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 atom 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 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 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 atom C (g) 711.407 716.892 ± 0.048 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 Nitrogen atom N (g) 470.579 472.441 ± 0.024 kJ/mol 14.006740 ± 0.000070 17778-88-0*0 Chlorine atom Cl (g) 119.621 121.302 ± 0.0011 kJ/mol 35.45270 ± 0.00090 22537-15-1*0 Carbon dioxide CO2 (g) -393.109 -393.475 ± 0.015 kJ/mol 44.00950 ± 0.00100 124-38-9*0 Fluorine atom F (g) 77.253 79.359 ± 0.048 kJ/mol 18.99840320 ± 0.00000050 14762-94-8*0 Methane CH4 (g) -66.556 -74.525 ± 0.056 kJ/mol 16.04246 ± 0.00085 74-82-8*0 Water H2O (cr,l) -286.308 -285.836 ± 0.027 kJ/mol 18.01528 ± 0.00033 7732-18-5*500 Water H2O (g) -238.938 -241.842 ± 0.027 kJ/mol 18.01528 ± 0.00033 7732-18-5*0 Ethane CH3CH3 (g) -68.33 -83.96 ± 0.13 kJ/mol 30.0690 ± 0.0017 74-84-0*0 Hydron H+ (g) 1528.084 1530.047 ± 0.000 kJ/mol 1.007391 ± 0.000070 12408-02-5*0 Bromine atom Br (g) 117.917 111.855 ± 0.056 kJ/mol 79.90400 ± 0.00100 10097-32-2*0 Ethylene CH2CH2 (g) 60.91 52.39 ± 0.12 kJ/mol 28.0532 ± 0.0016 74-85-1*0 Hydrogen chloride HCl (g) -91.989 -92.173 ± 0.0062 kJ/mol 36.46064 ± 0.00090 7647-01-0*0 Hydroxyl OH (g) 37.242 37.482 ± 0.027 kJ/mol 17.00734 ± 0.00031 3352-57-6*0 Methyl CH3 (g) 149.829 146.414 ± 0.080 kJ/mol 15.03452 ± 0.00083 2229-07-4*0 Carbon monoxide CO (g) -113.802 -110.522 ± 0.026 kJ/mol 28.01010 ± 0.00085 630-08-0*0 Methanol CH3OH (g) -189.95 -200.84 ± 0.15 kJ/mol 32.04186 ± 0.00090 67-56-1*0 Hydrogen fluoride HF (g) -272.679 -272.726 ± 0.049 kJ/mol 20.006343 ± 0.000070 7664-39-3*0 Hydrogen bromide HBr (g) -27.72 -35.57 ± 0.16 kJ/mol 80.9119 ± 0.0010 10035-10-6*0 Iodine atom I (g) 107.157 106.757 ± 0.0021 kJ/mol 126.904470 ± 0.000030 14362-44-8*0 Formaldehyde CH2O (g) -105.347 -109.186 ± 0.098 kJ/mol 30.02598 ± 0.00087 50-00-0*0 Acetylene HCCH (g) 228.83 228.27 ± 0.13 kJ/mol 26.0373 ± 0.0016 74-86-2*0 Ethyl CH3CH2 (g) 130.94 119.87 ± 0.28 kJ/mol 29.0611 ± 0.0016 2025-56-1*0 Propane CH3CH2CH3 (g) -82.74 -105.03 ± 0.19 kJ/mol 44.0956 ± 0.0025 74-98-6*0 Ethanol CH3CH2OH (g) -216.92 -234.64 ± 0.21 kJ/mol 46.0684 ± 0.0017 64-17-5*0 Chloromethane CH3Cl (g) -74.17 -82.10 ± 0.25 kJ/mol 50.4872 ± 0.0012 74-87-3*0 Nitric oxide NO (g) 90.616 91.120 ± 0.065 kJ/mol 30.00614 ± 0.00031 10102-43-9*0 Ammonia NH3 (g) -38.565 -45.557 ± 0.030 kJ/mol 17.03056 ± 0.00022 7664-41-7*0 Hydrogen cyanide HCN (g) 129.668 129.283 ± 0.091 kJ/mol 27.02538 ± 0.00081 74-90-8*0 Nitrogen dioxide ONO (g) 36.855 34.048 ± 0.065 kJ/mol 46.00554 ± 0.00060 10102-44-0*0 Methyl fluoride CH3F (g) -227.44 -235.47 ± 0.24 kJ/mol 34.03292 ± 0.00083 593-53-3*0 Hydrogen iodide HI (g) 28.646 26.470 ± 0.036 kJ/mol 127.912410 ± 0.000076 10034-85-2*0 Propene CH3CHCH2 (g) 34.98 19.98 ± 0.21 kJ/mol 42.0797 ± 0.0024 115-07-1*0 Hydroxyde [OH]- (g) -139.099 -139.066 ± 0.027 kJ/mol 17.00789 ± 0.00031 14280-30-9*0 Hydrogen peroxide H2O2 (g) -129.492 -135.478 ± 0.063 kJ/mol 34.01468 ± 0.00062 7722-84-1*0 Dioxidanyl HO2 (g) 15.12 12.21 ± 0.15 kJ/mol 33.00674 ± 0.00060 3170-83-0*0 Methyl bromide CH3Br (g) -20.18 -35.58 ± 0.27 kJ/mol 94.9385 ± 0.0013 74-83-9*0 Benzene C6H6 (g) 100.58 83.07 ± 0.23 kJ/mol 78.1118 ± 0.0048 71-43-2*0 Hypochlorous acid HOCl (g) -73.875 -76.815 ± 0.028 kJ/mol 52.46004 ± 0.00095 7790-92-3*0 Acetaldehyde CH3CHO (g) -154.96 -165.44 ± 0.28 kJ/mol 44.0526 ± 0.0017 75-07-0*0 Dibromine Br2 (g) 45.68 30.89 ± 0.12 kJ/mol 159.8080 ± 0.0020 7726-95-6*0 Fluoride F- (g) -250.912 -249.127 ± 0.048 kJ/mol 18.99895178 ± 0.00000050 16984-48-8*0 Tetrafluoromethane CF4 (g) -927.41 -933.39 ± 0.26 kJ/mol 88.00431 ± 0.00080 75-73-0*0 Methylene CH2 (g, triplet) 391.03 391.59 ± 0.12 kJ/mol 14.02658 ± 0.00081 2465-56-7*1 Methylene CH2 (g, singlet) 428.70 429.11 ± 0.12 kJ/mol 14.02658 ± 0.00081 2465-56-7*2 Methylidyne CH (g) 592.81 596.15 ± 0.11 kJ/mol 13.01864 ± 0.00080 3315-37-5*0 Tetrachloromethane CCl4 (g) -93.50 -95.67 ± 0.45 kJ/mol 153.8215 ± 0.0037 56-23-5*0 Diiodine I2 (g) 65.497 62.417 ± 0.0041 kJ/mol 253.808940 ± 0.000060 7553-56-2*0 Formic acid HC(O)OH (g, syn) -371.06 -378.38 ± 0.22 kJ/mol 46.0254 ± 0.0010 64-18-6*1 Propyne CH3CCH (g) 192.82 185.76 ± 0.25 kJ/mol 40.0639 ± 0.0024 74-99-7*0 Fluoroform CF3H (g) -688.79 -695.74 ± 0.44 kJ/mol 70.01385 ± 0.00080 75-46-7*0 Toluene C6H5CH3 (g) 73.44 50.15 ± 0.34 kJ/mol 92.1384 ± 0.0056 108-88-3*0 Oxonium [H3O]+ (g) 605.84 599.09 ± 0.17 kJ/mol 19.02267 ± 0.00037 13968-08-6*0 Chloride Cl- (g) -228.953 -227.346 ± 0.0021 kJ/mol 35.45325 ± 0.00090 16887-00-6*0 Bromide Br- (g) -206.620 -212.682 ± 0.056 kJ/mol 79.90455 ± 0.00100 24959-67-9*0 Ozone OOO (g) 144.396 141.734 ± 0.039 kJ/mol 47.99820 ± 0.00090 10028-15-6*0 Hypobromous acid HOBr (g) -51.71 -62.18 ± 0.59 kJ/mol 96.9113 ± 0.0010 13517-11-8*0 Methoxy CH3O (g) 28.99 21.62 ± 0.29 kJ/mol 31.03392 ± 0.00088 2143-68-2*0 n-Butane CH3CH2CH2CH3 (g) -98.65 -125.96 ± 0.26 kJ/mol 58.1222 ± 0.0033 106-97-8*0 Chloroethane CH3CH2Cl (g) -96.80 -111.38 ± 0.20 kJ/mol 64.5138 ± 0.0019 75-00-3*0 Methylamine CH3NH2 (g) -7.01 -21.72 ± 0.31 kJ/mol 31.05714 ± 0.00088 74-89-5*0 Chlorine monoxide ClO (g) 101.125 101.716 ± 0.035 kJ/mol 51.45210 ± 0.00095 14989-30-1*0 Trifluoromethyl CF3 (g) -465.02 -467.82 ± 0.49 kJ/mol 69.00591 ± 0.00080 2264-21-3*0 Ethylium [CH3CH2]+ (g) 914.95 902.87 ± 0.31 kJ/mol 29.0606 ± 0.0016 14936-94-8*0 Hydroxymethyl CH2OH (g) -10.49 -16.80 ± 0.28 kJ/mol 31.03392 ± 0.00088 2597-43-5*0 Oxomethylium [HCO]+ (g) 827.804 827.220 ± 0.098 kJ/mol 29.01749 ± 0.00086 17030-74-9*0 Vinyl CH2CH (g) 301.14 296.94 ± 0.34 kJ/mol 27.0452 ± 0.0016 2669-89-8*0 Imidogen NH (g) 358.74 358.79 ± 0.17 kJ/mol 15.014680 ± 0.000099 13774-92-0*0 Allene CH2CCH2 (g) 197.37 189.89 ± 0.26 kJ/mol 40.0639 ± 0.0024 463-49-0*0 Methoxide [CH3O]- (g) -122.48 -130.21 ± 0.31 kJ/mol 31.03447 ± 0.00088 3315-60-4*0 Nitrilomethyl CN (g) 436.71 439.99 ± 0.15 kJ/mol 26.01744 ± 0.00080 2074-87-5*0 Dioxymethyl CH2OO (g) 111.90 104.90 ± 0.63 kJ/mol 46.0254 ± 0.0010 56077-92-0*0 Difluorophosgene COF2 (g) -603.40 -606.50 ± 0.48 kJ/mol 66.00691 ± 0.00085 353-50-4*0 Nitric acid HNO3 (g) -124.49 -134.20 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*0 Ketene CH2CO (g) -45.37 -48.49 ± 0.13 kJ/mol 42.0367 ± 0.0016 463-51-4*0 Formyl HCO (g) 41.429 41.805 ± 0.098 kJ/mol 29.01804 ± 0.00086 2597-44-6*0 Phenol C6H5OH (g) -74.52 -93.12 ± 0.68 kJ/mol 94.1112 ± 0.0048 108-95-2*0 Methylium [CH3]+ (g) 1099.234 1095.291 ± 0.078 kJ/mol 15.03397 ± 0.00083 14531-53-4*0 Hypoflorous acid HOF (g) -84.40 -87.30 ± 0.19 kJ/mol 36.00574 ± 0.00031 14034-79-8*0 Iodide I- (g) -187.995 -188.396 ± 0.0021 kJ/mol 126.905019 ± 0.000030 20461-54-5*0 Vinyl chloride CH2CHCl (g) 29.44 21.86 ± 0.31 kJ/mol 62.4979 ± 0.0018 75-01-4*0 Phenyl C6H5 (g) 350.19 336.83 ± 0.56 kJ/mol 77.1039 ± 0.0048 2396-01-2*0 Cyanogen chloride ClCN (g) 135.04 135.73 ± 0.47 kJ/mol 61.4701 ± 0.0012 506-77-4*0 Cyanogen bromide BrCN (g) 187.1 180.5 ± 1.1 kJ/mol 105.9214 ± 0.0013 506-68-3*0 Methyl iodide CH3I (g) 24.40 14.86 ± 0.18 kJ/mol 141.93899 ± 0.00083 74-88-4*0 Acetone CH3C(O)CH3 (g) -199.56 -216.25 ± 0.32 kJ/mol 58.0791 ± 0.0025 67-64-1*0 Oxygen atom anion O- (g) 105.868 108.097 ± 0.0021 kJ/mol 15.99995 ± 0.00030 14337-01-0*0 Ethoxide [CH3CH2O]- (g) -163.35 -178.29 ± 0.53 kJ/mol 45.0610 ± 0.0017 16331-64-9*0 Hydrogen chloride HCl (aq, 600 H2O) -166.454 ± 0.024 kJ/mol 36.46064 ± 0.00090 7647-01-0*834 Amidogen NH2 (g) 188.91 186.02 ± 0.12 kJ/mol 16.02262 ± 0.00016 13770-40-6*0 Trihydrogen cation [H3]+ (g) 1110.304 1106.696 ± 0.013 kJ/mol 3.02327 ± 0.00021 28132-48-1*0 iso-Butane CH(CH3)3 (g) -106.16 -134.76 ± 0.32 kJ/mol 58.1222 ± 0.0033 75-28-5*0 Dichloromethane CH2Cl2 (g) -87.55 -94.41 ± 0.49 kJ/mol 84.9320 ± 0.0020 75-09-2*0 Tetrabromomethane CBr4 (g) 133.2 103.5 ± 1.3 kJ/mol 331.6267 ± 0.0041 558-13-4*0 Methylene fluoride CH2F2 (g) -443.00 -450.58 ± 0.36 kJ/mol 52.02339 ± 0.00081 75-10-5*0 Oxygen difluoride FOF (g) 26.80 24.55 ± 0.24 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 2-Propynyl CH2CCH (g) 353.99 351.43 ± 0.38 kJ/mol 39.0559 ± 0.0024 2932-78-7*0 Propynylidene HCCCH (g, triplet) 543.38 546.38 ± 0.63 kJ/mol 38.0480 ± 0.0024 67152-18-5*1 Chloroform CHCl3 (g) -97.43 -102.34 ± 0.52 kJ/mol 119.3767 ± 0.0028 67-66-3*0 Oxygen atom cation O+ (g) 1560.786 1562.644 ± 0.0021 kJ/mol 15.99885 ± 0.00030 14581-93-2*0 1,2-Propadiene-1,3-diylidene CCC (g) 814.62 823.58 ± 0.55 kJ/mol 36.0321 ± 0.0024 12075-35-3*0 Cyanic fluoride FCN (g) 8.78 9.11 ± 0.71 kJ/mol 45.01584 ± 0.00080 1495-50-7*0 Allyl CH2CHCH2 (g) 179.54 167.82 ± 0.55 kJ/mol 41.0718 ± 0.0024 1981-80-2*0 1-Hydroxyethyl CH3CHOH (g, gauche-anti) -42.00 -55.43 ± 0.65 kJ/mol 45.0605 ± 0.0017 2348-46-1*1 2-Hydroxyethyl CH2CH2OH (g, gauche-syn) -12.84 -26.11 ± 0.63 kJ/mol 45.0605 ± 0.0017 4422-54-2*1 Methylperoxy CH3OO (g) 22.31 12.66 ± 0.50 kJ/mol 47.0333 ± 0.0010 2143-58-0*0 Tetrafluoroethylene C2F4 (g) -671.33 -674.73 ± 0.58 kJ/mol 100.0150 ± 0.0016 116-14-3*0 Chlorine fluoride ClF (g) -55.622 -55.717 ± 0.055 kJ/mol 54.45110 ± 0.00090 7790-89-8*0 Diazynium [NNH]+ (g) 1042.54 1038.93 ± 0.68 kJ/mol 29.02087 ± 0.00016 12357-66-3*0 Methanimine CH2NH (g) 96.25 88.34 ± 0.62 kJ/mol 29.04126 ± 0.00083 2053-29-4*0 Nitrite [ONO]- (g) -182.63 -185.44 ± 0.46 kJ/mol 46.00609 ± 0.00060 14797-65-0*0 Hydride H- (g) 143.264 145.228 ± 0.000 kJ/mol 1.008489 ± 0.000070 12184-88-2*0 Nitrosyl hydride HNO (g) 109.93 106.96 ± 0.11 kJ/mol 31.01408 ± 0.00032 14332-28-6*0 Nitrous acid HONO (g, trans) -73.023 -79.167 ± 0.079 kJ/mol 47.01348 ± 0.00061 7782-77-6*1 Ethynylene C2 (g) 820.28 828.74 ± 0.27 kJ/mol 24.0214 ± 0.0016 12070-15-4*0 Ethynyl CCH (g) 563.87 567.99 ± 0.15 kJ/mol 25.0293 ± 0.0016 2122-48-7*0 Methyl hydroperoxide CH3OOH (g) -115.03 -127.85 ± 0.76 kJ/mol 48.0413 ± 0.0010 3031-73-0*0 iso-Propyl CH3CHCH3 (g) 105.05 88.18 ± 0.56 kJ/mol 43.0877 ± 0.0024 2025-55-0*0 Phosgene CCl2O (g) -217.44 -219.13 ± 0.27 kJ/mol 98.9155 ± 0.0020 75-44-5*0 Fluoromethylidyne CF (g) 243.14 246.74 ± 0.13 kJ/mol 31.00910 ± 0.00080 3889-75-6*0 Phenylium [C6H5]+ (g) 1148.45 1135.67 ± 0.88 kJ/mol 77.1034 ± 0.0048 17333-73-2*0 Fluorooxidanyl FO (g) 110.27 110.89 ± 0.15 kJ/mol 34.99780 ± 0.00030 12061-70-0*0 Hypoiodous acid HOI (g) -54.2 -59.0 ± 3.1 kJ/mol 143.91181 ± 0.00031 14332-21-9*0 Methanium [CH5]+ (g) 921.98 911.73 ± 0.45 kJ/mol 17.04985 ± 0.00087 15135-49-6*0 Hydroxylamine NH2OH (g, trans) -33.24 -43.62 ± 0.50 kJ/mol 33.02996 ± 0.00037 7803-49-8*1 Oxirane O(CH2CH2) (g) -40.01 -52.55 ± 0.38 kJ/mol 44.0526 ± 0.0017 75-21-8*0 Hydroxyformyl HOCO (g, trans) -181.19 -184.16 ± 0.50 kJ/mol 45.0174 ± 0.0010 2564-86-5*1 Formate [HC(O)O]- (g) -462.90 -466.55 ± 0.56 kJ/mol 45.0180 ± 0.0010 71-47-6*0 Isocyanic acid HNCO (g) -115.84 -118.84 ± 0.31 kJ/mol 43.02478 ± 0.00086 75-13-8*0 Chlorotrifluoromethane CF3Cl (g) -704.89 -710.00 ± 0.72 kJ/mol 104.4586 ± 0.0012 75-72-9*0 Bromotrifluoromethane CF3Br (g) -639.28 -651.40 ± 0.51 kJ/mol 148.9099 ± 0.0013 75-63-8*0 Fluorobenzene C6H5F (g) -99.10 -114.77 ± 0.89 kJ/mol 96.1023 ± 0.0048 462-06-6*0 Nitromethane CH3N(O)O (g) -60.85 -74.75 ± 0.46 kJ/mol 61.0401 ± 0.0010 75-52-5*0 Chlorine dioxide OClO (g) 101.32 98.85 ± 0.27 kJ/mol 67.4515 ± 0.0011 10049-04-4*0 Dioxygen cation [O2]+ (g) 1164.585 1165.221 ± 0.0092 kJ/mol 31.99825 ± 0.00060 12185-07-8*0 Methylidyne CH (g, quartet) 664.61 667.94 ± 0.60 kJ/mol 13.01864 ± 0.00080 3315-37-5*2 Aminomethyl CH2NH2 (g) 158.90 149.06 ± 0.44 kJ/mol 30.04920 ± 0.00085 10507-29-6*0 Ethoxy CH3CH2O (g, X 2A") 1.84 -12.07 ± 0.52 kJ/mol 45.0605 ± 0.0017 2154-50-9*51 Cyanato NCO (g) 127.03 127.50 ± 0.35 kJ/mol 42.01684 ± 0.00086 22400-26-6*0 Dimethylamine (CH3)2NH (g) 3.53 -18.11 ± 0.48 kJ/mol 45.0837 ± 0.0017 124-40-3*0 Bromoform CBr3H (g) 75.2 49.1 ± 1.3 kJ/mol 252.7306 ± 0.0031 75-25-2*0 Hydrogen fluoride HF (aq) -334.48 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*800 Bromine monoxide BrO (g) 131.14 123.61 ± 0.28 kJ/mol 95.9034 ± 0.0010 15656-19-6*0 Hypobromite [BrO]- (g) -96.15 -103.63 ± 0.54 kJ/mol 95.9039 ± 0.0010 14380-62-2*0 Fluorodioxidanyl FOO (g) 26.80 25.09 ± 0.26 kJ/mol 50.99720 ± 0.00060 15499-23-7*0 Peroxynitrous acid HOONO (g, cis, cis) -6.10 -14.54 ± 0.36 kJ/mol 63.01288 ± 0.00091 14691-52-2*3 Cyclopropane CH2(CH2CH2) (g) 70.77 53.63 ± 0.47 kJ/mol 42.0797 ± 0.0024 75-19-4*0 Propadienylidene CH2CC (g) 554.43 555.57 ± 0.41 kJ/mol 38.0480 ± 0.0024 60731-10-4*0 1-Butene CH2CHCH2CH3 (g) 20.86 -0.09 ± 0.38 kJ/mol 56.1063 ± 0.0032 106-98-9*0 Acetyl CH3CO (g) -3.37 -10.03 ± 0.36 kJ/mol 43.0446 ± 0.0016 3170-69-2*0 Dichloromethylene CCl2 (g, singlet) 229.49 230.67 ± 0.65 kJ/mol 82.9161 ± 0.0020 1605-72-7*2 Fluoroethane CH3CH2F (g) -257.21 -272.07 ± 0.38 kJ/mol 48.0595 ± 0.0016 353-36-6*0 Ethyl bromide CH3CH2Br (g) -41.12 -63.07 ± 0.26 kJ/mol 108.9651 ± 0.0019 74-96-4*0 Vinyl fluoride CH2CHF (g) -134.62 -142.43 ± 0.48 kJ/mol 46.0436 ± 0.0016 75-02-5*0 Vinyl bromide CH2CHBr (g) 88.77 73.97 ± 0.61 kJ/mol 106.9492 ± 0.0019 593-60-2*0 2-Bromoethanol BrCH2CH2OH (g) -196.57 -220.63 ± 0.57 kJ/mol 124.9645 ± 0.0019 540-51-2*0 Chlorobenzene C6H5Cl (g) 67.13 52.17 ± 0.61 kJ/mol 112.5566 ± 0.0049 108-90-7*0 Difluorodioxidane FOOF (g) 35.29 31.57 ± 0.41 kJ/mol 69.99561 ± 0.00060 7783-44-0*0 Nitrous oxide NNO (g) 85.991 82.562 ± 0.097 kJ/mol 44.01288 ± 0.00033 10024-97-2*0 (E)-Diazene HNNH (g, trans) 207.09 199.95 ± 0.44 kJ/mol 30.02936 ± 0.00020 15626-43-4*0 Hydroxyoxomethylium [HOCO]+ (g) 600.69 597.60 ± 0.44 kJ/mol 45.0169 ± 0.0010 638-71-1*0 Trioxidane HOOOH (g, trans) -81.71 -90.55 ± 0.72 kJ/mol 50.01408 ± 0.00091 14699-99-1*1 Vinylium [CH2CH]+ (g) 1119.15 1115.70 ± 0.59 kJ/mol 27.0447 ± 0.0016 14604-48-9*0 Hydroxymethylium [CH2OH]+ (g) 717.75 709.80 ± 0.18 kJ/mol 31.03337 ± 0.00088 18682-95-6*0 Cyanogen NCCN (g) 308.24 310.18 ± 0.43 kJ/mol 52.0349 ± 0.0016 460-19-5*0 Propyl CH3CH2CH2 (g) 118.27 100.87 ± 0.60 kJ/mol 43.0877 ± 0.0024 2143-61-5*0 Dioxidanide [HO2]- (g) -88.87 -91.53 ± 0.35 kJ/mol 33.00729 ± 0.00060 14691-59-9*0 n-Butyl CH3CH2CH2CH2 (g) 102.52 80.02 ± 0.72 kJ/mol 57.1143 ± 0.0033 2492-36-6*0 1,3-Butadiene CH2CHCHCH2 (g) 125.05 110.57 ± 0.40 kJ/mol 54.0904 ± 0.0032 106-99-0*0 n-Pentane CH3CH2CH2CH2CH3 (g) -114.50 -146.38 ± 0.31 kJ/mol 72.1488 ± 0.0041 109-66-0*0 Ethynide [CCH]- (g) 277.42 280.83 ± 0.18 kJ/mol 25.0299 ± 0.0016 29075-95-4*0 Formic acid HC(O)OH (g) -371.06 -378.36 ± 0.22 kJ/mol 46.0254 ± 0.0010 64-18-6*0 2-Chloroethanol ClCH2CH2OH (g) -250.05 -266.76 ± 0.63 kJ/mol 80.5132 ± 0.0019 107-07-3*0 Bromobenzene C6H5Br (g) 126.6 104.6 ± 1.3 kJ/mol 157.0079 ± 0.0049 108-86-1*0 Benzaldehyde C6H5C(O)H (g) -19.22 -37.02 ± 0.92 kJ/mol 106.1219 ± 0.0056 100-52-7*0 Hypofluorite [FO]- (g) -108.85 -108.68 ± 0.48 kJ/mol 34.99835 ± 0.00030 12763-66-5*0 Chlorous acid HOClO (g) 25.75 20.69 ± 0.63 kJ/mol 68.4594 ± 0.0011 13898-47-0*0 Water H2O (l) -285.836 ± 0.027 kJ/mol 18.01528 ± 0.00033 7732-18-5*590 Iodoxyl radical IO (g) 126.97 125.04 ± 0.82 kJ/mol 142.90387 ± 0.00030 14696-98-1*0 Ammonium [NH4]+ (g) 643.04 631.73 ± 0.21 kJ/mol 18.03795 ± 0.00029 14798-03-9*0 Azanide [NH2]- (g) 114.89 112.02 ± 0.33 kJ/mol 16.02317 ± 0.00016 17655-31-1*0 Hydroxyamidogen HNOH (g, trans) 101.6 94.8 ± 1.1 kJ/mol 32.02202 ± 0.00034 13940-32-4*1 Nitrate [NO3]- (g) -300.30 -306.77 ± 0.62 kJ/mol 62.00549 ± 0.00090 14797-55-8*0 Cyanogen iodide ICN (g) 222.5 222.0 ± 1.6 kJ/mol 152.92191 ± 0.00080 506-78-5*0 Formyl anion [HCO]- (g) 11.63 12.02 ± 0.44 kJ/mol 29.01859 ± 0.00086 57340-31-5*0 2-Propynylidyne CCCH (g) 717.94 722.29 ± 0.81 kJ/mol 37.0400 ± 0.0024 53590-28-6*0 Isobutene CH2C(CH3)2 (g) 3.95 -17.12 ± 0.43 kJ/mol 56.1063 ± 0.0032 115-11-7*0 Methanetetraylbisamidogen NCN (g) 450.41 450.81 ± 0.68 kJ/mol 40.02418 ± 0.00081 2669-76-3*0 Trichloromethyl CCl3 (g) 71.91 71.43 ± 0.86 kJ/mol 118.3688 ± 0.0028 3170-80-7*0 Chloromethylene CHCl (g, singlet) 320.24 320.52 ± 0.89 kJ/mol 48.4713 ± 0.0012 2108-20-5*2 Methylene bromide CH2Br2 (g) 25.5 4.1 ± 1.1 kJ/mol 173.8346 ± 0.0022 74-95-3*0 2-Fluoroethanol FCH2CH2OH (g) -406.6 -423.9 ± 1.3 kJ/mol 64.0589 ± 0.0017 371-62-0*0 Phenide [C6H5]- (g) 244.44 231.01 ± 0.42 kJ/mol 77.1044 ± 0.0048 30922-78-2*0 Phenolate [C6H5O]- (g) -146.09 -161.56 ± 0.93 kJ/mol 93.1038 ± 0.0048 3229-70-7*0 Chloronium [HClH]+ (g) 881.3 878.2 ± 1.1 kJ/mol 37.46803 ± 0.00091 36658-55-6*0 Chlorine trifluoride FCl(F)F (g) -158.6 -162.7 ± 1.2 kJ/mol 92.44791 ± 0.00090 7790-91-2*0 Iodine monochloride ICl (g) 19.024 17.391 ± 0.013 kJ/mol 162.35717 ± 0.00090 7790-99-0*0 Iodotrifluoromethane CF3I (g) -583.82 -589.70 ± 0.55 kJ/mol 195.91038 ± 0.00080 2314-97-8*0 Nitrogen atom cation N+ (g) 1872.907 1875.688 ± 0.024 kJ/mol 14.006191 ± 0.000070 14158-23-7*0 Azido radical NNN (g) 452.25 449.66 ± 0.60 kJ/mol 42.02022 ± 0.00021 12596-60-0*0 Trinitrogen cation [NNN]+ (g) 1519.41 1516.88 ± 0.89 kJ/mol 42.01967 ± 0.00021 12185-03-4*0 Oxonitrate anion [NO]- (g) 87.91 87.94 ± 0.12 kJ/mol 30.00669 ± 0.00031 14967-78-3*0 Carbon monoxide cation [CO]+ (g) 1238.308 1241.588 ± 0.026 kJ/mol 28.00955 ± 0.00085 12144-04-6*0 Nitrosyl ion [NO]+ (g) 984.484 984.479 ± 0.065 kJ/mol 30.00559 ± 0.00031 14452-93-8*0 Nitroxyl H2NO (g) 71.13 64.52 ± 0.90 kJ/mol 32.02202 ± 0.00034 13408-29-2*0 Hydrazoic acid HNNN (g) 297.90 291.61 ± 0.49 kJ/mol 43.02816 ± 0.00022 7782-79-8*0 Ethanium [C2H7]+ (g, bridged C2) 874.39 858.12 ± 0.62 kJ/mol 31.0764 ± 0.0017 24669-33-8*1 Acetylium [CH3CO]+ (g) 666.87 659.58 ± 0.47 kJ/mol 43.0441 ± 0.0016 15762-07-9*0 Cyanide [CN]- (g) 63.964 67.250 ± 0.095 kJ/mol 26.01799 ± 0.00080 57-12-5*0 Hydroxymethylene HCOH (g, trans) 112.70 108.93 ± 0.28 kJ/mol 30.02598 ± 0.00087 19710-56-6*1 Carbonic acid C(O)(OH)2 (g, cis-cis) -602.74 -612.91 ± 0.79 kJ/mol 62.0248 ± 0.0012 463-79-6*1 Hydrogen bromide HBr (aq) -120.71 ± 0.16 kJ/mol 80.9119 ± 0.0010 10035-10-6*800 n-Hexane CH3CH2CH2CH2CH2CH3 (g) -130.10 -166.98 ± 0.34 kJ/mol 86.1754 ± 0.0049 110-54-3*0 1-Hydroxyethylium [CH3CHOH]+ (g, anti) 609.13 594.70 ± 0.39 kJ/mol 45.0600 ± 0.0017 18682-96-7*1 Ethoxy CH3CH2O (g, A 2A') 6.09 -8.35 ± 0.52 kJ/mol 45.0605 ± 0.0017 2154-50-9*52 Dicarbon monoxide CCO (g, triplet) 377.3 381.3 ± 1.1 kJ/mol 40.0208 ± 0.0016 12071-23-7*1 Formic acid HC(O)OH (g, anti) -354.70 -361.94 ± 0.39 kJ/mol 46.0254 ± 0.0010 64-18-6*2 Formyloxidanyl HC(O)O (g, 2A1) -125.57 -127.23 ± 0.56 kJ/mol 45.0174 ± 0.0010 16499-21-1*1 Trimethylamine (CH3)3N (g) 1.16 -27.69 ± 0.92 kJ/mol 59.1103 ± 0.0025 75-50-3*0 Chlorodifluoromethane CHClF2 (g) -476.4 -482.5 ± 1.2 kJ/mol 86.4681 ± 0.0012 75-45-6*0 Fluoromethylene CHF (g, singlet) 148.34 148.62 ± 0.46 kJ/mol 32.01704 ± 0.00080 13453-52-6*2 Fluoroformyl FCO (g) -176.61 -176.03 ± 0.39 kJ/mol 47.00850 ± 0.00085 1871-24-5*0 Hydrogen chloride HCl (aq) -166.993 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*800 Bromonium [HBrH]+ (g) 925.2 914.5 ± 1.5 kJ/mol 81.9193 ± 0.0010 36658-54-5*0 Hydrogen peroxide cation [H2O2]+ (g, trans) 896.57 889.59 ± 0.58 kJ/mol 34.01413 ± 0.00062 12325-10-9*1 Hydrazine NH2NH2 (g) 111.56 97.41 ± 0.49 kJ/mol 32.04524 ± 0.00031 302-01-2*0 Ethylidene CH3CH (g, triplet) 361.30 354.30 ± 0.91 kJ/mol 28.0532 ± 0.0016 4218-50-2*1 Vinyl anion [CH2CH]- (g) 237.01 232.59 ± 0.87 kJ/mol 27.0458 ± 0.0016 25012-81-1*0 Aminomethylium [CH2NH2]+ (g) 763.55 751.58 ± 0.66 kJ/mol 30.04865 ± 0.00085 488821-23-4*0 Peroxyformic acid HC(O)OOH (g, cis) -279.8 -289.1 ± 1.1 kJ/mol 62.0248 ± 0.0012 107-32-4*1 1-Methylethenyl CH3CCH2 (g) 262.81 252.46 ± 0.78 kJ/mol 41.0718 ± 0.0024 15552-77-9*0 trans-2-Butene CH3CHCHCH3 (g, trans) 9.24 -11.32 ± 0.41 kJ/mol 56.1063 ± 0.0032 624-64-6*0 cis-2-Butene CH3CHCHCH3 (g, cis) 13.93 -7.34 ± 0.42 kJ/mol 56.1063 ± 0.0032 590-18-1*0 Cyclopentane CH2(CH2CH2CH2CH2) (g) -45.04 -77.61 ± 0.44 kJ/mol 70.1329 ± 0.0041 287-92-3*0 Cyclopentadiene CH2(CHCHCHCH) (g) 149.85 132.73 ± 0.76 kJ/mol 66.1011 ± 0.0040 542-92-7*0 1-Hydroxyethyl CH3CHOH (g, gauche-syn) -40.46 -53.93 ± 0.93 kJ/mol 45.0605 ± 0.0017 2348-46-1*2 Protonated oxirane [(CH2CH2)OH]+ (g) 725.23 709.06 ± 0.67 kJ/mol 45.0600 ± 0.0017 *38607-31-7*0 Ethenol CH2CHOH (g, syn) -112.76 -123.95 ± 0.84 kJ/mol 44.0526 ± 0.0017 557-75-5*1 Oxoethenyl HCCO (g) 176.97 178.09 ± 0.61 kJ/mol 41.0287 ± 0.0016 51095-15-9*0 Methanediol CH2(OH)2 (g, conrot gauche) -379.2 -393.4 ± 1.1 kJ/mol 48.0413 ± 0.0010 463-57-0*1 Trioxidanide [HOOO]- (g, gauche) -120.0 -123.1 ± 1.6 kJ/mol 49.00669 ± 0.00090 89965-38-8*2 Acetyl chloride CH3C(O)Cl (g) -232.68 -241.55 ± 0.33 kJ/mol 78.4973 ± 0.0019 75-36-5*0 Methyl formate HC(O)OCH3 (g, syn-staggered) -344.73 -357.78 ± 0.59 kJ/mol 60.0520 ± 0.0017 107-31-3*1 Chlorohydroxymethyl CH(Cl)OH (g, syn-gauche) -54.7 -60.7 ± 1.1 kJ/mol 65.4787 ± 0.0012 147139-06-8*1 1,1-Dichloroethene CH2CCl2 (g) 8.91 2.92 ± 0.51 kJ/mol 96.9427 ± 0.0024 75-35-4*0 Tetrachloroethene CCl2CCl2 (g) -22.3 -23.1 ± 1.1 kJ/mol 165.8322 ± 0.0039 127-18-4*0 Difluorodichloromethane CF2Cl2 (g) -490.42 -495.18 ± 0.97 kJ/mol 120.9129 ± 0.0020 75-71-8*0 Fluorodichloromethane CHFCl2 (g) -278.7 -284.0 ± 1.3 kJ/mol 102.9224 ± 0.0020 75-43-4*0 Trifluoromethylium [CF3]+ (g) 409.16 406.09 ± 0.52 kJ/mol 69.00536 ± 0.00080 18851-76-8*0 Fluoromethylene CHF (g, triplet) 210.16 210.50 ± 0.72 kJ/mol 32.01704 ± 0.00080 13453-52-6*1 Formyl fluoride HFCO (g) -378.64 -382.23 ± 0.33 kJ/mol 48.01644 ± 0.00086 1493-02-3*0 Methyl nitrite CH3ONO (g, cis) -55.58 -67.36 ± 0.45 kJ/mol 61.0401 ± 0.0010 624-91-9*2 Chlorine pentafluoride FCl(F)(F)(F)F (g) -226.1 -234.2 ± 1.7 kJ/mol 130.44472 ± 0.00090 13637-63-3*0 Chloro hypochlorite ClOCl (g) 79.78 77.97 ± 0.36 kJ/mol 86.9048 ± 0.0018 7791-21-1*0 Chlorooxy hypochlorite ClOOCl (g) 134.55 131.32 ± 0.56 kJ/mol 102.9042 ± 0.0019 12292-23-8*0 Peroxyhypochlorous acid HOOCl (g) 3.93 -1.34 ± 0.95 kJ/mol 68.4594 ± 0.0011 67952-07-2*0 Hypoiodite [IO]- (g) -102.48 -104.29 ± 0.88 kJ/mol 142.90442 ± 0.00030 15065-65-3*0 Dinitrogen cation [N2]+ (g) 1503.311 1503.312 ± 0.0011 kJ/mol 28.01293 ± 0.00014 13966-04-6*0 Carbon dioxide cation [CO2]+ (g) 936.092 936.927 ± 0.017 kJ/mol 44.00895 ± 0.00100 12181-61-2*0 Nitrogen sesquioxide ONNO2 (g) 90.71 86.15 ± 0.15 kJ/mol 76.01168 ± 0.00091 10544-73-7*0 Ammonium [NH4]+ (aq) -133.080 ± 0.056 kJ/mol 18.03795 ± 0.00029 14798-03-9*800 Hydrazino NH2NH (g) 234.80 224.28 ± 0.78 kJ/mol 31.03730 ± 0.00025 13598-46-4*0 Ethylidene CH3CH (g, singlet) 373.69 366.46 ± 0.98 kJ/mol 28.0532 ± 0.0016 4218-50-2*2 Methylamidogen CH3NH (g) 187.21 176.56 ± 0.49 kJ/mol 30.04920 ± 0.00085 15622-51-2*0 Hydrogen isocyanide cation [HNC]+ (g) 1353.0 1352.9 ± 1.3 kJ/mol 27.02483 ± 0.00081 74158-11-5*0 Prop-2-ylium [CH3CHCH3]+ (g) 822.90 805.64 ± 0.25 kJ/mol 43.0871 ± 0.0024 19252-53-0*0 Propargylenide [HCCCH]- (g, transoid 2B) 434.5 437.1 ± 1.1 kJ/mol 38.0485 ± 0.0024 82906-05-6*1 neo-Pentane C(CH3)4 (g) -134.69 -167.57 ± 0.40 kJ/mol 72.1488 ± 0.0041 463-82-1*0 Dichloride [Cl2]- (g) -229.8 -228.7 ± 1.4 kJ/mol 70.9059 ± 0.0018 12595-89-0*0 2-Hydroxyethyl CH2CH2OH (g, gauche-anti) -9.91 -22.54 ± 0.91 kJ/mol 45.0605 ± 0.0017 4422-54-2*2 Chlorine atom cation Cl+ (g) 1370.806 1372.602 ± 0.0011 kJ/mol 35.45215 ± 0.00090 24203-47-2*0 Dimethyl ether CH3OCH3 (g) -166.53 -184.04 ± 0.45 kJ/mol 46.0684 ± 0.0017 115-10-6*0 Methanediol CH2(OH)2 (g, disrot gauche) -368.8 -382.0 ± 1.2 kJ/mol 48.0413 ± 0.0010 463-57-0*2 (Methylamino)methyl CH3NHCH2 (g) 167.56 151.10 ± 0.97 kJ/mol 44.0758 ± 0.0017 31277-24-4*0 Dimethylamidogen (CH3)2N (g) 173.7 156.3 ± 1.5 kJ/mol 44.0758 ± 0.0017 15337-44-7*0 Bromotrichloromethane CCl3Br (g) -32.87 -42.01 ± 0.60 kJ/mol 198.2728 ± 0.0030 75-62-7*0 Chloromethylidyne CCl (g) 430.42 434.18 ± 0.67 kJ/mol 47.4634 ± 0.0012 3889-76-7*0 Chloromethanol CH2(Cl)OH (g) -232.1 -242.4 ± 1.2 kJ/mol 66.4866 ± 0.0013 15454-33-8*0 Chloromethoxy CH2(Cl)O (g) -11.7 -18.5 ± 1.1 kJ/mol 65.4787 ± 0.0012 114282-89-2*0 1,1-Dichloroethane CH3CHCl2 (g) -119.76 -132.54 ± 0.51 kJ/mol 98.9586 ± 0.0024 75-34-3*0 1,1,1-Trichloroethane CH3CCl3 (g) -134.42 -145.00 ± 0.52 kJ/mol 133.4033 ± 0.0031 71-55-6*0 Hydroperoxonium [H2OOH]+ (g, trans) 738.1 727.8 ± 1.2 kJ/mol 35.02207 ± 0.00064 70850-26-9*1 Tetraiodomethane CI4 (g) 332.0 326.9 ± 4.1 kJ/mol 519.62858 ± 0.00081 507-25-5*0 o-Benzyne C6H4 (g, singlet) 468.05 459.13 ± 0.88 kJ/mol 76.0960 ± 0.0048 462-80-6*2 Benzyl C6H5CH2 (g) 230.23 211.42 ± 0.62 kJ/mol 91.1305 ± 0.0056 2154-56-5*0 Acetonyl CH3C(O)CH2 (g) -19.17 -31.88 ± 0.99 kJ/mol 57.0712 ± 0.0024 3122-07-4*0 Propionaldehyde CH3CH2CHO (g) -171.40 -186.80 ± 0.25 kJ/mol 58.0791 ± 0.0025 123-38-6*0 Bromonium Br+ (g) 1257.778 1251.715 ± 0.057 kJ/mol 79.90345 ± 0.00100 22541-56-6*0 Nitric acid HNO3 (aq) -206.63 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*800 Oxoammoniumyl [HNO]+ (g) 1092.40 1089.47 ± 0.68 kJ/mol 31.01353 ± 0.00032 63559-87-5*0 Trioxidane HOOOH (g, cis) -72.39 -80.88 ± 0.92 kJ/mol 50.01408 ± 0.00091 14699-99-1*2 Peroxynitrous acid HOONO (g, trans, perp) 7.57 0.49 ± 0.41 kJ/mol 63.01288 ± 0.00091 14691-52-2*1 Chlorodioxidanyl ClOO (g) 103.91 102.82 ± 0.37 kJ/mol 67.4515 ± 0.0011 17376-09-9*0 Ethylidyne CH3C (g) 508.56 504.86 ± 0.87 kJ/mol 27.0452 ± 0.0016 67624-57-1*0 Ethylidyne CH3C (g, quartet) 640.6 636.1 ± 1.2 kJ/mol 27.0452 ± 0.0016 67624-57-1*2 Methylamidogen anion [CH3NH]- (g) 144.95 134.12 ± 0.68 kJ/mol 30.04975 ± 0.00085 54448-39-4*0 Iminomethyl cation [HCNH]+ (g) 953.3 949.3 ± 1.4 kJ/mol 28.03277 ± 0.00082 196216-36-1*0 Fluoronium [HFH]+ (g, singlet) 774.10 771.16 ± 0.88 kJ/mol 21.01373 ± 0.00014 12206-67-6*2 Perchloryl OCl(O)O (g) 191.68 186.01 ± 0.61 kJ/mol 83.4509 ± 0.0013 13932-10-0*0 1-Propenyl CH3CHCH (g, cis) 277.99 267.20 ± 0.79 kJ/mol 41.0718 ± 0.0024 6067-68-1*2 Hydrogen fluoride HF (aq, 20 H2O) -321.03 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*818 1-Propynyl CH3CC (g) 528.39 526.03 ± 0.75 kJ/mol 39.0559 ± 0.0024 89342-91-6*0 Propargylenide [HCCCH]- (g, cisoid 2A) 437.0 439.5 ± 1.1 kJ/mol 38.0485 ± 0.0024 82906-05-6*2 2-Propyn-1-ylium-1-ylidene [CCCH]+ (g) 1598.0 1602.9 ± 1.3 kJ/mol 37.0395 ± 0.0024 75104-46-0*0 t-Butyl (CH3)3C (g) 75.44 50.14 ± 0.68 kJ/mol 57.1143 ± 0.0033 1605-73-8*0 2-Butyne CH3CCCH3 (g) 158.96 145.99 ± 0.59 kJ/mol 54.0904 ± 0.0032 503-17-3*0 1-Butyne CH3CH2CCH (g) 179.36 165.77 ± 0.67 kJ/mol 54.0904 ± 0.0032 107-00-6*0 iso-Pentane CH3CH2CH(CH3)2 (g) -119.26 -153.31 ± 0.44 kJ/mol 72.1488 ± 0.0041 78-78-4*0 Isoprene CH2C(CH3)CHCH2 (g) 95.97 75.44 ± 0.70 kJ/mol 68.1170 ± 0.0040 78-79-5*0 2-Hydroxyethyl CH2CH2OH (g, staggered-anti) -4.9 -17.4 ± 1.3 kJ/mol 45.0605 ± 0.0017 4422-54-2*3 Vinoxy CH2CHO (g) 22.42 15.58 ± 0.77 kJ/mol 43.0446 ± 0.0016 6912-06-7*0 Acetyl anion [CH3CO]- (g) -44.0 -49.6 ± 1.4 kJ/mol 43.0452 ± 0.0016 78944-68-0*0 Ketene CH2CO (g, triplet) 182.5 177.5 ± 1.3 kJ/mol 42.0367 ± 0.0016 463-51-4*1 Water dimer (H2O)2 (g) -491.097 -499.137 ± 0.052 kJ/mol 36.03056 ± 0.00066 25655-83-8*0 Hydroxyformyl HOCO (g, cis) -174.34 -177.37 ± 0.53 kJ/mol 45.0174 ± 0.0010 2564-86-5*2 Hydroxyformyl anion [HOCO]- (g, cis) -319.50 -322.27 ± 0.60 kJ/mol 45.0180 ± 0.0010 78944-70-4*2 2-Hydrotrioxy OO(H)O (g) 299.7 294.0 ± 1.2 kJ/mol 49.00614 ± 0.00090 *12500-78-6*0 1-Propanol CH3CH2CH2OH (g) -231.44 -255.28 ± 0.25 kJ/mol 60.0950 ± 0.0025 71-23-8*0 (Dimethylamino)methyl (CH3)2NCH2 (g) 165.1 142.0 ± 1.4 kJ/mol 58.1024 ± 0.0025 30208-47-0*0 Chloromethide [CH2Cl]- (g) 56.5 53.3 ± 2.0 kJ/mol 49.4798 ± 0.0012 60291-29-4*0 cis-1,2-Dichloroethene CHClCHCl (g, cis) 3.46 -2.54 ± 0.56 kJ/mol 96.9427 ± 0.0024 156-59-2*0 Fluorotrichloromethane CCl3F (g) -286.4 -289.6 ± 1.2 kJ/mol 137.3672 ± 0.0028 75-69-4*0 Difluoromethylene CF2 (g) -193.94 -193.47 ± 0.39 kJ/mol 50.00751 ± 0.00080 2154-59-8*0 Hexafluoroethane CF3CF3 (g) -1334.5 -1342.8 ± 1.5 kJ/mol 138.0118 ± 0.0016 76-16-4*0 1,1-Difluoroethane CHF2CH3 (g) -489.06 -502.78 ± 0.65 kJ/mol 66.0500 ± 0.0016 75-37-6*0 1,1-Difluoroethene CH2CF2 (g) -343.60 -350.66 ± 0.94 kJ/mol 64.0341 ± 0.0016 75-38-7*0 Tricarbon dioxide OCCCO (g) -94.8 -92.7 ± 1.4 kJ/mol 68.0309 ± 0.0025 504-64-3*0 Ethylbenzene C6H5CH2CH3 (g) 58.18 29.72 ± 0.55 kJ/mol 106.1650 ± 0.0064 100-41-4*0 Phenylethene C6H5CHCH2 (g) 169.66 148.33 ± 0.55 kJ/mol 104.1491 ± 0.0064 100-42-5*0 Phenylacetylene C6H5CCH (g) 332.4 317.2 ± 1.1 kJ/mol 102.1332 ± 0.0064 536-74-3*0 Difluoride [F2]- (g) -291.0 -290.2 ± 1.5 kJ/mol 37.9973550 ± 0.0000010 12184-85-9*0 Acetonate [CH3C(O)CH2]- (g) -188.5 -202.1 ± 1.1 kJ/mol 57.0717 ± 0.0024 24262-31-5*0 Bromine monochloride BrCl (g) 21.882 14.439 ± 0.060 kJ/mol 115.3567 ± 0.0013 13863-41-7*0 Iodine monobromide IBr (g) 49.718 40.771 ± 0.067 kJ/mol 206.8085 ± 0.0010 7789-33-5*0 Nitrosyl nitrite ONONO (g, sym) 93.0 87.8 ± 1.3 kJ/mol 76.01168 ± 0.00091 122413-35-8*1 Nitroxyl NO3 (g) 79.38 74.13 ± 0.19 kJ/mol 62.00494 ± 0.00090 12033-49-7*0 Isodiazene NNH2 (g) 307.52 300.44 ± 0.75 kJ/mol 30.02936 ± 0.00020 28647-38-3*0 Nitryl hydride HN(O)O (g) -37.2 -44.1 ± 1.5 kJ/mol 47.01348 ± 0.00061 90266-90-3*0 Carbon atom cation C+ (g) 1797.860 1803.458 ± 0.048 kJ/mol 12.01015 ± 0.00080 14067-05-1*0 Dioxygen anion [O2]- (g) -43.36 -42.72 ± 0.17 kJ/mol 31.99935 ± 0.00060 11062-77-4*0 Methanide [CH3]- (g) 141.08 137.63 ± 0.30 kJ/mol 15.03507 ± 0.00083 15194-58-8*0 Methyliumyl [CH2]+ (g) 1393.17 1394.03 ± 0.12 kJ/mol 14.02603 ± 0.00081 15091-72-2*0 Methyliumylidene [CH]+ (g) 1619.765 1623.108 ± 0.056 kJ/mol 13.01809 ± 0.00080 24361-82-8*0 Methylidyne anion [CH]- (g) 474.97 478.30 ± 0.85 kJ/mol 13.01919 ± 0.00080 28604-54-8*0 Trioxygen difluoride FOOOF (g, trans) 112.5 106.7 ± 1.2 kJ/mol 85.99501 ± 0.00090 16829-28-0*1 Ethanide [CH3CH2]- (g) 152.9 141.8 ± 1.2 kJ/mol 29.0616 ± 0.0016 25013-41-6*0 Oxidanylium [OH]+ (g) 1293.182 1293.211 ± 0.035 kJ/mol 17.00679 ± 0.00031 12259-29-9*0 Methyleneamidogen CH2N (g) 241.95 238.30 ± 0.67 kJ/mol 28.03332 ± 0.00082 15845-29-1*0 (E)-Iminomethyl HCNH (g, trans) 275.83 272.22 ± 0.71 kJ/mol 28.03332 ± 0.00082 54980-10-8*0 Nitrilomethylium [CN]+ (g) 1778.0 1781.5 ± 1.2 kJ/mol 26.01689 ± 0.00080 12539-57-0*0 Fluoroacetylene HCCF (g) 104.89 105.60 ± 0.41 kJ/mol 44.0277 ± 0.0016 2713-09-9*0 Methanol cation [CH3OH]+ (g) 856.90 846.58 ± 0.32 kJ/mol 32.04131 ± 0.00090 12538-91-9*0 Methyloxonium [CH3OH2]+ (g) 589.8 575.6 ± 1.2 kJ/mol 33.04925 ± 0.00092 17836-08-7*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 Hydroxyde [OH]- (aq) -230.020 ± 0.029 kJ/mol 17.00789 ± 0.00031 14280-30-9*800 Carbonic acid C(O)(OH)2 (g, cis-trans) -596.87 -606.98 ± 0.85 kJ/mol 62.0248 ± 0.0012 463-79-6*2 Carbonic acid C(O)(OH)2 (g, trans-trans) -561.64 -570.49 ± 0.98 kJ/mol 62.0248 ± 0.0012 463-79-6*3 1,2-Propadienyl anion [CH2CCH]- (g) 265.65 262.44 ± 0.73 kJ/mol 39.0565 ± 0.0024 64066-06-4*0 1-Propynyl anion [CH3CC]- (g) 264.45 260.98 ± 0.76 kJ/mol 39.0565 ± 0.0024 36147-87-2*0 Chloric acid HOCl(O)O (g) 2.2 -4.9 ± 1.6 kJ/mol 84.4588 ± 0.0013 7790-93-4*0 Chlorate [OCl(O)O]- (g) -207.4 -212.9 ± 1.6 kJ/mol 83.4514 ± 0.0013 14866-68-3*0 Hypochloroperoxoous acid, hydroxy ester HOOOCl (g, syn) 49.2 42.2 ± 1.9 kJ/mol 84.4588 ± 0.0013 928652-99-7*1 Cyclohexane CH2(CH2CH2CH2CH2CH2) (g) -83.64 -123.20 ± 0.36 kJ/mol 84.1595 ± 0.0049 110-82-7*0 Ozonide [OOO]- (g) -58.48 -60.84 ± 0.21 kJ/mol 47.99875 ± 0.00090 12596-80-4*0 2-Hydroxyethylium [CH2CH2OH]+ (g, staggered-anti) 1019.2 1006.3 ± 1.7 kJ/mol 45.0600 ± 0.0017 38607-31-7*3 Ethynol HCCOH (g) 95.3 93.2 ± 1.5 kJ/mol 42.0367 ± 0.0016 32038-79-2*0 Hydroxyformyl anion [HOCO]- (g, trans) -313.69 -315.63 ± 0.61 kJ/mol 45.0180 ± 0.0010 78944-70-4*1 2-Propanol CH3CH(OH)CH3 (g) -248.87 -272.97 ± 0.32 kJ/mol 60.0950 ± 0.0025 67-63-0*0 Acetic acid CH3C(O)OH (g, syn) -418.51 -432.63 ± 0.52 kJ/mol 60.0520 ± 0.0017 64-19-7*1 Ethylene glycol (CH2OH)2 (g) -369.81 -389.44 ± 0.49 kJ/mol 62.0678 ± 0.0018 107-21-1*0 (Methylamino)methyl cation [CH3NHCH2]+ (g) 728.81 710.19 ± 0.99 kJ/mol 44.0752 ± 0.0017 *31277-24-4*0 Dichloromethyl CHCl2 (g) 92.02 90.11 ± 0.88 kJ/mol 83.9240 ± 0.0020 3474-12-2*0 Chloromethyl CH2Cl (g) 118.47 115.39 ± 0.87 kJ/mol 49.4793 ± 0.0012 6806-86-6*0 Methyl hypochlorite CH3OCl (g) -52.9 -62.9 ± 1.4 kJ/mol 66.4866 ± 0.0013 593-78-2*0 1,2-Dichloroethane CH2ClCH2Cl (g) -118.48 -130.43 ± 0.54 kJ/mol 98.9586 ± 0.0024 107-06-2*0 Dichloroacetylene ClCCCl (g) 230.08 233.39 ± 0.98 kJ/mol 94.9268 ± 0.0024 7572-29-4*0 Fluorochloromethane CH2FCl (g) -256.3 -263.5 ± 1.3 kJ/mol 68.4777 ± 0.0012 593-70-4*0 Trioxidanyl HOOO (g, trans) 25.31 23.32 ± 0.13 kJ/mol 49.00614 ± 0.00090 12500-78-6*1 Formyl chloride CHClO (g) -179.97 -183.18 ± 0.77 kJ/mol 64.4707 ± 0.0012 2565-30-2*0 Chloroformyl ClCO (g) -21.91 -20.52 ± 0.49 kJ/mol 63.4628 ± 0.0012 2602-42-8*0 1,3-Butadiyne HCCCCH (g) 458.35 460.07 ± 0.82 kJ/mol 50.0587 ± 0.0032 460-12-8*0 o-Benzyne anion [C6H4]- (g) 413.73 404.63 ± 0.97 kJ/mol 76.0965 ± 0.0048 100569-88-8*0 Oxygen atom O (g, singlet) 436.666 438.523 ± 0.0021 kJ/mol 15.99940 ± 0.00030 17778-80-2*2 Benzylide [C6H5CH2]- (g) 142.01 123.10 ± 0.45 kJ/mol 91.1310 ± 0.0056 18860-15-6*0 Fluorobenzene cation [C6H5F]+ (g) 788.88 773.86 ± 0.89 kJ/mol 96.1018 ± 0.0048 34468-25-2*0 Nitrosobenzene C6H5NO (g) 215.7 198.7 ± 1.2 kJ/mol 107.1100 ± 0.0048 586-96-9*0 Nitromethyl CH2N(O)O (g) 138.8 129.4 ± 1.2 kJ/mol 60.0321 ± 0.0010 16787-85-2*0 Hydrogen chloride HCl (aq, 100 H2O) -165.759 ± 0.025 kJ/mol 36.46064 ± 0.00090 7647-01-0*828 Dinitrogen pentoxide O2NONO2 (g) 24.41 14.84 ± 0.35 kJ/mol 108.0105 ± 0.0015 10102-03-1*0 Fluoride F- (aq) -334.48 ± 0.16 kJ/mol 18.99895178 ± 0.00000050 16984-48-8*800 Diazenyl NNH (g) 252.17 249.25 ± 0.47 kJ/mol 29.02142 ± 0.00016 36882-13-0*0 Trioxidanylium [HOOO]+ (g, trans) 1070.6 1064.3 ± 1.4 kJ/mol 49.00559 ± 0.00090 74241-49-9*1 Peroxynitric acid HOON(O)O (g) -42.6 -53.0 ± 1.3 kJ/mol 79.0123 ± 0.0012 26404-66-0*0 Nitrosyl chloride ClNO (g) 54.450 52.548 ± 0.067 kJ/mol 65.45884 ± 0.00095 2696-92-6*0 Carbon dioxide CO2 (g, triplet) 49.8 50.6 ± 1.1 kJ/mol 44.00950 ± 0.00100 124-38-9*1 Methane cation [CH4]+ (g) 1150.83 1144.45 ± 0.25 kJ/mol 16.04191 ± 0.00085 20741-88-2*0 Methylene anion [CH2]- (g) 328.49 328.92 ± 0.50 kJ/mol 14.02713 ± 0.00081 50928-07-9*0 Oxoniumyl ion [H2O]+ (g) 978.464 975.561 ± 0.029 kJ/mol 18.01473 ± 0.00033 56583-62-1*0 Ethanium [C2H7]+ (g) 874.39 858.15 ± 0.62 kJ/mol 31.0764 ± 0.0017 24669-33-8*0 Acetylene cation [HCCH]+ (g) 1328.84 1328.18 ± 0.13 kJ/mol 26.0367 ± 0.0016 25641-79-6*0 Vinylidene CCH2 (g) 411.25 412.17 ± 0.33 kJ/mol 26.0373 ± 0.0016 2143-69-3*0 1-Ethylium-1-ylidene [CH3C]+ (g) 1329.6 1328.2 ± 1.2 kJ/mol 27.0447 ± 0.0016 78949-84-5*0 Ethylidyne anion [CH3C]- (g) 456.4 452.4 ± 1.4 kJ/mol 27.0458 ± 0.0016 117768-70-4*0 Vinylidene anion [CCH2]- (g) 364.14 363.96 ± 0.63 kJ/mol 26.0378 ± 0.0016 66295-36-1*0 Ethynylium [CCH]+ (g) 1687.59 1690.92 ± 0.16 kJ/mol 25.0288 ± 0.0016 16456-59-0*0 Methyloxoniumylidene [CH3O]+ (g) 1062.29 1054.48 ± 0.75 kJ/mol 31.03337 ± 0.00088 58157-09-8*0 Hydroxymethylene HCOH (g, cis) 131.12 127.38 ± 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 Iodide I- (aq) -56.824 ± 0.089 kJ/mol 126.905019 ± 0.000030 20461-54-5*800 Isoformyl COH (g) 217.29 217.67 ± 0.69 kJ/mol 29.01804 ± 0.00086 71080-92-7*0 1-Propenyl CH3CHCH (g, trans) 280.03 269.22 ± 0.81 kJ/mol 41.0718 ± 0.0024 6067-68-1*1 Cyclopropene CH2(CHCH) (g) 292.34 283.61 ± 0.55 kJ/mol 40.0639 ± 0.0024 2781-85-3*0 Dioxidenium [HO2]+ (g) 1110.87 1107.98 ± 0.11 kJ/mol 33.00619 ± 0.00060 12207-52-2*0 Bifluoride [(HF)(F)]- (g, singlet) -481.8 -480.6 ± 1.9 kJ/mol 39.005295 ± 0.000070 *18130-74-0*2 Chloryl hydride HCl(O)O (g) 197.6 191.2 ± 1.6 kJ/mol 68.4594 ± 0.0011 174365-32-3*0 Water anion [(H)(OH)]- (g, vdW ?) 31.3 29.8 ± 3.1 kJ/mol 18.01583 ± 0.00033 12259-30-2*100 Hydrogen fluoride HF (aq, 30 H2O) -321.08 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*820 Cyclobutane CH2(CH2CH2CH2) (g) 52.35 27.82 ± 0.41 kJ/mol 56.1063 ± 0.0032 287-23-0*0 Hydrogen difluoride (F)(HF) (g, lin) -198.5 -198.4 ± 1.2 kJ/mol 39.004746 ± 0.000070 12528-21-1*1 n-Heptane CH3(CH2)5CH3 (g) -145.71 -187.58 ± 0.48 kJ/mol 100.2019 ± 0.0057 142-82-5*0 n-Octane CH3(CH2)6CH3 (g) -161.46 -208.29 ± 0.67 kJ/mol 114.2285 ± 0.0065 111-65-9*0 1-Hydroxyethylium [CH3CHOH]+ (g, syn) 611.1 596.6 ± 1.3 kJ/mol 45.0600 ± 0.0017 18682-96-7*2 Ethenol CH2CHOH (g, anti) -108.24 -119.04 ± 0.89 kJ/mol 44.0526 ± 0.0017 557-75-5*2 Vinyl alcohol cation [CH2CHOH]+ (g, anti) 778.9 767.6 ± 1.4 kJ/mol 44.0520 ± 0.0017 57239-63-1*2 Oxiranyl CH2(CHO) (g) 172.7 164.4 ± 1.4 kJ/mol 43.0446 ± 0.0016 31586-84-2*0 Oxiranylium [CH2(CHO)]+ (g, singlet) 901.5 893.5 ± 1.4 kJ/mol 43.0441 ± 0.0016 57789-76-1*2 C=O=C COC (g, triplet) 652.9 657.2 ± 2.3 kJ/mol 40.0208 ± 0.0016 *12071-23-7*1 C=O=C COC (g, singlet) 720.0 724.3 ± 1.9 kJ/mol 40.0208 ± 0.0016 *12071-23-7*2 Oxirene O(CHCH) (g, singlet) 272.85 272.15 ± 0.98 kJ/mol 42.0367 ± 0.0016 157-18-6*2 Oxirene O(CHCH) (g, t-triplet) 388.7 384.5 ± 2.6 kJ/mol 42.0367 ± 0.0016 157-18-6*11 Formic acid cation [HC(O)OH]+ (g, syn) 721.92 714.83 ± 0.26 kJ/mol 46.0248 ± 0.0010 50614-05-6*1 Dioxirane CH2(OO) (g) 9.45 1.78 ± 0.55 kJ/mol 46.0254 ± 0.0010 157-26-6*0 Formyloxidanyl HC(O)O (g, 2B2) -121.76 -125.11 ± 0.56 kJ/mol 45.0174 ± 0.0010 16499-21-1*2 Isofulminic acid HCNO (g) 170.92 169.46 ± 0.49 kJ/mol 43.02478 ± 0.00086 51060-05-0*0 Methyl formate HC(O)OCH3 (g, anti-eclipsed) -324.7 -337.2 ± 1.9 kJ/mol 60.0520 ± 0.0017 107-31-3*2 Dimethylamide [(CH3)2N]- (g) 122.2 103.8 ± 1.7 kJ/mol 44.0763 ± 0.0017 34285-60-4*0 Chlorine difluoride FClF (g) -47.1 -48.2 ± 1.4 kJ/mol 73.44951 ± 0.00090 24801-48-7*0 Hexachloroethane CCl3CCl3 (g) -147.4 -149.8 ± 1.6 kJ/mol 236.7376 ± 0.0056 67-72-1*0 1,1,2-Trichloroethane CH2ClCHCl2 (g) -136.5 -148.2 ± 1.4 kJ/mol 133.4033 ± 0.0031 79-00-5*0 Methyl iodide CH3I (l) -12.28 ± 0.20 kJ/mol 141.93899 ± 0.00083 74-88-4*590 Difluoromethylene CF2 (g, triplet) 43.25 43.97 ± 0.39 kJ/mol 50.00751 ± 0.00080 2154-59-8*1 Difluoromethylene CF2 (g, singlet) -193.94 -193.47 ± 0.39 kJ/mol 50.00751 ± 0.00080 2154-59-8*2 Bromide Br- (aq) -120.71 ± 0.16 kJ/mol 79.90455 ± 0.00100 24959-67-9*800 Ethyl iodide CH3CH2I (l) -9.42 -39.29 ± 0.49 kJ/mol 155.9656 ± 0.0016 75-03-6*500 Fluoro(fluorooxy)methylene FCOF (g, cis) -135.8 -137.0 ± 2.1 kJ/mol 66.00691 ± 0.00085 479587-30-9*2 Azide ion [NNN]- (g) 193.51 189.93 ± 0.91 kJ/mol 42.02077 ± 0.00021 14343-69-2*0 Dibromophosgene COBr2 (g) -97.96 -113.89 ± 0.37 kJ/mol 187.8181 ± 0.0022 593-95-3*0 Oxygen atom O (g, triplet) 246.844 249.229 ± 0.0021 kJ/mol 15.99940 ± 0.00030 17778-80-2*1 Benzene C6H6 (cr,l) 50.68 49.13 ± 0.23 kJ/mol 78.1118 ± 0.0048 71-43-2*500 o-Benzyne C6H4 (g) 468.05 459.13 ± 0.88 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) 587.1 577.5 ± 1.2 kJ/mol 76.0960 ± 0.0048 3355-34-8*2 Phenoxy C6H5O (g) 71.37 56.08 ± 0.94 kJ/mol 93.1033 ± 0.0048 2122-46-5*0 Benzoyl fluoride C6H5C(O)F (g) -288.0 -304.4 ± 1.5 kJ/mol 124.1124 ± 0.0056 455-32-3*0 Iodobenzene C6H5I (g) 177.7 161.7 ± 1.0 kJ/mol 204.0084 ± 0.0048 591-50-4*0 1H-Triazirin-1-yl N(NN) (g) 585.9 584.1 ± 2.0 kJ/mol 42.02022 ± 0.00021 912535-95-6*0 (E)-Diazene cation [HNNH]+ (g, trans) 1132.46 1125.53 ± 0.66 kJ/mol 30.02881 ± 0.00020 59952-06-6*0 (Z)-Diazene HNNH (g, cis) 228.81 221.67 ± 0.64 kJ/mol 30.02936 ± 0.00020 15626-42-3*0 Hydroxyaminiumyl [NOH]+ (g) 1160.8 1157.9 ± 1.5 kJ/mol 31.01353 ± 0.00032 63559-88-6*0 Hydroxyamidogen HNOH (g, cis) 123.6 117.0 ± 1.7 kJ/mol 32.02202 ± 0.00034 13940-32-4*2 Hydroxyaminylium [HNOH]+ (g, trans) 1019.6 1012.5 ± 2.5 kJ/mol 32.02147 ± 0.00034 66097-71-0*1 Dioxyamidogen HNOO (g, cis) 240.4 233.7 ± 1.8 kJ/mol 47.01348 ± 0.00061 71843-95-3*2 Peroxynitrous acid HOONO (g, cis, perp) -0.43 -7.48 ± 0.53 kJ/mol 63.01288 ± 0.00091 14691-52-2*2 Chlorosyl hydride HClO (g) 141.9 139.1 ± 1.7 kJ/mol 52.46004 ± 0.00095 71572-35-5*0 Bifluoride [FFH]- (g, triplet) -68.0 -67.6 ± 1.6 kJ/mol 39.005295 ± 0.000070 *18130-74-0*1 Dioxiranylidene C(OO) (g) 190.3 191.1 ± 1.4 kJ/mol 44.00950 ± 0.00100 138832-57-2*0 Methylidyne CH (g, doublet) 592.81 596.15 ± 0.11 kJ/mol 13.01864 ± 0.00080 3315-37-5*1 Aquachlorine cation [ClOH2]+ (g) 821.8 815.0 ± 1.7 kJ/mol 53.46743 ± 0.00096 142599-65-3*0 Ethylidyne CH3C (g, doublet) 508.56 504.86 ± 0.87 kJ/mol 27.0452 ± 0.0016 67624-57-1*1 Trioxidaniumyl [HOOOH]+ (g, t, t) 925.7 916.4 ± 1.5 kJ/mol 50.01353 ± 0.00091 161321-37-5*2 Methylammonium [CH3NH3]+ (g) 628.1 609.2 ± 1.4 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) 192.72 188.97 ± 0.96 kJ/mol 28.03387 ± 0.00082 28892-56-0*0 (Z)-Iminomethyl HCNH (g, cis) 294.51 291.02 ± 0.92 kJ/mol 28.03332 ± 0.00082 54980-11-9*0 Aminomethylidyne CNH2 (g) 371.9 368.3 ± 1.1 kJ/mol 28.03332 ± 0.00082 84654-89-7*0 Hydrogen isocyanide HNC (g) 192.02 192.40 ± 0.38 kJ/mol 27.02538 ± 0.00081 6914-07-4*0 Chloroacetylene HCCCl (g) 228.04 228.90 ± 0.77 kJ/mol 60.4820 ± 0.0018 593-63-5*0 Methyleneoxonium CH2OH2 (g) 152.49 144.17 ± 0.49 kJ/mol 32.04186 ± 0.00090 177788-17-9*0 Hydroxymethylene anion [HCOH]- (g, trans) 147.2 144.1 ± 1.6 kJ/mol 30.02653 ± 0.00087 207914-87-2*1 Iodine atom cation I+ (g) 1115.549 1115.149 ± 0.0062 kJ/mol 126.903921 ± 0.000030 22541-93-1*0 Hydroxymethyliumylidene [COH]+ (g) 986.04 987.68 ± 0.83 kJ/mol 29.01749 ± 0.00086 60528-75-8*0 Isoformyl anion [(CO)(H)]- (g, vdW singlet ?) 55.8 58.4 ± 1.8 kJ/mol 29.01859 ± 0.00086 81747-63-9*1 Propylium [CH3CH2CH2]+ (g) 856.94 838.72 ± 0.93 kJ/mol 43.0871 ± 0.0024 19252-52-9*0 Oxywater (H2O)O (g) 64.8 58.2 ± 1.3 kJ/mol 34.01468 ± 0.00062 171363-09-0*0 Cyclopropyl CH(CH2CH2) (g) 302.7 290.0 ± 1.6 kJ/mol 41.0718 ± 0.0024 2417-82-5*0 Trioxodinitrate anion [ONNO2]- (g, vdW) -104.9 -108.8 ± 2.4 kJ/mol 76.01223 ± 0.00091 194856-62-7*100 Cycloprop-1-enyl CH2(CHC) (g) 527.56 522.98 ± 0.69 kJ/mol 39.0559 ± 0.0024 19528-44-0*0 Cycloprop-2-enyl CH(CHCH) (g) 490.27 485.66 ± 0.64 kJ/mol 39.0559 ± 0.0024 28933-84-8*0 Cyclopropenylidene C(CHCH) (g) 497.07 496.11 ± 0.46 kJ/mol 38.0480 ± 0.0024 16165-40-5*0 Triiodide ion [I3]- (aq) -51.37 ± 0.80 kJ/mol 380.713959 ± 0.000090 14900-04-0*800 2-Propynylidyne anion [CCCH]- (g) 539.96 544.81 ± 0.84 kJ/mol 37.0406 ± 0.0024 82893-67-2*0 Cyclopropynyl CH(CC) (g) 710.7 714.8 ± 1.1 kJ/mol 37.0400 ± 0.0024 119178-99-3*0 Oxygen cation monohydrate [(HOH)O]+ (g) 1153.0 1147.5 ± 3.3 kJ/mol 34.01413 ± 0.00062 *31748-17-1*0 sec-Butyl CH3CH2CHCH3 (g) 90.19 65.42 ± 0.98 kJ/mol 57.1143 ± 0.0033 2348-55-2*0 t-Butylium [(CH3)3C]+ (g) 733.77 710.50 ± 0.98 kJ/mol 57.1137 ± 0.0033 14804-25-2*0 iso-Butyl (CH3)2CHCH2 (g) 97.01 73.02 ± 0.77 kJ/mol 57.1143 ± 0.0033 4630-45-9*0 Methylcyclopropane CH3CH(CH2CH2) (g) 47.6 24.3 ± 1.3 kJ/mol 56.1063 ± 0.0032 594-11-6*0 Dihydrogen fluoride anion [HFH]- (g, triplet) 133.2 131.9 ± 1.6 kJ/mol 21.01483 ± 0.00014 117339-92-1*1 Cyclobutene C4H6 (g) 176.79 159.74 ± 0.92 kJ/mol 54.0904 ± 0.0032 822-35-5*0 Peroxychlorous acid HOOClO (g, syn) 96.2 90.2 ± 2.1 kJ/mol 84.4588 ± 0.0013 177778-92-6*1 Chlorine fluoride cation [ClF]+ (g) 1165.52 1165.70 ± 0.49 kJ/mol 54.45055 ± 0.00090 12432-44-9*0 Vinyl alcohol cation [CH2CHOH]+ (g, syn) 787.1 775.9 ± 1.1 kJ/mol 44.0520 ± 0.0017 57239-63-1*1 Vinoxy cation [CH2CHO]+ (g, triplet) 1020.1 1013.1 ± 1.6 kJ/mol 43.0441 ± 0.0016 *35731-40-9*1 Vinoxide [CH2CHO]- (g) -153.58 -160.63 ± 0.77 kJ/mol 43.0452 ± 0.0016 35731-40-9*0 Dinitrogen tetraoxide O2NNO2 (g) 20.14 10.85 ± 0.14 kJ/mol 92.0111 ± 0.0012 10544-72-6*0 Hydrogen fluoride HF (aq, 40 H2O) -321.12 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*821 Perchloric acid HOCl(O)(O)O (g) 13.2 1.8 ± 1.8 kJ/mol 100.4582 ± 0.0015 7601-90-3*0 Acetic acid CH3C(O)OH (aq) -485.20 ± 0.23 kJ/mol 60.0520 ± 0.0017 64-19-7*800 COC vdW (CO)(C) (g, triplet) 589.3 598.1 ± 1.9 kJ/mol 40.0208 ± 0.0016 *12071-24-8*1 Oxirene O(CHCH) (g, c-triplet) 390.8 386.6 ± 2.7 kJ/mol 42.0367 ± 0.0016 157-18-6*12 Methylperoxy anion [CH3OO]- (g) -89.81 -99.96 ± 0.68 kJ/mol 47.0339 ± 0.0010 35683-44-4*0 Fluorohydrochlorine cation [FClH]+ (g) 975.3 972.3 ± 2.0 kJ/mol 55.45849 ± 0.00090 70110-64-4*0 Formyloxoniumylidene [HC(O)O]+ (g) 1017.3 1013.8 ± 1.4 kJ/mol 45.0169 ± 0.0010 54375-27-8*0 Dioxymethylene HCOO (g, trans) 364.0 361.6 ± 2.7 kJ/mol 45.0174 ± 0.0010 438586-67-5*1 2-Hydrotrioxy cation [OO(H)O]+ (g) 1297.9 1291.3 ± 1.5 kJ/mol 49.00559 ± 0.00090 *74241-49-9*0 Cyanic acid HOCN (g) -12.20 -14.91 ± 0.49 kJ/mol 43.02478 ± 0.00086 420-05-3*0 Fulminic acid HONC (g) 235.38 233.68 ± 0.48 kJ/mol 43.02478 ± 0.00086 506-85-4*0 Isocyanate [NCO]- (g) -221.09 -221.31 ± 0.54 kJ/mol 42.01739 ± 0.00086 71000-82-3*0 Nitrosomethylidyne CNO (g) 389.5 390.8 ± 1.5 kJ/mol 42.01684 ± 0.00086 82267-15-0*0 Oxazirinyl C(NO) (g) 449.9 450.7 ± 1.5 kJ/mol 42.01684 ± 0.00086 228850-18-8*0 Dimethylmethyleneammonium [(CH3)2NCH2]+ (g) 695.9 670.8 ± 1.4 kJ/mol 58.1018 ± 0.0025 28149-27-1*0 Isocyanogen CNCN (g) 410.8 413.1 ± 1.7 kJ/mol 52.0349 ± 0.0016 83951-85-3*0 Diisocyanogen CNNC (g) 610.2 613.1 ± 1.8 kJ/mol 52.0349 ± 0.0016 78800-21-2*0 Cyanoamidogen HNCN (g) 325.0 322.6 ± 1.8 kJ/mol 41.03212 ± 0.00082 12347-01-2*0 Trichloromethide [CCl3]- (g) -125.0 -124.4 ± 2.0 kJ/mol 118.3693 ± 0.0028 14478-07-0*0 Oxygen anion monohydrate [(HOH)O]- (g) -239.1 -244.4 ± 3.0 kJ/mol 34.01523 ± 0.00062 31748-17-1*0 Deuterium atom D (g) 219.804 221.717 ± 0.000 kJ/mol 2.01410177800 ± 0.00000000040 16873-17-9*0 Chlorine difluoride cation [FClF]+ (g) 998.9 996.7 ± 1.7 kJ/mol 73.44896 ± 0.00090 32629-46-2*0 Trichloroethene CHClCCl2 (g) -10.8 -14.1 ± 1.6 kJ/mol 131.3874 ± 0.0031 79-01-6*0 2-Hydrotrioxy anion [OO(H)O]- (g) 27.5 21.8 ± 1.4 kJ/mol 49.00669 ± 0.00090 *89965-38-8*0 Bromodichloromethane CHCl2Br (g) -37.6 -49.3 ± 1.3 kJ/mol 163.8280 ± 0.0022 75-27-4*0 Difluorodibromomethane CF2Br2 (g) -366.0 -383.7 ± 1.4 kJ/mol 209.8155 ± 0.0022 75-61-6*0 Dichlorodibromomethane CCl2Br2 (g) 20.7 5.0 ± 1.5 kJ/mol 242.7241 ± 0.0028 594-18-3*0 Bromodifluoromethane CHF2Br (g) -410.85 -424.05 ± 0.49 kJ/mol 130.9194 ± 0.0013 1511-62-2*0 Oxofluoronium [FO]+ (g) 1342.64 1342.59 ± 0.81 kJ/mol 34.99725 ± 0.00030 12763-67-6*0 1,2-Difluoroethane CH2FCH2F (g) -434.44 -447.87 ± 0.86 kJ/mol 66.0500 ± 0.0016 624-72-6*0 1,2-Difluoroacetylene FCCF (g) 2.77 5.59 ± 0.66 kJ/mol 62.0182 ± 0.0016 689-99-6*0 Fluoro(fluorooxy)methylene FCOF (g, trans) -38.8 -40.4 ± 2.1 kJ/mol 66.00691 ± 0.00085 479587-30-9*1 Phenylium [C6H5]+ (g, triplet) 1251.1 1238.0 ± 1.9 kJ/mol 77.1034 ± 0.0048 17333-73-2*1 Hydrogen difluoride cation [FFH]+ (g) 1174.3 1171.3 ± 1.5 kJ/mol 39.004198 ± 0.000070 *126950-54-7*0 Chlorobenzene cation [C6H5Cl]+ (g) 942.46 928.54 ± 0.61 kJ/mol 112.5561 ± 0.0049 55450-32-3*0 Chlorobenzene C6H5Cl (cr,l) 11.21 ± 0.59 kJ/mol 112.5566 ± 0.0049 108-90-7*500 Bromobenzene cation [C6H5Br]+ (g) 994.7 973.2 ± 1.3 kJ/mol 157.0074 ± 0.0049 55450-33-4*0 Iodobenzene C6H5I (cr,l) 112.8 112.9 ± 1.1 kJ/mol 204.0084 ± 0.0048 591-50-4*500 Nitrobenzene C6H5N(O)O (g) 81.5 61.5 ± 1.4 kJ/mol 123.1094 ± 0.0049 98-95-3*0 Chlorine chlorite ClOClO (g, gauche) 168.6 166.2 ± 1.3 kJ/mol 102.9042 ± 0.0019 105206-44-8*3 Methyl nitrite CH3ONO (g, cis-trans equilib) -55.58 -66.25 ± 0.45 kJ/mol 61.0401 ± 0.0010 624-91-9*0 Carbon atom anion C- (g) 589.631 594.777 ± 0.049 kJ/mol 12.01125 ± 0.00080 14337-00-9*0 Dioxymethylidyne COO (g) 299.8 301.1 ± 1.7 kJ/mol 44.00950 ± 0.00100 791121-04-5*0 Nitronium [ONO]+ (g) 961.78 958.22 ± 0.20 kJ/mol 46.00499 ± 0.00060 14522-82-8*0 Trifluoromethide [CF3]- (g) -637.7 -639.5 ± 1.8 kJ/mol 69.00646 ± 0.00080 54128-17-5*0 2-Cyclopropyn-1-ylidene C(CC) (g, triplet) 899.2 906.1 ± 1.6 kJ/mol 36.0321 ± 0.0024 102508-15-6*1 Propynylidyne cation [C(CC)]+ (g) 1947.0 1954.9 ± 2.0 kJ/mol 36.0316 ± 0.0024 154702-35-9*0 Dioxaziridinyl N(OO) (g) 355.1 352.6 ± 1.5 kJ/mol 46.00554 ± 0.00060 66252-29-7*0 Hydrogen fluoride HF (aq, 50 H2O) -321.14 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*822 Bromo hypobromite BrOBr (g) 120.1 103.7 ± 1.4 kJ/mol 175.8074 ± 0.0020 21308-80-5*0 Ethylene cation [CH2CH2]+ (g) 1075.22 1068.01 ± 0.12 kJ/mol 28.0526 ± 0.0016 34470-02-5*0 Peroxyimidogen NOO (g) 405.4 403.4 ± 1.9 kJ/mol 46.00554 ± 0.00060 *60488-31-5*0 Chlorosyl ion [ClO]+ (g) 1150.85 1150.69 ± 0.66 kJ/mol 51.45155 ± 0.00095 12301-79-0*0 Hydrogen fluoride HF (aq, 35 H2O) -321.10 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*904 Iminomethyl anion [HCNH]- (g, trans) 237.4 233.6 ± 1.8 kJ/mol 28.03387 ± 0.00082 90623-30-6*1 Fluoronium [HFH]+ (g) 774.10 771.16 ± 0.88 kJ/mol 21.01373 ± 0.00014 12206-67-6*0 Cyanogen iodide anion [ICN]- (g) 86.5 88.8 ± 8.1 kJ/mol 152.92246 ± 0.00080 1356929-44-6*0 Oxadiazirine O(NN) (g) 351.7 349.8 ± 1.7 kJ/mol 44.01288 ± 0.00033 227934-45-4*0 Formaldehyde cation [CH2O]+ (g) 944.89 941.27 ± 0.10 kJ/mol 30.02543 ± 0.00087 54288-05-0*0 Iodine atom I (g, 2P3/2) 107.157 106.757 ± 0.0021 kJ/mol 126.904470 ± 0.000030 14362-44-8*1 NON NON (g) 545.5 542.3 ± 1.7 kJ/mol 44.01288 ± 0.00033 227934-46-5*0 Isoformyl anion [COH]- (g, triplet) 267.4 268.0 ± 1.6 kJ/mol 29.01859 ± 0.00086 81747-63-9*2 Fluoronium [(HF)(H)]+ (g, triplet) 1490.1 1491.5 ± 1.9 kJ/mol 21.01373 ± 0.00014 12206-67-6*1 Azidonitrene NNNN (g, Cs) 692.1 687.5 ± 1.4 kJ/mol 56.02696 ± 0.00028 147363-92-6*2 Dioxygenyl ion monohydrate [(H2O)(O2)]+ (g) 828.7 821.6 ± 2.1 kJ/mol 50.01353 ± 0.00091 11083-61-7*0 Diazenide [NNH]- (g, vdW) 175.7 176.7 ± 1.6 kJ/mol 29.02197 ± 0.00016 71004-29-0*100 Chlorite [OClO]- (g) -105.62 -107.80 ± 0.35 kJ/mol 67.4520 ± 0.0011 14998-27-7*0 2-Propynylium [CH2CCH]+ (g) 1193.46 1190.65 ± 0.38 kJ/mol 39.0554 ± 0.0024 21540-27-2*0 2-Cyclopropen-1-ylium-1-yl [C(CHCH)]+ (g) 1382.0 1381.0 ± 1.1 kJ/mol 38.0474 ± 0.0024 85398-75-0*0 Dihydrogen fluoride anion [(F)(HH)]- (g, singlet) -257.0 -260.1 ± 1.9 kJ/mol 21.01483 ± 0.00014 *117339-92-1*2 Propynylidene HCCCH (g, cis singlet) 597.6 599.3 ± 1.2 kJ/mol 38.0480 ± 0.0024 67152-18-5*3 Propenediylidene CHCHC (g) 796.3 797.4 ± 1.3 kJ/mol 38.0480 ± 0.0024 60731-11-5*0 Cyclopentene CH2(CH2CHCHCH2) (g) 58.09 33.82 ± 0.45 kJ/mol 68.1170 ± 0.0040 142-29-0*0 Ethyloxoniumyl [CH3CH2OH]+ (g) 783.6 766.5 ± 1.7 kJ/mol 46.0679 ± 0.0017 34480-55-2*0 1-Hydroxyethylium [CH3CHOH]+ (g) 609.13 594.70 ± 0.39 kJ/mol 45.0600 ± 0.0017 18682-96-7*0 Hydrogen difluoride (F)(HF) (g, perp) -187.4 -187.1 ± 1.6 kJ/mol 39.004746 ± 0.000070 12528-21-1*2 Peroxychlorite [OClOO]- (g) -34.3 -34.2 ± 2.0 kJ/mol 83.4514 ± 0.0013 852472-63-0*0 Trihydrogen dioxide anion [HOHOH]- (g) -487.5 -495.8 ± 1.1 kJ/mol 35.02317 ± 0.00064 12501-19-8*0 1-Chloro ozone ClOOO (g, cis vdW) 226.3 223.1 ± 2.3 kJ/mol 83.4509 ± 0.0013 141801-66-3*101 Acetaldehyde cation [CH3CHO]+ (g) 832.03 822.05 ± 0.28 kJ/mol 44.0520 ± 0.0017 36505-03-0*0 Oxiranylium [CH2(CHO)]+ (g, triplet) 1233.6 1226.6 ± 1.8 kJ/mol 43.0441 ± 0.0016 57789-76-1*1 Oxiranyl anion [CH2(CHO)]- (g) 121.3 113.2 ± 1.6 kJ/mol 43.0452 ± 0.0016 72722-59-9*0 Ketene CH2CO (g, singlet) -45.37 -48.49 ± 0.13 kJ/mol 42.0367 ± 0.0016 463-51-4*2 Fluorochlorate [ClF]- (g) -256.03 -255.43 ± 0.81 kJ/mol 54.45165 ± 0.00090 12272-56-9*0 Ethynol anion [HCCO]- (g) -48.51 -47.26 ± 0.89 kJ/mol 41.0293 ± 0.0016 64066-01-9*0 Dicarbon monoxide anion [CCO]- (g) 154.4 158.0 ± 1.1 kJ/mol 40.0213 ± 0.0016 87191-88-6*0 Dicarbon monoxide CCO (g, singlet) 440.4 444.7 ± 1.1 kJ/mol 40.0208 ± 0.0016 12071-23-7*2 COC vdW (CO)(C) (g, singlet) 725.2 733.5 ± 2.0 kJ/mol 40.0208 ± 0.0016 *12071-24-8*2 C=O-C cation [COC]+ (g, doublet) 1575.8 1582.9 ± 2.4 kJ/mol 40.0203 ± 0.0016 83483-98-1*1 C=O=C anion [COC]- (g) 549.8 553.5 ± 2.2 kJ/mol 40.0213 ± 0.0016 *87191-88-6*0 Hydroxyimidogen NOH (g) 217.93 215.04 ± 0.90 kJ/mol 31.01408 ± 0.00032 35337-59-8*0 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 Nitrous acid HONO (g, cis) -71.39 -77.74 ± 0.29 kJ/mol 47.01348 ± 0.00061 7782-77-6*2 OH-CO vdW complex (OH)(CO) (g, vdW) -80.31 -77.42 ± 0.96 kJ/mol 45.0174 ± 0.0010 *2564-85-4*100 CO-HO vdW complex (CO)(HO) (g, vdW) -77.6 -73.6 ± 1.8 kJ/mol 45.0174 ± 0.0010 *2564-84-3*100 H-CO2 vdW complex (H)(CO2) (g, vdW) -179.3 -178.3 ± 2.2 kJ/mol 45.0174 ± 0.0010 *2564-83-2*100 Dibromide [Br2]- (g) -199.2 -213.3 ± 2.0 kJ/mol 159.8085 ± 0.0020 12595-70-9*0 Isocyanic acid cation [HNCO]+ (g) 1003.04 1000.38 ± 0.51 kJ/mol 43.02423 ± 0.00086 444010-28-0*0 Isofulminic acid cation [HCNO]+ (g) 1215.8 1213.0 ± 1.3 kJ/mol 43.02423 ± 0.00086 114766-65-3*0 Acetic acid CH3C(O)OH (aq, 1500 H2O) -484.93 ± 0.23 kJ/mol 60.0520 ± 0.0017 64-19-7*840 Dioxygen O2 (g, singlet) 94.410 94.383 ± 0.000 kJ/mol 31.99880 ± 0.00060 7782-44-7*2 Acetyl chloride CH3C(O)Cl (l) -272.22 ± 0.33 kJ/mol 78.4973 ± 0.0019 75-36-5*500 Chlorohydrofluorine cation [ClFH]+ (g) 1000.8 998.1 ± 2.1 kJ/mol 55.45849 ± 0.00090 70110-63-3*0 (Formyloxy)methyl HC(O)OCH2 (g, syn) -148.7 -156.9 ± 1.7 kJ/mol 59.0440 ± 0.0017 3122-12-1*1 Glyoxal (CHO)2 (g, trans) -206.91 -212.55 ± 0.52 kJ/mol 58.0361 ± 0.0017 107-22-2*1 Chloride Cl- (aq) -166.993 ± 0.023 kJ/mol 35.45325 ± 0.00090 16887-00-6*800 Diazoethenylidene NNCC (g) 657.0 659.6 ± 3.0 kJ/mol 52.0349 ± 0.0016 130760-10-0*0 Isocyanomethylidyne CNC (g) 671.3 675.7 ± 3.6 kJ/mol 38.0281 ± 0.0016 53590-27-5*0 Fluorosyl fluoride FFO (g, triplet) 192.6 193.1 ± 2.3 kJ/mol 53.99621 ± 0.00030 86825-57-2*1 Diazomethyl HCNN (g) 472.9 470.4 ± 2.0 kJ/mol 41.03212 ± 0.00082 20813-32-5*0 Isocyanoamidogen HNNC (g) 492.8 490.8 ± 2.0 kJ/mol 41.03212 ± 0.00082 947408-73-3*0 Tetrachloromethane CCl4 (l) -108.76 -128.17 ± 0.45 kJ/mol 153.8215 ± 0.0037 56-23-5*500 Dichloromethylene anion [CCl2]- (g) 75.63 77.90 ± 0.78 kJ/mol 82.9166 ± 0.0020 118364-73-1*0 Dichloromethylium [CHCl2]+ (g) 894.6 891.4 ± 1.2 kJ/mol 83.9235 ± 0.0020 56932-33-3*0 Dichloromethide [CHCl2]- (g) -41.3 -43.0 ± 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) 346.12 346.42 ± 0.89 kJ/mol 48.4713 ± 0.0012 2108-20-5*1 1,2-Dichloroethane CH2ClCH2Cl (cr,l) -165.63 ± 0.56 kJ/mol 98.9586 ± 0.0024 107-06-2*500 1,1-Dichloroethane CH3CHCl2 (cr,l) -163.40 ± 0.54 kJ/mol 98.9586 ± 0.0024 75-34-3*500 Chlorosyl chloride ClClO (g) 134.5 133.2 ± 1.4 kJ/mol 86.9048 ± 0.0018 86825-56-1*0 Hydroxydioxonitrate [HNO3]- (g) -190.5 -194.8 ± 3.2 kJ/mol 63.01343 ± 0.00091 58875-09-5*0 Chloroform CHCl3 (l) -133.73 ± 0.52 kJ/mol 119.3767 ± 0.0028 67-66-3*590 Chlorodibromomethane CHClBr2 (g) 18.8 -0.0 ± 3.4 kJ/mol 208.2793 ± 0.0023 124-48-1*0 Fluorotribromomethane CBr3F (g) -107.2 -131.2 ± 1.6 kJ/mol 270.7211 ± 0.0031 353-54-8*0 Chlorotribromomethane CBr3Cl (g) 77.3 54.4 ± 1.6 kJ/mol 287.1754 ± 0.0032 594-15-0*0 Chlorobromomethane CH2ClBr (g) -29.0 -43.0 ± 1.3 kJ/mol 129.3833 ± 0.0016 74-97-5*0 Fluoromethyliumylidene [CF]+ (g) 1122.67 1125.89 ± 0.48 kJ/mol 31.00855 ± 0.00080 33412-11-2*0 Fluoromethylene CHF (g) 148.34 148.62 ± 0.46 kJ/mol 32.01704 ± 0.00080 13453-52-6*0 Ethyl iodide CH3CH2I (g) 8.69 -7.19 ± 0.49 kJ/mol 155.9656 ± 0.0016 75-03-6*0 1,2-Dibromoacetylene BrCCBr (g) 333.3 322.4 ± 3.6 kJ/mol 183.8294 ± 0.0026 624-61-3*0 Azanylium [NH2]+ (g) 1266.55 1264.48 ± 0.12 kJ/mol 16.02207 ± 0.00016 15194-15-7*0 Fluoro(fluorooxy)methylene FCOF (g, vdW triplet) -100.9 -99.1 ± 2.1 kJ/mol 66.00691 ± 0.00085 479587-30-9*101 Fluorooxomethylium [FCO]+ (g) 724.6 724.3 ± 1.4 kJ/mol 47.00795 ± 0.00085 38264-00-5*0 Fluoroisoformyl COF (g) -38.8 -33.4 ± 2.0 kJ/mol 47.00850 ± 0.00085 *1871-24-5*0 Benzene cation [C6H6]+ (g) 992.47 976.00 ± 0.23 kJ/mol 78.1113 ± 0.0048 34504-50-2*0 Hydrogen fluoride HF (aq, 22 H2O) -321.04 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*902 Ammonia NH3 (aq, undissoc) -80.890 ± 0.053 kJ/mol 17.03056 ± 0.00022 7664-41-7*1000 Ammonium nitrate (NH4)NO3 (cr,l) -350.29 -365.25 ± 0.18 kJ/mol 80.04344 ± 0.00095 6484-52-2*500 2-Oxopropylium [CH3C(O)CH2]+ (g) 784.4 770.6 ± 1.8 kJ/mol 57.0707 ± 0.0024 54088-52-7*0 1,2-Dibromoethane (CBrH2)2 (g) -10.9 -37.8 ± 1.3 kJ/mol 187.8612 ± 0.0026 106-93-4*0 Nirous oxide cation [NNO]+ (g) 1329.67 1326.77 ± 0.12 kJ/mol 44.01233 ± 0.00033 12269-46-4*0 (E)-Diazene anion [HNNH]- (g, trans) 265.5 258.7 ± 2.0 kJ/mol 30.02991 ± 0.00020 *59952-06-6*0 Methylimidogen CH3N (g) 323.1 315.4 ± 1.7 kJ/mol 29.04126 ± 0.00083 27770-42-9*0 (Z)-Diazene cation [HNNH]+ (g, cis) 1157.0 1150.1 ± 1.3 kJ/mol 30.02881 ± 0.00020 86631-37-0*0 Iminomethyl anion [HCNH]- (g, cis) 252.7 248.9 ± 1.8 kJ/mol 28.03387 ± 0.00082 90623-30-6*2 Hydrogen cyanide cation [HCN]+ (g) 1442.52 1442.06 ± 0.20 kJ/mol 27.02483 ± 0.00081 12601-62-6*0 1-Hydrazinylium-1-yl [NNH2]+ (g) 1143.4 1136.4 ± 1.4 kJ/mol 30.02881 ± 0.00020 63986-30-1*0 Diiodide [I2]- (g) -178.13 -180.72 ± 0.48 kJ/mol 253.809489 ± 0.000060 12190-71-5*0 Methyleneoxonium cation [CH2OH2]+ (g) 827.8 818.3 ± 1.7 kJ/mol 32.04131 ± 0.00090 *177788-17-9*0 Hydroxymethanide [CH2OH]- (g) 9.4 2.8 ± 1.7 kJ/mol 31.03447 ± 0.00088 55830-71-2*0 Formaldehyde CH2O (g, singlet) -105.347 -109.186 ± 0.098 kJ/mol 30.02598 ± 0.00087 50-00-0*2 Hydrogen peroxide cation [H2O2]+ (g, cis) 930.4 923.6 ± 1.0 kJ/mol 34.01413 ± 0.00062 12325-10-9*2 Oxadiazirine anion [O(NN)]- (g) 95.1 95.5 ± 2.9 kJ/mol 44.01343 ± 0.00033 350586-31-1*0 Hydroxymethylene cation [HCOH]+ (g, cis) 986.4 982.8 ± 1.6 kJ/mol 30.02543 ± 0.00087 135395-06-1*2 Hydroxymethylene cation [HCOH]+ (g, gauche quartet) 1482.1 1479.4 ± 1.9 kJ/mol 30.02543 ± 0.00087 135395-06-1*3 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 Aquacarbon H2OC (g, singlet vdW) 467.6 465.5 ± 1.9 kJ/mol 30.02598 ± 0.00087 81434-73-3*102 Aquacarbon cation [H2OC]+ (g) 1196.1 1193.0 ± 1.7 kJ/mol 30.02543 ± 0.00087 *81434-73-3*0 Trioxidaniumyl [HOOOH]+ (g, c, t) 935.4 926.4 ± 1.6 kJ/mol 50.01353 ± 0.00091 161321-37-5*3 Peroxyformic acid HC(O)OOH (g, trans) -265.8 -273.8 ± 1.7 kJ/mol 62.0248 ± 0.0012 107-32-4*2 Peroxyformic acid HC(O)OOH (g, gauche) -265.6 -273.5 ± 1.6 kJ/mol 62.0248 ± 0.0012 107-32-4*3 Hydrogen fluoride HF (aq, 10 H2O) -320.86 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*815 Diazenide [NNH]- (g, triplet) 347.5 344.6 ± 1.6 kJ/mol 29.02197 ± 0.00016 71004-29-0*1 Fluorodioxidanide [FOO]- (g) -256.9 -256.1 ± 1.9 kJ/mol 50.99775 ± 0.00060 23553-17-5*0 Propynylidene cation [HCCCH]+ (g) 1410.8 1413.4 ± 1.3 kJ/mol 38.0474 ± 0.0024 75123-91-0*0 Propynylidene HCCCH (g, trans singlet) 597.3 599.1 ± 1.1 kJ/mol 38.0480 ± 0.0024 67152-18-5*4 Hydroxylamine NH2OH (g, cis) -15.0 -25.5 ± 1.9 kJ/mol 33.02996 ± 0.00037 7803-49-8*2 Propadienylidenide [CH2CC]- (g) 381.16 382.06 ± 0.42 kJ/mol 38.0485 ± 0.0024 109292-49-1*0 1,2-Propadien-1-ylium-1-yl [CH2CC]+ (g) 1561.7 1562.9 ± 1.4 kJ/mol 38.0474 ± 0.0024 110714-00-6*0 Hydroxylamine cation [NH2OH]+ (g) 857.9 848.0 ± 2.2 kJ/mol 33.02941 ± 0.00037 62675-55-2*0 Dihydrogen fluoride anion [(HF)(H)]- (g, singlet) -61.9 -60.5 ± 3.2 kJ/mol 21.01483 ± 0.00014 117339-92-1*2 Hydrogen chloride HCl (aq, 75 H2O) -165.559 ± 0.026 kJ/mol 36.46064 ± 0.00090 7647-01-0*825 Nitroxyl cation [H2NO]+ (g) 946.15 939.02 ± 0.87 kJ/mol 32.02147 ± 0.00034 *51375-41-8*0 n-Pentane CH3CH2CH2CH2CH3 (cr,l) -156.15 -173.12 ± 0.31 kJ/mol 72.1488 ± 0.0041 109-66-0*500 iso-Pentane CH3CH2CH(CH3)2 (l) -178.53 ± 0.44 kJ/mol 72.1488 ± 0.0041 78-78-4*500 neo-Pentane C(CH3)4 (l) -189.96 ± 0.40 kJ/mol 72.1488 ± 0.0041 463-82-1*500 Cyclopentane CH2(CH2CH2CH2CH2) (l) -106.29 ± 0.44 kJ/mol 70.1329 ± 0.0041 287-92-3*590 1,5-Hexadiene CH2CHCH2CH2CHCH2 (g) 108.34 83.75 ± 0.40 kJ/mol 82.1436 ± 0.0049 592-42-7*0 Chlorine oxide peroxide OClOO (g, vdW) 226.5 227.4 ± 2.5 kJ/mol 83.4509 ± 0.0013 141801-67-4*100 2-Hydroxyethylium [CH2CH2OH]+ (g, gauche) 1024.4 1011.8 ± 2.3 kJ/mol 45.0600 ± 0.0017 38607-31-7*1 Ethoxy CH3CH2O (g) 1.84 -11.59 ± 0.52 kJ/mol 45.0605 ± 0.0017 2154-50-9*0 Ethyloxoniumylidene [CH3CH2O]+ (g) 988.8 975.1 ± 1.9 kJ/mol 45.0600 ± 0.0017 54387-07-4*0 Dihydrogen fluoride (H)(HF) (g) -55.9 -54.9 ± 1.6 kJ/mol 21.01428 ± 0.00014 12592-22-2*1 Hydroxyaminylium [HNOH]+ (g, cis) 1048.6 1041.5 ± 2.6 kJ/mol 32.02147 ± 0.00034 66097-71-0*2 Nitrosyl fluoride FNO (g) -85.82 -88.18 ± 0.93 kJ/mol 49.00454 ± 0.00031 7789-25-5*0 Formylmethyl anion [CH2CHO]- (g, perp triplet) 140.5 134.2 ± 1.9 kJ/mol 43.0452 ± 0.0016 64723-93-9*0 Hydroxyamidogen anion [HNOH]- (g) 90.9 85.0 ± 2.9 kJ/mol 32.02257 ± 0.00034 *66097-71-0*0 Dicarbon monoxide cation [CCO]+ (g) 1434.0 1439.1 ± 2.2 kJ/mol 40.0203 ± 0.0016 12287-08-0*0 1,3-Butadiyne-1,4-diyl CCCC (g) 1052.45 1062.43 ± 0.67 kJ/mol 48.0428 ± 0.0032 78015-07-3*0 C=O-C cation [COC]+ (g, quartet) 1812.6 1816.6 ± 2.4 kJ/mol 40.0203 ± 0.0016 83483-98-1*2 1-Chloro ozone anion [ClOOO]- (g, perp) -108.9 -111.4 ± 2.2 kJ/mol 83.4514 ± 0.0013 224299-15-4*3 Oxirene cation [O(CHCH)]+ (g) 1109.0 1105.5 ± 5.2 kJ/mol 42.0361 ± 0.0016 94664-69-4*0 1-Chloro ozone anion [ClOOO]- (g, cis) -66.8 -68.7 ± 2.1 kJ/mol 83.4514 ± 0.0013 224299-15-4*1 Dihydrogen cation [H2]+ (g) 1488.364 1488.480 ± 0.000 kJ/mol 2.01533 ± 0.00014 12184-90-6*0 Nitrosyl nitrate ON(O2)NO (g, perp) 70.6 62.3 ± 1.8 kJ/mol 92.0111 ± 0.0012 *15969-55-8*0 Formic acid anion [HC(O)OH]- (g, anti) -241.2 -246.9 ± 1.9 kJ/mol 46.0259 ± 0.0010 19066-82-1*2 Bifluoride [FHF]- (g) -705.22 -709.07 ± 0.36 kJ/mol 39.005295 ± 0.000070 18130-74-0*0 Dioxirane cation [CH2(OO)]+ (g) 1050.8 1043.2 ± 2.0 kJ/mol 46.0248 ± 0.0010 232262-10-1*0 Dioxymethyl cation [CH2OO]+ (g) 1075.0 1068.6 ± 1.8 kJ/mol 46.0248 ± 0.0010 232262-11-2*0 Deuterium atom cation D+ (g) 1532.210 1534.123 ± 0.000 kJ/mol 2.01355319809 ± 0.00000000040 14464-47-2*0 Dioxymethylene HCOO (g, cis) 341.1 338.9 ± 3.4 kJ/mol 45.0174 ± 0.0010 438586-67-5*2 Dioxofluorine OFO (g) 524.0 523.2 ± 1.1 kJ/mol 50.99720 ± 0.00060 175861-93-5*0 Trifluoride ion [F3]- (g) -348.9 -349.7 ± 2.6 kJ/mol 56.9957582 ± 0.0000015 25730-99-8*0 Cyanato cation [NCO]+ (g) 1261.56 1262.07 ± 0.59 kJ/mol 42.01629 ± 0.00086 17247-99-3*0 Nitrous acid HONO (g) -73.023 -78.680 ± 0.079 kJ/mol 47.01348 ± 0.00061 7782-77-6*0 Nitrosomethyliumylidene [CNO]+ (g) 1509.9 1510.9 ± 1.9 kJ/mol 42.01629 ± 0.00086 67197-19-7*0 Fulminate [CNO]- (g) 59.2 59.5 ± 1.9 kJ/mol 42.01739 ± 0.00086 28269-67-2*0 Acetic acid CH3C(O)OH (l) -484.11 -483.68 ± 0.18 kJ/mol 60.0520 ± 0.0017 64-19-7*500 Acetic acid CH3C(O)OH (aq, 75 H2O) -484.73 ± 0.23 kJ/mol 60.0520 ± 0.0017 64-19-7*825 Acetic acid CH3C(O)OH (aq, 700 H2O) -484.91 ± 0.23 kJ/mol 60.0520 ± 0.0017 64-19-7*835 Dioxaziridinyl cation [N(OO)]+ (g) 1365.8 1363.3 ± 1.7 kJ/mol 46.00499 ± 0.00060 *66252-29-7*0 (Formyloxy)methyl HC(O)OCH2 (g, anti) -133.6 -141.8 ± 2.2 kJ/mol 59.0440 ± 0.0017 3122-12-1*2 Ethane cation [CH3CH3]+ (g) 1043.20 1029.19 ± 0.60 kJ/mol 30.0685 ± 0.0017 34488-65-8*0 Glyoxal (CHO)2 (g, cis) -188.51 -193.95 ± 0.69 kJ/mol 58.0361 ± 0.0017 107-22-2*2 Glyoxal (CHO)2 (g) -206.91 -212.47 ± 0.52 kJ/mol 58.0361 ± 0.0017 107-22-2*0 Fluoroniumyl ion [HF]+ (g) 1275.556 1275.788 ± 0.050 kJ/mol 20.005795 ± 0.000070 12381-92-9*0 Dimethylaminylium [(CH3)2N]+ (g) 1040.0 1024.6 ± 1.8 kJ/mol 44.0752 ± 0.0017 49784-85-2*0 Isocyanogen anion [CNCN]- (g, trans) 383.7 387.4 ± 2.6 kJ/mol 52.0354 ± 0.0016 *83951-85-3*1 Diisocyanogen cation [CNNC]+ (g, trans) 1823.1 1825.9 ± 3.5 kJ/mol 52.0343 ± 0.0016 *78800-21-2*1 Cyanomethylidyne CCN (g) 676.1 680.5 ± 1.9 kJ/mol 38.0281 ± 0.0016 4120-02-9*0 Dioxaziridinyl anion [N(OO)]- (g) 295.9 293.4 ± 1.7 kJ/mol 46.00609 ± 0.00060 66252-31-1*0 Perchloryloxy OCl(O)(O)O (g) 248.6 241.0 ± 1.8 kJ/mol 99.4503 ± 0.0015 12133-63-0*0 Hydrogen fluoride HF (aq, 60 H2O) -321.16 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*823 Dichloromethylene CCl2 (g, triplet) 313.62 314.82 ± 0.90 kJ/mol 82.9161 ± 0.0020 1605-72-7*1 Perchlorate [OCl(O)(O)O]- (g) -263.2 -272.1 ± 2.2 kJ/mol 99.4508 ± 0.0015 14797-73-0*0 Trioxidanylium [HOOO]+ (g, cis) 1085.3 1079.1 ± 1.5 kJ/mol 49.00559 ± 0.00090 74241-49-9*2 Azidonitrene NNNN (g, C2h) 660.8 657.6 ± 1.6 kJ/mol 56.02696 ± 0.00028 147363-92-6*1 Ethylene anion [CH2CH2]- (g, anti ?) 232.1 224.5 ± 2.0 kJ/mol 28.0537 ± 0.0016 34527-91-8*1 Chloromethyliumyl [CHCl]+ (g) 1207.3 1207.6 ± 2.0 kJ/mol 48.4708 ± 0.0012 89877-51-0*0 Chloromethylene anion [CHCl]- (g) 203.42 204.23 ± 0.94 kJ/mol 48.4719 ± 0.0012 75466-08-9*0 Chlorohydroxymethyl CH(Cl)OH (g, anti-gauche) -46.0 -51.6 ± 2.0 kJ/mol 65.4787 ± 0.0012 147139-06-8*2 1,1,2-Trichloroethane CH2ClCHCl2 (l) -188.5 ± 1.4 kJ/mol 133.4033 ± 0.0031 79-00-5*500 Hexachloroethane CCl3CCl3 (cr,l) -216.6 ± 2.9 kJ/mol 236.7376 ± 0.0056 67-72-1*500 trans-1,2-Dichloroethene CHClCHCl (g, trans) 5.29 -0.13 ± 0.56 kJ/mol 96.9427 ± 0.0024 156-60-5*0 Chlorine difluoride anion [FClF]- (g) -504.9 -505.8 ± 1.9 kJ/mol 73.45005 ± 0.00090 16892-05-0*0 Tetrachloroethene CCl2CCl2 (l) -62.9 ± 1.1 kJ/mol 165.8322 ± 0.0039 127-18-4*500 Azanylium [NH3]+ (g) 944.272 937.318 ± 0.030 kJ/mol 17.03001 ± 0.00022 19496-55-0*0 Hydrofluorate ion [HF]- (g) -75.6 -75.1 ± 1.8 kJ/mol 20.006892 ± 0.000070 37249-79-9*0 Chlorine difluoride ClFF (g) 22.5 23.8 ± 1.9 kJ/mol 73.44951 ± 0.00090 91483-78-2*0 Nitric acid HNO3 (aq, 1000 H2O) -206.31 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*839 Hydrogen chloride HCl (aq, 2000 H2O) -166.685 ± 0.024 kJ/mol 36.46064 ± 0.00090 7647-01-0*841 Fluorochlorobromomethane CHFClBr (g) -219.3 -231.7 ± 5.5 kJ/mol 147.3737 ± 0.0016 593-98-6*0 Fluoromethyliumyl [CHF]+ (g) 1116.9 1117.2 ± 2.4 kJ/mol 32.01649 ± 0.00080 89877-52-1*0 Fluoromethylene anion [CHF]- (g) 95.94 96.47 ± 0.64 kJ/mol 32.01759 ± 0.00080 71267-42-0*0 Peroxyimidogen cation [NOO]+ (g) 1409.6 1406.8 ± 1.9 kJ/mol 46.00499 ± 0.00060 *60488-32-6*0 Fluorodioxidenium [FOO]+ (g) 1221.9 1219.5 ± 2.0 kJ/mol 50.99665 ± 0.00060 139584-95-5*0 Polytetrafluoroethylene C2F4 (s) -829.49 ± 0.58 kJ/mol 100.0150 ± 0.0016 9002-84-0*591 Nitric acid HNO3 (cr,l) -179.01 -173.29 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*500 Dihydrooxooxygen cation [(H2O)O]+ (g) 994.5 987.8 ± 1.6 kJ/mol 34.01413 ± 0.00062 177329-59-8*0 cis-1,2-Difluoroethene CHFCHF (g, cis) -302.9 -309.7 ± 1.1 kJ/mol 64.0341 ± 0.0016 1630-77-9*0 trans-1,2-Difluoroethene CHFCHF (g, trans) -299.7 -306.1 ± 1.1 kJ/mol 64.0341 ± 0.0016 1630-78-0*0 Bromoacetylene HCCBr (g) 282.4 275.9 ± 2.2 kJ/mol 104.9333 ± 0.0019 593-61-3*0 Formyl fluoride cation [HFCO]+ (g) 816.6 813.3 ± 1.3 kJ/mol 48.01589 ± 0.00086 99766-68-4*0 Formyl fluoride [FCO]- (g) -405.4 -403.9 ± 1.8 kJ/mol 47.00905 ± 0.00085 62227-71-8*0 Fluoroisoformyl cation [COF]+ (g) 1347.5 1348.9 ± 2.5 kJ/mol 47.00795 ± 0.00085 *1871-25-6*0 Hydrogen fluoride HF (aq, 18 H2O) -321.01 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*901 Aminyliumyl [NH]+ (g) 1659.03 1659.96 ± 0.24 kJ/mol 15.014131 ± 0.000099 19067-62-0*0 Peroxyimidogen anion [NOO]- (g) 165.0 162.7 ± 1.7 kJ/mol 46.00609 ± 0.00060 60488-31-5*0 Fluorosyl fluoride anion [FFO]- (g, doublet) -147.2 -146.9 ± 3.0 kJ/mol 53.99675 ± 0.00030 *86825-57-2*2 Hydrogen fluoride HF (l) -302.39 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*590 o-Benzyne cation [C6H4]+ (g) 1393.8 1385.8 ± 1.7 kJ/mol 76.0954 ± 0.0048 70220-84-7*0 m-Benzyne cation [C6H4]+ (g) 1365.5 1357.0 ± 1.9 kJ/mol 76.0954 ± 0.0048 121058-08-0*0 p-Benzyne C6H4 (g, triplet) 603.5 594.2 ± 1.2 kJ/mol 76.0960 ± 0.0048 3355-34-8*1 Hydrogen bromide HBr (aq, 600 H2O) -120.23 ± 0.16 kJ/mol 80.9119 ± 0.0010 10035-10-6*834 Xenon cation Xe+ (g) 1170.354 1170.354 ± 0.0062 kJ/mol 131.2895 ± 0.0200 24203-25-6*0 Hydrogen bromide HBr (aq, 5000 H2O) -120.52 ± 0.16 kJ/mol 80.9119 ± 0.0010 10035-10-6*844 Acetylene anion [HCCH]- (g, trans ?) 356.9 356.7 ± 1.9 kJ/mol 26.0378 ± 0.0016 50443-89-5*1 Krypton hydride cation [KrH]+ (g) 1106.33 1104.55 ± 0.69 kJ/mol 84.8074 ± 0.1000 37276-90-7*0 Allylium [CH2CHCH2]+ (g) 964.09 952.53 ± 0.55 kJ/mol 41.0713 ± 0.0024 1724-44-3*0 Allyl anion [CH2CHCH2]- (g) 133.02 123.27 ± 0.86 kJ/mol 41.0723 ± 0.0024 1724-46-5*0 1-Propenyl cation [CH3CHCH]+ (g, cis) 1232.6 1222.3 ± 1.7 kJ/mol 41.0713 ± 0.0024 50457-58-4*2 1-Propenyl anion [CH3CHCH]- (g, cis) 203.6 192.4 ± 1.8 kJ/mol 41.0723 ± 0.0024 65887-20-9*2 1-Propenyl cation [CH3CHCH]+ (g, trans) 1234.3 1223.9 ± 1.7 kJ/mol 41.0713 ± 0.0024 50457-58-4*1 1-Propenyl anion [CH3CHCH]- (g, trans) 210.2 199.1 ± 1.8 kJ/mol 41.0723 ± 0.0024 65887-20-9*1 Methylimidogen anion [CH3N]- (g) 321.1 313.5 ± 1.8 kJ/mol 29.04181 ± 0.00083 82539-34-2*0 Trioxodinitrate anion [ONNO2]- (g, non-vdW) -88.5 -95.6 ± 2.1 kJ/mol 76.01223 ± 0.00091 194856-62-7*1 Hydrogen fluoride HF (aq, 55 H2O) -321.16 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*905 Trioxidanylium [HOOO]+ (g) 1070.6 1064.3 ± 1.4 kJ/mol 49.00559 ± 0.00090 74241-49-9*0 Cycloprop-2-enylium [CH(CHCH)]+ (g) 1080.7 1075.6 ± 1.4 kJ/mol 39.0554 ± 0.0024 26810-74-2*0 Ethynylene cation [C2]+ (g) 1967.9 1974.5 ± 1.9 kJ/mol 24.0209 ± 0.0016 12595-79-8*0 Methyleneaminylium [CH2N]+ (g, triplet) 1456.6 1453.0 ± 2.2 kJ/mol 28.03277 ± 0.00082 53518-13-1*1 Propynylidene HCCCH (g) 543.38 546.38 ± 0.63 kJ/mol 38.0480 ± 0.0024 67152-18-5*0 Hypobromous acid cation [HOBr]+ (g) 974.82 964.20 ± 0.64 kJ/mol 96.9108 ± 0.0010 154804-02-1*0 Cyclopropyne CH2(CC) (g) 791.3 790.8 ± 1.4 kJ/mol 38.0480 ± 0.0024 60701-63-5*0 Cyclopropenyliumdiyl [CH(CC)]+ (g) 1692.0 1694.9 ± 1.9 kJ/mol 37.0395 ± 0.0024 127476-05-5*0 Cyclopropynyl anion [CH(CC)]- (g) 517.8 520.8 ± 1.1 kJ/mol 37.0406 ± 0.0024 136861-42-2*0 Hypochlorous acid cation [HOCl]+ (g) 998.91 995.86 ± 0.90 kJ/mol 52.45949 ± 0.00095 71606-47-8*0 Nitrate [NO3]- (aq) -206.63 ± 0.18 kJ/mol 62.00549 ± 0.00090 14797-55-8*800 Hypofluorous acid anion [HOF]- (g, quartet) 155.3 154.7 ± 2.6 kJ/mol 36.00629 ± 0.00031 36505-07-4*2 Nitrogen hydride oxide H3NO (g) 71.6 60.4 ± 2.0 kJ/mol 33.02996 ± 0.00037 38544-48-8*0 Nirous oxide anion [NNO]- (g) 99.2 96.6 ± 1.9 kJ/mol 44.01343 ± 0.00033 12274-12-3*0 Hydrogen chloride HCl (aq, 140 H2O) -165.948 ± 0.026 kJ/mol 36.46064 ± 0.00090 7647-01-0*907 Aminomethyliumylidene [CNH2]+ (g) 1168.3 1165.1 ± 2.2 kJ/mol 28.03277 ± 0.00082 86784-42-1*0 Cyclopentene CH2(CH2CHCHCH2) (l) 4.98 ± 0.42 kJ/mol 68.1170 ± 0.0040 142-29-0*590 Hydrogen chloride HCl (aq, 1500 H2O) -166.639 ± 0.025 kJ/mol 36.46064 ± 0.00090 7647-01-0*840 Nitroxyl anion [H2NO]- (g) 48.7 41.7 ± 2.0 kJ/mol 32.02257 ± 0.00034 51375-41-8*0 Tribromide [Br3]- (g) -287.6 -308.0 ± 1.9 kJ/mol 239.7125 ± 0.0030 14522-80-6*0 Nitrosyl nitrite ONONO (g, t, c) 109.3 105.2 ± 1.8 kJ/mol 76.01168 ± 0.00091 122413-35-8*2 Ethanol CH3CH2OH (l) -269.34 -277.10 ± 0.21 kJ/mol 46.0684 ± 0.0017 64-17-5*500 Hydrogen chloride HCl (aq, 74 H2O) -165.548 ± 0.027 kJ/mol 36.46064 ± 0.00090 7647-01-0*953 Methylammoniumyl [CH3NH2]+ (g) 865.1 851.2 ± 1.8 kJ/mol 31.05659 ± 0.00088 34516-31-9*0 1-Hydroxyethyl anion [CH3CHOH]- (g) -19.9 -33.3 ± 2.9 kJ/mol 45.0610 ± 0.0017 88032-18-2*0 1,2-Propadien-1-yl-3-ylidene anion [CCC]- (g) 621.9 629.3 ± 1.3 kJ/mol 36.0326 ± 0.0024 109292-47-9*0 Trifluorine cation [F3]+ (g) 1529.5 1527.4 ± 2.3 kJ/mol 56.9946610 ± 0.0000015 64710-22-1*0 2-Cyclopropyn-1-ylidene C(CC) (g, singlet) 993.8 1000.6 ± 2.5 kJ/mol 36.0321 ± 0.0024 102508-15-6*2 Acetaldehyde anion [CH3CHO]- (g) -61.8 -72.1 ± 2.1 kJ/mol 44.0531 ± 0.0017 60427-04-5*0 Hydrogen chloride HCl (aq, 2439 H2O) -166.714 ± 0.024 kJ/mol 36.46064 ± 0.00090 7647-01-0*951 Propynylidyne anion [C(CC)]- (g) 664.9 672.2 ± 1.6 kJ/mol 36.0326 ± 0.0024 500574-36-7*0 Ketene cation [CH2CO]+ (g) 882.20 879.18 ± 0.13 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) 1139.3 1142.1 ± 2.9 kJ/mol 41.0282 ± 0.0016 92056-63-8*0 Bicyclo[1.1.0]buta-1,3-diene-2,4-diyl C(CC)C (g) 1047.48 1055.08 ± 0.72 kJ/mol 48.0428 ± 0.0032 12184-80-4*0 Hydrooxonitrate [HNO]- (g) 78.59 75.67 ± 0.99 kJ/mol 31.01463 ± 0.00032 66057-02-1*0 Triazirine HN(NN) (g) 464.1 457.6 ± 2.6 kJ/mol 43.02816 ± 0.00022 157-29-9*0 Ethynol cation [HCCOH]+ (g) 1063.5 1061.3 ± 2.9 kJ/mol 42.0361 ± 0.0016 84005-02-7*0 Methyl hydroperoxide cation [CH3OOH]+ (g) 833.5 820.3 ± 2.2 kJ/mol 48.0407 ± 0.0010 112465-88-0*0 Methoxyoxoniumylidene [CH3OO]+ (g) 1012.9 1004.6 ± 2.0 kJ/mol 47.0328 ± 0.0010 86475-50-5*0 Hydroxyimidogen anion [NOH]- (g) 229.9 227.4 ± 2.3 kJ/mol 31.01463 ± 0.00032 *35337-59-8*0 Dioxirane anion [CH2(OO)]- (g) -170.4 -177.2 ± 3.9 kJ/mol 46.0259 ± 0.0010 *157-26-6*0 Peroxychloric acid HOOCl(O)O (g) 77.5 69.3 ± 2.6 kJ/mol 100.4582 ± 0.0015 177778-91-5*0 Dioxymethyl anion [CH2OO]- (g) 55.0 49.8 ± 1.4 kJ/mol 46.0259 ± 0.0010 93207-29-5*0 Hypochlorous acid anion [HOCl]- (g) 198.7 198.3 ± 2.5 kJ/mol 52.46059 ± 0.00095 34524-94-2*0 Methylamine anion [CH3NH2]- (g) 83.9 69.0 ± 2.8 kJ/mol 31.05769 ± 0.00088 81096-79-9*0 Formyloxidanyl HC(O)O (g) -125.57 -126.93 ± 0.56 kJ/mol 45.0174 ± 0.0010 16499-21-1*0 Dioxiranyl HC(OO) (g) 216.2 212.8 ± 2.4 kJ/mol 45.0174 ± 0.0010 120595-16-6*0 Deuterium hydride cation [HD]+ (g) 1490.498 1490.587 ± 0.000 kJ/mol 3.021493 ± 0.000070 12181-16-7*0 Oxobromonium [BrO]+ (g) 1139.2 1131.4 ± 1.6 kJ/mol 95.9029 ± 0.0010 142315-39-7*0 2-Propanol CH3CH(OH)CH3 (cr,l) -305.60 -318.40 ± 0.32 kJ/mol 60.0950 ± 0.0025 67-63-0*500 1-Propanol CH3CH2CH2OH (cr,l) -290.56 -302.74 ± 0.24 kJ/mol 60.0950 ± 0.0025 71-23-8*500 Tetranitrogen cation [N4]+ (g) 1392.8 1392.5 ± 1.5 kJ/mol 56.02641 ± 0.00028 12185-04-5*0 Hydroxyoxoammoniumyl [HONO]+ (g) 984.1 977.6 ± 1.8 kJ/mol 47.01293 ± 0.00061 80371-48-8*0 Cyanogen bromide anion [BrCN]- (g) 58.2 54.6 ± 3.8 kJ/mol 105.9220 ± 0.0013 54092-05-6*0 Oxazirinyl cation [C(NO)]+ (g) 1565.4 1566.1 ± 2.3 kJ/mol 42.01629 ± 0.00086 *228850-18-8*0 Oxazirinyl anion [C(NO)]- (g) 448.0 448.8 ± 2.4 kJ/mol 42.01739 ± 0.00086 28269-68-3*0 Acetic acid CH3C(O)OH (g, syn-anti equilib) -418.51 -432.63 ± 0.52 kJ/mol 60.0520 ± 0.0017 64-19-7*0 Bromine dioxide OBrO (g) 167.1 157.5 ± 3.0 kJ/mol 111.9028 ± 0.0012 21255-83-4*0 Dinitrogen pentoxide O2NONO2 (cr,l) -41.06 ± 0.42 kJ/mol 108.0105 ± 0.0015 10102-03-1*500 Methoxycarbonyl C(O)OCH3 (g, anti-staggered) -150.1 -158.0 ± 2.1 kJ/mol 59.0440 ± 0.0017 16481-04-2*1 Dioxygen O2 (g, triplet) -0.000 -0.000 ± 0.000 kJ/mol 31.99880 ± 0.00060 7782-44-7*1 Diazenium [NH2NH]+ (g) 968.59 957.33 ± 0.77 kJ/mol 31.03675 ± 0.00025 37369-93-0*0 Oxalic acid (COOH)2 (g) -710.8 -721.4 ± 2.1 kJ/mol 90.0349 ± 0.0020 144-62-7*0 2-Chloro ozone anion [ClO(O)O]- (g) -103.4 -105.7 ± 3.2 kJ/mol 83.4514 ± 0.0013 *141801-67-4*0 Fluorine atom cation F+ (g) 1758.301 1760.599 ± 0.048 kJ/mol 18.99785462 ± 0.00000050 14701-13-4*0 Water H2O (l, eq.press.) -285.838 ± 0.027 kJ/mol 18.01528 ± 0.00033 7732-18-5*589 Methanol anion [CH3OH]- (g) -89.0 -99.7 ± 2.8 kJ/mol 32.04241 ± 0.00090 68474-04-4*0 Isocyanogen anion [CNCN]- (g, cis) 386.6 389.5 ± 3.0 kJ/mol 52.0354 ± 0.0016 *83951-85-3*2 Diisocyanogen cation [CNNC]+ (g, cis) 1835.1 1837.8 ± 3.5 kJ/mol 52.0343 ± 0.0016 *78800-21-2*2 Ethanium [C2H7]+ (g, classical Cs I) 888.8 870.3 ± 1.8 kJ/mol 31.0764 ± 0.0017 24669-33-8*2 Ethanium [C2H7]+ (g, classical Cs II) 895.2 877.3 ± 1.9 kJ/mol 31.0764 ± 0.0017 24669-33-8*3 Hydroperoxyimidogen HOON (g, trans) 103.3 99.7 ± 2.4 kJ/mol 47.01348 ± 0.00061 877456-58-1*1 Cyanoamidogen anion [HNCN]- (g) 72.0 69.0 ± 1.8 kJ/mol 41.03267 ± 0.00082 67131-47-9*0 Cyanamide H2NCN (g) 140.8 134.5 ± 1.5 kJ/mol 42.04006 ± 0.00082 420-04-2*0 Diazomethylene CNN (g) 578.8 579.5 ± 3.8 kJ/mol 40.02418 ± 0.00081 2468-81-7*0 Trichloromethylium [CCl3]+ (g) 854.24 852.72 ± 0.96 kJ/mol 118.3683 ± 0.0028 27130-34-3*0 Dichloromethyliumyl [CCl2]+ (g) 1121.6 1122.6 ± 1.8 kJ/mol 82.9156 ± 0.0020 55945-51-2*0 Ethylene anion [CH2CH2]- (g, syn ?) 231.6 225.5 ± 2.0 kJ/mol 28.0537 ± 0.0016 34527-91-8*2 Formaldehyde anion [CH2O]- (g) -26.7 -28.3 ± 2.0 kJ/mol 30.02653 ± 0.00087 27837-46-3*0 Hydrogen chloride HCl (aq, 150 H2O) -165.981 ± 0.024 kJ/mol 36.46064 ± 0.00090 7647-01-0*829 Formaldehyde CH2O (g, triplet) 196.044 192.713 ± 0.098 kJ/mol 30.02598 ± 0.00087 50-00-0*1 Bromine atom Br (g, 2P3/2) 117.917 111.855 ± 0.056 kJ/mol 79.90400 ± 0.00100 10097-32-2*1 Nitric acid cation [HNO3]+ (g) 1029.14 1020.08 ± 0.69 kJ/mol 63.01233 ± 0.00091 272109-63-4*0 Trichloroethene CHClCCl2 (l) -48.7 ± 1.6 kJ/mol 131.3874 ± 0.0031 79-01-6*590 Aminomethyl anion [CH2NH2]- (g) 209.2 199.0 ± 2.1 kJ/mol 30.04975 ± 0.00085 74215-21-7*0 Chlorosyl chloride cation [ClClO]+ (g) 1132.6 1130.8 ± 2.0 kJ/mol 86.9043 ± 0.0018 *86825-56-1*0 Chloromethane cation [CH3Cl]+ (g) 1015.11 1008.34 ± 0.25 kJ/mol 50.4867 ± 0.0012 12538-71-5*0 1-Ethylium-1-yl [CH3CH]+ (g) 1182.1 1174.7 ± 3.2 kJ/mol 28.0526 ± 0.0016 85944-79-2*0 Ethylidene anion [CH3CH]- (g) 325.8 318.4 ± 1.9 kJ/mol 28.0537 ± 0.0016 35829-99-3*0 Fluorosyl fluoride cation [FFO]+ (g, quartet) 1413.0 1413.4 ± 3.5 kJ/mol 53.99566 ± 0.00030 *86825-50-5*1 Peroxyhypochlorite [ClOO]- (g) -249.23 -248.20 ± 0.37 kJ/mol 67.4520 ± 0.0011 224299-14-3*0 Methylaminilium [CH3NH]+ (g) 1134.8 1125.0 ± 2.1 kJ/mol 30.04865 ± 0.00085 49784-84-1*0 Fluorobromomethane CH2FBr (g) -198.0 -212.4 ± 5.5 kJ/mol 112.9290 ± 0.0013 373-52-4*0 Chloroniumyl ion [HCl]+ (g) 1137.797 1137.731 ± 0.0051 kJ/mol 36.46009 ± 0.00090 12258-94-5*0 Chlorine difluoride cation [ClFF]+ (g) 1346.3 1344.9 ± 2.1 kJ/mol 73.44896 ± 0.00090 86825-59-4*0 Fluorodibromomethane CHFBr2 (g) -160.0 -179.5 ± 5.5 kJ/mol 191.8250 ± 0.0022 1868-53-7*0 Difluorochlorobromomethane CF2ClBr (g) -431.5 -442.2 ± 5.5 kJ/mol 165.3642 ± 0.0016 353-59-3*0 Dichlorofluorobromomethane CCl2FBr (g) -230.2 -240.0 ± 5.5 kJ/mol 181.8185 ± 0.0022 353-58-2*0 Dibromofluorochloromethane CBr2FCl (g) -170.8 -187.4 ± 5.5 kJ/mol 226.2698 ± 0.0023 353-55-9*0 Chlorine difluoride anion [ClFF]- (g) -319.0 -319.1 ± 2.2 kJ/mol 73.45005 ± 0.00090 91419-41-9*0 Krypton cation Kr+ (g) 1350.756 1350.756 ± 0.000 kJ/mol 83.7995 ± 0.1000 16915-28-9*0 Difluoromethyliumyl [CF2]+ (g) 908.35 908.78 ± 0.91 kJ/mol 50.00696 ± 0.00080 54250-40-7*0 Hydrogen fluoride HF (aq, 23 H2O) -321.05 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*903 Methanimine cation [CH2NH]+ (g) 1056.0 1049.1 ± 1.8 kJ/mol 29.04071 ± 0.00083 65130-65-6*0 Methanimine anion [CH2NH]- (g) 224.3 217.1 ± 2.2 kJ/mol 29.04181 ± 0.00083 127593-73-1*0 Ammonium radical NH4 (g) 190.01 179.43 ± 0.43 kJ/mol 18.03850 ± 0.00029 92075-50-8*0 Dibromine Br2 (aq) -2.16 ± 0.20 kJ/mol 159.8080 ± 0.0020 7726-95-6*800 Hydrogen fluoride HF (aq, 22.2 H2O) -321.04 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*888 Ozone cation [OOO]+ (g) 1352.870 1350.531 ± 0.041 kJ/mol 47.99765 ± 0.00090 12596-82-6*0 Hydrogen fluoride HF (aq, 37 H2O) -321.11 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*890 Hydrogen fluoride HF (aq, 55.51 H2O) -321.16 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*891 Hydrogen bromide HBr (aq, 2570 H2O) -120.46 ± 0.16 kJ/mol 80.9119 ± 0.0010 10035-10-6*952 Aminomethyliumyl [CHNH2]+ (g) 1039.5 1031.8 ± 2.3 kJ/mol 29.04071 ± 0.00083 89302-94-3*0 Difluorophosgene cation [COF2]+ (g) 653.41 650.78 ± 0.57 kJ/mol 66.00636 ± 0.00085 73256-56-1*0 Difluorophosgene anion [COF2]- (g) -603.6 -605.5 ± 3.4 kJ/mol 66.00745 ± 0.00085 474815-26-4*0 Carbon atom C (g, triplet) 711.407 716.892 ± 0.048 kJ/mol 12.01070 ± 0.00080 7440-44-0*1 Chlorohydroxymethylene ClCOH (g, trans) 13.9 11.0 ± 2.6 kJ/mol 64.4707 ± 0.0012 147723-60-2*1 (Chlorooxy)methylene HCOCl (g, cis) 119.1 117.8 ± 2.7 kJ/mol 64.4707 ± 0.0012 331419-80-8*2 Chloryl ion [OClO]+ (g) 1100.15 1097.49 ± 0.52 kJ/mol 67.4510 ± 0.0011 25052-55-5*0 Dibromophosgene COBr2 (l) -144.18 ± 0.96 kJ/mol 187.8181 ± 0.0022 593-95-3*590 2-Chloroethanol ClCH2CH2OH (l) -315.10 ± 0.56 kJ/mol 80.5132 ± 0.0019 107-07-3*590 2-Bromoethanol BrCH2CH2OH (l) -274.83 ± 0.48 kJ/mol 124.9645 ± 0.0019 540-51-2*590 Hydrogen bromide HBr (aq, 3000 H2O) -120.47 ± 0.16 kJ/mol 80.9119 ± 0.0010 10035-10-6*842 Imidogen anion [NH]- (g) 322.62 322.67 ± 0.17 kJ/mol 15.015229 ± 0.000099 23841-33-0*0 Trioxidanyl HOOO (g, cis) 26.28 23.01 ± 0.19 kJ/mol 49.00614 ± 0.00090 12500-78-6*2 Hypofluorous acid cation [HOF]+ (g) 1141.99 1138.98 ± 0.87 kJ/mol 36.00519 ± 0.00031 90243-22-4*0 Phenylium [C6H5]+ (g, singlet) 1148.45 1135.67 ± 0.88 kJ/mol 77.1034 ± 0.0048 17333-73-2*2 Chlorosyl chloride anion [ClClO]- (g) -185.4 -184.7 ± 2.3 kJ/mol 86.9053 ± 0.0018 *86825-55-0*0 Carbon atom C (g, singlet) 833.338 838.485 ± 0.048 kJ/mol 12.01070 ± 0.00080 7440-44-0*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) 465.1 455.5 ± 1.3 kJ/mol 76.0965 ± 0.0048 219298-17-6*0 Chloryl chloride ClCl(O)O (g) 126.1 122.1 ± 1.7 kJ/mol 102.9042 ± 0.0019 117489-73-3*0 Benzylium [C6H5CH2]+ (g) 929.66 910.16 ± 0.63 kJ/mol 91.1299 ± 0.0056 6711-19-9*0 Hydrogen bromide HBr (aq, 2000 H2O) -120.42 ± 0.16 kJ/mol 80.9119 ± 0.0010 10035-10-6*841 Aminomethylene anion [CHNH2]- (g) 353.0 346.1 ± 2.3 kJ/mol 29.04181 ± 0.00083 207914-86-1*0 Phenyloxoniumylidene [C6H5O]+ (g) 902.9 888.6 ± 2.4 kJ/mol 93.1028 ± 0.0048 41071-17-4*0 Fluorosyl fluoride anion [FFO]- (g, quartet) -56.6 -56.1 ± 2.4 kJ/mol 53.99675 ± 0.00030 *86825-57-2*1 Hydrogen difluoride cation [FFH]+ (g, singlet) 1174.3 1171.3 ± 1.5 kJ/mol 39.004198 ± 0.000070 *126950-54-7*2 Ammonium chloride (NH4)Cl (cr) -311.728 -314.889 ± 0.063 kJ/mol 53.49120 ± 0.00095 12125-02-9*510 Acetylene anion [HCCH]- (g, cis ?) 380.1 380.3 ± 1.9 kJ/mol 26.0378 ± 0.0016 50443-89-5*2 Fluorobenzene C6H5F (cr,l) -151.82 -149.40 ± 0.89 kJ/mol 96.1023 ± 0.0048 462-06-6*500 Bromobenzene C6H5Br (cr,l) 59.9 ± 1.3 kJ/mol 157.0079 ± 0.0049 108-86-1*500 Ammonium bromide (NH4)Br (cr) -253.48 -270.05 ± 0.17 kJ/mol 97.9425 ± 0.0010 12124-97-9*510 Acetone CH3C(O)CH3 (cr,l) -244.51 -247.63 ± 0.32 kJ/mol 58.0791 ± 0.0025 67-64-1*500 Tribromine Br3 (g) 155.8 134.1 ± 3.2 kJ/mol 239.7120 ± 0.0030 11094-39-6*0 Propionaldehyde CH3CH2CHO (cr,l) -218.20 -216.75 ± 0.29 kJ/mol 58.0791 ± 0.0025 123-38-6*500 Triazirinylium ion [N(NN)]+ (g) 1608.8 1605.9 ± 1.6 kJ/mol 42.01967 ± 0.00021 92220-05-8*0 Monoammonium succinate (CH2COOH)2(NH3) (cr) -1068.01 ± 0.72 kJ/mol 135.1186 ± 0.0035 38457-08-8*510 Diammonium succinate (CH2COOH)2(NH3)2 (cr) -1182.56 ± 0.48 kJ/mol 152.1492 ± 0.0035 2226-88-2*510 Nitrosyl nitrate ONONO2 (g, t) 48.2 40.2 ± 1.8 kJ/mol 92.0111 ± 0.0012 15969-55-8*1 1-Methylethenylium [CH3CCH2]+ (g) 995.9 986.4 ± 2.7 kJ/mol 41.0713 ± 0.0024 50457-57-3*0 Isocyanic fluoride FNC (g) 301.3 303.1 ± 1.8 kJ/mol 45.01584 ± 0.00080 16992-26-0*0 Formic acid HC(O)OH (cr,l) -431.56 -424.73 ± 0.21 kJ/mol 46.0254 ± 0.0010 64-18-6*500 Bromoniumyl [HBr]+ (g) 1097.95 1090.10 ± 0.16 kJ/mol 80.9114 ± 0.0010 12258-64-9*0 1-Methylethenyl anion [CH3CCH2]- (g) 199.2 188.0 ± 2.8 kJ/mol 41.0723 ± 0.0024 65887-19-6*0 Hydrogen fluoride HF (aq, 400 H2O) -321.45 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*832 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) 588.8 590.1 ± 2.3 kJ/mol 38.0485 ± 0.0024 *161054-36-0*0 Hydroxyoxoammoniumyl [HONO]+ (g, trans) 984.1 977.6 ± 1.8 kJ/mol 47.01293 ± 0.00061 80371-48-8*1 Isocyanogen chloride ClNC (g) 314.6 316.2 ± 2.4 kJ/mol 61.4701 ± 0.0012 75754-69-7*0 (Z)-Diazene anion [HNNH]- (g, cis) 280.0 273.3 ± 2.0 kJ/mol 30.02991 ± 0.00020 *86631-37-0*0 Carbon dioxide cation [CO2]+ (g, quartet) 1335.0 1335.5 ± 2.4 kJ/mol 44.00895 ± 0.00100 12181-61-2*1 Carbon monoxide anion [CO]- (g) 30.0 33.7 ± 2.3 kJ/mol 28.01065 ± 0.00085 12539-63-8*0 Nitrous acid anion [HONO]- (g, cis) -107.0 -111.7 ± 2.4 kJ/mol 47.01403 ± 0.00061 256393-36-9*2 NON anion [NON]- (g) 495.3 492.8 ± 2.5 kJ/mol 44.01343 ± 0.00033 *227934-47-6*0 Peroxyhypochlorous acid anion [HOOCl]- (g, cis quartet) -32.2 -34.0 ± 2.6 kJ/mol 68.4600 ± 0.0011 *67952-08-3*2 Iodine monochloride ICl (cr) -36.511 -35.537 ± 0.063 kJ/mol 162.35717 ± 0.00090 7790-99-0*510 Acetic acid CH3C(O)OH (g, anti) -397.4 -411.2 ± 1.2 kJ/mol 60.0520 ± 0.0017 64-19-7*2 Isocyanogen bromide BrNC (g) 341.5 335.8 ± 3.4 kJ/mol 105.9214 ± 0.0013 65997-98-0*0 Acetic acid CH3C(O)OH (aq, 1000 H2O) -484.93 ± 0.23 kJ/mol 60.0520 ± 0.0017 64-19-7*839 Oxygen difluoride anion [FOF]- (g) -202.1 -201.9 ± 2.7 kJ/mol 53.99675 ± 0.00030 *7783-41-7*0 Trioxidanyl HOOO (g) 25.31 23.22 ± 0.13 kJ/mol 49.00614 ± 0.00090 12500-78-6*0 Methyl formate HC(O)OCH3 (l) -386.13 ± 0.59 kJ/mol 60.0520 ± 0.0017 107-31-3*500 Hydroxylamine NH2OH (aq, undissoc) -97.1 ± 2.2 kJ/mol 33.02996 ± 0.00037 7803-49-8*1000 Ethylene glycol (CH2OH)2 (cr,l) -448.71 -455.23 ± 0.38 kJ/mol 62.0678 ± 0.0018 107-21-1*500 Hydrogen chloride HCl (aq, 1000 H2O) -166.567 ± 0.024 kJ/mol 36.46064 ± 0.00090 7647-01-0*839 Isocyanogen iodide INC (g) 341.7 341.9 ± 4.9 kJ/mol 152.92191 ± 0.00080 66004-32-8*0 Oxalic acid (COOH)2 (cr) -819.30 ± 0.46 kJ/mol 90.0349 ± 0.0020 144-62-7*500 Isocyanogen iodide anion [INC]- (g) 123.0 125.1 ± 9.3 kJ/mol 152.92246 ± 0.00080 *66004-32-8*0 Dimethylamine (CH3)2NH (l) -43.71 ± 0.39 kJ/mol 45.0837 ± 0.0017 124-40-3*500 Nitrosyl nitrite anion [ONONO]- (g, t, t) -103.1 -106.2 ± 2.8 kJ/mol 76.01223 ± 0.00091 *122413-35-8*1 Dinitrogen dioxide ONNO (g, cis) 172.88 171.12 ± 0.14 kJ/mol 60.01228 ± 0.00062 16824-89-8*2 Trimethylamine (CH3)3N (l) -49.8 ± 1.0 kJ/mol 59.1103 ± 0.0025 75-50-3*500 Cyclobutane CH2(CH2CH2CH2) (l) 3.92 ± 0.41 kJ/mol 56.1063 ± 0.0032 287-23-0*590 Cyanogen cation [NCCN]+ (g) 1598.34 1600.57 ± 0.44 kJ/mol 52.0343 ± 0.0016 37354-81-7*0 Cyanogen anion [NCCN]- (g) 282.1 285.2 ± 3.3 kJ/mol 52.0354 ± 0.0016 11118-88-0*0 Isocyanogen cation [CNCN]+ (g) 1652.9 1654.2 ± 1.8 kJ/mol 52.0343 ± 0.0016 133415-63-1*0 Methylcyclopropane CH3CH(CH2CH2) (l) 1.80 ± 0.59 kJ/mol 56.1063 ± 0.0032 594-11-6*590 Methanol CH3OH (l) -235.20 -238.53 ± 0.15 kJ/mol 32.04186 ± 0.00090 67-56-1*500 Diisocyanogen anion [CNNC]- (g) 456.8 463.7 ± 5.7 kJ/mol 52.0354 ± 0.0016 *78800-22-3*0 Diazoethenylidene cation [NNCC]+ (g) 1777.1 1779.1 ± 6.1 kJ/mol 52.0343 ± 0.0016 *130760-10-0*0 Diazoethenylidene anion [NNCC]- (g) 536.0 538.6 ± 5.8 kJ/mol 52.0354 ± 0.0016 *130760-11-1*0 3H-diazirin-3-ylidene-methylene CC(NN) (g) 833.7 836.1 ± 3.6 kJ/mol 52.0349 ± 0.0016 204253-88-3*0 Isocyanomethyliumylidene [CNC]+ (g) 1612.6 1618.1 ± 6.2 kJ/mol 38.0276 ± 0.0016 78271-45-1*0 Isocyanomethylidyne anion [CNC]- (g) 478.6 482.3 ± 5.9 kJ/mol 38.0287 ± 0.0016 *53590-27-5*0 Methylamine CH3NH2 (l) -47.01 ± 0.36 kJ/mol 31.05714 ± 0.00088 74-89-5*500 Cyanomethyliumylidene [CCN]+ (g) 1711.1 1716.5 ± 6.0 kJ/mol 38.0276 ± 0.0016 76619-90-4*0 Cyanomethylidyne anion [CCN]- (g) 406.7 410.3 ± 5.7 kJ/mol 38.0287 ± 0.0016 12373-35-2*0 2,3-didehydro-1H-azirin-1-yl N(CC) (g) 722.2 726.2 ± 4.9 kJ/mol 38.0281 ± 0.0016 439586-06-8*0 Cyanoaminyliumyl [NCN]+ (g) 1671.9 1673.3 ± 2.9 kJ/mol 40.02363 ± 0.00081 316122-03-9*0 Cyanoamidogen anion [NCN]- (g) 210.89 210.90 ± 0.81 kJ/mol 40.02473 ± 0.00081 189879-95-6*0 Cyanamide H2NCN (cr) 58.89 ± 0.54 kJ/mol 42.04006 ± 0.00082 420-04-2*500 Diazomethyliumyl [CNN]+ (g) 1641.8 1643.6 ± 4.3 kJ/mol 40.02363 ± 0.00081 307495-90-5*0 Diazomethylene anion [CNN]- (g) 407.9 408.0 ± 3.9 kJ/mol 40.02473 ± 0.00081 205498-92-6*0 Deuterium hydride HD (g) 0.328 0.319 ± 0.000 kJ/mol 3.022042 ± 0.000070 13983-20-5*0 Methanol dimer (CH3OH)2 (g) -398.3 -419.0 ± 1.4 kJ/mol 64.0837 ± 0.0018 42845-44-3*0 Isodiazene anion [NNH2]- (g) 380.9 374.0 ± 2.1 kJ/mol 30.02991 ± 0.00020 *63986-30-1*0 1-Ethenylium-1-yl [CCH2]+ (g) 1507.1 1507.1 ± 2.1 kJ/mol 26.0367 ± 0.0016 80541-07-7*0 Chloromethyliumylidene [CCl]+ (g) 1282.6 1285.7 ± 2.4 kJ/mol 47.4629 ± 0.0012 69773-94-0*0 Chloromethylidyne anion [CCl]- (g) 319.7 323.4 ± 2.5 kJ/mol 47.4639 ± 0.0012 117129-77-8*0 Dioxiranylidene cation [C(OO)]+ (g) 1409.1 1410.3 ± 2.6 kJ/mol 44.00895 ± 0.00100 *138832-57-2*0 Trifluorine F3 (g) 80.6 81.9 ± 2.6 kJ/mol 56.9952096 ± 0.0000015 73455-86-4*0 Chlorine chlorite ClOClO (g, cis) 177.4 175.0 ± 2.2 kJ/mol 102.9042 ± 0.0019 105206-44-8*2 Cyclopropyl anion [CH(CH2CH2)]- (g) 263.5 250.8 ± 2.5 kJ/mol 41.0723 ± 0.0024 1724-45-4*0 Dioxiranylidene anion [C(OO)]- (g, ?) -110.2 -109.7 ± 3.0 kJ/mol 44.01005 ± 0.00100 *138832-58-3*0 Carbon monoxide CO (g, triplet) 465.581 469.288 ± 0.026 kJ/mol 28.01010 ± 0.00085 630-08-0*1 Trihydrogen H(HH) (g, 2p 2A2" Ry) 756.931 754.146 ± 0.015 kJ/mol 3.02382 ± 0.00021 12184-91-7*2 Hydrogen fluoride HF (aq, 18.5 H2O) -321.02 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*887 Hydrogen chloride HCl (aq, 3000 H2O) -166.743 ± 0.024 kJ/mol 36.46064 ± 0.00090 7647-01-0*842 1,1,1-Trichloroethane CH3CCl3 (l) -177.63 ± 0.52 kJ/mol 133.4033 ± 0.0031 71-55-6*500 Trioxidane HOOOH (g) -81.71 -90.31 ± 0.72 kJ/mol 50.01408 ± 0.00091 14699-99-1*0 Nitrogen sesquioxide cation [ONNO2]+ (g, vdW) 1027.7 1023.8 ± 3.4 kJ/mol 76.01113 ± 0.00091 *10544-73-7*0 Vinyl chloride CH2CHCl (cr,l) -2.7 1.9 ± 1.9 kJ/mol 62.4979 ± 0.0018 75-01-4*500 Poly(vinylchloride) CH2CHCl (s, poly) -84.6 -94.0 ± 1.3 kJ/mol 62.4979 ± 0.0018 9002-86-2*500 Paraformaldehyde CH2O (cr, paraformaldehyde) -179.2 ± 1.6 kJ/mol 30.02598 ± 0.00087 30525-89-4*500 1,1-Dichloroethene CH2CCl2 (l) -23.82 ± 0.51 kJ/mol 96.9427 ± 0.0024 75-35-4*500 Isoprene CH2C(CH3)CHCH2 (cr,l) 48.67 ± 0.73 kJ/mol 68.1170 ± 0.0040 78-79-5*500 n-Hexane CH3CH2CH2CH2CH2CH3 (cr,l) -180.03 -198.69 ± 0.34 kJ/mol 86.1754 ± 0.0049 110-54-3*500 Oxadiazirine [O(NN)]+ (g) 1509.9 1507.4 ± 2.4 kJ/mol 44.01233 ± 0.00033 *227934-45-4*0 Cyclohexane CH2(CH2CH2CH2CH2CH2) (l) -156.33 ± 0.36 kJ/mol 84.1595 ± 0.0049 110-82-7*500 Nitrato [NO3]+ (g) 1290.55 1285.84 ± 0.86 kJ/mol 62.00439 ± 0.00090 133057-96-2*0 Dihydrogen fluoride (HF)(H) (g) -56.5 -54.2 ± 1.7 kJ/mol 21.01428 ± 0.00014 12592-22-2*2 Dichloromethane CH2Cl2 (l) -123.42 ± 0.50 kJ/mol 84.9320 ± 0.0020 75-09-2*590 n-Heptane CH3(CH2)5CH3 (cr,l) -201.78 -224.23 ± 0.48 kJ/mol 100.2019 ± 0.0057 142-82-5*500 Oxygen difluoride cation [FOF]+ (g) 1292.10 1289.58 ± 0.66 kJ/mol 53.99566 ± 0.00030 39432-25-2*0 n-Octane CH3(CH2)6CH3 (cr,l) -226.70 -249.82 ± 0.67 kJ/mol 114.2285 ± 0.0065 111-65-9*500 Nitric acid HNO3 (aq, 1 H2O) -186.85 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*801 1,5-Hexadiene CH2CHCH2CH2CHCH2 (cr,l) 54.39 ± 0.32 kJ/mol 82.1436 ± 0.0049 592-42-7*500 1-Propynylium [CH3CC]+ (g) 1547.1 1545.1 ± 3.1 kJ/mol 39.0554 ± 0.0024 24858-94-4*0 Hydrogen peroxide H2O2 (cr,l) -193.185 -187.368 ± 0.079 kJ/mol 34.01468 ± 0.00062 7722-84-1*500 1,2-Propadien-1-ylium-1-yl-3-ylidene [CCC]+ (g, lin) 1982.1 1991.2 ± 2.2 kJ/mol 36.0316 ± 0.0024 118090-85-0*1 Trioxirane O(OO) (g) 272.9 270.3 ± 1.3 kJ/mol 47.99820 ± 0.00090 153851-84-4*0 Ammonia anion [NH3]- (g) 94.3 87.3 ± 2.4 kJ/mol 17.03111 ± 0.00022 37353-00-7*0 Difluoromethylene anion [CF2]- (g) -211.21 -209.99 ± 0.60 kJ/mol 50.00805 ± 0.00080 66212-40-6*0 Nitric acid HNO3 (aq, 3 H2O) -197.76 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*805 Nitrosyl nitrite ONONO (g, c, p) 125.7 120.4 ± 2.1 kJ/mol 76.01168 ± 0.00091 122413-35-8*3 Fluoromethylidyne anion [CF]- (g) 200.8 204.3 ± 1.9 kJ/mol 31.00965 ± 0.00080 33412-12-3*0 Hydrochlorate ion [HCl]- (g) -25.2 -24.2 ± 2.5 kJ/mol 36.46119 ± 0.00090 63099-75-2*0 Cycloprop-1-enylium [CH2(CHC)]+ (g) 1502.3 1498.1 ± 2.2 kJ/mol 39.0554 ± 0.0024 117067-78-4*0 Cycloprop-1-enyl anion [CH2(CHC)]- (g) 373.5 369.0 ± 2.2 kJ/mol 39.0565 ± 0.0024 80251-77-0*0 Oxygen atom hexacation [O]+6 (g) 42035.28 42037.14 ± 0.12 kJ/mol 15.99611 ± 0.00030 14158-22-6*0 Nitric acid trihydrate HNO3(H2O)3 (cr,l) -1062.12 -1055.27 ± 0.21 kJ/mol 117.0587 ± 0.0019 13444-83-2*500 1,2-Difluoroacetylene cation [FCCF]+ (g) 1081.2 1084.3 ± 1.5 kJ/mol 62.0177 ± 0.0016 268566-70-7*0 Dioxymethylidyne cation [COO]+ (g, doublet) 1436.6 1439.1 ± 2.7 kJ/mol 44.00895 ± 0.00100 *791121-04-5*2 Propane cation [CH3CH2CH3]+ (g) 974.6 954.7 ± 1.7 kJ/mol 44.0951 ± 0.0025 34479-70-4*0 Azide ion [NNN]- (aq) 272.61 ± 0.48 kJ/mol 42.02077 ± 0.00021 14343-69-2*800 Dihydrogen cation [H2]+ (g, ortho) 1489.060 1488.480 ± 0.000 kJ/mol 2.01533 ± 0.00014 12184-90-6*1 Nitric acid monohydrate HNO3(H2O) (cr,l) -479.18 -472.68 ± 0.19 kJ/mol 81.0282 ± 0.0012 13444-82-1*500 Carbon dioxide anion [CO2]- (g) -340.6 -340.1 ± 2.2 kJ/mol 44.01005 ± 0.00100 14485-07-5*0 NON cation [NON]+ (g) 1443.9 1444.1 ± 2.8 kJ/mol 44.01233 ± 0.00033 *227934-46-5*0 Peroxyhypochlorous acid cation [HOOCl]+ (g, trans) 1030.3 1024.5 ± 2.5 kJ/mol 68.4589 ± 0.0011 *67952-07-2*1 Chloro(chlorooxy)methylene ClCOCl (g, cis) 73.5 73.7 ± 3.6 kJ/mol 98.9155 ± 0.0020 479587-31-0*2 Hydrogen difluoride cation [(HF)(F)]+ (g, triplet) 1267.6 1265.4 ± 4.1 kJ/mol 39.004198 ± 0.000070 *126950-54-7*1 Cycloprop-2-enyl anion [CH(CHCH)]- (g) 514.8 511.8 ± 2.2 kJ/mol 39.0565 ± 0.0024 20829-57-6*0 Chlorooxomethylium [ClCO]+ (g) 783.7 783.9 ± 2.2 kJ/mol 63.4623 ± 0.0012 38264-03-8*0 Hydrogen difluoride cation [FHF]+ (g, triplet ?) 1241. 1238. ± 17. kJ/mol 39.004198 ± 0.000070 126950-54-7*1 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 2-Iodoethanol ICH2CH2OH (l) -207.3 ± 2.4 kJ/mol 171.9650 ± 0.0017 624-76-0*590 Dioxymethylidyne cation [(C)(OO)]+ (g, vdW quartet) 1388.2 1391.7 ± 3.2 kJ/mol 44.00895 ± 0.00100 *791121-04-5*101 1,3-Butadiyne cation [HCCCCH]+ (g) 1440.20 1442.07 ± 0.86 kJ/mol 50.0581 ± 0.0032 55468-55-8*0 Tricarbon dioxide cation [OCCCO]+ (g) 928.4 931.9 ± 1.4 kJ/mol 68.0304 ± 0.0025 151528-67-5*0 Tricarbon dioxide anion [OCCCO]- (g) -134.0 -130.3 ± 3.2 kJ/mol 68.0314 ± 0.0025 109362-94-9*0 Benzene anion [C6H6]- (g) 209.0 197.1 ± 1.2 kJ/mol 78.1124 ± 0.0048 34562-85-1*0 Peroxychlorous acid HOOClO (g, anti) 103.5 97.7 ± 2.5 kJ/mol 84.4588 ± 0.0013 177778-92-6*2 Tetrazete N(NNN) (g, D2h) 764.9 759.0 ± 1.8 kJ/mol 56.02696 ± 0.00028 42851-09-2*0 Hydraziniumyl [NH2NH2]+ (g) 886.6 873.2 ± 2.0 kJ/mol 32.04469 ± 0.00031 20771-51-1*0 Difluorodioxidanium [FOOF]+ (g, trans) 1283.6 1279.1 ± 2.3 kJ/mol 69.99506 ± 0.00060 *7783-44-0*1 o-Benzyne C6H4 (g, triplet) 625.6 616.3 ± 1.1 kJ/mol 76.0960 ± 0.0048 462-80-6*1 Chlorodioxidenium [ClOO]+ (g) 1202.7 1200.4 ± 3.4 kJ/mol 67.4510 ± 0.0011 64710-10-7*0 Hydrazine NH2NH2 (cr,l) 57.23 50.67 ± 0.18 kJ/mol 32.04524 ± 0.00031 302-01-2*500 Tetraoxodinitrogen cation [O2NNO2]+ (g) 1030.6 1025.1 ± 2.6 kJ/mol 92.0105 ± 0.0012 64476-91-1*0 m-Benzyne C6H4 (g) 527.0 518.5 ± 1.2 kJ/mol 76.0960 ± 0.0048 1828-89-3*0 Hydrogen chloride HCl (aq, 200 H2O) -166.107 ± 0.024 kJ/mol 36.46064 ± 0.00090 7647-01-0*830 p-Benzyne cation [C6H4]+ (g) 1425.8 1418.5 ± 2.1 kJ/mol 76.0954 ± 0.0048 121058-09-1*0 p-Benzyne C6H4 (g) 587.1 577.6 ± 1.2 kJ/mol 76.0960 ± 0.0048 3355-34-8*0 Toluene C6H5CH3 (l) 19.87 12.11 ± 0.34 kJ/mol 92.1384 ± 0.0056 108-88-3*500 Hydronium radical (H2O)(H) (g, vdW) -18.5 -21.6 ± 2.1 kJ/mol 19.02322 ± 0.00037 12168-76-2*100 Ethylbenzene C6H5CH2CH3 (cr,l) -12.55 ± 0.55 kJ/mol 106.1650 ± 0.0064 100-41-4*500 Phenylethene C6H5CHCH2 (cr,l) 104.29 ± 0.48 kJ/mol 104.1491 ± 0.0064 100-42-5*500 Hydrogen bromide HBr (aq, 1000 H2O) -120.32 ± 0.16 kJ/mol 80.9119 ± 0.0010 10035-10-6*839 Phenylacetylene C6H5CCH (cr,l) 273.4 ± 1.1 kJ/mol 102.1332 ± 0.0064 536-74-3*500 Phenol C6H5OH (cr,l) -146.32 -162.17 ± 0.68 kJ/mol 94.1112 ± 0.0048 108-95-2*500 Cyclopropenylidene anion [C(CHCH)]- (g) 544.3 543.8 ± 2.2 kJ/mol 38.0485 ± 0.0024 *16165-40-5*0 Benzaldehyde C6H5C(O)H (cr,l) -85.7 -86.7 ± 1.1 kJ/mol 106.1219 ± 0.0056 100-52-7*500 Carbide [C2]- (g) 504.86 511.43 ± 0.52 kJ/mol 24.0219 ± 0.0016 12595-78-7*0 Fluorobenzene anion [C6H5F]- (g) -18.3 -30.2 ± 1.8 kJ/mol 96.1029 ± 0.0048 34561-55-2*0 Peroxynitrous acid HOONO (g) -6.10 -12.73 ± 0.36 kJ/mol 63.01288 ± 0.00091 14691-52-2*0 Tetraazatetrahedrane N4 (g, Td) 763.7 757.2 ± 1.7 kJ/mol 56.02696 ± 0.00028 12596-63-3*0 Bromosyl bromide BrBrO (g) 178.6 162.8 ± 2.1 kJ/mol 175.8074 ± 0.0020 68322-97-4*0 Iodobenzene cation [C6H5I]+ (g) 1022.7 1007.2 ± 1.0 kJ/mol 204.0078 ± 0.0048 38406-85-8*0 Dioxygen difluoride OOF2 (g) 75.1 71.6 ± 3.6 kJ/mol 69.99561 ± 0.00060 183051-89-0*0 Hydrazoic acid cation [HNNN]+ (g) 1333.65 1327.98 ± 0.83 kJ/mol 43.02761 ± 0.00022 58852-14-5*0 Nitrobenzene C6H5N(O)O (cr,l) 6.4 ± 1.4 kJ/mol 123.1094 ± 0.0049 98-95-3*500 Perchloryl cation [OCl(O)O]+ (g) 1252.0 1246.3 ± 2.5 kJ/mol 83.4504 ± 0.0013 23594-88-9*0 Hydrazoic acid anion [HNNN]- (g, trans) 309.0 302.7 ± 2.3 kJ/mol 43.02871 ± 0.00022 203264-98-6*1 Nitromethane CH3N(O)O (cr,l) -114.19 -113.00 ± 0.43 kJ/mol 61.0401 ± 0.0010 75-52-5*500 2,2,4-Trimethylpentane (CH3)2CHCH2C(CH3)3 (cr,l) -224.5 -258.9 ± 1.5 kJ/mol 114.2285 ± 0.0065 540-84-1*500 Trifluoroethylene C2HF3 (g) -482.7 -487.7 ± 8.4 kJ/mol 82.0245 ± 0.0016 359-11-5*0 Norbornadiene (CHCH)CHCH2CH(CHCH) (g) 237.9 212.5 ± 1.2 kJ/mol 92.1384 ± 0.0056 121-46-0*0 Norbornadiene (CHCH)CHCH2CH(CHCH) (l) 179.1 ± 1.1 kJ/mol 92.1384 ± 0.0056 121-46-0*500 2,3-Butanedione (CH3CO)2 (cr,l) -365.54 ± 0.54 kJ/mol 86.0892 ± 0.0033 431-03-8*500 2,3-Butanedione (CH3CO)2 (g) -310.19 -326.75 ± 0.70 kJ/mol 86.0892 ± 0.0033 431-03-8*0 Succinic acid (CH2COOH)2 (cr,l) -918.57 -940.30 ± 0.13 kJ/mol 118.0880 ± 0.0034 110-15-6*500 1,2-Diiodoethane (CIH2)2 (g) 87.78 73.12 ± 0.90 kJ/mol 281.8621 ± 0.0016 624-73-7*0 1,2-Diiodoethane (CIH2)2 (cr,l) 9.25 ± 0.60 kJ/mol 281.8621 ± 0.0016 624-73-7*500 1,1-Dibromoethane CHBr2CH3 (g) -9.2 -36.3 ± 7.8 kJ/mol 187.8612 ± 0.0026 557-91-5*0 Dihydrogen H2 (g, ortho) 1.417 0.019 ± 0.000 kJ/mol 2.01588 ± 0.00014 1333-74-0*1 Xenon hydride cation [XeH]+ (g) 1038.15 1036.37 ± 0.89 kJ/mol 132.2974 ± 0.0200 37276-91-8*0 Nitrosyl nitrate ONONO2 (g, cis-perp) 60.5 52.5 ± 2.0 kJ/mol 92.0111 ± 0.0012 15969-55-8*2 Hydroxylamine NH2OH (g) -33.24 -43.61 ± 0.50 kJ/mol 33.02996 ± 0.00037 7803-49-8*0 Carbon monoxide CO (g, singlet) -113.802 -110.522 ± 0.026 kJ/mol 28.01010 ± 0.00085 630-08-0*2 Dioxofluorine cation [OFO]+ (g) 1667.0 1664.8 ± 2.8 kJ/mol 50.99665 ± 0.00060 223566-05-0*0 Hydroxyoxoammoniumyl [HONO]+ (g, cis) 1014.7 1008.4 ± 2.0 kJ/mol 47.01293 ± 0.00061 80371-48-8*2 Nitrous acid anion [HONO]- (g, trans) -106.3 -110.2 ± 2.5 kJ/mol 47.01403 ± 0.00061 256393-36-9*1 Water trimer (H2O)3 (g) -762.75 -776.85 ± 0.21 kJ/mol 54.04584 ± 0.00099 31014-12-7*0 Methylene CH2 (g) 391.03 391.59 ± 0.12 kJ/mol 14.02658 ± 0.00081 2465-56-7*0 Hydrazoic acid HNNN (aq) 272.61 ± 0.48 kJ/mol 43.02816 ± 0.00022 7782-79-8*800 mu-Oxodichlorine cation [ClOCl]+ (g) 1130.44 1126.83 ± 0.63 kJ/mol 86.9043 ± 0.0018 51174-96-0*0 Nitrogen atom N (g, quartet) 470.579 472.441 ± 0.024 kJ/mol 14.006740 ± 0.000070 17778-88-0*1 mu-Oxodichlorate anion [ClOCl]- (g) -147.8 -147.7 ± 2.5 kJ/mol 86.9053 ± 0.0018 365546-30-1*0 Polyoxymethylene CH2O (cr, polyoxymethylene) -170.89 ± 0.21 kJ/mol 30.02598 ± 0.00087 9002-81-7*500 Trihydrogen cation [H3]+ (g, para) 1110.304 1106.697 ± 0.013 kJ/mol 3.02327 ± 0.00021 28132-48-1*2 Dioxaziridine HN(OO) (g) 277.2 270.5 ± 2.0 kJ/mol 47.01348 ± 0.00061 67394-35-8*0 Propylene cation [CH3CHCH2]+ (g) 975.07 962.11 ± 0.35 kJ/mol 42.0792 ± 0.0024 34504-10-4*0 Cyclopentadiene CH2(CHCHCHCH) (l) 108.73 ± 0.61 kJ/mol 66.1011 ± 0.0040 542-92-7*590 Hydrogen iodide HI (aq) -56.824 ± 0.089 kJ/mol 127.912410 ± 0.000076 10034-85-2*800 Formaldehyde CH2O (aq) -171.16 ± 0.59 kJ/mol 30.02598 ± 0.00087 50-00-0*800 Ethynylene C2 (g, singlet) 820.28 826.85 ± 0.27 kJ/mol 24.0214 ± 0.0016 12070-15-4*2 Dihydrogen anion [H2]- (g) 253.8 254.7 ± 1.2 kJ/mol 2.01643 ± 0.00014 12184-89-3*0 Tetrabromomethane CBr4 (cr, monoclinic) 49.0 ± 1.4 kJ/mol 331.6267 ± 0.0041 558-13-4*500 Tetraiodomethane CI4 (cr, monoclinic) 392.5 ± 8.0 kJ/mol 519.62858 ± 0.00081 507-25-5*500 Methyl bromide CH3Br (l) -55.90 -58.92 ± 0.28 kJ/mol 94.9385 ± 0.0013 74-83-9*590 Tetroxidane HOOOOH (g) -33.8 -44.3 ± 2.4 kJ/mol 66.0135 ± 0.0012 29683-94-1*0 Dihydrogen cation [H2]+ (g, para) 1488.364 1488.480 ± 0.000 kJ/mol 2.01533 ± 0.00014 12184-90-6*2 Hydrogen peroxide H2O2 (g, para) -129.492 -135.478 ± 0.063 kJ/mol 34.01468 ± 0.00062 7722-84-1*2 Acetic acid CH3C(O)OH (aq, 500 H2O) -484.91 ± 0.23 kJ/mol 60.0520 ± 0.0017 64-19-7*833 Trioxirane cation [O(OO)]+ (g) 1444.6 1442.4 ± 2.2 kJ/mol 47.99765 ± 0.00090 *153851-84-4*0 Acetic acid CH3C(O)OH (aq, 10000 H2O) -484.96 ± 0.23 kJ/mol 60.0520 ± 0.0017 64-19-7*850 Isocyanogen bromide anion [BrNC]- (g) 105.4 102.2 ± 4.6 kJ/mol 105.9220 ± 0.0013 *238754-53-5*0 Dioxofluorine anion [OFO]- (g) 155.9 154.3 ± 2.5 kJ/mol 50.99775 ± 0.00060 *175861-93-5*0 Peroxyhypochlorous acid cation [HOOCl]+ (g, cis) 1050.8 1045.1 ± 2.5 kJ/mol 68.4589 ± 0.0011 *67952-07-2*2 1,2-Propadien-1-ylium-1-yl-3-ylidene [CCC]+ (g) 1947.0 1954.9 ± 2.0 kJ/mol 36.0316 ± 0.0024 118090-85-0*0 Fluorine atom F (g, 2P3/2) 77.253 79.038 ± 0.048 kJ/mol 18.99840320 ± 0.00000050 14762-94-8*1 1-Hydroxyethyl CH3CHOH (g) -42.00 -55.43 ± 0.65 kJ/mol 45.0605 ± 0.0017 2348-46-1*0 Hydroxylamine NH2OH (cr,l) -107.62 ± 0.66 kJ/mol 33.02996 ± 0.00037 7803-49-8*500 Methyl formate HC(O)OCH3 (g) -344.73 -357.78 ± 0.59 kJ/mol 60.0520 ± 0.0017 107-31-3*0 Oxygen atom pentacation [O]+5 (g) 28708.788 28710.646 ± 0.053 kJ/mol 15.99666 ± 0.00030 14127-66-3*0 Deuteride D- (g) 146.991 148.904 ± 0.0021 kJ/mol 2.01465035791 ± 0.00000000040 14452-69-8*0 Hydrogen peroxide cation [H2O2]+ (g, cis, para) 930.4 923.6 ± 1.0 kJ/mol 34.01413 ± 0.00062 12325-10-9*22 Hydroxymethylene HCOH (g) 112.70 108.94 ± 0.28 kJ/mol 30.02598 ± 0.00087 19710-56-6*0 Chlorine atom Cl (g, 2P3/2) 119.621 121.228 ± 0.0011 kJ/mol 35.45270 ± 0.00090 22537-15-1*1 Ethyl bromide CH3CH2Br (l) -55.52 -91.05 ± 0.27 kJ/mol 108.9651 ± 0.0019 74-96-4*500 Oxonium [H3O]+ (g, para) 605.84 599.09 ± 0.17 kJ/mol 19.02267 ± 0.00037 13968-08-6*2 Vinyl iodide CH2CHI (g) 139.7 130.8 ± 1.2 kJ/mol 153.9497 ± 0.0016 593-66-8*0 Trihydrogen (H)(HH) (g, vdW) 215.9 218.3 ± 1.1 kJ/mol 3.02382 ± 0.00021 12184-91-7*100 Peroxyhypochlorous acid anion [HOOCl]- (g, trans quartet) -2.9 -3.3 ± 2.6 kJ/mol 68.4600 ± 0.0011 *67952-08-3*1 Hydrogen peroxide cation [H2O2]+ (g, trans, ortho) 896.57 889.59 ± 0.58 kJ/mol 34.01413 ± 0.00062 12325-10-9*11 Tribromide [Br3]- (aq) -129.29 ± 0.26 kJ/mol 239.7125 ± 0.0030 14522-80-6*800 Chlorine trifluoride cation [FCl(F)F]+ (g) 1053.4 1049.1 ± 2.5 kJ/mol 92.44736 ± 0.00090 478167-77-0*0 Oxygen atom octacation [O]+8 (g) 197447.75 197449.60 ± 0.12 kJ/mol 15.99501 ± 0.00030 21450-98-6*0 2-Chloro ozone ClO(O)O (g) 265.8 265.3 ± 3.7 kJ/mol 83.4509 ± 0.0013 *141801-66-3*0 Hydrazoic acid HNNN (aq, undissoc) 257.62 ± 0.48 kJ/mol 43.02816 ± 0.00022 7782-79-8*1000 Oxygen atom heptacation [O]+7 (g) 113369.48 113371.34 ± 0.12 kJ/mol 15.99556 ± 0.00030 14274-89-6*0 Acetaldehyde CH3CHO (cr,l) -186.94 -191.66 ± 0.33 kJ/mol 44.0526 ± 0.0017 75-07-0*500 Tetraoxodinitrate anion [O2NNO2]- (g) -184.6 -187.8 ± 2.4 kJ/mol 92.0116 ± 0.0012 63552-02-3*0 Tricarbon dioxide OCCCO (cr,l) -131.6 -116.5 ± 1.4 kJ/mol 68.0309 ± 0.0025 504-64-3*500 Oxygen atom tetracation [O]+4 (g) 17719.207 17721.064 ± 0.025 kJ/mol 15.99721 ± 0.00030 14127-65-2*0 Cyclopropane cation [CH2(CH2CH2)]+ (g) 1022.3 1006.9 ± 1.8 kJ/mol 42.0792 ± 0.0024 34496-93-0*0 Iodine atom I (g, 2P1/2) 198.109 197.709 ± 0.0021 kJ/mol 126.904470 ± 0.000030 14362-44-8*2 1,3-Butadiyn-4-ylium-1-yl [CCCC]+ (g) 2109.9 2120.5 ± 2.9 kJ/mol 48.0423 ± 0.0032 124708-46-9*0 m-Benzyne C6H4 (g, triplet) 614.6 605.2 ± 1.4 kJ/mol 76.0960 ± 0.0048 1828-89-3*1 Bromodioxy BrOO (g) 118.2 109.1 ± 4.3 kJ/mol 111.9028 ± 0.0012 67177-47-3*0 Hydrogen fluoride HF (aq, 45 H2O) -321.13 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*906 Difluorodioxidanium [FOOF]+ (g, cis) 1287.2 1283.0 ± 2.3 kJ/mol 69.99506 ± 0.00060 *7783-44-0*2 Iodine monochloride ICl (l) -24.048 ± 0.063 kJ/mol 162.35717 ± 0.00090 7790-99-0*590 Oxoniumyl ion [H2O]+ (g, ortho) 978.464 975.561 ± 0.029 kJ/mol 18.01473 ± 0.00033 56583-62-1*1 Dinitrogen dimer (N2)2 (g) -0.88 0.84 ± 0.67 kJ/mol 56.02696 ± 0.00028 *7727-37-9*0 Oxygen atom trication [O]+3 (g) 10249.929 10252.880 ± 0.018 kJ/mol 15.99775 ± 0.00030 14127-64-1*0 Trihydrogen H(HH) (g, 2s 2A1' Ry) 745.878 743.094 ± 0.062 kJ/mol 3.02382 ± 0.00021 12184-91-7*1 Diatomic bromine cation [Br2]+ (g) 1060.32 1045.37 ± 0.23 kJ/mol 159.8075 ± 0.0020 12595-71-0*0 Ammonium hydroxide NH4OH (aq, undissoc) -366.726 ± 0.062 kJ/mol 35.04584 ± 0.00047 1336-21-6*1000 1,3-Butadiynyl anion [CCCC]- (g) 677.7 686.8 ± 1.2 kJ/mol 48.0433 ± 0.0032 59158-53-1*0 Difluorine cation [F2]+ (g) 1514.301 1514.475 ± 0.013 kJ/mol 37.9962578 ± 0.0000010 12184-86-0*0 Hydrazine monohydrate (NH2NH2)(H2O) (l) -242.68 ± 0.19 kJ/mol 50.06052 ± 0.00053 7803-57-8*500 Dihydrogen H2 (g, para) -0.000 -0.058 ± 0.000 kJ/mol 2.01588 ± 0.00014 1333-74-0*2 Nitrosyl nitrite anion [ONONO]- (g, t, c) -100.3 -103.5 ± 2.9 kJ/mol 76.01223 ± 0.00091 *122413-35-8*2 Hypochloroperoxoous acid, hydroxy ester HOOOCl (g, anti) 49.5 42.6 ± 2.5 kJ/mol 84.4588 ± 0.0013 928652-99-7*2 Methylaminyliumyl [CH3N]+ (g, doublet ?) 1388.3 1382.0 ± 2.6 kJ/mol 29.04071 ± 0.00083 56924-51-7*1 Acetylene anion [HCCH]- (g) 356.9 356.7 ± 1.9 kJ/mol 26.0378 ± 0.0016 50443-89-5*0 Bicyclo[1.1.0]buta-1,3-dien-4-ylium-2-yl [C(CC)C]+ (g) 2087.4 2097.2 ± 2.7 kJ/mol 48.0423 ± 0.0032 289679-91-0*0 3H-Diazirin-3-ylidene C(NN) (g) 578.0 578.4 ± 4.0 kJ/mol 40.02418 ± 0.00081 253308-70-2*0 Water H2O (cr) -286.308 -292.749 ± 0.027 kJ/mol 18.01528 ± 0.00033 7732-18-5*510 Tribromine cation [Br3]+ (g) 1035.9 1013.2 ± 2.6 kJ/mol 239.7115 ± 0.0030 33105-86-1*0 Trioxygen difluoride FOOOF (g) 112.5 107.3 ± 1.2 kJ/mol 85.99501 ± 0.00090 16829-28-0*0 Hydrazoic acid anion [HNNN]- (g, cis) 316.2 310.0 ± 2.3 kJ/mol 43.02871 ± 0.00022 203264-98-6*2 Water H2O (g, para) -238.938 -241.842 ± 0.027 kJ/mol 18.01528 ± 0.00033 7732-18-5*2 (Z)-1,2-Diiodoethene C2H2I2 (g) 215.71 207.43 ± 0.44 kJ/mol 279.8462 ± 0.0016 590-26-1*0 (E)-1,2-Diiodoethene C2H2I2 (g) 214.82 207.43 ± 0.44 kJ/mol 279.8462 ± 0.0016 590-27-2*0 Fluorosyl fluoride FFO (g, singlet) 227. 225. ± 21. kJ/mol 53.99621 ± 0.00030 86825-57-2*2 Bicyclo[1.1.0]buta-1,3-dien-2-yl anion [C(CC)C]- (g) 803.6 811.3 ± 2.1 kJ/mol 48.0433 ± 0.0032 289679-89-6*0 1,2-Dibromoethane (CBrH2)2 (cr,l) -79.5 ± 1.3 kJ/mol 187.8612 ± 0.0026 106-93-4*500 Oxygen atom dication [O]+2 (g) 4949.459 4953.000 ± 0.013 kJ/mol 15.99830 ± 0.00030 14127-63-0*0 Deuterium molecule cation [D2]+ (g) 1492.286 1492.361 ± 0.000 kJ/mol 4.02765497609 ± 0.00000000080 12184-84-8*0 Hydroxymethylene cation [HCOH]+ (g) 971.9 968.3 ± 1.4 kJ/mol 30.02543 ± 0.00087 135395-06-1*0 Chlorine pentafluoride cation [FCl(F)(F)(F)F]+ (g) 1005.8 996.8 ± 3.3 kJ/mol 130.44417 ± 0.00090 478167-78-1*0 Water dimer cation [(H2O)2]+ (g) 556.8 546.3 ± 3.0 kJ/mol 36.03001 ± 0.00066 158061-35-9*0 Hydroxymethylene anion [HCOH]- (g) 147.2 144.2 ± 1.6 kJ/mol 30.02653 ± 0.00087 207914-87-2*0 Diazene cation [HNNH]+ (g, trans-cis equilib) 1132.46 1125.53 ± 0.66 kJ/mol 30.02881 ± 0.00020 76986-17-9*1 Cyanogen iodide cation [ICN]+ (g) 1271.3 1271.2 ± 1.6 kJ/mol 152.92136 ± 0.00080 34749-78-5*0 Peroxychlorous acid HOOClO (g) 96.2 90.6 ± 2.1 kJ/mol 84.4588 ± 0.0013 177778-92-6*0 Oxirene O(CHCH) (g) 272.85 272.15 ± 0.98 kJ/mol 42.0367 ± 0.0016 157-18-6*0 Nitrogen atom anion N- (g) 487.6 489.9 ± 2.5 kJ/mol 14.007289 ± 0.000070 17778-87-9*0 Chlorine chlorite ClOClO (g) 168.6 166.4 ± 1.3 kJ/mol 102.9042 ± 0.0019 105206-44-8*0 Hydrogen cyanide anion [HCN]- (g) 129.516 129.038 ± 0.091 kJ/mol 27.02593 ± 0.00081 12334-27-9*0 2-Hydroxyethylium [CH2CH2OH]+ (g) 1019.2 1007.0 ± 1.7 kJ/mol 45.0600 ± 0.0017 38607-31-7*0 Dinitrogen dioxide ONNO (g, trans) 192.2 188.6 ± 1.8 kJ/mol 60.01228 ± 0.00062 16824-89-8*1 Water anion [H2O]- (g) -50.1 -53.0 ± 4.3 kJ/mol 18.01583 ± 0.00033 12259-30-2*0 Chlorohydroxymethyl CH(Cl)OH (g) -54.7 -60.4 ± 1.1 kJ/mol 65.4787 ± 0.0012 147139-06-8*0 Hydrazoic acid HNNN (cr,l) 261.48 ± 0.65 kJ/mol 43.02816 ± 0.00022 7782-79-8*500 Isocyanic fluoride cation [FNC]+ (g) 1618.4 1619.0 ± 4.0 kJ/mol 45.01529 ± 0.00080 *16992-26-0*0 Methane anion [CH4]- (g) 27.3 19.4 ± 5.1 kJ/mol 16.04301 ± 0.00085 27680-53-1*0 Oxonium [H3O]+ (g, ortho) 605.90 599.09 ± 0.17 kJ/mol 19.02267 ± 0.00037 13968-08-6*1 Carbon atom C (g, quintuplet) 1114.970 1120.117 ± 0.048 kJ/mol 12.01070 ± 0.00080 7440-44-0*3 O--HH Complex (H2)(O) (g, vdW C2v ?) 247.2 248.2 ± 2.0 kJ/mol 18.01528 ± 0.00033 *7732-18-5*102 Isocyanic fluoride anion [FNC]- (g) 74.3 76.0 ± 5.7 kJ/mol 45.01639 ± 0.00080 357426-78-9*0 Nitrogen atom N (g, doublet) 700.554 702.457 ± 0.024 kJ/mol 14.006740 ± 0.000070 17778-88-0*2 Hydrobromate ion [HBr]- (g) -5.7 -12.2 ± 4.3 kJ/mol 80.9125 ± 0.0010 85532-97-4*0 Hydrogen peroxide H2O2 (aq) -190.78 ± 0.30 kJ/mol 34.01468 ± 0.00062 7722-84-1*800 Fluoro(fluorooxy)methylene FCOF (g) -135.8 -137.0 ± 2.1 kJ/mol 66.00691 ± 0.00085 479587-30-9*0 Trihydrogen H(HH) (g, Ry) 745.878 743.199 ± 0.062 kJ/mol 3.02382 ± 0.00021 12184-91-7*0 Dichlorine cation [Cl2]+ (g) 1108.287 1108.266 ± 0.013 kJ/mol 70.9049 ± 0.0018 12595-90-3*0 Fluorosyl fluoride anion [FFO]- (g) -147.2 -146.9 ± 3.0 kJ/mol 53.99675 ± 0.00030 *86825-57-2*0 Formic acid cation [HC(O)OH]+ (g) 721.92 715.38 ± 0.26 kJ/mol 46.0248 ± 0.0010 50614-05-6*0 (Methylamino)methyl anion [CH3NHCH2]- (g) 200.9 184.0 ± 3.2 kJ/mol 44.0763 ± 0.0017 *31277-25-5*0 Isocyanogen chloride anion [ClNC]- (g) 102.8 107.3 ± 3.9 kJ/mol 61.4707 ± 0.0012 923019-39-0*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 Phosgene cation [CCl2O]+ (g) 897.1 896.0 ± 1.7 kJ/mol 98.9150 ± 0.0020 73249-38-4*0 Phosgene CCl2O (cr, l, I+liquid) -242.72 ± 0.27 kJ/mol 98.9155 ± 0.0020 75-44-5*501 Phosgene CCl2O (cr, l, II+liquid) -255.43 -242.72 ± 0.27 kJ/mol 98.9155 ± 0.0020 75-44-5*502 Diiodine cation [I2]+ (g) 963.523 960.408 ± 0.018 kJ/mol 253.808391 ± 0.000060 28712-14-3*0 Chloro(chlorooxy)methylene ClCOCl (g) 73.5 73.7 ± 3.6 kJ/mol 98.9155 ± 0.0020 479587-31-0*0 Chloro(chlorooxy)methylene ClCOCl (g, trans?) 112. 114. ± 16. kJ/mol 98.9155 ± 0.0020 479587-31-0*1 Formic acid anion [HC(O)OH]- (g) -256.2 -262.3 ± 1.8 kJ/mol 46.0259 ± 0.0010 19066-82-1*0 Methyl fluoride cation [CH3F]+ (g) 981.81 974.32 ± 0.62 kJ/mol 34.03237 ± 0.00083 59122-96-2*0 Chlorohydroxymethylene ClCOH (g, cis) 14.3 11.4 ± 3.2 kJ/mol 64.4707 ± 0.0012 147723-60-2*2 Chlorohydroxymethylene ClCOH (g) 13.9 11.2 ± 2.6 kJ/mol 64.4707 ± 0.0012 147723-60-2*0 Methyl fluoride CH3F (l) -245.74 ± 0.45 kJ/mol 34.03292 ± 0.00083 593-53-3*590 (Chlorooxy)methylene HCOCl (g, trans) 155.4 155.2 ± 3.7 kJ/mol 64.4707 ± 0.0012 331419-80-8*1 (Chlorooxy)methylene HCOCl (g) 119.1 117.8 ± 2.7 kJ/mol 64.4707 ± 0.0012 331419-80-8*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 Chloromethane CH3Cl (l) -105.96 -101.99 ± 0.25 kJ/mol 50.4872 ± 0.0012 74-87-3*590 Chloroformyl anion [ClCO]- (g) -356.5 -352.9 ± 3.3 kJ/mol 63.4633 ± 0.0012 41976-93-6*0 Water H2O (cr, eq.press.) -286.310 -292.751 ± 0.027 kJ/mol 18.01528 ± 0.00033 7732-18-5*509 Diazene HNNH (g, trans-cis equilib) 207.09 199.96 ± 0.44 kJ/mol 30.02936 ± 0.00020 3618-05-1*1 Fluorosyl fluoride cation [FFO]+ (g) 1413.0 1413.4 ± 3.5 kJ/mol 53.99566 ± 0.00030 *86825-50-5*0 Dinitrogen tetraoxide O2NNO2 (cr,l) -37.87 -27.02 ± 0.19 kJ/mol 92.0111 ± 0.0012 10544-72-6*500 Nitrosyl nitrite anion [ONONO]- (g) -103.1 -106.2 ± 2.8 kJ/mol 76.01223 ± 0.00091 *122413-35-8*0 Diazene anion [HNNH]- (g, trans-cis equilib) 265.5 258.7 ± 2.0 kJ/mol 30.02991 ± 0.00020 100429-75-2*1 Ethane anion [CH3CH3]- (g) 41.9 26.6 ± 4.4 kJ/mol 30.0696 ± 0.0017 54064-82-3*0 (Dimethylamino)methyl anion [(CH3)2NCH2]- (g) 189.5 165.3 ± 3.3 kJ/mol 58.1029 ± 0.0025 125231-49-4*0 2-Iodoethanol ICH2CH2OH (g) -132.0 -150.2 ± 2.5 kJ/mol 171.9650 ± 0.0017 624-76-0*0 Cyanogen chloride cation [ClCN]+ (g) 1326.12 1327.45 ± 0.97 kJ/mol 61.4696 ± 0.0012 37612-72-9*0 Propargylenide [HCCCH]- (g) 434.5 437.7 ± 1.1 kJ/mol 38.0485 ± 0.0024 82906-05-6*0 Hydroperoxonium [H2OOH]+ (g, cis) 762.5 752.6 ± 2.0 kJ/mol 35.02207 ± 0.00064 70850-26-9*2 Cyanogen NCCN (cr,l) 273.99 289.24 ± 0.43 kJ/mol 52.0349 ± 0.0016 460-19-5*500 Hydrodioxonitrogen cation [HN(O)O]+ (g) 1129.6 1123.0 ± 3.2 kJ/mol 47.01293 ± 0.00061 252986-76-8*0 Methyl bromide cation [CH3Br]+ (g) 996.93 982.01 ± 0.27 kJ/mol 94.9380 ± 0.0013 12538-70-4*0 Trihydrogen cation [H3]+ (g, ortho) 1110.577 1106.695 ± 0.013 kJ/mol 3.02327 ± 0.00021 28132-48-1*1 Isoformyl anion [COH]- (g) 55.8 58.4 ± 1.8 kJ/mol 29.01859 ± 0.00086 81747-63-9*0 Chloroethane CH3CH2Cl (cr,l) -134.19 -135.81 ± 0.20 kJ/mol 64.5138 ± 0.0019 75-00-3*500 Ethenol CH2CHOH (g, syn-anti equilib) -112.76 -123.18 ± 0.84 kJ/mol 44.0526 ± 0.0017 557-75-5*0 Hydrogen peroxide cation [H2O2]+ (g) 896.57 889.59 ± 0.58 kJ/mol 34.01413 ± 0.00062 12325-10-9*0 Vinyl alcohol cation [CH2CHOH]+ (g, anti-syn equilib) 778.9 768.0 ± 1.4 kJ/mol 44.0520 ± 0.0017 57239-63-1*0 Methyl iodide cation [CH3I]+ (g) 944.69 935.29 ± 0.18 kJ/mol 141.93844 ± 0.00083 12538-72-6*0 Cyanogen chloride anion [ClCN]- (g) 46.7 51.1 ± 3.1 kJ/mol 61.4707 ± 0.0012 12281-43-5*0 Oxoniumyl ion [H2O]+ (g, para) 978.714 975.563 ± 0.029 kJ/mol 18.01473 ± 0.00033 56583-62-1*2 Isocyanogen anion [CNCN]- (g, trans-cis equilib) 383.7 387.8 ± 2.6 kJ/mol 52.0354 ± 0.0016 *83951-85-3*0 Trihydrogen HHH (g, TS) 254.5 250.7 ± 1.2 kJ/mol 3.02382 ± 0.00021 12184-91-7*200 Hydrodioxonitrate [HN(O)O]- (g) -62.4 -68.8 ± 3.3 kJ/mol 47.01403 ± 0.00061 61508-71-2*0 Fluoroform CF3H (l) -704.21 ± 0.47 kJ/mol 70.01385 ± 0.00080 75-46-7*590 Imidogen NH (g, triplet) 358.74 358.79 ± 0.17 kJ/mol 15.014680 ± 0.000099 13774-92-0*1 Difluorodioxidanium [FOOF]+ (g) 1283.6 1280.0 ± 2.3 kJ/mol 69.99506 ± 0.00060 *7783-44-0*0 Peroxyhypochlorous acid anion [HOOCl]- (g, quartet) -32.2 -34.0 ± 2.6 kJ/mol 68.4600 ± 0.0011 *67952-08-3*0 Imidogen NH (g, singlet) 509.34 509.39 ± 0.18 kJ/mol 15.014680 ± 0.000099 13774-92-0*2 Carbonic acid C(O)(OH)2 (g) -602.74 -612.05 ± 0.79 kJ/mol 62.0248 ± 0.0012 463-79-6*0 Diisocyanogen cation [CNNC]+ (g, trans-cis equilib) 1823.1 1826.1 ± 3.5 kJ/mol 52.0343 ± 0.0016 *78800-21-2*0 Diazenide [NNH]- (g) 175.7 176.7 ± 1.6 kJ/mol 29.02197 ± 0.00016 71004-29-0*0 Fluorosyl fluoride FFO (g) 192.6 193.1 ± 2.3 kJ/mol 53.99621 ± 0.00030 86825-57-2*0 Ethylene anion [CH2CH2]- (g) 232.1 225.6 ± 2.0 kJ/mol 28.0537 ± 0.0016 34527-91-8*0 Perchloric acid cation [HOCl(O)(O)O]+ (g) 1191.8 1182.2 ± 3.5 kJ/mol 100.4577 ± 0.0015 91712-47-9*0 Ethynylene C2 (g, triplet) 827.45 834.15 ± 0.27 kJ/mol 24.0214 ± 0.0016 12070-15-4*1 Hydrogen isocyanide anion [HNC]- (g) 191.57 191.76 ± 0.38 kJ/mol 27.02593 ± 0.00081 96913-22-3*0 Cyanic fluoride cation [FCN]+ (g) 1294.5 1294.9 ± 1.1 kJ/mol 45.01529 ± 0.00080 62532-69-8*0 Bromine atom Br (g, 2P1/2) 162.001 155.939 ± 0.056 kJ/mol 79.90400 ± 0.00100 10097-32-2*2 Isocyanogen chloride cation [ClNC]+ (g) 1480.9 1482.1 ± 3.9 kJ/mol 61.4696 ± 0.0012 956475-91-5*0 Isocyanogen bromide cation [BrNC]+ (g) 1470.3 1464.6 ± 5.9 kJ/mol 105.9209 ± 0.0013 238754-53-5*0 Hydroxyformyl HOCO (g, trans-cis equilib) -181.19 -183.77 ± 0.50 kJ/mol 45.0174 ± 0.0010 2564-86-5*0 Difluorodioxidane anion [FOOF]- (g) -251. -251. ± 28. kJ/mol 69.99615 ± 0.00060 *7783-45-1*0 Water H2O (g, ortho) -238.654 -241.842 ± 0.027 kJ/mol 18.01528 ± 0.00033 7732-18-5*1 Hydroxyformyl anion [HOCO]- (g, trans-cis equilib) -319.50 -321.58 ± 0.60 kJ/mol 45.0180 ± 0.0010 78944-70-4*0 Peroxychlorous acid HOOClO (g, perp ?) 102.3 96.2 ± 3.7 kJ/mol 84.4588 ± 0.0013 177778-92-6*3 Chlorine atom Cl (g, 2P1/2) 130.176 131.783 ± 0.0011 kJ/mol 35.45270 ± 0.00090 22537-15-1*2 Ethylidene CH3CH (g) 361.30 354.32 ± 0.91 kJ/mol 28.0532 ± 0.0016 4218-50-2*0 Bromoform CBr3H (l) 3.0 ± 1.3 kJ/mol 252.7306 ± 0.0031 75-25-2*590 Water H2O (cr, l, eq.press.) -286.310 -285.838 ± 0.027 kJ/mol 18.01528 ± 0.00033 7732-18-5*499 Phenol cation [C6H5OH]+ (g) 746.32 727.53 ± 0.68 kJ/mol 94.1107 ± 0.0048 40932-22-7*0 Hydrogen peroxide cation [H2O2]+ (g, trans, para) 896.60 889.59 ± 0.58 kJ/mol 34.01413 ± 0.00062 12325-10-9*12 Hydroperoxonium [H2OOH]+ (g) 738.1 727.8 ± 1.2 kJ/mol 35.02207 ± 0.00064 70850-26-9*0 Oxonium [H3O]+ (aq) -285.836 ± 0.027 kJ/mol 19.02267 ± 0.00037 13968-08-6*800 Hydroxyamidogen HNOH (g) 101.6 94.8 ± 1.1 kJ/mol 32.02202 ± 0.00034 13940-32-4*0 Cyclopropylium [CH(CH2CH2)]+ (g) 1104.7 1093.3 ± 4.1 kJ/mol 41.0713 ± 0.0024 1724-43-2*0 Benzaldehyde cation [C6H5C(O)H]+ (g) 896.9 880.2 ± 1.9 kJ/mol 106.1214 ± 0.0056 80226-59-1*0 Benzaldehyde anion [C6H5C(O)H]- (g) -60.1 -77.7 ± 1.2 kJ/mol 106.1225 ± 0.0056 34473-57-9*0 Methylene fluoride CH2F2 (l) -466.85 ± 0.39 kJ/mol 52.02339 ± 0.00081 75-10-5*590 C=O-C cation [COC]+ (g) 1575.8 1582.9 ± 2.4 kJ/mol 40.0203 ± 0.0016 83483-98-1*0 Dioxyamidogen HNOO (g, trans) 251.1 244.5 ± 2.5 kJ/mol 47.01348 ± 0.00061 71843-95-3*1 Hydroxyaminylium [HNOH]+ (g) 1019.6 1012.5 ± 2.5 kJ/mol 32.02147 ± 0.00034 66097-71-0*0 Hypochloroperoxoous acid, hydroxy ester HOOOCl (g) 49.2 42.4 ± 1.9 kJ/mol 84.4588 ± 0.0013 928652-99-7*0 2-Cyclopropyn-1-ylidene C(CC) (g) 899.2 906.1 ± 1.6 kJ/mol 36.0321 ± 0.0024 102508-15-6*0 Cyclopropane CH2(CH2CH2) (l) 35.52 ± 0.59 kJ/mol 42.0797 ± 0.0024 75-19-4*500 Trihydrogen H(HH) (g, TS) 477.4 474.7 ± 2.3 kJ/mol 3.02382 ± 0.00021 12184-91-7*201 Dinitrogen dioxide ONNO (g) 172.88 171.12 ± 0.14 kJ/mol 60.01228 ± 0.00062 16824-89-8*0 1,2-Propadien-1-yl-3-ylidene anion [CCC]- (g, lin) 621.9 629.3 ± 1.3 kJ/mol 36.0326 ± 0.0024 109292-47-9*1 Cyanogen bromide cation [BrCN]+ (g) 187.3 180.9 ± 1.1 kJ/mol 105.9209 ± 0.0013 34749-77-4*0 Iminomethyl HCNH (g) 275.83 272.23 ± 0.71 kJ/mol 28.03332 ± 0.00082 15691-95-9*0 Cyanic fluoride anion [FCN]- (g) -20.4 -18.4 ± 2.9 kJ/mol 45.01639 ± 0.00080 34507-50-1*0 Trioxygen difluoride FOOOF (g, cis) 113.6 107.8 ± 2.1 kJ/mol 85.99501 ± 0.00090 16829-28-0*2 Nitrosyl nitrite ONONO (g) 93.0 88.1 ± 1.3 kJ/mol 76.01168 ± 0.00091 122413-35-8*0 Trioxodinitrate anion [ONNO2]- (g) -104.9 -108.8 ± 2.4 kJ/mol 76.01223 ± 0.00091 194856-62-7*0 Dioxymethylene HCOO (g, cis-trans equilib) 341.1 338.9 ± 3.4 kJ/mol 45.0174 ± 0.0010 438586-67-5*0 Hydrogen peroxide cation [H2O2]+ (g, cis, ortho) 930.5 923.6 ± 1.0 kJ/mol 34.01413 ± 0.00062 12325-10-9*21 Chlorous acid cation [HOClO]+ (g) 996.6 991.6 ± 3.1 kJ/mol 68.4589 ± 0.0011 *99559-66-7*0 Chlorine pentafluoride anion [FCl(F)(F)(F)F]- (g) -619.3 -622.7 ± 4.4 kJ/mol 130.44526 ± 0.00090 184851-42-1*0 Methanediol CH2(OH)2 (g) -379.2 -392.6 ± 1.1 kJ/mol 48.0413 ± 0.0010 463-57-0*0 Oxirene O(CHCH) (g, triplet) 388.7 385.4 ± 2.6 kJ/mol 42.0367 ± 0.0016 157-18-6*1 Aminomethylidyne anion [CNH2]- (g, triplet) 481.6 478.0 ± 3.2 kJ/mol 28.03387 ± 0.00082 96808-04-7*1 Fluorine atom F (g, 2P1/2) 82.088 83.872 ± 0.048 kJ/mol 18.99840320 ± 0.00000050 14762-94-8*2 COC vdW (CO)(C) (g) 589.3 598.1 ± 1.9 kJ/mol 40.0208 ± 0.0016 *12071-24-8*0 Hydrazine anion [NH2NH2]- (g) 232.1 217.8 ± 4.1 kJ/mol 32.04579 ± 0.00031 65391-88-0*0 Chlorine trifluoride anion [FCl(F)F]- (g) -480.4 -481.9 ± 3.6 kJ/mol 92.44846 ± 0.00090 184289-50-7*0 Diazene cation [HNNH]+ (g, trans-iso-cis equilib) 1132.46 1125.81 ± 0.66 kJ/mol 30.02881 ± 0.00020 76986-17-9*0 Methyl nitrite CH3ONO (g, trans) -52.46 -64.42 ± 0.90 kJ/mol 61.0401 ± 0.0010 624-91-9*1 Methyl nitrite CH3ONO (cr,l) -88.82 ± 0.56 kJ/mol 61.0401 ± 0.0010 624-91-9*500 Hydrogen peroxide H2O2 (g, ortho) -129.472 -135.478 ± 0.063 kJ/mol 34.01468 ± 0.00062 7722-84-1*1 2,2,4-Trimethylpentane (CH3)2CHCH2C(CH3)3 (g) -171.4 -223.8 ± 1.5 kJ/mol 114.2285 ± 0.0065 540-84-1*0 Carbon atom C (diamond) 2.391 1.863 ± 0.044 kJ/mol 12.01070 ± 0.00080 7440-44-0*501 Dinitrogen anion [N2]- (g) 192.5 192.5 ± 1.7 kJ/mol 28.01403 ± 0.00014 12185-02-3*0 Nitrous acid anion [HONO]- (g) -107.0 -110.5 ± 2.4 kJ/mol 47.01403 ± 0.00061 256393-36-9*0 Methylaminyliumyl [CH3N]+ (g ?) 1388.3 1382.0 ± 2.6 kJ/mol 29.04071 ± 0.00083 56924-51-7*0 Iminomethyl anion [HCNH]- (g) 237.4 233.6 ± 1.8 kJ/mol 28.03387 ± 0.00082 90623-30-6*0 Hydroperoxyimidogen HOON (g, cis) 111.8 108.9 ± 2.8 kJ/mol 47.01348 ± 0.00061 877456-58-1*2 Peroxyhypochlorous acid cation [HOOCl]+ (g) 1030.3 1024.5 ± 2.5 kJ/mol 68.4589 ± 0.0011 *67952-07-2*0 Oxide [O]-2 (g) 651. 653. ± 15. kJ/mol 16.00050 ± 0.00030 16833-27-5*0 Succinic acid (CH2COOH)2 (g) -795.65 -817.79 ± 0.61 kJ/mol 118.0880 ± 0.0034 110-15-6*0 Iodine monochloride ICl (cr,l) -36.511 -35.537 ± 0.063 kJ/mol 162.35717 ± 0.00090 7790-99-0*500 Dicarbon monoxide CCO (g) 377.3 381.3 ± 1.1 kJ/mol 40.0208 ± 0.0016 12071-23-7*0 Peroxyformic acid HC(O)OOH (g) -279.8 -288.9 ± 1.1 kJ/mol 62.0248 ± 0.0012 107-32-4*0 3-Chloro-3-methyl-3H-diazirine (NNC)ClCH3 (g) 230. 218. ± 40. kJ/mol 90.5114 ± 0.0019 4222-21-3*0 Chlorous acid anion [HOClO]- (g) -154.3 -156.2 ± 3.3 kJ/mol 68.4600 ± 0.0011 99559-66-7*0 Trioxidaniumyl [HOOOH]+ (g) 925.7 916.8 ± 1.5 kJ/mol 50.01353 ± 0.00091 161321-37-5*0 Diazene HNNH (g, trans-cis-iso equilib) 207.09 199.96 ± 0.44 kJ/mol 30.02936 ± 0.00020 3618-05-1*0 1,1-Dibromoethane CHBr2CH3 (cr,l) -66.4 ± 1.4 kJ/mol 187.8612 ± 0.0026 557-91-5*500 Iodosyl ion [IO]+ (g) 1066.1 1064.1 ± 1.9 kJ/mol 142.90332 ± 0.00030 81182-81-2*0 Propynylidene HCCCH (g, singlet) 597.6 599.4 ± 1.2 kJ/mol 38.0480 ± 0.0024 67152-18-5*2 Methoxycarbonyl C(O)OCH3 (g) -150.1 -157.8 ± 2.1 kJ/mol 59.0440 ± 0.0017 16481-04-2*0 Diazanide [NH2NH]- (g) 249.4 239.3 ± 3.1 kJ/mol 31.03785 ± 0.00025 25415-88-7*0 Hydrazoic acid anion [HNNN]- (g) 309.0 303.1 ± 2.3 kJ/mol 43.02871 ± 0.00022 203264-98-6*0 1,2-Dichloroethene CHClCHCl (g) 3.46 -1.86 ± 0.56 kJ/mol 96.9427 ± 0.0024 540-59-0*0 (Formyloxy)methyl HC(O)OCH2 (g) -148.7 -156.8 ± 1.7 kJ/mol 59.0440 ± 0.0017 3122-12-1*0 Methylaminyliumyl [CH3N]+ (g, quartet) 1423.0 1416.1 ± 2.6 kJ/mol 29.04071 ± 0.00083 56924-51-7*2 2-Hydroxyethyl CH2CH2OH (g) -12.84 -26.11 ± 0.63 kJ/mol 45.0605 ± 0.0017 4422-54-2*0 Krypton dication [Kr]+2 (g) 3701.124 3701.124 ± 0.013 kJ/mol 83.7989 ± 0.1000 18469-91-5*0 Chloromethylene CHCl (g) 320.24 320.53 ± 0.89 kJ/mol 48.4713 ± 0.0012 2108-20-5*0 Xenon dication [Xe]+2 (g) 3194.14 3194.14 ± 0.36 kJ/mol 131.2889 ± 0.0200 14066-95-6*0 Dichloromethylene CCl2 (g) 229.49 230.67 ± 0.65 kJ/mol 82.9161 ± 0.0020 1605-72-7*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 ± 0.033 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 ± 1.5 kJ/mol 20.17586 ± 0.00060 14175-50-9*0 Neon octacation [Ne]+8 (g) 92018.2 92018.2 ± 1.5 kJ/mol 20.17531 ± 0.00060 14782-26-4*0 Neon nonacation [Ne]+9 (g) 207396.1 207396.1 ± 1.5 kJ/mol 20.17476 ± 0.00060 15721-59-2*0 Neon cation Ne+ (g) 2080.662 2080.769 ± 0.000 kJ/mol 20.17915 ± 0.00060 14782-23-1*0 Neon decacation [Ne]+10 (g) 338828.3 338828.3 ± 1.5 kJ/mol 20.17421 ± 0.00060 32218-07-8*0 Argon dimer cation [Ar2]+ (g) 1393.760 1391.173 ± 0.018 kJ/mol 79.8955 ± 0.0020 17596-58-6*0 Argon cation Ar+ (g) 1520.571 1520.580 ± 0.0011 kJ/mol 39.94745 ± 0.00100 14791-69-6*0 Argon dimer Ar2 (g) -1.013 -6.347 ± 0.0051 kJ/mol 79.8960 ± 0.0020 12595-59-4*0 Helium cation He+ (g) 2372.322 2372.322 ± 0.000 kJ/mol 4.0020534 ± 0.0000020 14234-48-1*0 Helium dication [He]+2 (g) 7622.839 7622.839 ± 0.000 kJ/mol 4.0015048 ± 0.0000020 12587-46-1*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 Argon anion Ar- (g, 2S1/2) 23. 23. ± 75. kJ/mol 39.94855 ± 0.00100 16544-90-4*1 Argon anion Ar- (g) 23. 23. ± 75. kJ/mol 39.94855 ± 0.00100 16544-90-4*0 Helium anion He- (g, 1s.2s2 2S1/2) 1868.43 1868.43 ± 0.11 kJ/mol 4.0031506 ± 0.0000020 14452-58-5*2 Helium anion He- (g, 1s.2s.2p 4P) 1904.823 1904.824 ± 0.0011 kJ/mol 4.0031506 ± 0.0000020 14452-58-5*3 Helium anion He- (g, 2p3 4S3/2) 5724.9 5724.9 ± 1.5 kJ/mol 4.0031506 ± 0.0000020 14452-58-5*4 Argon anion Ar- (g, 4S3/2) 1111.116 1111.116 ± 0.098 kJ/mol 39.94855 ± 0.00100 16544-90-4*2 Hydron H+ (aq) 0 0 exact 1.007391 ± 0.000070 12408-02-5*800