± 0.87 kJ/mol 32.02202 ± 0.00034 13940-32-4*0 Ammonium hydroxide NH4OH (aq, 400 H2O) -366.39 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*832 3-Buten-1-ynylium [CH2CHCC]+ (g) 1572.6 1570.2 ± 1.7 kJ/mol 51.0661 ± 0.0032 103928-84-3*0 But-3-en-1-yn-1-ide [CH2CHCC]- (g) 326.6 323.5 ± 1.4 kJ/mol 51.0672 ± 0.0032 58870-47-6*0 Hydrogen iodide HI (aq, 7 H2O) -51.304 ± 0.099 kJ/mol 127.912410 ± 0.000076 10034-85-2*812 Hydrogen bromide HBr (aq, 7000 H2O) -120.34 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*846 Acetic acid CH3C(O)OH (aq, undissoc) -484.79 ± 0.27 kJ/mol 60.0520 ± 0.0017 64-19-7*1000 Tetraoxidanyl HOOOO (g) 2.1 0.4 ± 2.9 kJ/mol 65.0055 ± 0.0012 69696-93-1*0 3-Methylene-1-cyclopropen-1-ylium [CH2C(CHC)]+ (g) 1398.7 1395.4 ± 1.7 kJ/mol 51.0661 ± 0.0032 117469-28-0*0 Nitric acid HON(O)O (aq, 555.1 H2O) -206.16 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*895 Acetic acid CH3C(O)OH (aq, 0.5 H2O) -483.01 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*923 Nitrogen sesquioxide cation [ONN(O)O]+ (g, vdW) 1027.7 1023.7 ± 4.8 kJ/mol 76.01113 ± 0.00091 *10544-73-7*0 2-Cyclopropen-1-ylidenemethylium [CHC(CHCH)]+ (g) 1346.4 1343.8 ± 1.8 kJ/mol 51.0661 ± 0.0032 112936-36-4*0 Diazene HNNH (g, trans-cis equilib) 207.11 199.98 ± 0.41 kJ/mol 30.02936 ± 0.00020 3618-05-1*1 Ethylperoxy CH3CH2OO (g) -6.27 -22.23 ± 0.64 kJ/mol 61.0599 ± 0.0017 3170-61-4*0 2-Iminoethyl CH2CHNH (g) 219.27 208.59 ± 0.86 kJ/mol 42.0599 ± 0.0016 73843-90-0*0 Ethylene anion [CH2CH2]- (g) 232.0 225.6 ± 2.0 kJ/mol 28.0537 ± 0.0016 34527-91-8*0 1,3-Cyclobutadien-1-ylium [C(CHCHCH)]+ (g) 1388.2 1383.3 ± 1.8 kJ/mol 51.0661 ± 0.0032 81913-77-1*0 Pentachloroethylium [CCl3CCl2]+ (g) 838.1 836.4 ± 3.3 kJ/mol 201.2844 ± 0.0048 *7094-17-9*0 Hydroxyaminylium [HNOH]+ (g) 1019.5 1012.3 ± 2.5 kJ/mol 32.02147 ± 0.00034 66097-71-0*0 2-Iminoethylium [CH2CHNH]+ (g) 1108.2 1097.6 ± 2.9 kJ/mol 42.0594 ± 0.0016 73843-91-1*0 Cyclobutenide [CH2(CHCHCH)]- (g) 320.3 307.8 ± 3.2 kJ/mol 53.0830 ± 0.0032 60211-42-9*0 Pentachloroethanide [CCl3CCl2]- (g) -281.8 -280.3 ± 3.9 kJ/mol 201.2854 ± 0.0048 263019-83-6*0 Hydrogen iodide HI (aq, 300 H2O) -56.275 ± 0.092 kJ/mol 127.912410 ± 0.000076 10034-85-2*831 2-Iminoethylium [CH2CHNH]+ (g, triplet) 1148.6 1140.1 ± 3.3 kJ/mol 42.0594 ± 0.0016 73843-91-1*1 Chlorine chlorite ClOClO (g) 168.6 166.4 ± 1.3 kJ/mol 102.9042 ± 0.0019 105206-44-8*0 Phenylperoxy cation [C6H5OO]+ (g) 1018.6 1001.5 ± 3.1 kJ/mol 109.1022 ± 0.0049 956036-17-2*0 Phenylperoxy anion [C6H5OO]- (g) -39.3 -56.2 ± 3.3 kJ/mol 109.1032 ± 0.0049 *956036-17-2*0 Ethoxyoxoniumylidene [CH3CH2OO]+ (g) 923.7 911.4 ± 1.5 kJ/mol 61.0594 ± 0.0017 268728-77-4*0 Ethoxyoxoniumylidene [CH3CH2OO]+ (g, singlet) 962.3 947.6 ± 1.7 kJ/mol 61.0594 ± 0.0017 268728-77-4*2 Formic acid HC(O)OH (aq, 30 H2O) -425.20 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*820 Diazomethyl HCNN (g, quartet) 652.7 649.8 ± 1.3 kJ/mol 41.03212 ± 0.00082 20813-32-5*2 Hydrogen chloride HCl (aq, 40 H2O) -164.926 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*821 Fulvene cation [CH2C(CHCHCHCH)]+ (g) 1043.6 1027.8 ± 2.7 kJ/mol 78.1113 ± 0.0048 34504-75-1*0 Fulvene anion [CH2C(CHCHCHCH)]- (g) 191.3 176.3 ± 4.0 kJ/mol 78.1124 ± 0.0048 34504-63-7*0 Diazomethyl HCNN (g, t-quartet) 653.0 650.0 ± 2.3 kJ/mol 41.03212 ± 0.00082 20813-32-5*21 Hydrogen iodide HI (aq, 7000 H2O) -56.668 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*846 Ethoxyoxoniumylidene [CH3CH2OO]+ (g, gauche singlet) 967.4 951.5 ± 2.4 kJ/mol 61.0594 ± 0.0017 268728-77-4*23 Acetic acid CH3C(O)OH (aq, 1 H2O) -482.91 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*801 Fulvenone cation [OCC(CHCHCHCH)]+ (g) 913.4 903.3 ± 1.9 kJ/mol 92.0948 ± 0.0048 884319-80-6*0 Chlorine pentafluoride anion [FCl(F)(F)(F)F]- (g) -619.1 -622.6 ± 4.3 kJ/mol 130.44526 ± 0.00090 184851-42-1*0 Acetic acid CH3C(O)OH (aq, 1.5 H2O) -482.86 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*802 Hydrogen iodide HI (aq, 1000 H2O) -56.467 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*839 Nitrogen atom heptacation [N]+7 (g) 143853.26 143855.12 ± 0.23 kJ/mol 14.002900 ± 0.000070 40549-08-4*0 Silicon atom tetracation [Si]+4 (g) 10401.14 10404.12 ± 0.59 kJ/mol 28.08331 ± 0.00030 22537-24-2*0 Silicon anion Si- (g) 316.32 319.30 ± 0.59 kJ/mol 28.08605 ± 0.00030 14337-02-1*0 Ammonium hydroxide NH4OH (aq, 600 H2O) -366.38 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*834 Diazomethylium [HCNN]+ (g) 1395.7 1394.1 ± 1.3 kJ/mol 41.03157 ± 0.00082 271249-81-1*0 Disilicon anion [Si2]- (g) 375.2 379.1 ± 1.8 kJ/mol 56.17155 ± 0.00060 64236-73-3*0 1,2-Dichloroethene CHClCHCl (g) 3.79 -1.53 ± 0.55 kJ/mol 96.9427 ± 0.0024 540-59-0*0 2-Iminoethyl anion [CH2CHNH]- (g) 104.4 94.0 ± 2.1 kJ/mol 42.0604 ± 0.0016 73843-87-5*0 Bromine atom Br (g, 2P1/2) 162.010 155.947 ± 0.055 kJ/mol 79.90400 ± 0.00100 10097-32-2*2 Nitric acid HON(O)O (aq, 25 H2O) -205.99 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*819 Ethaneperoxolate [CH3CH2OO]- (g) -120.50 -136.57 ± 0.72 kJ/mol 61.0604 ± 0.0017 268728-75-2*0 Acetic acid CH3C(O)OH (aq, 2 H2O) -482.87 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*803 Ammonium hydroxide NH4OH (aq, 7000 H2O) -366.28 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*846 Hydrogen iodide HI (aq, 8 H2O) -52.23 ± 0.12 kJ/mol 127.912410 ± 0.000076 10034-85-2*813 Acetic acid CH3C(O)OH (aq, 2.5 H2O) -482.96 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*804 Hydrogen fluoride HF (aq, 45 H2O) -321.95 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*906 Ammonium hydroxide NH4OH (aq, 700 H2O) -366.37 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*835 Ethaneperoxolate [CH3CH2OO]- (g, trans) -120.0 -135.6 ± 1.9 kJ/mol 61.0604 ± 0.0017 268728-75-2*1 Silicon carbide anion [SiC]- (g) 509.8 514.5 ± 4.4 kJ/mol 40.09675 ± 0.00085 86017-99-4*0 Diazoethenylidene anion [NNCC]- (g) 529.6 532.2 ± 3.5 kJ/mol 52.0354 ± 0.0016 *130760-11-1*0 Formic acid HC(O)OH (aq, 40 H2O) -425.22 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*821 Silicon carbide SiC (cr,l) -70.6 -71.6 ± 1.5 kJ/mol 40.09620 ± 0.00085 409-21-2*500 Tetrafluorosilane cation [SiF4]+ (g) -137.3 -141.6 ± 5.9 kJ/mol 104.07856 ± 0.00030 62859-94-3*0 Acetic acid CH3C(O)OH (aq, 3 H2O) -483.04 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*805 1-Iminoethyl CH3CNH (g) 233.0 222.9 ± 1.1 kJ/mol 42.0599 ± 0.0016 128365-64-0*0 Dichlorovinylidene CCCl2 (g) 424.2 427.5 ± 3.0 kJ/mol 94.9268 ± 0.0024 20394-25-6*0 1-Iminoethyl CH3CNH (g, syn) 252.3 242.3 ± 2.0 kJ/mol 42.0599 ± 0.0016 128365-64-0*1 Nitrosodioxaziridine ONN(OO) (g, cis) 413.9 408.1 ± 3.2 kJ/mol 76.01168 ± 0.00091 132871-99-9*2 Chlorovinylidene CCHCl (g) 429.2 430.9 ± 2.9 kJ/mol 60.4820 ± 0.0018 70277-82-6*0 1-Iminoethylium [CH3CNH]+ (g) 833.6 823.1 ± 3.0 kJ/mol 42.0594 ± 0.0016 *128365-64-0*0 O--HH Complex (H2)(O) (g, vdW Cinfv ?) 247.6 248.9 ± 2.7 kJ/mol 18.01528 ± 0.00033 *7732-18-5*101 1-Iminoethylium [CH3CNH]+ (g, triplet) 1342.1 1333.2 ± 3.9 kJ/mol 42.0594 ± 0.0016 *128365-64-0*1 Silylene SiH2 (g) 271.42 269.76 ± 0.86 kJ/mol 30.10138 ± 0.00033 13825-90-6*0 1-Hydroperoxyethylium [CH3CHOOH]+ (g) 690.5 675.6 ± 1.5 kJ/mol 61.0594 ± 0.0017 *126898-98-4*0 Hydrogen fluoride HF (aq, 900 H2O) -322.65 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*838 Formic acid HC(O)OH (aq, 50 H2O) -425.24 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*822 Hydrogen fluoride HF (aq, 25 H2O) -321.88 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*819 Disilane cation [SiH3SiH3]+ (g) 1030.3 1017.5 ± 2.2 kJ/mol 62.21809 ± 0.00073 96301-43-8*0 Peroxyhypochlorous acid cation [HOOCl]+ (g) 1030.4 1024.6 ± 2.5 kJ/mol 68.4589 ± 0.0011 *67952-07-2*0 1-Iminoethylium [CH3CNH]+ (g, syn-triplet) 1378.3 1368.7 ± 4.3 kJ/mol 42.0594 ± 0.0016 *128365-64-0*11 Hydrogen bromide HBr (aq, 900 H2O) -120.09 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*838 Hydrogen chloride HCl (aq, 4000 H2O) -166.763 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*843 1-Iminoethanide [CH3CNH]- (g) 185.6 175.5 ± 3.2 kJ/mol 42.0604 ± 0.0016 *128365-65-1*0 Hydrogen fluoride HF (aq, 250 H2O) -322.13 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*908 1-Hydroperoxyethylium [CH3CHOOH]+ (g, triplet) 841.3 830.1 ± 1.7 kJ/mol 61.0594 ± 0.0017 *126898-98-4*1 Hydrogen isocyanide anion [HNC]- (g) 191.61 191.79 ± 0.32 kJ/mol 27.02593 ± 0.00081 96913-22-3*0 Disilene SiH2SiH2 (g) 288.6 280.0 ± 1.9 kJ/mol 60.20276 ± 0.00066 15435-77-5*0 Hydrogen iodide HI (aq, 10000 H2O) -56.693 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*850 Fluoromethane cation [CH3F]+ (g) 981.84 974.34 ± 0.62 kJ/mol 34.03237 ± 0.00083 59122-96-2*0 1-Iminoethanide [CH3CNH]- (g, syn) 193.1 182.5 ± 3.6 kJ/mol 42.0604 ± 0.0016 *128365-65-1*1 Fluoromethane CH3F (l) -245.72 ± 0.45 kJ/mol 34.03292 ± 0.00083 593-53-3*590 Silylsilylene SiH3SiH (g) 317.1 309.3 ± 2.0 kJ/mol 60.20276 ± 0.00066 50420-90-1*0 Hydrogen bromide HBr (aq, 50000 H2O) -120.44 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*855 Chloromethane CH3Cl (l) -106.51 -102.54 ± 0.19 kJ/mol 50.4872 ± 0.0012 74-87-3*590 Hydrogen bromide HBr (aq, 700 H2O) -120.04 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*835 1-Hydroperoxyethylium [CH3CHOOH]+ (g, cis singlet) 691.8 676.1 ± 2.3 kJ/mol 61.0594 ± 0.0017 *126898-98-4*22 Ammonium hydroxide NH4OH (aq, 20000 H2O) -366.18 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*852 Bromomethane cation [CH3Br]+ (g) 996.59 981.67 ± 0.21 kJ/mol 94.9380 ± 0.0013 12538-70-4*0 1-Hydroperoxyethylium [CH3CHOOH]+ (g, cis triplet) 843.6 831.6 ± 2.6 kJ/mol 61.0594 ± 0.0017 *126898-98-4*12 Difluorodioxidane anion [FOOF]- (g) -251. -251. ± 28. kJ/mol 69.99615 ± 0.00060 *7783-45-1*0 Di-mu-hydrodihydrodisilicon HSi(HSiHH) (g) 374.5 364.3 ± 2.4 kJ/mol 60.20276 ± 0.00066 129970-82-7*0 Di-mu-hydrodihydrodisilicon HSi(HSiHH) (g, trans) 374.5 364.2 ± 2.4 kJ/mol 60.20276 ± 0.00066 129970-82-7*1 Di-mu-hydrodihydrodisilicon HSi(HSiHH) (g, trans-triplet) 544.1 536.0 ± 3.7 kJ/mol 60.20276 ± 0.00066 129970-82-7*11 Di-mu-hydrodihydrodisilicon cation [HSi(HSiHH)]+ (g) 1180.1 1172.5 ± 3.3 kJ/mol 60.20221 ± 0.00066 *129970-82-7*0 Di-mu-hydrodihydrodisilicon anion [HSi(HSiHH)]- (g) 288.3 280.2 ± 3.4 kJ/mol 60.20331 ± 0.00066 *129970-83-8*0 Iodine monochloride ICl (cr,l) -36.511 -35.537 ± 0.063 kJ/mol 162.35717 ± 0.00090 7790-99-0*500 3H-diazirin-3-ylidene-methylene CC(NN) (g) 837.3 839.9 ± 2.3 kJ/mol 52.0349 ± 0.0016 204253-88-3*0 Propane CH3CH2CH3 (cr,l) -110.21 -121.20 ± 0.66 kJ/mol 44.0956 ± 0.0025 74-98-6*500 Hydrogen chloride HCl (aq, 50 H2O) -165.186 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*822 N-Methylenemethaniminium [CH2NCH2]+ (g) 904.2 893.3 ± 3.1 kJ/mol 42.0594 ± 0.0016 88333-01-1*0 Hydrogen fluoride HF (aq, 15 H2O) -321.79 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*817 Nitric acid HON(O)O (aq, 30 H2O) -206.02 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*820 Fluorine atom F (g, 2P1/2) 82.088 83.873 ± 0.017 kJ/mol 18.99840320 ± 0.00000050 14762-94-8*2 Tetroxidane HOOOOH (g) -33.29 -43.22 ± 0.44 kJ/mol 66.0135 ± 0.0012 29683-94-1*0 Hydrogen bromide HBr (aq, 25 H2O) -118.36 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*819 Hydrogen bromide HBr (aq, 30 H2O) -118.59 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*820 2-Hydroperoxyethyl CH2CH2OOH (g) 64.5 51.2 ± 1.3 kJ/mol 61.0599 ± 0.0017 126898-97-3*0 Nitric acid HON(O)O (aq, 50 H2O) -206.03 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*822 Water H2O (g, ortho) -238.616 -241.803 ± 0.022 kJ/mol 18.01528 ± 0.00033 7732-18-5*1 Dioxodiazoxane ONONO (g) 93.0 88.1 ± 1.3 kJ/mol 76.01168 ± 0.00091 122413-35-8*0 2-Hydroperoxyethyl CH2CH2OOH (g, gauche) 64.5 50.8 ± 1.3 kJ/mol 61.0599 ± 0.0017 126898-97-3*3 N-Methylenemethaniminium [CH2NCH2]+ (g, triplet) 1157.1 1147.2 ± 4.0 kJ/mol 42.0594 ± 0.0016 88333-01-1*1 Hydrogen bromide HBr (aq, 40 H2O) -118.91 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*821 Iodomethane cation [CH3I]+ (g) 944.69 935.30 ± 0.18 kJ/mol 141.93844 ± 0.00083 12538-72-6*0 Propylidene anion [CH3CH2CH]- (g) 300.8 286.7 ± 3.2 kJ/mol 42.0803 ± 0.0024 *121408-55-7*0 Hydrogen bromide HBr (aq, 200 H2O) -119.76 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*830 Hydrogen chloride HCl (aq, 55.51 H2O) -165.293 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*891 Fluoroform CHF3 (l) -704.71 ± 0.41 kJ/mol 70.01385 ± 0.00080 75-46-7*590 Hydrogen iodide HI (aq, 9 H2O) -52.89 ± 0.16 kJ/mol 127.912410 ± 0.000076 10034-85-2*814 Hydrogen bromide HBr (aq, 50 H2O) -119.11 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*822 Hydrogen iodide HI (aq, 1250 H2O) -56.497 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*954 Hydrogen chloride HCl (aq, 900 H2O) -166.541 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*838 Hydroxysilyl anion [SiH2OH]- (g) -219.2 -227.0 ± 2.1 kJ/mol 47.10927 ± 0.00047 78450-47-2*0 Hydroxysilyl anion [SiH2OH]- (g, anti) -218.9 -226.8 ± 2.7 kJ/mol 47.10927 ± 0.00047 78450-47-2*2 Hydrogen bromide HBr (aq, 55.51 H2O) -119.19 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*891 Carbon trianion [C]-3 (g) 1813.2 1818.6 ± 5.9 kJ/mol 12.01235 ± 0.00080 50802-48-7*0 N-Methylidynemethanaminium [CH3NCH]+ (g) 881.0 870.2 ± 3.0 kJ/mol 42.0594 ± 0.0016 64709-60-0*0 Ammonium hydroxide NH4OH (aq, 200 H2O) -366.37 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*830 Benzvalene cation [((CHCH)(CH(CHCH)CH))]+ (g) 1200.2 1184.8 ± 2.7 kJ/mol 78.1113 ± 0.0048 81050-63-7*0 Ethane anion [CH3CH3]- (g) 41.8 26.5 ± 4.4 kJ/mol 30.0696 ± 0.0017 54064-82-3*0 Dioxymethylene HCOO (g) 341.8 339.8 ± 3.0 kJ/mol 45.0174 ± 0.0010 438586-67-5*0 (Methylimino)methyl CH3NCH (g) 277.9 267.8 ± 1.1 kJ/mol 42.0599 ± 0.0016 117928-23-1*0 Nitric oxide NO (aq, undissoc) 79.224 ± 0.079 kJ/mol 30.00614 ± 0.00031 10102-43-9*1000 Fluorosyl fluoride cation [FFO]+ (g) 1413.1 1413.4 ± 3.5 kJ/mol 53.99566 ± 0.00030 *86825-50-5*0 2-Hydroperoxyethyl CH2CH2OOH (g, anti) 65.0 51.6 ± 2.2 kJ/mol 61.0599 ± 0.0017 126898-97-3*1 Hydrogen fluoride HF (aq, 500 H2O) -322.36 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*833 Ammonium hydroxide NH4OH (aq, 1.5 H2O) -364.33 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*802 (Methylimino)methyl CH3NCH (g, cis) 297.0 287.0 ± 2.0 kJ/mol 42.0599 ± 0.0016 117928-23-1*2 (Methylimino)methanide [CH3NCH]- (g) 222.9 212.1 ± 3.2 kJ/mol 42.0604 ± 0.0016 *64709-60-0*0 (Methylimino)methanide [CH3NCH]- (g, cis) 236.5 225.6 ± 3.6 kJ/mol 42.0604 ± 0.0016 *64709-60-0*2 Butadienylacetylene CH2CHCHCHCCH (g) 358.7 346.3 ± 1.9 kJ/mol 78.1118 ± 0.0048 10420-90-3*0 Hydrogen fluoride HF (aq, 35 H2O) -321.92 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*904 (3Z)-1,3-Hexadien-5-yne CH2CHCHCHCCH (g, cis) 358.7 346.2 ± 2.5 kJ/mol 78.1118 ± 0.0048 5222-76-4*0 Divinylacetylene CH2CHCCCHCH2 (g) 361.8 350.6 ± 2.0 kJ/mol 78.1118 ± 0.0048 821-08-9*0 Hydrogen peroxide cation [HOOH]+ (g, trans, para) 897.31 890.31 ± 0.51 kJ/mol 34.01413 ± 0.00062 12325-10-9*12 Divinylacetylene CH2CHCCCHCH2 (g, trans) 362.4 351.3 ± 2.6 kJ/mol 78.1118 ± 0.0048 821-08-9*1 Biallenyl CH2CCHCHCCH2 (g) 410.6 399.5 ± 1.5 kJ/mol 78.1118 ± 0.0048 29776-96-3*0 Ammonium hydroxide NH4OH (aq, 2.5 H2O) -364.92 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*804 Biallenyl CH2CCHCHCCH2 (g, cis) 419.4 408.1 ± 2.3 kJ/mol 78.1118 ± 0.0048 29776-96-3*2 Propargylallene CH2CCHCH2CCH (g) 431.4 420.0 ± 1.4 kJ/mol 78.1118 ± 0.0048 33142-15-3*0 1-Aminoethenylium [CH2CNH2]+ (g) 900.0 889.1 ± 3.0 kJ/mol 42.0594 ± 0.0016 *139597-26-5*0 Propargylallene CH2CCHCH2CCH (g, cis) 432.3 420.7 ± 2.2 kJ/mol 78.1118 ± 0.0048 33142-15-3*2 Acetic acid CH3C(O)OH (aq, 4 H2O) -483.15 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*807 2-Hydroperoxyethyl CH2CH2OOH (g, gauche-anti) 65.5 51.5 ± 2.2 kJ/mol 61.0599 ± 0.0017 126898-97-3*31 3-Methylene-1-penten-4-yne CH2CHC(CH2)CCH (g) 362.5 350.2 ± 2.2 kJ/mol 78.1118 ± 0.0048 6929-96-0*0 3-Methylene-1-penten-4-yne CH2CHC(CH2)CCH (g, gauche) 374.6 362.3 ± 2.8 kJ/mol 78.1118 ± 0.0048 6929-96-0*3 1,2,3,5-Hexatetraene CH2CCCHCHCH2 (g) 391.7 380.3 ± 1.6 kJ/mol 78.1118 ± 0.0048 60239-33-0*0 Acetic acid CH3C(O)OH (aq, 4.5 H2O) -483.19 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*808 1,2,3,5-Hexatetraene CH2CCCHCHCH2 (g, cis) 400.5 388.9 ± 2.3 kJ/mol 78.1118 ± 0.0048 60239-33-0*2 1-Aminoethenide [CH2CNH2]- (g) 215.9 205.1 ± 3.2 kJ/mol 42.0604 ± 0.0016 139597-26-5*0 mu-Oxodioxodinitrogen [ONONO]+ (g, t, t) 984.0 981.1 ± 3.2 kJ/mol 76.01113 ± 0.00091 87950-63-8*1 Nitric acid HON(O)O (aq, 55.51 H2O) -206.02 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*891 Acetic acid CH3C(O)OH (aq, 5 H2O) -483.22 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*809 Propene CH3CHCH2 (cr,l) 7.68 3.97 ± 0.82 kJ/mol 42.0797 ± 0.0024 115-07-1*500 Nitrato [ON(O)O]+ (g) 1290.59 1285.88 ± 0.86 kJ/mol 62.00439 ± 0.00090 133057-96-2*0 Bromoform CHBr3 (l) 8.2 ± 1.1 kJ/mol 252.7306 ± 0.0031 75-25-2*590 Hydrogen fluoride HF (aq, 22.2 H2O) -321.86 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*888 Diazanide [NH2NH]- (g) 249.3 239.2 ± 3.1 kJ/mol 31.03785 ± 0.00025 25415-88-7*0 Hydroxymethylene cation [HCOH]+ (g) 971.9 968.3 ± 1.4 kJ/mol 30.02543 ± 0.00087 135395-06-1*0 2-Hydroperoxyethyl CH2CH2OOH (g, anti-syn) 65.5 51.9 ± 2.2 kJ/mol 61.0599 ± 0.0017 126898-97-3*12 Difluoromethane CH2F2 (l) -468.92 ± 0.36 kJ/mol 52.02339 ± 0.00081 75-10-5*590 Hydroxymethylene anion [HCOH]- (g) 147.1 144.2 ± 1.6 kJ/mol 30.02653 ± 0.00087 207914-87-2*0 1-Methylallyl CH3CHCHCH2 (g) 152.54 136.07 ± 0.79 kJ/mol 55.0984 ± 0.0032 15819-46-2*0 Hydrogen bromide HBr (aq, 555.1 H2O) -120.00 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*895 Hydrogen fluoride HF (aq, 264.3 H2O) -322.14 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*909 1-Methyl-1-propenyl CH3CCHCH3 (g) 240.00 224.61 ± 0.66 kJ/mol 55.0984 ± 0.0032 71790-71-1*0 Ethenyldioxy CH2CHOO (g) 118.7 109.8 ± 1.3 kJ/mol 59.0440 ± 0.0017 88181-72-0*0 1-Methyl-1-propenyl CH3CCHCH3 (g, cis) 243.3 227.0 ± 1.9 kJ/mol 55.0984 ± 0.0032 71790-71-1*2 Hydrogen iodide HI (aq, 10 H2O) -53.38 ± 0.17 kJ/mol 127.912410 ± 0.000076 10034-85-2*815 Ammonium hydroxide NH4OH (aq, 3.5 H2O) -365.29 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*806 1-Butenyl CH3CH2CHCH (g) 263.36 246.31 ± 0.68 kJ/mol 55.0984 ± 0.0032 2669-61-6*0 Hydrogen iodide HI (aq, 12 H2O) -54.02 ± 0.17 kJ/mol 127.912410 ± 0.000076 10034-85-2*816 1-Butenyl CH3CH2CHCH (g, gauche) 263.8 246.5 ± 1.9 kJ/mol 55.0984 ± 0.0032 2669-61-6*3 Acetic acid CH3C(O)OH (aq, 6 H2O) -483.29 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*811 Hydrogen bromide HBr (aq, 4000 H2O) -120.29 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*843 Ethylamine CH3CH2NH2 (cr,l) -76.95 ± 0.67 kJ/mol 45.0837 ± 0.0017 75-04-7*500 Hydrogen bromide HBr (aq, 75 H2O) -119.37 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*825 Hydrogen chloride HCl (aq, 7000 H2O) -166.822 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*846 Acetic acid CH3C(O)OH (aq, 7 H2O) -483.36 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*812 Ammonium hydroxide NH4OH (aq, 25 H2O) -366.24 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*819 2-Aminoethenyl CHCHNH2 (g) 319.7 310.1 ± 1.3 kJ/mol 42.0599 ± 0.0016 176964-54-8*0 1-Aminoethyl anion [CH3CHNH2]- (g) 174.3 156.8 ± 3.2 kJ/mol 44.0763 ± 0.0017 59263-55-7*0 Ammonium hydroxide NH4OH (aq, 4.5 H2O) -365.54 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*808 Hydrogen iodide HI (aq, 555.1 H2O) -56.379 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*895 Ethylaminylium [CH3CH2NH]+ (g, triplet) 1092.2 1077.1 ± 2.4 kJ/mol 44.0752 ± 0.0017 54387-08-5*1 Ethylaminylium [CH3CH2NH]+ (g, anti-triplet) 1094.7 1078.9 ± 2.9 kJ/mol 44.0752 ± 0.0017 54387-08-5*12 Hydrogen iodide HI (aq, 15 H2O) -54.589 ± 0.092 kJ/mol 127.912410 ± 0.000076 10034-85-2*817 2-Aminoethenylium [CHCHNH2]+ (g, triplet) 1110.5 1099.8 ± 2.4 kJ/mol 42.0594 ± 0.0016 64724-21-6*1 Hydrogen bromide HBr (aq, 100 H2O) -119.51 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*828 2-Aminoethenyl anion [CHCHNH2]- (g) 230.1 219.4 ± 2.6 kJ/mol 42.0604 ± 0.0016 *64724-21-6*0 N-Methylethanamine CH3CH2NHCH3 (cr,l) -75.1 ± 2.3 kJ/mol 59.1103 ± 0.0025 624-78-2*500 Peroxychlorous acid HOOClO (g) 95.4 89.8 ± 2.0 kJ/mol 84.4588 ± 0.0013 177778-92-6*0 Hydrogen fluoride HF (aq, 600 H2O) -322.44 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*834 Ethenyldioxy CH2CHOO (g, syn) 122.9 113.1 ± 2.2 kJ/mol 59.0440 ± 0.0017 88181-72-0*2 2-Methyl-2-propanamine (CH3)3CNH2 (l) -150.58 ± 0.53 kJ/mol 73.1369 ± 0.0033 75-64-9*590 Acetic acid CH3C(O)OH (aq, 8 H2O) -483.44 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*813 Acetic acid CH3C(O)OH (aq, 9 H2O) -483.52 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*814 Aminomethylidyne anion [CNH2]- (g, triplet) 481.6 478.1 ± 3.2 kJ/mol 28.03387 ± 0.00082 96808-04-7*1 Naphtalene cation [C6H4(C4H4)]+ (g) 956.97 933.90 ± 0.55 kJ/mol 128.1700 ± 0.0080 34512-27-1*0 Naphtalene anion [C6H4(C4H4)]- (g) 187.7 164.8 ± 3.0 kJ/mol 128.1711 ± 0.0080 34509-91-6*0 Formic acid HC(O)OH (aq, 55.51 H2O) -425.25 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*891 Isocyanoamidogen HNNC (g) 489.7 487.7 ± 1.2 kJ/mol 41.03212 ± 0.00082 947408-73-3*0 Acetic acid CH3C(O)OH (aq, 10 H2O) -483.60 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*815 Propylidyne CH3CH2C (g) 492.6 483.0 ± 1.2 kJ/mol 41.0718 ± 0.0024 85056-54-8*0 Acetic acid CH3C(O)OH (aq, 12 H2O) -483.75 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*816 Ammonium hydroxide NH4OH (aq, 5 H2O) -365.62 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*809 Ammonium hydroxide NH4OH (aq, 6 H2O) -365.75 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*811 Nitric acid HON(O)O (aq, 100 H2O) -206.04 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*828 Diazene cation [HNNH]+ (g, trans-iso-cis equilib) 1132.48 1125.82 ± 0.64 kJ/mol 30.02881 ± 0.00020 76986-17-9*0 1,2-Butadiene CH3CHCCH2 (cr,l) 137.78 138.84 ± 0.63 kJ/mol 54.0904 ± 0.0032 590-19-2*500 Oxiranylium [CH2(CHO)]+ (g) 901.3 893.3 ± 1.4 kJ/mol 43.0441 ± 0.0016 57789-76-1*0 Methylaminyliumyl [CH3N]+ (g, quartet) 1422.9 1416.0 ± 2.2 kJ/mol 29.04071 ± 0.00083 56924-51-7*2 Nitric acid HON(O)O (aq, 4 H2O) -200.28 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*807 Ammonium hydroxide NH4OH (aq, 8 H2O) -365.92 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*813 Chlorous acid anion [HOClO]- (g) -154.3 -156.1 ± 3.3 kJ/mol 68.4600 ± 0.0011 99559-66-7*0 Ethylimidogen anion [CH3CH2N]- (g) 277.3 263.4 ± 3.6 kJ/mol 43.0684 ± 0.0016 82539-33-1*0 Nitric acid HON(O)O (aq, 7 H2O) -203.77 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*812 Trioxidane HOOOH (g) -81.72 -90.32 ± 0.41 kJ/mol 50.01408 ± 0.00091 14699-99-1*0 Oxiranyl anion [CH2(CHO)]- (g) 121.3 113.4 ± 1.5 kJ/mol 43.0452 ± 0.0016 72722-59-9*0 Acetic acid CH3C(O)OH (aq, 15 H2O) -483.92 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*817 Butadiynylium [CCCCH]+ (g) 1781.3 1787.8 ± 3.2 kJ/mol 49.0502 ± 0.0032 76108-67-3*0 Ammonium hydroxide NH4OH (aq, 55.51 H2O) -366.33 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*891 Hydrogen bromide HBr (aq, 100000 H2O) -120.44 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*861 Formic acid cation [HC(O)OH]+ (g) 721.95 715.41 ± 0.25 kJ/mol 46.0248 ± 0.0010 50614-05-6*0 Formic acid anion [HC(O)OH]- (g) -256.2 -262.3 ± 1.8 kJ/mol 46.0259 ± 0.0010 19066-82-1*0 Ethylimidogen cation [CH3CH2N]+ (g, quartet) 1394.6 1381.3 ± 3.6 kJ/mol 43.0673 ± 0.0016 *82539-33-1*1 Dinitrogen anion [N2]- (g) 192.5 192.5 ± 1.7 kJ/mol 28.01403 ± 0.00014 12185-02-3*0 Helium He (g, singlet) -0.000 -0.000 ± 0.000 kJ/mol 4.0026020 ± 0.0000020 7440-59-7*2 1-Aziridinylium [N(CH2CH2)]+ (g, triplet) 1265.6 1253.9 ± 3.1 kJ/mol 42.0594 ± 0.0016 91127-35-4*1 Ammonium hydroxide NH4OH (aq, 300 H2O) -366.38 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*831 Helium dication [He]+2 (g) 7622.839 7622.839 ± 0.000 kJ/mol 4.0015048 ± 0.0000020 12587-46-1*0 Acetic acid CH3C(O)OH (aq, 20 H2O) -484.11 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*818 Acetic acid CH3C(O)OH (aq, 25 H2O) -484.23 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*819 1-Aziridinide [N(CH2CH2)]- (g) 243.9 231.5 ± 3.3 kJ/mol 42.0604 ± 0.0016 1358579-49-3*0 Isocyanoamidogen HNNC (g, quartet) 828.2 825.6 ± 1.3 kJ/mol 41.03212 ± 0.00082 947408-73-3*2 Isocyanoamidogen HNNC (g, t-quartet) 837.9 835.2 ± 2.1 kJ/mol 41.03212 ± 0.00082 947408-73-3*21 Dihelium He2 (g, singlet) 1761.349 1757.613 ± 0.018 kJ/mol 8.0052040 ± 0.0000040 12184-98-4*2 Nitric acid HON(O)O (aq, 50000 H2O) -206.48 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*855 Hydrohelate [HeH]- (g) 143.256 139.027 ± 0.0021 kJ/mol 5.011091 ± 0.000070 12325-01-8*0 Diazene cation [HNNH]+ (g, trans-cis equilib) 1132.48 1125.55 ± 0.64 kJ/mol 30.02881 ± 0.00020 76986-17-9*1 Hydrogen iodide HI (aq, 75 H2O) -55.965 ± 0.099 kJ/mol 127.912410 ± 0.000076 10034-85-2*825 Nitric acid HON(O)O (aq, 5000 H2O) -206.36 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*844 Acetic acid CH3C(O)OH (aq, 30 H2O) -484.32 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*820 Ammonium hydroxide NH4OH (aq, 1500 H2O) -366.36 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*840 Nitrous oxide NNO (aq, undissoc) 61.42 ± 0.11 kJ/mol 44.01288 ± 0.00033 10024-97-2*1000 Hydrogen iodide HI (aq, 150 H2O) -56.137 ± 0.097 kJ/mol 127.912410 ± 0.000076 10034-85-2*829 2-Methyliumylidynehydrazin-2-ium-1-ide [HNNC]+ (g) 1544.1 1542.4 ± 1.7 kJ/mol 41.03157 ± 0.00082 *947408-73-3*0 Acetic acid CH3C(O)OH (aq, 40 H2O) -484.43 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*821 Nitric acid HON(O)O (aq, 2 H2O) -193.74 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*803 Ammonium hydroxide NH4OH (aq, 75 H2O) -366.35 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*825 2-Methanidylidynehydrazin-2-ium-1-ide [HNNC]- (g) 281.8 279.1 ± 1.4 kJ/mol 41.03267 ± 0.00082 *947408-74-4*0 Ethynylamidogen anion [HCCNH]- (g) 233.7 230.5 ± 3.2 kJ/mol 40.0446 ± 0.0016 64066-03-1*0 Neon decacation [Ne]+10 (g) 338828.3 338828.3 ± 1.4 kJ/mol 20.17421 ± 0.00060 32218-07-8*0 Neon hydride NeH (g) 215.989 211.755 ± 0.024 kJ/mol 21.18764 ± 0.00060 17438-52-7*0 2-Methanidylidynehydrazin-2-ium-1-ide [HNNC]- (g, triplet) 518.6 516.2 ± 1.6 kJ/mol 41.03267 ± 0.00082 *947408-74-4*1 Hydroneonate [NeH]- (g) 143.096 142.084 ± 0.035 kJ/mol 21.18819 ± 0.00060 75514-98-6*0 Hydrogen bromide HBr (aq, 111 H2O) -119.56 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*892 Ethynylaminylium [HCCNH]+ (g) 1277.8 1277.4 ± 2.6 kJ/mol 40.0435 ± 0.0016 103835-08-1*0 Hydrogen bromide HBr (aq, 150 H2O) -119.67 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*829 Acetic acid CH3C(O)OH (aq, 50 H2O) -484.51 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*822 Krypton dication [Kr]+2 (g) 3701.124 3701.124 ± 0.013 kJ/mol 83.7989 ± 0.1000 18469-91-5*0 Hydrogen iodide HI (aq, 800 H2O) -56.434 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*837 Xenon dication [Xe]+2 (g) 3194.14 3194.14 ± 0.36 kJ/mol 131.2889 ± 0.0200 14066-95-6*0 Formate [HC(O)O]- (aq) -425.47 ± 0.45 kJ/mol 45.0180 ± 0.0010 71-47-6*800 2-Butynylium [CH3CCCH2]+ (g) 1085.8 1077.6 ± 1.3 kJ/mol 53.0820 ± 0.0032 64235-83-2*0 Formic acid HC(O)OH (aq, 75 H2O) -425.27 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*825 Hydrogen peroxide HOOH (g, ortho) -129.393 -135.399 ± 0.058 kJ/mol 34.01468 ± 0.00062 7722-84-1*1 Hydrogen iodide HI (aq, 20000 H2O) -56.731 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*852 2-Methanidylidynehydrazin-2-ium-1-ide [HNNC]- (g, t-triplet) 531.6 530.2 ± 2.3 kJ/mol 41.03267 ± 0.00082 *947408-74-4*11 Hydrogen bromide HBr (aq, 400 H2O) -119.93 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*832 Acetic acid CH3C(O)OH (aq, 55.51 H2O) -484.54 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*891 Formic acid HC(O)OH (aq, 300 H2O) -425.34 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*831 Sulfur atom hexacation [S]+6 (g) 26947.2 26949.0 ± 3.4 kJ/mol 32.0627 ± 0.0060 22537-26-4*0 Formic acid HC(O)OH (aq, 0.25 H2O) -424.94 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*924 Sulfur atom dianion [S]-2 (g) 454.1 455.9 ± 3.2 kJ/mol 32.0671 ± 0.0060 18496-25-8*0 Hydrogen iodide HI (aq, 20 H2O) -55.09 ± 0.12 kJ/mol 127.912410 ± 0.000076 10034-85-2*818 Disulfur cation [S2]+ (g) 1030.21 1030.80 ± 0.33 kJ/mol 64.1315 ± 0.0120 12597-02-3*0 Disulfur anion [S2]- (g) -33.95 -33.01 ± 0.52 kJ/mol 64.1325 ± 0.0120 12185-15-8*0 Hydroperoxonium [H2OOH]+ (g) 738.2 727.9 ± 1.2 kJ/mol 35.02207 ± 0.00064 70850-26-9*0 2-Aziridinyl NH(CHCH2) (g) 360.6 349.2 ± 1.7 kJ/mol 42.0599 ± 0.0016 *23838-09-7*0 Sulfonyl cation [OSO]+ (g) 897.07 894.80 ± 0.13 kJ/mol 64.0643 ± 0.0060 12439-77-9*0 Sulfur dioxide OSO (cr,l) -331.4 -320.1 ± 1.9 kJ/mol 64.0648 ± 0.0060 7446-09-5*500 Formic acid HC(O)OH (aq, 0.5 H2O) -425.15 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*923 Hydrogen bromide HBr (aq, 10000 H2O) -120.37 ± 0.12 kJ/mol 80.9119 ± 0.0010 10035-10-6*850 Formic acid HC(O)OH (aq, 1 H2O) -425.43 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*801 Formic acid HC(O)OH (aq, 1.5 H2O) -425.53 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*802 Oxosulfate [SO]- (g) -102.60 -101.83 ± 0.50 kJ/mol 48.0659 ± 0.0060 12269-52-2*0 Ammonium hydroxide NH4OH (aq, 750 H2O) -366.37 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*836 Sulfur trioxide cation [OS(O)O]+ (g) 847.66 844.76 ± 0.68 kJ/mol 80.0637 ± 0.0061 12710-95-1*0 Formic acid HC(O)OH (aq, 2 H2O) -425.50 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*803 Sulfite [OS(O)O]-2 (g) -275.1 -280.6 ± 4.4 kJ/mol 80.0653 ± 0.0061 14265-45-3*0 2-Aziridinylium [NH(CHCH2)]+ (g) 1010.6 998.6 ± 3.3 kJ/mol 42.0594 ± 0.0016 *91127-35-4*0 Diazene anion [HNNH]- (g, trans-cis-iso equilib) 265.5 258.7 ± 2.0 kJ/mol 30.02991 ± 0.00020 100429-75-2*0 Sulfur oxide peroxide OSOO (g) -26.0 -30.2 ± 2.3 kJ/mol 80.0642 ± 0.0061 175799-68-5*0 Formic acid HC(O)OH (aq, 2.5 H2O) -425.46 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*804 Sulfur oxide peroxide OSOO (g, trans) -3.4 -7.0 ± 3.0 kJ/mol 80.0642 ± 0.0061 175799-68-5*1 Hydrogen fluoride HF (aq, 1000 H2O) -322.72 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*839 Hydrogen fluoride HF (aq, 55.51 H2O) -321.97 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*891 Sulfuryl dichloride cation [OS(O)Cl2]+ (g) 814.2 809.8 ± 3.2 kJ/mol 134.9697 ± 0.0063 *7791-25-5*0 Dichlorodioxosulfate [OS(O)Cl2]- (g) -604.8 -607.3 ± 3.5 kJ/mol 134.9707 ± 0.0063 12599-04-1*0 Formic acid HC(O)OH (aq, 3 H2O) -425.42 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*805 Disulfur oxide cation [SSO]+ (g) 970.65 969.37 ± 0.61 kJ/mol 80.1309 ± 0.0120 135758-60-0*0 Oxothioxosulfate [SSO]- (g) -231.83 -233.43 ± 0.87 kJ/mol 80.1319 ± 0.0120 12143-07-6*0 Hydrogen cyanide anion [HCN]- (g) 129.521 129.042 ± 0.087 kJ/mol 27.02593 ± 0.00081 12334-27-9*0 Hydrogen chloride HCl (aq, 10000 H2O) -166.847 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*850 Sulfoniumyl [H2S]+ (g) 992.71 989.80 ± 0.19 kJ/mol 34.0813 ± 0.0060 26453-60-1*0 Dihydrogen sulfide ion [H2S]- (g) 108.3 107.0 ± 3.2 kJ/mol 34.0824 ± 0.0060 12311-21-6*0 2-Aziridinylium [NH(CHCH2)]+ (g, triplet) 1304.6 1292.9 ± 4.1 kJ/mol 42.0594 ± 0.0016 *91127-35-4*1 Methoxyethene CH2CHOCH3 (g) -89.5 -106.8 ± 1.1 kJ/mol 58.0791 ± 0.0025 107-25-5*0 Ammonium hydroxide NH4OH (aq, 900 H2O) -366.37 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*838 Hydrogen iodide HI (aq, 25 H2O) -55.35 ± 0.11 kJ/mol 127.912410 ± 0.000076 10034-85-2*819 Sulfuric acid cation [OS(O)(OH)2]+ (g) 401.3 388.3 ± 3.3 kJ/mol 98.0789 ± 0.0061 247933-66-0*0 Nitrous acid anion [HONO]- (g) -105.83 -109.30 ± 0.78 kJ/mol 47.01403 ± 0.00061 256393-36-9*0 2-Aziridinylium [NH(CHCH2)]+ (g, syn-triplet) 1334.6 1323.6 ± 4.8 kJ/mol 42.0594 ± 0.0016 *91127-35-4*11 Diazene anion [HNNH]- (g, trans-cis equilib) 265.5 258.7 ± 2.0 kJ/mol 30.02991 ± 0.00020 100429-75-2*1 Cycloprop-2-yliumyl [CH2(CHCH)]+ (g) 1225.40 1218.24 ± 0.59 kJ/mol 40.0633 ± 0.0024 65812-78-4*0 Sulfate [SO4]-2 (aq) -909.08 ± 0.14 kJ/mol 96.0647 ± 0.0061 14808-79-8*800 1-Methylene-2-propenylium [CH2CHCCH2]+ (g) 1059.4 1049.3 ± 1.7 kJ/mol 53.0820 ± 0.0032 62698-26-4*0 Tetroxidane HOOOOH (g, C2 I) -31.26 -41.77 ± 0.64 kJ/mol 66.0135 ± 0.0012 29683-94-1*22 Sulfuric acid OS(O)(OH)2 (aq, 10 H2O) -880.34 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*815 Sulfuric acid OS(O)(OH)2 (aq, 12 H2O) -881.95 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*816 Sulfuric acid OS(O)(OH)2 (aq, 15 H2O) -883.44 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*817 Sulfuric acid OS(O)(OH)2 (aq, 20 H2O) -884.73 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*818 Sulfuric acid OS(O)(OH)2 (aq, 25 H2O) -885.40 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*819 Sulfuric acid OS(O)(OH)2 (aq, 30 H2O) -885.80 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*820 1,2-Difluoroethene CHFCHF (g) -302.83 -308.92 ± 0.89 kJ/mol 64.0341 ± 0.0016 1691-13-0*0 Formic acid HC(O)OH (aq, 4 H2O) -425.36 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*807 Hydrogen fluoride HF (aq, 10000 H2O) -325.44 ± 0.17 kJ/mol 20.006343 ± 0.000070 7664-39-3*850 Sulfuric acid OS(O)(OH)2 (aq, 150 H2O) -888.00 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*829 Sulfuric acid OS(O)(OH)2 (aq, 200 H2O) -888.44 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*830 Sulfuric acid OS(O)(OH)2 (aq, 300 H2O) -889.19 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*831 Sulfuric acid OS(O)(OH)2 (aq, 400 H2O) -889.79 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*832 Sulfuric acid OS(O)(OH)2 (aq, 500 H2O) -890.31 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*833 Sulfuric acid OS(O)(OH)2 (aq, 600 H2O) -890.80 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*834 Diisocyanogen anion [CNNC]- (g) 456.8 462.5 ± 3.6 kJ/mol 52.0354 ± 0.0016 *78800-22-3*0 Acetic acid CH3C(O)OH (aq, 111 H2O) -484.67 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*892 Sulfuric acid OS(O)(OH)2 (aq, 900 H2O) -891.86 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*838 Diazirinyl HC(NN) (g) 491.06 487.67 ± 0.96 kJ/mol 41.03212 ± 0.00082 69967-71-1*0 Difluorovinylidene anion [CCF2]- (g) -88.2 -87.1 ± 2.3 kJ/mol 62.0188 ± 0.0016 107693-92-5*0 Cyanic fluoride cation [FCN]+ (g) 1294.2 1294.7 ± 1.1 kJ/mol 45.01529 ± 0.00080 62532-69-8*0 Sulfuric acid OS(O)(OH)2 (aq, 4000 H2O) -896.93 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*843 Dibromovinylidene CCBr2 (g) 510.5 499.4 ± 4.1 kJ/mol 183.8294 ± 0.0026 261771-36-2*0 Nitric acid HON(O)O (aq, 500 H2O) -206.15 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*833 Formic acid HC(O)OH (aq, 5 H2O) -425.30 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*809 Sulfuric acid OS(O)(OH)2 (aq, 20000 H2O) -903.14 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*852 Sulfuric acid OS(O)(OH)2 (aq, 50000 H2O) -905.84 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*855 Sulfuric acid OS(O)(OH)2 (aq, 100000 H2O) -907.13 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*861 Fluorovinylidene CCHF (g) 298.9 300.1 ± 3.1 kJ/mol 44.0277 ± 0.0016 70302-00-0*0 Ammonium hydroxide NH4OH (aq, 12 H2O) -366.06 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*816 Acetic acid CH3C(O)OH (aq, 200 H2O) -484.74 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*830 Nitric acid HON(O)O (aq, 10 H2O) -205.00 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*815 Acetic acid CH3C(O)OH (aq, 300 H2O) -484.76 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*831 Bromovinylidene CCHBr (g) 466.4 460.4 ± 3.8 kJ/mol 104.9333 ± 0.0019 161957-27-3*0 Water anion [H2O]- (g) -50.1 -53.0 ± 4.3 kJ/mol 18.01583 ± 0.00033 12259-30-2*0 Ketene CH2CO (g, ortho singlet) -45.23 -48.41 ± 0.11 kJ/mol 42.0367 ± 0.0016 463-51-4*22 Difluorophosgene anion [CF2O]- (g) -602.3 -604.2 ± 3.3 kJ/mol 66.00745 ± 0.00085 474815-26-4*0 Cyanic fluoride anion [FCN]- (g) -20.7 -18.7 ± 2.9 kJ/mol 45.01639 ± 0.00080 34507-50-1*0 Acetic acid CH3C(O)OH (aq, 400 H2O) -484.78 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*832 Formic acid HC(O)OH (aq, 111 H2O) -425.30 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*892 Fluoro(fluorooxy)methylene FCOF (g) -134.8 -136.0 ± 1.3 kJ/mol 66.00691 ± 0.00085 479587-30-9*0 Carbonylbis(oxy) OC(O)O (g) -144.7 -145.8 ± 2.4 kJ/mol 60.0089 ± 0.0012 16518-45-9*0 Diazirenide [HC(NN)]- (g, triplet) 504.8 501.3 ± 2.9 kJ/mol 41.03267 ± 0.00082 130614-84-5*1 2-Aziridinide [NH(CHCH2)]- (g) 315.9 303.8 ± 3.5 kJ/mol 42.0604 ± 0.0016 111127-93-6*0 2-Aziridinide [NH(CHCH2)]- (g, syn) 329.8 317.8 ± 4.0 kJ/mol 42.0604 ± 0.0016 111127-93-6*1 Trioxygen difluoride FOOOF (g, cis) 113.6 107.8 ± 2.0 kJ/mol 85.99501 ± 0.00090 16829-28-0*2 Sulfur hydroxide oxide OHS(O)(O)O (g) -474.0 -483.0 ± 1.7 kJ/mol 97.0715 ± 0.0061 12337-07-4*0 Sulfur hydroxide oxide OHS(O)(O)O (g, eclipsed) -473.2 -482.5 ± 2.5 kJ/mol 97.0715 ± 0.0061 12337-07-4*2 Sulfur hydroxide oxide cation [OHS(O)(O)O]+ (g) 659.0 648.8 ± 3.5 kJ/mol 97.0710 ± 0.0061 *12337-07-4*0 Sulfur hydroxide oxide cation [OHS(O)(O)O]+ (g, staggered) 663.6 652.6 ± 3.9 kJ/mol 97.0710 ± 0.0061 *12337-07-4*1 Acetic acid CH3C(O)OH (aq, 500 H2O) -484.79 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*833 Hydrogen iodide HI (aq, 30 H2O) -55.51 ± 0.11 kJ/mol 127.912410 ± 0.000076 10034-85-2*820 Sulfurous acid S(O)(OH)2 (g, trans) -506.9 -517.6 ± 1.3 kJ/mol 82.0801 ± 0.0061 7782-99-2*1 Sulfurous acid S(O)(OH)2 (g, gauche) -497.3 -507.4 ± 1.4 kJ/mol 82.0801 ± 0.0061 7782-99-2*3 Fluorine atom nonacation [F]+9 (g) 262121.1 262122.9 ± 1.8 kJ/mol 18.99346598 ± 0.00000050 35424-07-8*0 Acetic acid CH3C(O)OH (aq, 555.1 H2O) -484.79 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*895 Sulfite [OS(O)O]-2 (aq) -635.18 ± 0.16 kJ/mol 80.0653 ± 0.0061 14265-45-3*800 Sulfurous acid S(O)(OH)2 (aq, 100 H2O) -610.03 ± 0.15 kJ/mol 82.0801 ± 0.0061 7782-99-2*828 Sulfurous acid S(O)(OH)2 (aq, 150 H2O) -610.75 ± 0.15 kJ/mol 82.0801 ± 0.0061 7782-99-2*829 Sulfurous acid S(O)(OH)2 (aq, 200 H2O) -611.28 ± 0.15 kJ/mol 82.0801 ± 0.0061 7782-99-2*830 Sulfurous acid S(O)(OH)2 (aq, 250 H2O) -611.72 ± 0.15 kJ/mol 82.0801 ± 0.0061 7782-99-2*908 Sulfurous acid S(O)(OH)2 (aq, 300 H2O) -612.09 ± 0.15 kJ/mol 82.0801 ± 0.0061 7782-99-2*831 Sulfurous acid S(O)(OH)2 (aq, 400 H2O) -612.69 ± 0.15 kJ/mol 82.0801 ± 0.0061 7782-99-2*832 Sulfurous acid S(O)(OH)2 (aq, 500 H2O) -613.19 ± 0.15 kJ/mol 82.0801 ± 0.0061 7782-99-2*833 Sulfurous acid S(O)(OH)2 (aq, 750 H2O) -614.13 ± 0.15 kJ/mol 82.0801 ± 0.0061 7782-99-2*836 Sulfurous acid S(O)(OH)2 (aq, 1000 H2O) -614.82 ± 0.15 kJ/mol 82.0801 ± 0.0061 7782-99-2*839 Sulfurous acid S(O)(OH)2 (aq, 1500 H2O) -615.91 ± 0.15 kJ/mol 82.0801 ± 0.0061 7782-99-2*840 Sulfurous acid S(O)(OH)2 (aq, 2000 H2O) -616.67 ± 0.15 kJ/mol 82.0801 ± 0.0061 7782-99-2*841 Sulfurous acid S(O)(OH)2 (aq, 3000 H2O) -617.71 ± 0.15 kJ/mol 82.0801 ± 0.0061 7782-99-2*842 Sulfurous acid S(O)(OH)2 (aq, 3500 H2O) -618.12 ± 0.15 kJ/mol 82.0801 ± 0.0061 7782-99-2*899 Sulfurous acid S(O)(OH)2 (aq, 4000 H2O) -618.45 ± 0.15 kJ/mol 82.0801 ± 0.0061 7782-99-2*843 Sulfurous acid S(O)(OH)2 (aq, 5000 H2O) -619.04 ± 0.15 kJ/mol 82.0801 ± 0.0061 7782-99-2*844 Sulfurous acid S(O)(OH)2 (aq, 7500 H2O) -620.02 ± 0.15 kJ/mol 82.0801 ± 0.0061 7782-99-2*847 Sulfurous acid S(O)(OH)2 (aq, 10000 H2O) -620.61 ± 0.15 kJ/mol 82.0801 ± 0.0061 7782-99-2*850 Sulfonic acid SH(O)(O)OH (g) -482.1 -494.7 ± 1.4 kJ/mol 82.0801 ± 0.0061 *7782-99-2*0 Hydrogen iodide HI (aq, 40 H2O) -55.697 ± 0.096 kJ/mol 127.912410 ± 0.000076 10034-85-2*821 Tetroxidane HOOOOH (g, C2 II) -30.93 -41.38 ± 0.64 kJ/mol 66.0135 ± 0.0012 29683-94-1*23 1,2-Butadienylium [CH3CHCCH]+ (g) 1099.2 1089.8 ± 1.2 kJ/mol 53.0820 ± 0.0032 *65114-67-2*0 (Dimethylamino)methyl anion [(CH3)2NCH2]- (g) 190.5 166.3 ± 3.3 kJ/mol 58.1029 ± 0.0025 125231-49-4*0 Oxonium [H3O]+ (aq) -285.798 ± 0.022 kJ/mol 19.02267 ± 0.00037 13968-08-6*800 Platinum atom cation Pt+ (g) 1427.8 1428.3 ± 1.7 kJ/mol 195.0775 ± 0.0020 20561-56-2*0 Platinum atom anion Pt- (g) 358.4 358.9 ± 1.7 kJ/mol 195.0785 ± 0.0020 40817-31-0*0 Methoxyethene CH2CHOCH3 (g, trans) -82.1 -99.2 ± 2.4 kJ/mol 58.0791 ± 0.0025 107-25-5*1 Platinum dimer cation [Pt2]+ (g) 1661.0 1659.6 ± 4.3 kJ/mol 390.1555 ± 0.0040 73146-08-4*0 Platinum dimer anion [Pt2]- (g) 640.3 639.8 ± 3.9 kJ/mol 390.1565 ± 0.0040 153298-77-2*0 Cyanogen NCCN (cr,l) 273.92 289.17 ± 0.42 kJ/mol 52.0349 ± 0.0016 460-19-5*500 Platinum hydride cation [PtH]+ (g) 1336. 1355. ± 22. kJ/mol 196.0854 ± 0.0020 87882-39-1*0 Chlorous acid cation [HOClO]+ (g) 996.6 991.6 ± 3.1 kJ/mol 68.4589 ± 0.0011 *99559-66-7*0 Hydrogen atom H (ad, Pt(111) fcc) -37.0 -40.2 ± 1.1 kJ/mol 1.007940 ± 0.000070 12385-13-6*1001000 Formic acid HC(O)OH (aq, 6 H2O) -425.26 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*811 Ammonium hydroxide NH4OH (aq, 800 H2O) -366.37 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*837 Cyclopropylidene C(CH2CH2) (g) 474.96 466.93 ± 0.84 kJ/mol 40.0639 ± 0.0024 2143-70-6*0 Isocyanogen anion [CNCN]- (g) 386.6 388.7 ± 3.3 kJ/mol 52.0354 ± 0.0016 *83951-85-3*0 Hydrogen atom H (ad, Pt(111) atop) -32. -34. ± 20. kJ/mol 1.007940 ± 0.000070 12385-13-6*1002000 Formic acid HC(O)OH (aq, 7 H2O) -425.23 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*812 Formic acid HC(O)OH (aq, 8 H2O) -425.21 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*813 Formic acid HC(O)OH (aq, 9 H2O) -425.20 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*814 Formic acid HC(O)OH (aq, 10 H2O) -425.19 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*815 Formic acid HC(O)OH (aq, 12 H2O) -425.19 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*816 Formic acid HC(O)OH (aq, 15 H2O) -425.19 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*817 Argon cation Ar+ (g) 1520.571 1520.580 ± 0.000 kJ/mol 39.94745 ± 0.00100 14791-69-6*0 Argon dimer cation [Ar2]+ (g) 1393.760 1391.173 ± 0.018 kJ/mol 79.8955 ± 0.0020 17596-58-6*0 Argon atom dication [Ar]+2 (g) 4186.429 4186.468 ± 0.013 kJ/mol 39.94690 ± 0.00100 15056-24-3*0 Argon dimer Ar2 (g) -1.013 -6.347 ± 0.0051 kJ/mol 79.8960 ± 0.0020 12595-59-4*0 Argon anion Ar- (g, 2S1/2) 25. 25. ± 28. kJ/mol 39.94855 ± 0.00100 16544-90-4*1 Neon anion Ne- (g) 13. 13. ± 29. kJ/mol 20.18025 ± 0.00060 20205-95-2*0 Argon anion Ar- (g) 25. 25. ± 28. kJ/mol 39.94855 ± 0.00100 16544-90-4*0 Helium anion He- (g, 1s2.2s 2S1/2) 51. 51. ± 130. kJ/mol 4.0031506 ± 0.0000020 14452-58-5*1 Helium anion He- (g) 51. 51. ± 130. kJ/mol 4.0031506 ± 0.0000020 14452-58-5*0 Dihelium He2 (g, halo singlet) -0.000 -6.197 ± 0.000 kJ/mol 8.0052040 ± 0.0000040 12184-98-4*3 Dihelium He2 (g) -0.000 -6.197 ± 0.000 kJ/mol 8.0052040 ± 0.0000040 12184-98-4*0 Dinitrogen N2 (aq, undissoc) -10.30 ± 0.32 kJ/mol 28.01348 ± 0.00014 7727-37-9*1000 Dichlorine Cl2 (cr,l) -30.21 -18.49 ± 0.51 kJ/mol 70.9054 ± 0.0018 7782-50-5*500 Helium anion He- (g, 1s.2s2 2S1/2) 1868.42 1868.42 ± 0.19 kJ/mol 4.0031506 ± 0.0000020 14452-58-5*2 Helium He (aq, undissoc) -0.69 ± 0.16 kJ/mol 4.0026020 ± 0.0000020 7440-59-7*1000 Dichlorine Cl2 (aq, undissoc) -16.54 ± 0.12 kJ/mol 70.9054 ± 0.0018 7782-50-5*1000 Dihydrogen H2 (aq, undissoc) -4.099 ± 0.080 kJ/mol 2.01588 ± 0.00014 1333-74-0*1000 Neon Ne (aq, undissoc) -3.87 ± 0.16 kJ/mol 20.17970 ± 0.00060 7440-01-9*1000 Dioxygen O2 (aq, undissoc) -11.961 ± 0.041 kJ/mol 31.99880 ± 0.00060 7782-44-7*1000 Argon anion Ar- (g, 4S3/2) 1111.116 1111.116 ± 0.098 kJ/mol 39.94855 ± 0.00100 16544-90-4*2 Argon Ar (aq, undissoc) -12.24 ± 0.16 kJ/mol 39.94800 ± 0.00100 7440-37-1*1000 Krypton anion Kr- (g) 110. 110. ± 350. kJ/mol 83.8005 ± 0.1000 20205-93-0*0 Krypton Kr (aq, undissoc) -15.63 ± 0.16 kJ/mol 83.8000 ± 0.1000 7439-90-9*1000 Xenon Xe (aq, undissoc) -19.39 ± 0.64 kJ/mol 131.2900 ± 0.0200 7440-63-3*1000 Radon cation Rn+ (g) 1037.07 1037.07 ± 0.61 kJ/mol 221.9995 ± 0.1000 22541-65-7*0 Radon Rn (aq, undissoc) -21.33 ± 0.96 kJ/mol 222.0000 ± 0.1000 10043-92-2*1000 Hydron H+ (aq) 0 0 exact 1.007391 ± 0.000070 12408-02-5*800