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) 711.401 716.886 ± 0.050 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) 470.578 472.440 ± 0.024 kJ/mol 14.006740 ± 0.000070 17778-88-0*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) 77.263 79.369 ± 0.048 kJ/mol 18.99840320 ± 0.00000050 14762-94-8*0 Methane CH4 (g) -66.550 -74.519 ± 0.057 kJ/mol 16.04246 ± 0.00085 74-82-8*0 Water H2O (cr,l) -286.300 -285.828 ± 0.027 kJ/mol 18.01528 ± 0.00033 7732-18-5*500 Water H2O (g) -238.930 -241.833 ± 0.027 kJ/mol 18.01528 ± 0.00033 7732-18-5*0 Chlorine atom Cl (g) 119.621 121.302 ± 0.0011 kJ/mol 35.45270 ± 0.00090 22537-15-1*0 Bromine atom Br (g) 117.917 111.854 ± 0.056 kJ/mol 79.90400 ± 0.00100 10097-32-2*0 Ethane C2H6 (g) -68.29 -83.91 ± 0.14 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 Hydroxyl OH (g) 37.250 37.490 ± 0.027 kJ/mol 17.00734 ± 0.00031 3352-57-6*0 Ethylene C2H4 (g) 60.96 52.45 ± 0.13 kJ/mol 28.0532 ± 0.0016 74-85-1*0 Carbon monoxide CO (g) -113.803 -110.523 ± 0.026 kJ/mol 28.01010 ± 0.00085 630-08-0*0 Hydrogen chloride HCl (g) -91.989 -92.173 ± 0.0062 kJ/mol 36.46064 ± 0.00090 7647-01-0*0 Methyl CH3 (g) 149.788 146.374 ± 0.080 kJ/mol 15.03452 ± 0.00083 2229-07-4*0 Hydrogen bromide HBr (g) -27.81 -35.66 ± 0.16 kJ/mol 80.9119 ± 0.0010 10035-10-6*0 Methanol CH3OH (g) -189.82 -200.71 ± 0.16 kJ/mol 32.04186 ± 0.00090 67-56-1*0 Hydrogen fluoride HF (g) -272.668 -272.715 ± 0.049 kJ/mol 20.006343 ± 0.000070 7664-39-3*0 Iodine atom I (g) 107.157 106.757 ± 0.0021 kJ/mol 126.904470 ± 0.000030 14362-44-8*0 Formaldehyde H2CO (g) -105.349 -109.188 ± 0.099 kJ/mol 30.02598 ± 0.00087 50-00-0*0 Acetylene HCCH (g) 228.83 228.27 ± 0.14 kJ/mol 26.0373 ± 0.0016 74-86-2*0 Nitric oxide NO (g) 90.617 91.121 ± 0.065 kJ/mol 30.00614 ± 0.00031 10102-43-9*0 Ethanol CH3CH2OH (g) -216.89 -234.61 ± 0.21 kJ/mol 46.0684 ± 0.0017 64-17-5*0 Methyl chloride CH3Cl (g) -74.25 -82.18 ± 0.25 kJ/mol 50.4872 ± 0.0012 74-87-3*0 Ethyl CH3CH2 (g) 130.92 119.86 ± 0.28 kJ/mol 29.0611 ± 0.0016 2025-56-1*0 Propane CH3CH2CH3 (g) -82.75 -105.03 ± 0.19 kJ/mol 44.0956 ± 0.0025 74-98-6*0 Nitrogen dioxide ONO (g) 36.856 34.049 ± 0.065 kJ/mol 46.00554 ± 0.00060 10102-44-0*0 Ammonia NH3 (g) -38.562 -45.554 ± 0.030 kJ/mol 17.03056 ± 0.00022 7664-41-7*0 Hydrogen cyanide HCN (g) 129.660 129.275 ± 0.091 kJ/mol 27.02538 ± 0.00081 74-90-8*0 Hydrogen iodide HI (g) 28.641 26.466 ± 0.036 kJ/mol 127.912410 ± 0.000076 10034-85-2*0 Methyl fluoride CH3F (g) -227.77 -235.80 ± 0.23 kJ/mol 34.03292 ± 0.00083 593-53-3*0 Methyl bromide CH3Br (g) -20.36 -35.76 ± 0.27 kJ/mol 94.9385 ± 0.0013 74-83-9*0 Hydrogen peroxide H2O2 (g) -129.471 -135.457 ± 0.064 kJ/mol 34.01468 ± 0.00062 7722-84-1*0 Hydroxyde [OH]- (g) -139.091 -139.058 ± 0.027 kJ/mol 17.00789 ± 0.00031 14280-30-9*0 Dioxidanyl HO2 (g) 15.16 12.26 ± 0.16 kJ/mol 33.00674 ± 0.00060 3170-83-0*0 Propylene CH3CHCH2 (g) 35.00 19.99 ± 0.22 kJ/mol 42.0797 ± 0.0024 115-07-1*0 Tetrafluoromethane CF4 (g) -927.41 -933.39 ± 0.25 kJ/mol 88.00431 ± 0.00080 75-73-0*0 Fluoride F- (g) -250.901 -249.117 ± 0.048 kJ/mol 18.99895178 ± 0.00000050 16984-48-8*0 Hypochlorous acid HOCl (g) -73.867 -76.807 ± 0.028 kJ/mol 52.46004 ± 0.00095 7790-92-3*0 Acetaldehyde CH3CHO (g) -154.97 -165.45 ± 0.28 kJ/mol 44.0526 ± 0.0017 75-07-0*0 Benzene C6H6 (g) 100.62 83.11 ± 0.25 kJ/mol 78.1118 ± 0.0048 71-43-2*0 Dibromine Br2 (g) 45.68 30.89 ± 0.11 kJ/mol 159.8080 ± 0.0020 7726-95-6*0 Diiodine I2 (g) 65.497 62.417 ± 0.0041 kJ/mol 253.808940 ± 0.000060 7553-56-2*0 Methylidyne CH (g) 592.78 596.12 ± 0.11 kJ/mol 13.01864 ± 0.00080 3315-37-5*0 Formic acid HC(O)OH (g, syn) -371.12 -378.45 ± 0.22 kJ/mol 46.0254 ± 0.0010 64-18-6*1 Fluoroform CF3H (g) -688.92 -695.87 ± 0.43 kJ/mol 70.01385 ± 0.00080 75-46-7*0 Oxonium [H3O]+ (g) 605.85 599.10 ± 0.17 kJ/mol 19.02267 ± 0.00037 13968-08-6*0 Hypoflorous acid HOF (g) -84.37 -87.27 ± 0.19 kJ/mol 36.00574 ± 0.00031 14034-79-8*0 Hypobromous acid HOBr (g) -51.38 -61.85 ± 0.57 kJ/mol 96.9113 ± 0.0010 13517-11-8*0 Methyl iodide CH3I (g) 24.48 14.94 ± 0.17 kJ/mol 141.93899 ± 0.00083 74-88-4*0 Trifluoromethyl CF3 (g) -465.15 -467.94 ± 0.49 kJ/mol 69.00591 ± 0.00080 2264-21-3*0 Propyne CH3CCH (g) 192.80 185.74 ± 0.25 kJ/mol 40.0639 ± 0.0024 74-99-7*0 Methylene CH2 (g, triplet) 390.96 391.52 ± 0.12 kJ/mol 14.02658 ± 0.00081 2465-56-7*1 Methylene CH2 (g, singlet) 428.62 429.03 ± 0.13 kJ/mol 14.02658 ± 0.00081 2465-56-7*2 Vinyl C2H3 (g) 301.11 296.91 ± 0.33 kJ/mol 27.0452 ± 0.0016 2669-89-8*0 Ketene CH2CO (g) -45.45 -48.57 ± 0.13 kJ/mol 42.0367 ± 0.0016 463-51-4*0 Tetrachloromethane CCl4 (g) -94.27 -96.44 ± 0.64 kJ/mol 153.8215 ± 0.0037 56-23-5*0 Imidogen NH (g) 358.73 358.77 ± 0.17 kJ/mol 15.014680 ± 0.000099 13774-92-0*0 Allene CH2CCH2 (g) 197.34 189.85 ± 0.26 kJ/mol 40.0639 ± 0.0024 463-49-0*0 n-Butane CH3CH2CH2CH3 (g) -98.63 -125.94 ± 0.27 kJ/mol 58.1222 ± 0.0033 106-97-8*0 Difluorophosgene COF2 (g) -603.50 -606.60 ± 0.46 kJ/mol 66.00691 ± 0.00085 353-50-4*0 Bromide Br- (g) -206.620 -212.683 ± 0.056 kJ/mol 79.90455 ± 0.00100 24959-67-9*0 Oxomethylium [HCO]+ (g) 827.802 827.217 ± 0.099 kJ/mol 29.01749 ± 0.00086 17030-74-9*0 Iodide I- (g) -187.995 -188.396 ± 0.0021 kJ/mol 126.905019 ± 0.000030 20461-54-5*0 Nitric acid HNO3 (g) -124.48 -134.19 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*0 Formyl HCO (g) 41.426 41.803 ± 0.099 kJ/mol 29.01804 ± 0.00086 2597-44-6*0 Hydroxymethyl CH2OH (g) -10.26 -16.57 ± 0.33 kJ/mol 31.03392 ± 0.00088 2597-43-5*0 Chloroxyl radical ClO (g) 101.124 101.715 ± 0.035 kJ/mol 51.45210 ± 0.00095 14989-30-1*0 Methylium [CH3]+ (g) 1099.243 1095.299 ± 0.078 kJ/mol 15.03397 ± 0.00083 14531-53-4*0 Ozone OOO (g) 144.396 141.733 ± 0.039 kJ/mol 47.99820 ± 0.00090 10028-15-6*0 Cyanogen chloride ClCN (g) 135.03 135.72 ± 0.44 kJ/mol 61.4701 ± 0.0012 506-77-4*0 Phenyl C6H5 (g) 350.37 337.08 ± 0.57 kJ/mol 77.1039 ± 0.0048 2396-01-2*0 Ethylium [CH3CH2]+ (g) 915.03 902.95 ± 0.32 kJ/mol 29.0606 ± 0.0016 14936-94-8*0 Methoxide [CH3O]- (g) -122.54 -130.27 ± 0.35 kJ/mol 31.03447 ± 0.00088 3315-60-4*0 Methoxy CH3O (g) 28.90 21.53 ± 0.34 kJ/mol 31.03392 ± 0.00088 2143-68-2*0 Tetrabromomethane CBr4 (g) 131.5 101.9 ± 1.1 kJ/mol 331.6267 ± 0.0041 558-13-4*0 Oxygen atom anion O- (g) 105.868 108.097 ± 0.0021 kJ/mol 15.99995 ± 0.00030 14337-01-0*0 Nitrilomethyl CN (g) 436.73 440.01 ± 0.15 kJ/mol 26.01744 ± 0.00080 2074-87-5*0 Cyanogen fluoride FCN (g) 8.88 9.21 ± 0.68 kJ/mol 45.01584 ± 0.00080 1495-50-7*0 Chloride Cl- (g) -228.953 -227.346 ± 0.0021 kJ/mol 35.45325 ± 0.00090 16887-00-6*0 Trihydrogen cation [H3]+ (g) 1110.304 1106.696 ± 0.013 kJ/mol 3.02327 ± 0.00021 28132-48-1*0 Cyanogen bromide BrCN (g) 187.41 180.62 ± 0.73 kJ/mol 105.9214 ± 0.0013 506-68-3*0 Methylene fluoride CH2F2 (g) -443.16 -450.73 ± 0.36 kJ/mol 52.02339 ± 0.00081 75-10-5*0 2-Propynyl CH2CCH (g) 354.00 351.44 ± 0.38 kJ/mol 39.0559 ± 0.0024 2932-78-7*0 Propynylidene HCCCH (g, triplet) 543.38 546.37 ± 0.63 kJ/mol 38.0480 ± 0.0024 67152-18-5*1 Dioxymethyl CH2OO (g) 112.43 105.42 ± 0.61 kJ/mol 46.0254 ± 0.0010 56077-92-0*0 Oxygen atom cation O+ (g) 1560.786 1562.644 ± 0.0021 kJ/mol 15.99885 ± 0.00030 14581-93-2*0 Hypochlorite [ClO]- (g) -118.60 -118.33 ± 0.13 kJ/mol 51.45265 ± 0.00095 14380-61-1*0 1,2-Propadiene-1,3-diylidene CCC (g) 814.52 823.47 ± 0.54 kJ/mol 36.0321 ± 0.0024 12075-35-3*0 Allyl CH2CHCH2 (g) 179.56 167.84 ± 0.54 kJ/mol 41.0718 ± 0.0024 1981-80-2*0 1-Hydroxyethyl CH3CHOH (g, gauche-anti) -42.17 -55.59 ± 0.61 kJ/mol 45.0605 ± 0.0017 2348-46-1*1 2-Hydroxyethyl CH2CH2OH (g, gauche-syn) -12.79 -26.06 ± 0.61 kJ/mol 45.0605 ± 0.0017 4422-54-2*1 Ethyl chloride CH3CH2Cl (g) -96.76 -111.35 ± 0.20 kJ/mol 64.5138 ± 0.0019 75-00-3*0 Hydride H- (g) 143.264 145.228 ± 0.000 kJ/mol 1.008489 ± 0.000070 12184-88-2*0 Oxygen difluoride FOF (g) 26.94 24.68 ± 0.25 kJ/mol 53.99621 ± 0.00030 7783-41-7*0 Methylenimine H2CNH (g) 96.53 88.62 ± 0.63 kJ/mol 29.04126 ± 0.00083 2053-29-4*0 Methylamine CH3NH2 (g) -5.97 -21.05 ± 0.46 kJ/mol 31.05714 ± 0.00088 74-89-5*0 Nitrite [ONO]- (g) -182.69 -185.50 ± 0.45 kJ/mol 46.00609 ± 0.00060 14797-65-0*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) -73.018 -79.161 ± 0.079 kJ/mol 47.01348 ± 0.00061 7782-77-6*1 Ethynylene C2 (g) 820.21 828.67 ± 0.27 kJ/mol 24.0214 ± 0.0016 12070-15-4*0 Ethynyl C2H (g) 563.87 567.99 ± 0.15 kJ/mol 25.0293 ± 0.0016 2122-48-7*0 Ethoxide [CH3CH2O]- (g) -164.14 -179.08 ± 0.52 kJ/mol 45.0610 ± 0.0017 16331-64-9*0 Chloroform CCl3H (g) -98.49 -103.39 ± 0.64 kJ/mol 119.3767 ± 0.0028 67-66-3*0 Methylene chloride CH2Cl2 (g) -87.85 -94.71 ± 0.59 kJ/mol 84.9320 ± 0.0020 75-09-2*0 Tetrafluoroethylene C2F4 (g) -671.52 -674.93 ± 0.57 kJ/mol 100.0150 ± 0.0016 116-14-3*0 Phenylium [C6H5]+ (g) 1148.47 1136.57 ± 0.89 kJ/mol 77.1034 ± 0.0048 17333-73-2*0 Hypoiodous acid HOI (g) -56.6 -61.3 ± 2.0 kJ/mol 143.91181 ± 0.00031 14332-21-9*0 Amidogen NH2 (g) 188.91 186.02 ± 0.12 kJ/mol 16.02262 ± 0.00016 13770-40-6*0 Methanium [CH5]+ (g) 922.07 911.83 ± 0.44 kJ/mol 17.04985 ± 0.00087 15135-49-6*0 Hydroxylamine NH2OH (g, trans) -33.12 -43.50 ± 0.49 kJ/mol 33.02996 ± 0.00037 7803-49-8*1 Oxirane O(CH2CH2) (g) -40.00 -52.54 ± 0.38 kJ/mol 44.0526 ± 0.0017 75-21-8*0 Methyl hydroperoxide CH3OOH (g) -114.90 -127.72 ± 0.74 kJ/mol 48.0413 ± 0.0010 3031-73-0*0 Hydroxyformyl HOCO (g, trans) -180.96 -183.92 ± 0.48 kJ/mol 45.0174 ± 0.0010 2564-86-5*1 Isocyanic acid HNCO (g) -115.85 -118.85 ± 0.31 kJ/mol 43.02478 ± 0.00086 75-13-8*0 Tetraiodomethane CI4 (g) 340.8 335.7 ± 1.3 kJ/mol 519.62858 ± 0.00081 507-25-5*0 Chlorotrifluoromethane CF3Cl (g) -704.97 -710.08 ± 0.72 kJ/mol 104.4586 ± 0.0012 75-72-9*0 Bromotrifluoromethane CF3Br (g) -639.45 -651.57 ± 0.50 kJ/mol 148.9099 ± 0.0013 75-63-8*0 Fluoromethylidyne CF (g) 243.11 246.71 ± 0.13 kJ/mol 31.00910 ± 0.00080 3889-75-6*0 Fluoroxyl radical FO (g) 110.26 110.88 ± 0.15 kJ/mol 34.99780 ± 0.00030 12061-70-0*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) 664.55 667.88 ± 0.59 kJ/mol 13.01864 ± 0.00080 3315-37-5*2 Ethoxy CH3CH2O (g, X 2A") 1.13 -12.77 ± 0.51 kJ/mol 45.0605 ± 0.0017 2154-50-9*51 Cyanato NCO (g) 127.02 127.49 ± 0.35 kJ/mol 42.01684 ± 0.00086 22400-26-6*0 Phosgene COCl2 (g) -217.43 -219.13 ± 0.27 kJ/mol 98.9155 ± 0.0020 75-44-5*0 Bromoform CBr3H (g) 74.3 48.1 ± 1.3 kJ/mol 252.7306 ± 0.0031 75-25-2*0 Vinyl chloride CH2CHCl (g) 29.57 22.10 ± 0.34 kJ/mol 62.4979 ± 0.0018 75-01-4*0 Acetone CH3C(O)CH3 (g) -199.45 -216.14 ± 0.36 kJ/mol 58.0791 ± 0.0025 67-64-1*0 Hydrogen fluoride HF (aq) -334.51 ± 0.17 kJ/mol 20.006343 ± 0.000070 7664-39-3*800 Hypobromite [BrO]- (g) -96.24 -103.73 ± 0.55 kJ/mol 95.9039 ± 0.0010 14380-62-2*0 Diazenylium [N2H]+ (g) 1042.78 1039.17 ± 0.73 kJ/mol 29.02087 ± 0.00016 12357-66-3*0 Peroxynitrous acid HOONO (g, cis, cis) -5.99 -14.43 ± 0.36 kJ/mol 63.01288 ± 0.00091 14691-52-2*3 Dioxygenyl fluoride FOO (g) 26.75 25.04 ± 0.27 kJ/mol 50.99720 ± 0.00060 15499-23-7*0 Cyclopropane CH2(CH2CH2) (g) 70.80 53.65 ± 0.46 kJ/mol 42.0797 ± 0.0024 75-19-4*0 Propadienylidene CH2CC (g) 554.44 555.59 ± 0.42 kJ/mol 38.0480 ± 0.0024 60731-10-4*0 Acetyl CH3CO (g) -3.32 -9.98 ± 0.37 kJ/mol 43.0446 ± 0.0016 3170-69-2*0 Methylperoxy CH3OO (g) 22.29 12.54 ± 0.49 kJ/mol 47.0333 ± 0.0010 2143-58-0*0 Ethyl fluoride CH3CH2F (g) -257.29 -272.16 ± 0.37 kJ/mol 48.0595 ± 0.0016 353-36-6*0 Ethyl bromide CH3CH2Br (g) -41.14 -63.09 ± 0.26 kJ/mol 108.9651 ± 0.0019 74-96-4*0 Vinyl fluoride CH2CHF (g) -134.71 -142.51 ± 0.47 kJ/mol 46.0436 ± 0.0016 75-02-5*0 Vinyl bromide CH2CHBr (g) 88.82 74.01 ± 0.59 kJ/mol 106.9492 ± 0.0019 593-60-2*0 2-Bromoethanol BrCH2CH2OH (g) -196.56 -220.63 ± 0.54 kJ/mol 124.9645 ± 0.0019 540-51-2*0 Fluorobenzene C6H5F (g) -99.29 -114.97 ± 0.83 kJ/mol 96.1023 ± 0.0048 462-06-6*0 Nitromethane CH3N(O)O (g) -60.86 -74.76 ± 0.47 kJ/mol 61.0401 ± 0.0010 75-52-5*0 Dioxidanide [HO2]- (g) -88.86 -91.52 ± 0.38 kJ/mol 33.00729 ± 0.00060 14691-59-9*0 Nitrous oxide NNO (g) 85.998 82.569 ± 0.097 kJ/mol 44.01288 ± 0.00033 10024-97-2*0 (E)-Diazene HNNH (g, trans) 207.35 200.21 ± 0.44 kJ/mol 30.02936 ± 0.00020 15626-43-4*0 Hydroxyoxomethylium [HOCO]+ (g) 600.76 597.68 ± 0.43 kJ/mol 45.0169 ± 0.0010 638-71-1*0 Vinylium [C2H3]+ (g) 1119.20 1115.75 ± 0.57 kJ/mol 27.0447 ± 0.0016 14604-48-9*0 Hydroxymethylium [CH2OH]+ (g) 717.85 709.91 ± 0.19 kJ/mol 31.03337 ± 0.00088 18682-95-6*0 Cyanogen NCCN (g) 308.17 310.12 ± 0.43 kJ/mol 52.0349 ± 0.0016 460-19-5*0 Cyanogen iodide ICN (g) 222.47 221.95 ± 0.99 kJ/mol 152.92191 ± 0.00080 506-78-5*0 iso-Propyl CH3CHCH3 (g) 105.28 88.68 ± 0.67 kJ/mol 43.0877 ± 0.0024 2025-55-0*0 Ethynide [C2H]- (g) 277.42 280.83 ± 0.19 kJ/mol 25.0299 ± 0.0016 29075-95-4*0 iso-Butane CH(CH3)3 (g) -106.17 -134.78 ± 0.33 kJ/mol 58.1222 ± 0.0033 75-28-5*0 n-Pentane CH3CH2CH2CH2CH3 (g) -114.47 -146.34 ± 0.31 kJ/mol 72.1488 ± 0.0041 109-66-0*0 2-Chloroethanol ClCH2CH2OH (g) -250.03 -266.74 ± 0.61 kJ/mol 80.5132 ± 0.0019 107-07-3*0 Hypofluorite [FO]- (g) -108.90 -108.73 ± 0.48 kJ/mol 34.99835 ± 0.00030 12763-66-5*0 Hydrogen chloride HCl (aq, 600 H2O) -166.454 ± 0.024 kJ/mol 36.46064 ± 0.00090 7647-01-0*834 Bromoxyl radical BrO (g) 131.12 123.59 ± 0.29 kJ/mol 95.9034 ± 0.0010 15656-19-6*0 Hydroxyamidogen HNOH (g, trans) 101.5 94.7 ± 1.0 kJ/mol 32.02202 ± 0.00034 13940-32-4*1 Nitrate [NO3]- (g) -300.25 -306.72 ± 0.61 kJ/mol 62.00549 ± 0.00090 14797-55-8*0 Water H2O (l) -285.828 ± 0.027 kJ/mol 18.01528 ± 0.00033 7732-18-5*590 Formyl anion [HCO]- (g) 11.62 12.01 ± 0.43 kJ/mol 29.01859 ± 0.00086 57340-31-5*0 Propyl CH3CH2CH2 (g) 117.92 100.81 ± 0.61 kJ/mol 43.0877 ± 0.0024 2143-61-5*0 2-Propynylidyne CCCH (g) 717.95 722.30 ± 0.81 kJ/mol 37.0400 ± 0.0024 53590-28-6*0 Dicarbon monoxide CCO (g, singlet) 454.95 459.28 ± 0.88 kJ/mol 40.0208 ± 0.0016 12071-23-7*2 Methanetetraylbisamidogen NCN (g) 450.39 450.80 ± 0.68 kJ/mol 40.02418 ± 0.00081 2669-76-3*0 Methylene bromide CH2Br2 (g) 24.9 3.5 ± 1.1 kJ/mol 173.8346 ± 0.0022 74-95-3*0 2-Fluoroethanol FCH2CH2OH (g) -406.8 -424.0 ± 1.1 kJ/mol 64.0589 ± 0.0017 371-62-0*0 Phenide [C6H5]- (g) 244.70 231.79 ± 0.43 kJ/mol 77.1044 ± 0.0048 30922-78-2*0 Bromobenzene C6H5Br (g) 126.5 104.5 ± 1.3 kJ/mol 157.0079 ± 0.0049 108-86-1*0 Hydrogen bromide HBr (aq) -120.80 ± 0.16 kJ/mol 80.9119 ± 0.0010 10035-10-6*800 Iodine monochloride ICl (g) 19.024 17.391 ± 0.013 kJ/mol 162.35717 ± 0.00090 7790-99-0*0 Iodotrifluoromethane CF3I (g) -583.99 -589.87 ± 0.54 kJ/mol 195.91038 ± 0.00080 2314-97-8*0 Nitrogen atom cation N+ (g) 1872.906 1875.687 ± 0.024 kJ/mol 14.006191 ± 0.000070 14158-23-7*0 Azido radical NNN (g) 452.24 449.65 ± 0.58 kJ/mol 42.02022 ± 0.00021 12596-60-0*0 Trinitrogen cation [NNN]+ (g) 1519.39 1516.86 ± 0.87 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) 1238.307 1241.586 ± 0.026 kJ/mol 28.00955 ± 0.00085 12144-04-6*0 Nitrosyl ion [NO]+ (g) 984.485 984.480 ± 0.065 kJ/mol 30.00559 ± 0.00031 14452-93-8*0 Nitroxyl H2NO (g) 71.34 64.73 ± 0.85 kJ/mol 32.02202 ± 0.00034 13408-29-2*0 Hydrazoic acid HNNN (g) 297.92 291.62 ± 0.48 kJ/mol 43.02816 ± 0.00022 7782-79-8*0 Ethonium [C2H7]+ (g, bridged C2) 874.54 858.27 ± 0.61 kJ/mol 31.0764 ± 0.0017 24669-33-8*1 Acetylium [CH3CO]+ (g) 667.18 660.02 ± 0.65 kJ/mol 43.0441 ± 0.0016 15762-07-9*0 Hydroxymethylene HCOH (g, trans) 112.40 108.63 ± 0.33 kJ/mol 30.02598 ± 0.00087 19710-56-6*1 Carbonic acid C(O)(OH)2 (g, cis-cis) -602.78 -612.95 ± 0.79 kJ/mol 62.0248 ± 0.0012 463-79-6*1 1-Butene CH2CHCH2CH3 (g) 20.88 -0.08 ± 0.38 kJ/mol 56.1063 ± 0.0032 106-98-9*0 n-Hexane CH3CH2CH2CH2CH2CH3 (g) -130.05 -166.93 ± 0.34 kJ/mol 86.1754 ± 0.0049 110-54-3*0 1-Hydroxyethylium [CH3CHOH]+ (g, anti) 609.14 594.72 ± 0.39 kJ/mol 45.0600 ± 0.0017 18682-96-7*1 Ethoxy CH3CH2O (g, A 2A') 5.38 -9.05 ± 0.51 kJ/mol 45.0605 ± 0.0017 2154-50-9*52 Dicarbon monoxide CCO (g, triplet) 376.30 380.34 ± 0.97 kJ/mol 40.0208 ± 0.0016 12071-23-7*1 Formic acid HC(O)OH (g, anti) -354.76 -362.00 ± 0.38 kJ/mol 46.0254 ± 0.0010 64-18-6*2 Formyloxidanyl HC(O)O (g, 2A1) -124.76 -126.42 ± 0.55 kJ/mol 45.0174 ± 0.0010 16499-21-1*1 Formate [HC(O)O]- (g) -462.11 -465.75 ± 0.55 kJ/mol 45.0180 ± 0.0010 71-47-6*0 Chlorodifluoromethane CHClF2 (g) -476.5 -482.6 ± 1.2 kJ/mol 86.4681 ± 0.0012 75-45-6*0 Fluoromethylene CHF (g, singlet) 148.26 148.54 ± 0.44 kJ/mol 32.01704 ± 0.00080 13453-52-6*2 Fluoroformyl FCO (g) -176.70 -176.12 ± 0.38 kJ/mol 47.00850 ± 0.00085 1871-24-5*0 Benzaldehyde C6H5C(O)H (g) -19.16 -36.96 ± 0.92 kJ/mol 106.1219 ± 0.0056 100-52-7*0 Chlorobenzene C6H5Cl (g) 67.13 52.18 ± 0.61 kJ/mol 112.5566 ± 0.0049 108-90-7*0 Hydrogen chloride HCl (aq) -166.994 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*800 Bromonium [HBrH]+ (g) 925.4 914.7 ± 1.2 kJ/mol 81.9193 ± 0.0010 36658-54-5*0 Hydrogen peroxide cation [H2O2]+ (g, trans) 896.87 889.89 ± 0.57 kJ/mol 34.01413 ± 0.00062 12325-10-9*1 Amide [NH2]- (g) 114.88 112.00 ± 0.33 kJ/mol 16.02317 ± 0.00016 17655-31-1*0 Hydrazine H2NNH2 (g) 111.84 97.68 ± 0.49 kJ/mol 32.04524 ± 0.00031 302-01-2*0 Fluoronium [HFH]+ (g) 774.42 771.47 ± 0.85 kJ/mol 21.01373 ± 0.00014 12206-67-6*0 Methanide [CH3]- (g) 146.05 142.61 ± 0.91 kJ/mol 15.03507 ± 0.00083 15194-58-8*0 Trioxidane HOOOH (g, trans) -81.43 -90.27 ± 0.70 kJ/mol 50.01408 ± 0.00091 14699-99-1*1 Ethylidene CH3CH (g, triplet) 361.45 354.45 ± 0.82 kJ/mol 28.0532 ± 0.0016 4218-50-2*1 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) 262.90 252.56 ± 0.71 kJ/mol 41.0718 ± 0.0024 15552-77-9*0 Isobutene CH2C(CH3)2 (g) 3.92 -17.15 ± 0.44 kJ/mol 56.1063 ± 0.0032 115-11-7*0 trans-2-Butene CH3CHCHCH3 (g, trans) 9.26 -11.30 ± 0.41 kJ/mol 56.1063 ± 0.0032 624-64-6*0 cis-2-Butene CH3CHCHCH3 (g, cis) 13.95 -7.32 ± 0.42 kJ/mol 56.1063 ± 0.0032 590-18-1*0 1,3-Butadiene CH2CHCHCH2 (g) 125.05 110.57 ± 0.42 kJ/mol 54.0904 ± 0.0032 106-99-0*0 Cyclopentane CH2(CH2CH2CH2CH2) (g) -45.01 -77.58 ± 0.44 kJ/mol 70.1329 ± 0.0041 287-92-3*0 1,3-Cyclopentadiene CH2(CHCHCHCH) (g) 149.89 132.77 ± 0.76 kJ/mol 66.1011 ± 0.0040 542-92-7*0 1-Hydroxyethyl CH3CHOH (g, gauche-syn) -40.66 -54.13 ± 0.86 kJ/mol 45.0605 ± 0.0017 2348-46-1*2 Protonated oxirane [(CH2CH2)OH]+ (g) 725.29 709.12 ± 0.64 kJ/mol 45.0600 ± 0.0017 *38607-31-7*0 Oxoethenyl HCCO (g) 176.85 177.96 ± 0.60 kJ/mol 41.0287 ± 0.0016 51095-15-9*0 Methanediol CH2(OH)2 (g, conrot gauche) -379.05 -393.25 ± 0.95 kJ/mol 48.0413 ± 0.0010 463-57-0*1 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) -344.75 -357.80 ± 0.58 kJ/mol 60.0520 ± 0.0017 107-31-3*1 Trioxidanide [HOOO]- (g, gauche) -121.0 -124.0 ± 1.4 kJ/mol 49.00669 ± 0.00090 89965-38-8*2 Difluorodichloromethane CF2Cl2 (g) -490.69 -495.46 ± 0.97 kJ/mol 120.9129 ± 0.0020 75-71-8*0 Fluorodichloromethane CHFCl2 (g) -278.9 -284.3 ± 1.2 kJ/mol 102.9224 ± 0.0020 75-43-4*0 Trifluoromethylium [CF3]+ (g) 409.00 405.93 ± 0.51 kJ/mol 69.00536 ± 0.00080 18851-76-8*0 Methyl nitrite CH3ONO (g, cis) -55.46 -67.24 ± 0.46 kJ/mol 61.0401 ± 0.0010 624-91-9*2 Dichlorine monoxide ClOCl (g) 79.76 77.95 ± 0.36 kJ/mol 86.9048 ± 0.0018 7791-21-1*0 Chlorine peroxide ClOOCl (g) 134.51 131.28 ± 0.56 kJ/mol 102.9042 ± 0.0019 12292-23-8*0 Iodoxyl radical IO (g) 127.0 125.0 ± 1.1 kJ/mol 142.90387 ± 0.00030 14696-98-1*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) 90.72 86.15 ± 0.15 kJ/mol 76.01168 ± 0.00091 10544-73-7*0 Ammonium [NH4]+ (g) 643.05 631.74 ± 0.21 kJ/mol 18.03795 ± 0.00029 14798-03-9*0 Chloronium [HClH]+ (g) 881.29 878.19 ± 0.97 kJ/mol 37.46803 ± 0.00091 36658-55-6*0 Ammonium [NH4]+ (aq) -133.077 ± 0.056 kJ/mol 18.03795 ± 0.00029 14798-03-9*800 Hydrazyl N2H3 (g) 235.28 224.62 ± 0.83 kJ/mol 31.03730 ± 0.00025 13598-46-4*0 Dioxygen difluoride FOOF (g) 33.66 29.94 ± 0.50 kJ/mol 69.99561 ± 0.00060 7783-44-0*0 Ethylidene CH3CH (g, singlet) 373.93 366.70 ± 0.86 kJ/mol 28.0532 ± 0.0016 4218-50-2*2 Hydrogen isocyanide cation [HNC]+ (g) 1352.9 1352.8 ± 1.2 kJ/mol 27.02483 ± 0.00081 74158-11-5*0 Propargylenide [HCCCH]- (g, transoid 2B) 434.6 437.1 ± 1.1 kJ/mol 38.0485 ± 0.0024 82906-05-6*1 2-Hydroxyethyl CH2CH2OH (g, gauche-anti) -10.04 -22.68 ± 0.85 kJ/mol 45.0605 ± 0.0017 4422-54-2*2 Dimethyl ether CH3OCH3 (g) -166.50 -184.01 ± 0.44 kJ/mol 46.0684 ± 0.0017 115-10-6*0 Methanediol CH2(OH)2 (g, disrot gauche) -368.51 -381.66 ± 0.99 kJ/mol 48.0413 ± 0.0010 463-57-0*2 Dichloride [Cl2]- (g) -230.4 -229.4 ± 1.4 kJ/mol 70.9059 ± 0.0018 12595-89-0*0 Chlorine dioxide OClO (g) 101.03 98.56 ± 0.30 kJ/mol 67.4515 ± 0.0011 10049-04-4*0 Hydroperoxonium [H2OOH]+ (g, trans) 738.17 727.91 ± 0.98 kJ/mol 35.02207 ± 0.00064 70850-26-9*1 Formyl fluoride HFCO (g) -378.72 -382.31 ± 0.33 kJ/mol 48.01644 ± 0.00086 1493-02-3*0 Nitric acid HNO3 (aq) -206.63 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*800 Hydrogen fluoride HF (aq, 20 H2O) -321.06 ± 0.17 kJ/mol 20.006343 ± 0.000070 7664-39-3*818 Oxoammoniumyl [HNO]+ (g) 1092.61 1089.69 ± 0.67 kJ/mol 31.01353 ± 0.00032 63559-87-5*0 Difluoride [F2]- (g) -290.8 -290.0 ± 1.4 kJ/mol 37.9973550 ± 0.0000010 12184-85-9*0 Peroxynitrous acid HOONO (g, trans, perp) 7.67 0.59 ± 0.40 kJ/mol 63.01288 ± 0.00091 14691-52-2*1 Vinylidene CCH2 (g) 411.28 412.20 ± 0.33 kJ/mol 26.0373 ± 0.0016 2143-69-3*0 Ethylidyne CH3C (g) 508.58 504.88 ± 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 Iminomethyl cation [HCNH]+ (g) 953.3 949.3 ± 1.5 kJ/mol 28.03277 ± 0.00082 196216-36-1*0 Chlorine superoxide ClOO (g) 103.82 102.73 ± 0.37 kJ/mol 67.4515 ± 0.0011 17376-09-9*0 Water dimer (H2O)2 (g) -491.081 -499.121 ± 0.053 kJ/mol 36.03056 ± 0.00066 25655-83-8*0 iso-Propylium [CH3CHCH3]+ (g) 822.88 805.62 ± 0.26 kJ/mol 43.0871 ± 0.0024 19252-53-0*0 Trioxidane HOOOH (g, cis) -72.03 -80.52 ± 0.81 kJ/mol 50.01408 ± 0.00091 14699-99-1*2 1-Propenyl CH3CHCH (g, cis) 277.98 267.19 ± 0.79 kJ/mol 41.0718 ± 0.0024 6067-68-1*2 1-Propynyl CH3CC (g) 529.01 526.65 ± 0.81 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 2-Butyne CH3CCCH3 (g) 158.96 146.00 ± 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) -119.22 -153.27 ± 0.44 kJ/mol 72.1488 ± 0.0041 78-78-4*0 Chlorine fluoride ClF (g) -55.612 -55.707 ± 0.055 kJ/mol 54.45110 ± 0.00090 7790-89-8*0 2-Hydroxyethyl CH2CH2OH (g, staggered-anti) -5.1 -17.5 ± 1.2 kJ/mol 45.0605 ± 0.0017 4422-54-2*3 Vinoxy CH2CHO (g) 22.46 15.61 ± 0.77 kJ/mol 43.0446 ± 0.0016 6912-06-7*0 Acetyl anion [CH3CO]- (g) -43.8 -49.4 ± 1.3 kJ/mol 43.0452 ± 0.0016 78944-68-0*0 Ketene CH2CO (g, triplet) 182.5 177.5 ± 1.1 kJ/mol 42.0367 ± 0.0016 463-51-4*1 Formic acid HC(O)OH (g) -371.12 -378.42 ± 0.22 kJ/mol 46.0254 ± 0.0010 64-18-6*0 Hydroxyformyl HOCO (g, cis) -174.04 -177.07 ± 0.51 kJ/mol 45.0174 ± 0.0010 2564-86-5*2 Hydroxyformyl anion [HOCO]- (g, cis) -319.36 -322.13 ± 0.58 kJ/mol 45.0180 ± 0.0010 78944-70-4*2 Fluorotrichloromethane CCl3F (g) -286.9 -290.1 ± 1.2 kJ/mol 137.3672 ± 0.0028 75-69-4*0 Bromotrichloromethane CCl3Br (g) -33.82 -42.97 ± 0.71 kJ/mol 198.2728 ± 0.0030 75-62-7*0 Difluoromethylene CF2 (g) -193.99 -193.51 ± 0.38 kJ/mol 50.00751 ± 0.00080 2154-59-8*0 Fluoromethylene CHF (g, triplet) 210.12 210.45 ± 0.68 kJ/mol 32.01704 ± 0.00080 13453-52-6*1 Hexafluoroethane CF3CF3 (g) -1334.5 -1342.8 ± 1.5 kJ/mol 138.0118 ± 0.0016 76-16-4*0 1,1-Difluoroethane CHF2CH3 (g) -489.09 -502.81 ± 0.65 kJ/mol 66.0500 ± 0.0016 75-37-6*0 2-Hydrotrioxy OO(H)O (g) 300.9 295.2 ± 1.1 kJ/mol 49.00614 ± 0.00090 *12500-78-6*0 1,1-Difluoroethene CH2CF2 (g) -343.72 -350.78 ± 0.85 kJ/mol 64.0341 ± 0.0016 75-38-7*0 Tricarbon dioxide OCCCO (g) -96.2 -94.1 ± 1.2 kJ/mol 68.0309 ± 0.0025 504-64-3*0 Iodobenzene C6H5I (g) 177.6 161.6 ± 1.0 kJ/mol 204.0084 ± 0.0048 591-50-4*0 Iodine monobromide IBr (g) 49.717 40.770 ± 0.067 kJ/mol 206.8085 ± 0.0010 7789-33-5*0 Nitrosyl nitrite ONONO (g, sym) 92.6 87.5 ± 1.2 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 H2NN (g) 307.99 300.93 ± 0.75 kJ/mol 30.02936 ± 0.00020 28647-38-3*0 Nitryl hydride HN(O)O (g) -37.2 -44.2 ± 1.5 kJ/mol 47.01348 ± 0.00061 90266-90-3*0 Carbon atom cation C+ (g) 1797.853 1803.451 ± 0.050 kJ/mol 12.01015 ± 0.00080 14067-05-1*0 Methyliumyl [CH2]+ (g) 1393.09 1393.95 ± 0.13 kJ/mol 14.02603 ± 0.00081 15091-72-2*0 Oxygen atom O (g, singlet) 436.666 438.523 ± 0.0021 kJ/mol 15.99940 ± 0.00030 17778-80-2*2 Methyliumylidene [CH]+ (g) 1619.758 1623.102 ± 0.057 kJ/mol 13.01809 ± 0.00080 24361-82-8*0 Methylidyne anion [CH]- (g) 475.47 478.79 ± 0.91 kJ/mol 13.01919 ± 0.00080 28604-54-8*0 Ozonide [OOO]- (g) -58.48 -60.83 ± 0.21 kJ/mol 47.99875 ± 0.00090 12596-80-4*0 (E)-Iminomethyl HCNH (g, trans) 275.92 272.30 ± 0.84 kJ/mol 28.03332 ± 0.00082 54980-10-8*0 Nitrilomethylium [CN]+ (g) 1778.3 1781.8 ± 1.2 kJ/mol 26.01689 ± 0.00080 12539-57-0*0 Fluoroacetylene HCCF (g) 104.73 105.44 ± 0.41 kJ/mol 44.0277 ± 0.0016 2713-09-9*0 Chloroacetylene HCCCl (g) 228.3 229.2 ± 1.1 kJ/mol 60.4820 ± 0.0018 593-63-5*0 Methanol cation [CH3OH]+ (g) 857.08 846.75 ± 0.33 kJ/mol 32.04131 ± 0.00090 12538-91-9*0 Methyloxonium [CH3OH2]+ (g) 589.9 575.7 ± 1.2 kJ/mol 33.04925 ± 0.00092 17836-08-7*0 Hydroxyde [OH]- (aq) -230.012 ± 0.029 kJ/mol 17.00789 ± 0.00031 14280-30-9*800 Oxidanylium [OH]+ (g) 1293.189 1293.218 ± 0.035 kJ/mol 17.00679 ± 0.00031 12259-29-9*0 Carbonic acid C(O)(OH)2 (g, cis-trans) -596.92 -607.04 ± 0.85 kJ/mol 62.0248 ± 0.0012 463-79-6*2 Carbonic acid C(O)(OH)2 (g, trans-trans) -561.70 -570.55 ± 0.98 kJ/mol 62.0248 ± 0.0012 463-79-6*3 1,2-Propadienyl anion [CH2CCH]- (g) 265.85 262.65 ± 0.72 kJ/mol 39.0565 ± 0.0024 64066-06-4*0 1-Propynyl anion [CH3CC]- (g) 265.06 261.60 ± 0.81 kJ/mol 39.0565 ± 0.0024 36147-87-2*0 Bromine monochloride BrCl (g) 21.880 14.437 ± 0.060 kJ/mol 115.3567 ± 0.0013 13863-41-7*0 neo-Pentane C(CH3)4 (g) -134.64 -167.52 ± 0.41 kJ/mol 72.1488 ± 0.0041 463-82-1*0 Cyclohexane CH2(CH2CH2CH2CH2CH2) (g) -83.59 -123.15 ± 0.36 kJ/mol 84.1595 ± 0.0049 110-82-7*0 2-Hydroxyethylium [CH2CH2OH]+ (g, staggered-anti) 1019.6 1006.8 ± 1.6 kJ/mol 45.0600 ± 0.0017 38607-31-7*3 Vinyl alcohol CH2CHOH (g, syn) -112.55 -123.86 ± 0.84 kJ/mol 44.0526 ± 0.0017 557-75-5*1 Ethynol HCCOH (g) 94.9 92.8 ± 1.3 kJ/mol 42.0367 ± 0.0016 32038-79-2*0 Hydroxyformyl anion [HOCO]- (g, trans) -313.53 -315.48 ± 0.59 kJ/mol 45.0180 ± 0.0010 78944-70-4*1 1-Propanol CH3CH2CH2OH (g) -231.38 -255.22 ± 0.26 kJ/mol 60.0950 ± 0.0025 71-23-8*0 2-Propanol CH3CH(OH)CH3 (g) -248.77 -272.86 ± 0.36 kJ/mol 60.0950 ± 0.0025 67-63-0*0 Acetic acid CH3C(O)OH (g, syn) -418.38 -432.50 ± 0.54 kJ/mol 60.0520 ± 0.0017 64-19-7*1 Ethylene glycol (CH2OH)2 (g) -369.80 -389.43 ± 0.49 kJ/mol 62.0678 ± 0.0018 107-21-1*0 Fluorochloromethane CH2FCl (g) -256.4 -263.6 ± 1.3 kJ/mol 68.4777 ± 0.0012 593-70-4*0 Chlorine atom cation Cl+ (g) 1370.806 1372.602 ± 0.0011 kJ/mol 35.45215 ± 0.00090 24203-47-2*0 Trioxidanyl HOOO (g, trans) 25.31 23.33 ± 0.13 kJ/mol 49.00614 ± 0.00090 12500-78-6*1 1,3-Butadiyne HCCCCH (g) 458.57 460.29 ± 0.86 kJ/mol 50.0587 ± 0.0032 460-12-8*0 Toluene C6H5CH3 (g) 73.56 50.27 ± 0.36 kJ/mol 92.1384 ± 0.0056 108-88-3*0 Fluorobenzene cation [C6H5F]+ (g) 788.69 774.00 ± 0.83 kJ/mol 96.1018 ± 0.0048 34468-25-2*0 Nitromethyl CH2N(O)O (g) 138.8 129.4 ± 1.2 kJ/mol 60.0321 ± 0.0010 16787-85-2*0 Dinitrogen pentoxide O2NONO2 (g) 24.41 14.84 ± 0.35 kJ/mol 108.0105 ± 0.0015 10102-03-1*0 Water anion [(H)(OH)]- (g, vdW ?) 30.5 29.0 ± 2.5 kJ/mol 18.01583 ± 0.00033 12259-30-2*100 Bromonium Br+ (g) 1257.777 1251.714 ± 0.056 kJ/mol 79.90345 ± 0.00100 22541-56-6*0 Peroxynitric acid HOON(O)O (g) -42.6 -54.1 ± 1.3 kJ/mol 79.0123 ± 0.0012 26404-66-0*0 Nitrosyl chloride ClNO (g) 54.451 52.549 ± 0.067 kJ/mol 65.45884 ± 0.00095 2696-92-6*0 Carbon dioxide CO2 (g, triplet) 49.48 50.33 ± 0.99 kJ/mol 44.00950 ± 0.00100 124-38-9*1 Methane cation [CH4]+ (g) 1150.84 1144.45 ± 0.25 kJ/mol 16.04191 ± 0.00085 20741-88-2*0 Ethonium [C2H7]+ (g) 874.54 858.30 ± 0.61 kJ/mol 31.0764 ± 0.0017 24669-33-8*0 Vinyl anion [C2H3]- (g) 237.24 232.82 ± 0.84 kJ/mol 27.0458 ± 0.0016 25012-81-1*0 Acetylene cation [HCCH]+ (g) 1328.85 1328.18 ± 0.14 kJ/mol 26.0367 ± 0.0016 25641-79-6*0 Bromide Br- (aq) -120.80 ± 0.16 kJ/mol 79.90455 ± 0.00100 24959-67-9*800 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) 456.8 452.8 ± 1.4 kJ/mol 27.0458 ± 0.0016 117768-70-4*0 Vinylidene anion [CCH2]- (g) 364.15 363.96 ± 0.62 kJ/mol 26.0378 ± 0.0016 66295-36-1*0 Iodide I- (aq) -56.829 ± 0.089 kJ/mol 126.905019 ± 0.000030 20461-54-5*800 Ethynylium [C2H]+ (g) 1687.59 1690.93 ± 0.16 kJ/mol 25.0288 ± 0.0016 16456-59-0*0 Aminomethyl CH2NH2 (g) 159.40 148.51 ± 0.58 kJ/mol 30.04920 ± 0.00085 10507-29-6*0 Methylamidogen anion [CH3NH]- (g) 145.99 134.64 ± 0.76 kJ/mol 30.04975 ± 0.00085 54448-39-4*0 Methyleneamidogen H2CN (g) 242.22 238.56 ± 0.85 kJ/mol 28.03332 ± 0.00082 15845-29-1*0 (Z)-Iminomethyl HCNH (g, cis) 294.5 291.0 ± 1.2 kJ/mol 28.03332 ± 0.00082 54980-11-9*0 Methyloxoniumylidene [CH3O]+ (g) 1062.43 1054.62 ± 0.72 kJ/mol 31.03337 ± 0.00088 58157-09-8*0 Hydroxymethylene HCOH (g, cis) 130.86 127.11 ± 0.34 kJ/mol 30.02598 ± 0.00087 19710-56-6*2 Hydroxymethylene cation [HCOH]+ (g, trans) 971.9 968.3 ± 1.3 kJ/mol 30.02543 ± 0.00087 135395-06-1*1 Hydrogen difluoride cation [FFH]+ (g) 1173.5 1170.6 ± 1.7 kJ/mol 39.004198 ± 0.000070 *126950-54-7*0 Oxoniumyl ion [H2O]+ (g) 978.472 975.569 ± 0.029 kJ/mol 18.01473 ± 0.00033 56583-62-1*0 Isoformyl COH (g) 217.30 217.69 ± 0.67 kJ/mol 29.01804 ± 0.00086 71080-92-7*0 Azide ion [NNN]- (g) 193.64 190.05 ± 0.89 kJ/mol 42.02077 ± 0.00021 14343-69-2*0 1-Propenyl CH3CHCH (g, trans) 280.02 269.21 ± 0.81 kJ/mol 41.0718 ± 0.0024 6067-68-1*1 Cyclopropene CH2(CHCH) (g) 292.54 283.81 ± 0.54 kJ/mol 40.0639 ± 0.0024 2781-85-3*0 Cyclobutane CH2(CH2CH2CH2) (g) 52.17 27.63 ± 0.47 kJ/mol 56.1063 ± 0.0032 287-23-0*0 Dioxidenium [HO2]+ (g) 1110.87 1107.98 ± 0.11 kJ/mol 33.00619 ± 0.00060 12207-52-2*0 n-Heptane CH3(CH2)5CH3 (g) -145.65 -187.52 ± 0.48 kJ/mol 100.2019 ± 0.0057 142-82-5*0 n-Octane CH3(CH2)6CH3 (g) -161.43 -208.26 ± 0.67 kJ/mol 114.2285 ± 0.0065 111-65-9*0 1-Hydroxyethylium [CH3CHOH]+ (g, syn) 611.1 596.7 ± 1.2 kJ/mol 45.0600 ± 0.0017 18682-96-7*2 1H-Triazirin-1-yl N(NN) (g) 585.9 584.1 ± 2.0 kJ/mol 42.02022 ± 0.00021 912535-95-6*0 Vinyl alcohol CH2CHOH (g, anti) -108.10 -118.62 ± 0.88 kJ/mol 44.0526 ± 0.0017 557-75-5*2 Vinyl alcohol cation [CH2CHOH]+ (g, anti) 779.2 768.0 ± 1.2 kJ/mol 44.0520 ± 0.0017 57239-63-1*2 Oxiranyl CH2(CHO) (g) 172.8 164.5 ± 1.4 kJ/mol 43.0446 ± 0.0016 31586-84-2*0 Oxiranylium [CH2(CHO)]+ (g, singlet) 901.6 893.6 ± 1.4 kJ/mol 43.0441 ± 0.0016 57789-76-1*2 C=O=C COC (g, triplet) 653.3 657.6 ± 2.2 kJ/mol 40.0208 ± 0.0016 *12071-23-7*1 C=O=C COC (g, singlet) 721.5 725.9 ± 1.6 kJ/mol 40.0208 ± 0.0016 *12071-23-7*2 Oxirene O(CHCH) (g, singlet) 272.81 272.12 ± 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) 721.86 714.77 ± 0.26 kJ/mol 46.0248 ± 0.0010 50614-05-6*1 Dioxirane CH2(OO) (g) 9.41 1.74 ± 0.54 kJ/mol 46.0254 ± 0.0010 157-26-6*0 Formyloxidanyl HC(O)O (g, 2B2) -120.94 -124.29 ± 0.55 kJ/mol 45.0174 ± 0.0010 16499-21-1*2 Isofulminic acid HCNO (g) 170.91 169.45 ± 0.49 kJ/mol 43.02478 ± 0.00086 51060-05-0*0 Trioxidanylium [HOOO]+ (g, trans) 1070.2 1063.9 ± 1.3 kJ/mol 49.00559 ± 0.00090 74241-49-9*1 Methyl formate HC(O)OCH3 (g, anti-eclipsed) -324.6 -337.1 ± 1.6 kJ/mol 60.0520 ± 0.0017 107-31-3*2 Methyl iodide CH3I (l) -12.20 ± 0.19 kJ/mol 141.93899 ± 0.00083 74-88-4*590 Difluoromethylene CF2 (g, triplet) 43.20 43.92 ± 0.38 kJ/mol 50.00751 ± 0.00080 2154-59-8*1 Difluoromethylene CF2 (g, singlet) -193.99 -193.51 ± 0.38 kJ/mol 50.00751 ± 0.00080 2154-59-8*2 Ethyl iodide CH3CH2I (l) -9.40 -39.26 ± 0.49 kJ/mol 155.9656 ± 0.0016 75-03-6*500 Fluoro(fluorooxy)methylene FCOF (g, cis) -135.8 -137.0 ± 2.0 kJ/mol 66.00691 ± 0.00085 479587-30-9*2 Dibromophosgene COBr2 (g) -97.98 -113.91 ± 0.37 kJ/mol 187.8181 ± 0.0022 593-95-3*0 Fluoride F- (aq) -334.51 ± 0.17 kJ/mol 18.99895178 ± 0.00000050 16984-48-8*800 Benzene C6H6 (cr,l) 50.72 49.17 ± 0.25 kJ/mol 78.1118 ± 0.0048 71-43-2*500 Benzoyl fluoride C6H5C(O)F (g) -288.0 -304.4 ± 1.5 kJ/mol 124.1124 ± 0.0056 455-32-3*0 (E)-Diazene cation [HNNH]+ (g, trans) 1132.58 1125.67 ± 0.67 kJ/mol 30.02881 ± 0.00020 59952-06-6*0 (E)-Diazene anion [HNNH]- (g, trans) 269.3 262.4 ± 1.7 kJ/mol 30.02991 ± 0.00020 *59952-06-6*0 (Z)-Diazene HNNH (g, cis) 229.21 222.08 ± 0.64 kJ/mol 30.02936 ± 0.00020 15626-42-3*0 Diazenyl N2H (g) 252.25 249.33 ± 0.48 kJ/mol 29.02142 ± 0.00016 36882-13-0*0 Hydroxyaminiumyl [NOH]+ (g) 1160.6 1157.7 ± 1.3 kJ/mol 31.01353 ± 0.00032 63559-88-6*0 Hydroxyamidogen HNOH (g, cis) 123.5 117.0 ± 1.4 kJ/mol 32.02202 ± 0.00034 13940-32-4*2 Hydroxyaminylium [HNOH]+ (g, trans) 1020.2 1013.0 ± 2.0 kJ/mol 32.02147 ± 0.00034 66097-71-0*1 Triiodide ion [I3]- (aq) -51.36 ± 0.80 kJ/mol 380.713959 ± 0.000090 14900-04-0*800 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) -0.35 -7.40 ± 0.53 kJ/mol 63.01288 ± 0.00091 14691-52-2*2 Dioxiranylidene C(OO) (g) 190.6 191.4 ± 1.3 kJ/mol 44.00950 ± 0.00100 138832-57-2*0 Deuterium atom D (g) 219.804 221.717 ± 0.000 kJ/mol 2.01410177800 ± 0.00000000040 16873-17-9*0 Hypoiodite [IO]- (g) -102.5 -104.4 ± 1.2 kJ/mol 142.90442 ± 0.00030 15065-65-3*0 Methylene anion [CH2]- (g) 328.48 328.91 ± 0.51 kJ/mol 14.02713 ± 0.00081 50928-07-9*0 Methylidyne CH (g, doublet) 592.78 596.12 ± 0.11 kJ/mol 13.01864 ± 0.00080 3315-37-5*1 Hydrogen fluoride HF (aq, 40 H2O) -321.15 ± 0.17 kJ/mol 20.006343 ± 0.000070 7664-39-3*821 Ethylidyne CH3C (g, doublet) 508.58 504.88 ± 0.87 kJ/mol 27.0452 ± 0.0016 67624-57-1*1 Trioxodinitrate anion [ONNO2]- (g, vdW) -104.4 -108.4 ± 2.3 kJ/mol 76.01223 ± 0.00091 194856-62-7*100 Aminomethylium [CH2NH2]+ (g) 763.9 752.0 ± 1.8 kJ/mol 30.04865 ± 0.00085 488821-23-4*0 Methylamidogen CH3NH (g) 187.86 177.14 ± 0.61 kJ/mol 30.04920 ± 0.00085 15622-51-2*0 Aminomethylene HCNH2 (g) 246.6 238.8 ± 1.6 kJ/mol 29.04126 ± 0.00083 35430-17-2*0 Methylimidogen H3CN (g) 323.8 316.0 ± 1.6 kJ/mol 29.04126 ± 0.00083 27770-42-9*0 Methyleneamidogen anion [H2CN]- (g) 193.1 189.3 ± 1.1 kJ/mol 28.03387 ± 0.00082 28892-56-0*0 Aminomethylidyne CNH2 (g) 372.2 368.7 ± 1.4 kJ/mol 28.03332 ± 0.00082 84654-89-7*0 Hydrogen isocyanide HNC (g) 192.00 192.39 ± 0.38 kJ/mol 27.02538 ± 0.00081 6914-07-4*0 Cyanide [CN]- (g) 63.956 67.242 ± 0.095 kJ/mol 26.01799 ± 0.00080 57-12-5*0 Methyleneoxonium CH2OH2 (g) 154.6 146.3 ± 1.4 kJ/mol 32.04186 ± 0.00090 177788-17-9*0 Hydroxymethylene HCOH (g, gauche triplet) 219.0 216.1 ± 1.1 kJ/mol 30.02598 ± 0.00087 19710-56-6*3 Hydroxymethylene anion [HCOH]- (g, trans) 147.4 144.4 ± 1.4 kJ/mol 30.02653 ± 0.00087 207914-87-2*1 Dinitrogen tetraoxide O2NNO2 (g) 20.15 10.86 ± 0.14 kJ/mol 92.0111 ± 0.0012 10544-72-6*0 Hydroxymethyliumylidene [COH]+ (g) 986.13 987.77 ± 0.80 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) 856.87 838.65 ± 0.83 kJ/mol 43.0871 ± 0.0024 19252-52-9*0 Cyclopropyl CH(CH2CH2) (g) 302.8 290.2 ± 1.6 kJ/mol 41.0718 ± 0.0024 2417-82-5*0 Cycloprop-1-enyl CH2(CHC) (g) 528.11 523.53 ± 0.78 kJ/mol 39.0559 ± 0.0024 19528-44-0*0 Cycloprop-2-enyl CH(CHCH) (g) 491.03 486.42 ± 0.77 kJ/mol 39.0559 ± 0.0024 28933-84-8*0 Cyclopropenylidene C(CHCH) (g) 497.07 496.12 ± 0.47 kJ/mol 38.0480 ± 0.0024 16165-40-5*0 2-Propynylidyne anion [CCCH]- (g) 539.97 544.82 ± 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 n-Butyl CH3CH2CH2CH2 (g) 101.48 78.25 ± 0.98 kJ/mol 57.1143 ± 0.0033 2492-36-6*0 Methylcyclopropane CH3CH(CH2CH2) (g) 47.5 24.3 ± 1.3 kJ/mol 56.1063 ± 0.0032 594-11-6*0 Cyclobutene CH2(CH2CHCH) (g) 176.79 159.74 ± 0.93 kJ/mol 54.0904 ± 0.0032 822-35-5*0 Oxygen cation monohydrate [(HOH)O]+ (g) 1153.2 1147.7 ± 3.2 kJ/mol 34.01413 ± 0.00062 *31748-17-1*0 Oxygen anion monohydrate [(HOH)O]- (g) -239.1 -244.3 ± 3.0 kJ/mol 34.01523 ± 0.00062 31748-17-1*0 Vinyl alcohol cation [CH2CHOH]+ (g, syn) 787.30 776.18 ± 0.99 kJ/mol 44.0520 ± 0.0017 57239-63-1*1 Vinoxy cation [CH2CHO]+ (g, triplet) 1020.2 1013.2 ± 1.6 kJ/mol 43.0441 ± 0.0016 *35731-40-9*1 Vinoxide [CH2CHO]- (g) -153.55 -160.60 ± 0.77 kJ/mol 43.0452 ± 0.0016 35731-40-9*0 Acetic acid CH3C(O)OH (aq) -485.18 ± 0.23 kJ/mol 60.0520 ± 0.0017 64-19-7*800 Ketene CH2CO (g, singlet) -45.45 -48.57 ± 0.13 kJ/mol 42.0367 ± 0.0016 463-51-4*2 COC vdW (CO)(C) (g, triplet) 589.8 598.6 ± 1.8 kJ/mol 40.0208 ± 0.0016 *12071-24-8*1 Oxirene O(CHCH) (g, c-triplet) 390.7 386.6 ± 2.7 kJ/mol 42.0367 ± 0.0016 157-18-6*12 Methylperoxy anion [CH3OO]- (g) -89.79 -99.94 ± 0.67 kJ/mol 47.0339 ± 0.0010 35683-44-4*0 Formyloxoniumylidene [HC(O)O]+ (g) 1016.9 1013.5 ± 1.2 kJ/mol 45.0169 ± 0.0010 54375-27-8*0 Dioxymethylene HCOO (g, trans) 363.6 361.2 ± 2.6 kJ/mol 45.0174 ± 0.0010 438586-67-5*1 Trioxidaniumyl [HOOOH]+ (g, t, t) 927.1 917.8 ± 1.3 kJ/mol 50.01353 ± 0.00091 161321-37-5*2 Cyanic acid HOCN (g) -12.21 -14.92 ± 0.49 kJ/mol 43.02478 ± 0.00086 420-05-3*0 Fulminic acid HONC (g) 235.37 233.67 ± 0.48 kJ/mol 43.02478 ± 0.00086 506-85-4*0 Isocyanate [NCO]- (g) -221.11 -221.33 ± 0.54 kJ/mol 42.01739 ± 0.00086 71000-82-3*0 Nitrosomethylidyne CNO (g) 389.4 390.7 ± 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 Dimethylamine (CH3)2NH (g) 5.91 -15.99 ± 0.67 kJ/mol 45.0837 ± 0.0017 124-40-3*0 Trimethylamine (CH3)3N (g) 4.48 -24.08 ± 0.63 kJ/mol 59.1103 ± 0.0025 75-50-3*0 Isocyanogen CNCN (g) 410.7 413.1 ± 1.6 kJ/mol 52.0349 ± 0.0016 83951-85-3*0 Diisocyanogen CNNC (g) 610.1 613.0 ± 1.7 kJ/mol 52.0349 ± 0.0016 78800-21-2*0 Fluorosyl ion [FO]+ (g) 1342.62 1342.57 ± 0.78 kJ/mol 34.99725 ± 0.00030 12763-67-6*0 Cyanoamidogen HNCN (g) 324.7 322.3 ± 1.7 kJ/mol 41.03212 ± 0.00082 12347-01-2*0 Oxywater (H2O)O (g) 65.0 58.5 ± 1.2 kJ/mol 34.01468 ± 0.00062 171363-09-0*0 Bromodichloromethane CHCl2Br (g) -38.6 -50.3 ± 1.3 kJ/mol 163.8280 ± 0.0022 75-27-4*0 Chlorous acid HOClO (g) 25.67 20.61 ± 0.67 kJ/mol 68.4594 ± 0.0011 13898-47-0*0 Difluorodibromomethane CF2Br2 (g) -366.7 -384.4 ± 1.4 kJ/mol 209.8155 ± 0.0022 75-61-6*0 Dichlorodibromomethane CCl2Br2 (g) 19.6 3.9 ± 1.5 kJ/mol 242.7241 ± 0.0028 594-18-3*0 Bromodifluoromethane CHF2Br (g) -410.92 -424.12 ± 0.49 kJ/mol 130.9194 ± 0.0013 1511-62-2*0 1,2-Difluoroethane CH2FCH2F (g) -434.51 -447.94 ± 0.86 kJ/mol 66.0500 ± 0.0016 624-72-6*0 2-Hydrotrioxy anion [OO(H)O]- (g) 27.6 21.9 ± 1.2 kJ/mol 49.00669 ± 0.00090 *89965-38-8*0 1,2-Difluoroacetylene FCCF (g) 2.45 5.27 ± 0.65 kJ/mol 62.0182 ± 0.0016 689-99-6*0 Fluoro(fluorooxy)methylene FCOF (g, trans) -38.9 -40.4 ± 1.9 kJ/mol 66.00691 ± 0.00085 479587-30-9*1 Chloroformyl ClCO (g) -21.93 -20.54 ± 0.49 kJ/mol 63.4628 ± 0.0012 2602-42-8*0 Phenylium [C6H5]+ (g, triplet) 1251.6 1239.4 ± 3.3 kJ/mol 77.1034 ± 0.0048 17333-73-2*1 Chlorobenzene cation [C6H5Cl]+ (g) 942.47 928.55 ± 0.61 kJ/mol 112.5561 ± 0.0049 55450-32-3*0 Chlorobenzene C6H5Cl (cr,l) 11.22 ± 0.59 kJ/mol 112.5566 ± 0.0049 108-90-7*500 Bromobenzene cation [C6H5Br]+ (g) 994.7 973.3 ± 1.3 kJ/mol 157.0074 ± 0.0049 55450-33-4*0 Iodobenzene C6H5I (cr,l) 112.7 112.8 ± 1.1 kJ/mol 204.0084 ± 0.0048 591-50-4*500 2-Hydrotrioxy cation [OO(H)O]+ (g) 1297.8 1291.2 ± 1.3 kJ/mol 49.00559 ± 0.00090 *74241-49-9*0 Methyl nitrite CH3ONO (g, cis-trans equilib) -55.46 -66.13 ± 0.46 kJ/mol 61.0401 ± 0.0010 624-91-9*0 1,2-Dichloroethane (CClH2)2 (g) -118.24 -130.18 ± 0.59 kJ/mol 98.9586 ± 0.0024 107-06-2*0 Carbon atom anion C- (g) 589.624 594.771 ± 0.050 kJ/mol 12.01125 ± 0.00080 14337-00-9*0 Chloride Cl- (aq) -166.994 ± 0.023 kJ/mol 35.45325 ± 0.00090 16887-00-6*800 Dioxymethylidyne COO (g) 298.6 299.9 ± 1.5 kJ/mol 44.00950 ± 0.00100 791121-04-5*0 Oxadiazirine O(NN) (g) 352.1 350.3 ± 1.4 kJ/mol 44.01288 ± 0.00033 227934-45-4*0 2-Cyclopropyn-1-ylidene C(CC) (g, triplet) 899.2 906.1 ± 1.5 kJ/mol 36.0321 ± 0.0024 102508-15-6*1 Propynylidyne cation [C(CC)]+ (g) 1948.3 1956.2 ± 2.0 kJ/mol 36.0316 ± 0.0024 154702-35-9*0 Ethylene cation [C2H4]+ (g) 1075.28 1068.07 ± 0.13 kJ/mol 28.0526 ± 0.0016 34470-02-5*0 Bifluoride [FHF]- (g) -709.1 -713.0 ± 1.7 kJ/mol 39.005295 ± 0.000070 18130-74-0*0 NON NON (g) 544.7 541.5 ± 1.5 kJ/mol 44.01288 ± 0.00033 227934-46-5*0 Iminomethyl anion [HCNH]- (g, trans) 238.9 235.1 ± 1.9 kJ/mol 28.03387 ± 0.00082 90623-30-6*1 Isoformyl anion [COH]- (g, triplet) 267.4 268.1 ± 1.6 kJ/mol 29.01859 ± 0.00086 81747-63-9*2 2-Propynylium [CH2CCH]+ (g) 1193.47 1190.66 ± 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 Propynylidene HCCCH (g, cis singlet) 597.6 599.3 ± 1.2 kJ/mol 38.0480 ± 0.0024 67152-18-5*3 Propenediylidene CHCHC (g) 796.2 797.4 ± 1.3 kJ/mol 38.0480 ± 0.0024 60731-11-5*0 Dioxygen anion [O2]- (g) -43.38 -42.74 ± 0.17 kJ/mol 31.99935 ± 0.00060 11062-77-4*0 Trifluoromethide [CF3]- (g) -637.7 -639.6 ± 1.6 kJ/mol 69.00646 ± 0.00080 54128-17-5*0 Hydrogen fluoride HF (aq, 22 H2O) -321.07 ± 0.17 kJ/mol 20.006343 ± 0.000070 7664-39-3*902 Cyclopentene CH2(CH2CHCHCH2) (g) 58.12 33.85 ± 0.45 kJ/mol 68.1170 ± 0.0040 142-29-0*0 Ethyloxoniumyl [CH3CH2OH]+ (g) 784.1 766.9 ± 1.5 kJ/mol 46.0679 ± 0.0017 34480-55-2*0 1-Hydroxyethylium [CH3CHOH]+ (g) 609.14 594.72 ± 0.39 kJ/mol 45.0600 ± 0.0017 18682-96-7*0 Acetaldehyde cation [CH3CHO]+ (g) 832.02 822.04 ± 0.29 kJ/mol 44.0520 ± 0.0017 36505-03-0*0 Oxiranylium [CH2(CHO)]+ (g, triplet) 1233.7 1226.7 ± 1.8 kJ/mol 43.0441 ± 0.0016 57789-76-1*1 Oxiranyl anion [CH2(CHO)]- (g) 121.4 113.3 ± 1.6 kJ/mol 43.0452 ± 0.0016 72722-59-9*0 Dibromine monoxide BrOBr (g) 120.9 104.4 ± 1.4 kJ/mol 175.8074 ± 0.0020 21308-80-5*0 Fluorochlorate [ClF]- (g) -255.99 -255.39 ± 0.80 kJ/mol 54.45165 ± 0.00090 12272-56-9*0 Ethynol anion [HCCO]- (g) -48.62 -47.37 ± 0.87 kJ/mol 41.0293 ± 0.0016 64066-01-9*0 Dicarbon monoxide anion [CCO]- (g) 153.8 157.5 ± 1.2 kJ/mol 40.0213 ± 0.0016 87191-88-6*0 Dicarbon monoxide cation [CCO]+ (g) 1433.5 1438.6 ± 1.8 kJ/mol 40.0203 ± 0.0016 12287-08-0*0 Hydroxyimidogen NOH (g) 217.45 214.57 ± 0.87 kJ/mol 31.01408 ± 0.00032 35337-59-8*0 COC vdW (CO)(C) (g, singlet) 727.2 735.5 ± 1.7 kJ/mol 40.0208 ± 0.0016 *12071-24-8*2 C=O-C cation [COC]+ (g, doublet) 1576.2 1583.3 ± 2.3 kJ/mol 40.0203 ± 0.0016 83483-98-1*1 C=O=C anion [COC]- (g) 551.0 554.7 ± 2.1 kJ/mol 40.0213 ± 0.0016 *87191-88-6*0 Aminylium [NH2]+ (g) 1266.55 1264.47 ± 0.12 kJ/mol 16.02207 ± 0.00016 15194-15-7*0 Formic acid cation [HC(O)OH]+ (g, anti) 723.8 716.7 ± 1.1 kJ/mol 46.0248 ± 0.0010 50614-05-6*2 Formic acid anion [HC(O)OH]- (g, syn) -255.6 -261.8 ± 1.7 kJ/mol 46.0259 ± 0.0010 19066-82-1*1 Nitrous acid HONO (g, cis) -71.37 -77.72 ± 0.29 kJ/mol 47.01348 ± 0.00061 7782-77-6*2 Peroxyhypochlorous acid HOOCl (g) 3.86 -1.42 ± 0.99 kJ/mol 68.4594 ± 0.0011 67952-07-2*0 OH-CO vdW complex (OH)(CO) (g, vdW) -80.30 -77.41 ± 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 -178.4 ± 2.2 kJ/mol 45.0174 ± 0.0010 *2564-83-2*100 Azidonitrene NNNN (g, Cs) 692.0 687.4 ± 1.4 kJ/mol 56.02696 ± 0.00028 147363-92-6*2 Isocyanic acid cation [HNCO]+ (g) 1003.03 1000.37 ± 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) -484.91 ± 0.23 kJ/mol 60.0520 ± 0.0017 64-19-7*840 Acetyl chloride CH3C(O)Cl (l) -272.21 ± 0.33 kJ/mol 78.4973 ± 0.0019 75-36-5*500 Chlorosyl ion [ClO]+ (g) 1150.69 1150.53 ± 0.66 kJ/mol 51.45155 ± 0.00095 12301-79-0*0 (Formyloxy)methyl HC(O)OCH2 (g, syn) -148.7 -156.8 ± 1.5 kJ/mol 59.0440 ± 0.0017 3122-12-1*1 Glyoxal (CHO)2 (g, trans) -206.99 -212.63 ± 0.52 kJ/mol 58.0361 ± 0.0017 107-22-2*1 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 Diazomethyl HCNN (g) 472.8 470.2 ± 2.0 kJ/mol 41.03212 ± 0.00082 20813-32-5*0 Isocyanoamidogen HNNC (g) 492.7 490.7 ± 2.0 kJ/mol 41.03212 ± 0.00082 947408-73-3*0 Tetrachloromethane CCl4 (l) -109.53 -128.94 ± 0.65 kJ/mol 153.8215 ± 0.0037 56-23-5*500 Dioxygenyl ion monohydrate [(H2O)(O2)]+ (g) 828.6 821.5 ± 1.9 kJ/mol 50.01353 ± 0.00091 11083-61-7*0 Chloroform CCl3H (l) -133.87 ± 0.63 kJ/mol 119.3767 ± 0.0028 67-66-3*590 Chlorodibromomethane CHClBr2 (g) 18.1 -0.6 ± 3.4 kJ/mol 208.2793 ± 0.0023 124-48-1*0 Fluorotribromomethane CBr3F (g) -108.3 -132.3 ± 1.6 kJ/mol 270.7211 ± 0.0031 353-54-8*0 Chlorotribromomethane CBr3Cl (g) 76.0 53.1 ± 1.6 kJ/mol 287.1754 ± 0.0032 594-15-0*0 Hydrogen fluoride HF (aq, 35 H2O) -321.13 ± 0.17 kJ/mol 20.006343 ± 0.000070 7664-39-3*904 Hydroxydioxonitrate [HNO3]- (g) -191.2 -195.6 ± 2.9 kJ/mol 63.01343 ± 0.00091 58875-09-5*0 Chlorobromomethane CH2ClBr (g) -29.3 -43.3 ± 1.4 kJ/mol 129.3833 ± 0.0016 74-97-5*0 Nitryl ion [ONO]+ (g) 961.78 958.22 ± 0.20 kJ/mol 46.00499 ± 0.00060 14522-82-8*0 Ammonia NH3 (aq, undissoc) -80.886 ± 0.053 kJ/mol 17.03056 ± 0.00022 7664-41-7*1000 Fluoromethyliumylidene [CF]+ (g) 1122.61 1125.83 ± 0.48 kJ/mol 31.00855 ± 0.00080 33412-11-2*0 Fluoromethylene CHF (g) 148.26 148.54 ± 0.44 kJ/mol 32.01704 ± 0.00080 13453-52-6*0 Ethyl iodide CH3CH2I (g) 8.72 -7.16 ± 0.49 kJ/mol 155.9656 ± 0.0016 75-03-6*0 1,2-Dichloroacetylene ClCCCl (g) 230.9 234.2 ± 1.9 kJ/mol 94.9268 ± 0.0024 7572-29-4*0 1,2-Dibromoacetylene BrCCBr (g) 333.1 322.2 ± 3.6 kJ/mol 183.8294 ± 0.0026 624-61-3*0 Fluoro(fluorooxy)methylene FCOF (g, vdW triplet) -101.0 -99.2 ± 2.0 kJ/mol 66.00691 ± 0.00085 479587-30-9*101 Fluorooxomethylium [FCO]+ (g) 724.2 723.9 ± 1.4 kJ/mol 47.00795 ± 0.00085 38264-00-5*0 Fluoroisoformyl COF (g) -39.2 -33.8 ± 1.7 kJ/mol 47.00850 ± 0.00085 *1871-24-5*0 Formyl chloride HClCO (g) -179.61 -182.81 ± 0.93 kJ/mol 64.4707 ± 0.0012 2565-30-2*0 Ammonium nitrate (NH4)NO3 (cr,l) -350.28 -365.25 ± 0.19 kJ/mol 80.04344 ± 0.00095 6484-52-2*500 Chlorosyl chloride ClClO (g) 134.4 133.2 ± 1.4 kJ/mol 86.9048 ± 0.0018 86825-56-1*0 Dioxaziridinyl N(OO) (g) 355.0 352.5 ± 1.3 kJ/mol 46.00554 ± 0.00060 66252-29-7*0 Benzene cation [C6H6]+ (g) 992.51 976.04 ± 0.25 kJ/mol 78.1113 ± 0.0048 34504-50-2*0 Dibromide [Br2]- (g) -200.1 -214.2 ± 2.0 kJ/mol 159.8085 ± 0.0020 12595-70-9*0 o-Benzyne C6H4 (g) 469.7 460.8 ± 1.4 kJ/mol 76.0960 ± 0.0048 462-80-6*0 o-Benzyne anion [C6H4]- (g) 415.5 407.0 ± 1.4 kJ/mol 76.0965 ± 0.0048 100569-88-8*0 Hydrogen fluoride HF (aq, 50 H2O) -321.17 ± 0.17 kJ/mol 20.006343 ± 0.000070 7664-39-3*822 Trihydrogen dioxide anion [HOHOH]- (g) -487.26 -495.52 ± 0.96 kJ/mol 35.02317 ± 0.00064 12501-19-8*0 Peroxyimidogen NOO (g) 409.4 407.4 ± 1.6 kJ/mol 46.00554 ± 0.00060 *60488-31-5*0 1,2-Dibromoethane (CBrH2)2 (g) -10.9 -37.7 ± 1.3 kJ/mol 187.8612 ± 0.0026 106-93-4*0 1,1-Dichloroethane CHCl2CH3 (g) -114.8 -127.5 ± 1.1 kJ/mol 98.9586 ± 0.0024 75-34-3*0 Dioxygen difluoride cation [FOOF]+ (g, trans) 1291.4 1287.5 ± 4.6 kJ/mol 69.99506 ± 0.00060 *7783-44-0*1 Acetylene anion [HCCH]- (g, trans ?) 357.4 357.2 ± 1.8 kJ/mol 26.0378 ± 0.0016 50443-89-5*1 1-Hydrazinylium-1-yl [H2NN]+ (g) 1145.2 1138.2 ± 1.5 kJ/mol 30.02881 ± 0.00020 63986-30-1*0 Methylammonium [CH3NH3]+ (g) 628.8 609.7 ± 2.5 kJ/mol 32.06453 ± 0.00091 17000-00-9*0 Isodiazene anion [H2NN]- (g) 387.1 380.2 ± 1.8 kJ/mol 30.02991 ± 0.00020 *63986-30-1*0 Oxygen atom O (g, triplet) 246.844 249.229 ± 0.0021 kJ/mol 15.99940 ± 0.00030 17778-80-2*1 Iminomethyl anion [HCNH]- (g, cis) 254.2 250.4 ± 1.9 kJ/mol 28.03387 ± 0.00082 90623-30-6*2 Hydrogen cyanide cation [HCN]+ (g) 1442.53 1442.06 ± 0.20 kJ/mol 27.02483 ± 0.00081 12601-62-6*0 Hydrogen fluoride HF (aq, 60 H2O) -321.20 ± 0.17 kJ/mol 20.006343 ± 0.000070 7664-39-3*823 Hydrogen peroxide cation [H2O2]+ (g, cis) 930.91 924.05 ± 0.94 kJ/mol 34.01413 ± 0.00062 12325-10-9*2 Hydrogen bromide HBr (aq, 600 H2O) -120.32 ± 0.16 kJ/mol 80.9119 ± 0.0010 10035-10-6*834 Hydrogen fluoride HF (aq, 30 H2O) -321.11 ± 0.17 kJ/mol 20.006343 ± 0.000070 7664-39-3*820 Methyleneoxonium cation [CH2OH2]+ (g) 828.6 819.2 ± 1.6 kJ/mol 32.04131 ± 0.00090 *177788-17-9*0 Hydroxymethanide [CH2OH]- (g) 9.2 2.6 ± 1.5 kJ/mol 31.03447 ± 0.00088 55830-71-2*0 Formaldehyde cation [H2CO]+ (g) 944.89 941.27 ± 0.10 kJ/mol 30.02543 ± 0.00087 54288-05-0*0 Hydroxymethylene cation [HCOH]+ (g, cis) 986.5 982.9 ± 1.4 kJ/mol 30.02543 ± 0.00087 135395-06-1*2 Hydroxymethylene cation [HCOH]+ (g, gauche quartet) 1481.6 1478.9 ± 1.7 kJ/mol 30.02543 ± 0.00087 135395-06-1*3 Hydroxymethylene anion [HCOH]- (g, cis) 160.6 157.9 ± 1.5 kJ/mol 30.02653 ± 0.00087 207914-87-2*2 Hydroxymethylene anion [HCOH]- (g, gauche quartet) 333.6 334.4 ± 1.8 kJ/mol 30.02653 ± 0.00087 207914-87-2*3 Aquacarbon H2OC (g, triplet) 441.4 439.8 ± 2.1 kJ/mol 30.02598 ± 0.00087 81434-73-3*1 Aquacarbon H2OC (g, singlet vdW) 470.2 468.1 ± 2.4 kJ/mol 30.02598 ± 0.00087 81434-73-3*102 Hydroxylamine NH2OH (g, cis) -14.7 -25.2 ± 1.5 kJ/mol 33.02996 ± 0.00037 7803-49-8*2 Hydroxylamine cation [NH2OH]+ (g) 858.0 848.1 ± 1.8 kJ/mol 33.02941 ± 0.00037 62675-55-2*0 Peroxyformic acid HC(O)OOH (g, trans) -265.8 -273.8 ± 1.6 kJ/mol 62.0248 ± 0.0012 107-32-4*2 Peroxyformic acid HC(O)OOH (g, gauche) -265.7 -273.6 ± 1.6 kJ/mol 62.0248 ± 0.0012 107-32-4*3 Hydrogen fluoride HF (aq, 10 H2O) -320.89 ± 0.17 kJ/mol 20.006343 ± 0.000070 7664-39-3*815 Hydrogen bromide HBr (aq, 5000 H2O) -120.61 ± 0.16 kJ/mol 80.9119 ± 0.0010 10035-10-6*844 Dioxygenyl fluoride cation [FOO]+ (g) 1221.2 1218.8 ± 2.0 kJ/mol 50.99665 ± 0.00060 139584-95-5*0 Propynylidene cation [HCCCH]+ (g) 1410.8 1413.4 ± 1.3 kJ/mol 38.0474 ± 0.0024 75123-91-0*0 Chlorine chlorite ClOClO (g) 168.3 165.8 ± 1.4 kJ/mol 102.9042 ± 0.0019 105206-44-8*0 Propynylidene HCCCH (g, trans singlet) 597.3 599.2 ± 1.1 kJ/mol 38.0480 ± 0.0024 67152-18-5*4 Propadienylidenide [CH2CC]- (g) 381.18 382.08 ± 0.43 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 Nitroxyl cation [H2NO]+ (g) 946.32 939.19 ± 0.84 kJ/mol 32.02147 ± 0.00034 *51375-41-8*0 Hydrogen fluoride HF (aq, 18 H2O) -321.04 ± 0.17 kJ/mol 20.006343 ± 0.000070 7664-39-3*901 Hydrogen chloride HCl (aq, 75 H2O) -165.559 ± 0.026 kJ/mol 36.46064 ± 0.00090 7647-01-0*825 Hydrogen chloride HCl (aq, 100 H2O) -165.760 ± 0.025 kJ/mol 36.46064 ± 0.00090 7647-01-0*828 Nitrosyl nitrate ON(O2)NO (g, perp) 70.6 62.3 ± 1.7 kJ/mol 92.0111 ± 0.0012 *15969-55-8*0 n-Pentane CH3CH2CH2CH2CH3 (l) -173.08 ± 0.32 kJ/mol 72.1488 ± 0.0041 109-66-0*500 Dioxygenyl fluoride anion [FOO]- (g) -256.8 -256.0 ± 1.9 kJ/mol 50.99775 ± 0.00060 23553-17-5*0 iso-Pentane CH3CH2CH(CH3)2 (l) -178.49 ± 0.44 kJ/mol 72.1488 ± 0.0041 78-78-4*500 Dioxofluorine OFO (g) 524.0 523.2 ± 1.0 kJ/mol 50.99720 ± 0.00060 175861-93-5*0 neo-Pentane C(CH3)4 (l) -189.91 ± 0.41 kJ/mol 72.1488 ± 0.0041 463-82-1*500 Cyclopentane CH2(CH2CH2CH2CH2) (l) -106.26 ± 0.44 kJ/mol 70.1329 ± 0.0041 287-92-3*590 Xenon cation Xe+ (g) 1170.354 1170.354 ± 0.0062 kJ/mol 131.2895 ± 0.0200 24203-25-6*0 Peroxyimidogen cation [NOO]+ (g) 1409.6 1406.8 ± 1.8 kJ/mol 46.00499 ± 0.00060 *60488-32-6*0 1,5-Hexadiene CH2CHCH2CH2CHCH2 (g) 108.39 83.80 ± 0.40 kJ/mol 82.1436 ± 0.0049 592-42-7*0 2-Hydroxyethylium [CH2CH2OH]+ (g, gauche) 1024.7 1012.2 ± 2.3 kJ/mol 45.0600 ± 0.0017 38607-31-7*1 Ethoxy CH3CH2O (g) 1.13 -12.29 ± 0.51 kJ/mol 45.0605 ± 0.0017 2154-50-9*0 Ethyloxoniumylidene [CH3CH2O]+ (g) 988.5 974.8 ± 1.8 kJ/mol 45.0600 ± 0.0017 54387-07-4*0 Hydroxyaminylium [HNOH]+ (g, cis) 1049.2 1042.1 ± 2.0 kJ/mol 32.02147 ± 0.00034 66097-71-0*2 Hydroxyamidogen anion [HNOH]- (g) 91.2 85.4 ± 2.1 kJ/mol 32.02257 ± 0.00034 *66097-71-0*0 Formylmethyl anion [CH2CHO]- (g, perp triplet) 140.5 134.2 ± 1.9 kJ/mol 43.0452 ± 0.0016 64723-93-9*0 Aminium [NH3]+ (g) 944.275 937.320 ± 0.030 kJ/mol 17.03001 ± 0.00022 19496-55-0*0 C=O-C cation [COC]+ (g, quartet) 1812.6 1816.6 ± 2.3 kJ/mol 40.0203 ± 0.0016 83483-98-1*2 Dihydrooxooxygen cation [(H2O)O]+ (g) 994.7 988.0 ± 1.4 kJ/mol 34.01413 ± 0.00062 177329-59-8*0 Oxirene cation [O(CHCH)]+ (g) 1109.0 1105.4 ± 5.2 kJ/mol 42.0361 ± 0.0016 94664-69-4*0 Formic acid anion [HC(O)OH]- (g, anti) -240.6 -246.3 ± 1.7 kJ/mol 46.0259 ± 0.0010 19066-82-1*2 Dioxirane cation [CH2(OO)]+ (g) 1050.7 1043.0 ± 1.9 kJ/mol 46.0248 ± 0.0010 232262-10-1*0 Dioxymethyl cation [CH2OO]+ (g) 1075.1 1068.7 ± 1.6 kJ/mol 46.0248 ± 0.0010 232262-11-2*0 Peroxyimidogen anion [NOO]- (g) 164.2 161.8 ± 1.5 kJ/mol 46.00609 ± 0.00060 60488-31-5*0 Dioxymethylene HCOO (g, cis) 339.6 337.4 ± 3.1 kJ/mol 45.0174 ± 0.0010 438586-67-5*2 Azidonitrene NNNN (g, C2h) 660.7 657.6 ± 1.6 kJ/mol 56.02696 ± 0.00028 147363-92-6*1 Aminyliumyl [NH]+ (g) 1658.96 1659.89 ± 0.25 kJ/mol 15.014131 ± 0.000099 19067-62-0*0 Cyanato cation [NCO]+ (g) 1261.56 1262.06 ± 0.59 kJ/mol 42.01629 ± 0.00086 17247-99-3*0 Nitrous acid HONO (g) -73.018 -78.675 ± 0.079 kJ/mol 47.01348 ± 0.00061 7782-77-6*0 Nitrosomethyliumylidene [CNO]+ (g) 1509.7 1510.7 ± 1.8 kJ/mol 42.01629 ± 0.00086 67197-19-7*0 Fulminate [CNO]- (g) 59.3 59.6 ± 1.8 kJ/mol 42.01739 ± 0.00086 28269-67-2*0 Acetic acid CH3C(O)OH (l) -484.09 -483.66 ± 0.18 kJ/mol 60.0520 ± 0.0017 64-19-7*500 Acetic acid CH3C(O)OH (aq, 75 H2O) -484.71 ± 0.23 kJ/mol 60.0520 ± 0.0017 64-19-7*825 Acetic acid CH3C(O)OH (aq, 700 H2O) -484.90 ± 0.23 kJ/mol 60.0520 ± 0.0017 64-19-7*835 Trioxidanylium [HOOO]+ (g, cis) 1084.9 1078.7 ± 1.4 kJ/mol 49.00559 ± 0.00090 74241-49-9*2 1,3-Butadiyne-1,4-diyl CCCC (g) 1052.35 1062.32 ± 0.67 kJ/mol 48.0428 ± 0.0032 78015-07-3*0 (Formyloxy)methyl HC(O)OCH2 (g, anti) -133.5 -141.7 ± 1.9 kJ/mol 59.0440 ± 0.0017 3122-12-1*2 Glyoxal (CHO)2 (g, cis) -188.56 -194.00 ± 0.68 kJ/mol 58.0361 ± 0.0017 107-22-2*2 Glyoxal (CHO)2 (g) -206.99 -212.55 ± 0.52 kJ/mol 58.0361 ± 0.0017 107-22-2*0 Isocyanogen anion [CNCN]- (g, trans) 383.9 387.6 ± 2.5 kJ/mol 52.0354 ± 0.0016 *83951-85-3*1 Diisocyanogen cation [CNNC]+ (g, trans) 1823.0 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 Trioxidaniumyl [HOOOH]+ (g, c, t) 937.0 928.0 ± 1.4 kJ/mol 50.01353 ± 0.00091 161321-37-5*3 Dihydrogen cation [H2]+ (g) 1488.364 1488.480 ± 0.000 kJ/mol 2.01533 ± 0.00014 12184-90-6*0 (Z)-Diazene cation [HNNH]+ (g, cis) 1157.2 1150.5 ± 1.3 kJ/mol 30.02881 ± 0.00020 86631-37-0*0 Hydrogen difluoride FHF (g) -200.7 -200.8 ± 1.8 kJ/mol 39.004746 ± 0.000070 12528-21-1*0 Fluorochlorobromomethane CHFClBr (g) -219.3 -231.7 ± 5.5 kJ/mol 147.3737 ± 0.0016 593-98-6*0 Hydrogen fluoride HF (l) -302.42 ± 0.17 kJ/mol 20.006343 ± 0.000070 7664-39-3*590 (Z)-Diazene anion [HNNH]- (g, cis) 284.0 277.5 ± 1.7 kJ/mol 30.02991 ± 0.00020 *86631-37-0*0 Fluoromethyliumyl [CHF]+ (g) 1116.9 1117.2 ± 2.1 kJ/mol 32.01649 ± 0.00080 89877-52-1*0 Fluoromethylene anion [CHF]- (g) 95.87 96.40 ± 0.62 kJ/mol 32.01759 ± 0.00080 71267-42-0*0 Ethane cation [C2H6]+ (g) 1043.26 1029.25 ± 0.59 kJ/mol 30.0685 ± 0.0017 34488-65-8*0 Diiodide [I2]- (g) -178.13 -180.72 ± 0.48 kJ/mol 253.809489 ± 0.000060 12190-71-5*0 Polytetrafluoroethylene C2F4 (s) -829.49 ± 0.58 kJ/mol 100.0150 ± 0.0016 9002-84-0*591 Trifluoride ion [F3]- (g) -364.3 -365.3 ± 2.5 kJ/mol 56.9957582 ± 0.0000015 25730-99-8*0 Nitric acid HNO3 (aq, 1000 H2O) -206.31 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*839 Iodine atom cation I+ (g) 1115.549 1115.149 ± 0.0062 kJ/mol 126.903921 ± 0.000030 22541-93-1*0 cis-1,2-Difluoroethene CHFCHF (g, cis) -303.0 -309.8 ± 1.1 kJ/mol 64.0341 ± 0.0016 1630-77-9*0 trans-1,2-Difluoroethene CHFCHF (g, trans) -299.8 -306.2 ± 1.1 kJ/mol 64.0341 ± 0.0016 1630-78-0*0 Bromoacetylene HCCBr (g) 282.3 275.8 ± 2.2 kJ/mol 104.9333 ± 0.0019 593-61-3*0 Nitric acid HNO3 (cr,l) -179.01 -173.28 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*500 Formyl fluoride cation [HFCO]+ (g) 816.4 813.1 ± 1.2 kJ/mol 48.01589 ± 0.00086 99766-68-4*0 Oxadiazirine anion [O(NN)]- (g) 99.6 100.0 ± 2.6 kJ/mol 44.01343 ± 0.00033 350586-31-1*0 Formyl fluoride [FCO]- (g) -405.3 -403.8 ± 1.7 kJ/mol 47.00905 ± 0.00085 62227-71-8*0 Fluoroisoformyl cation [COF]+ (g) 1347.4 1348.9 ± 2.1 kJ/mol 47.00795 ± 0.00085 *1871-25-6*0 Ethanide [CH3CH2]- (g) 152.1 141.0 ± 1.5 kJ/mol 29.0616 ± 0.0016 25013-41-6*0 Ethylene anion [C2H4]- (g, anti ?) 232.1 224.5 ± 2.0 kJ/mol 28.0537 ± 0.0016 34527-91-8*1 Hydrogen chloride HCl (aq, 2000 H2O) -166.685 ± 0.024 kJ/mol 36.46064 ± 0.00090 7647-01-0*841 Dioxaziridinyl cation [N(OO)]+ (g) 1365.9 1363.3 ± 1.5 kJ/mol 46.00499 ± 0.00060 *66252-29-7*0 Dioxaziridinyl anion [N(OO)]- (g) 295.7 293.3 ± 1.4 kJ/mol 46.00609 ± 0.00060 66252-31-1*0 Nirous oxide cation [NNO]+ (g) 1329.67 1326.78 ± 0.12 kJ/mol 44.01233 ± 0.00033 12269-46-4*0 Nitrosyl fluoride FNO (g) -85.81 -88.18 ± 0.93 kJ/mol 49.00454 ± 0.00031 7789-25-5*0 Ozone cation [OOO]+ (g) 1352.870 1350.530 ± 0.041 kJ/mol 47.99765 ± 0.00090 12596-82-6*0 Hydrogen fluoride HF (aq, 55 H2O) -321.19 ± 0.17 kJ/mol 20.006343 ± 0.000070 7664-39-3*905 Hydrogen chloride HCl (aq, 150 H2O) -165.981 ± 0.025 kJ/mol 36.46064 ± 0.00090 7647-01-0*829 Aminomethyl anion [CH2NH2]- (g) 212.0 201.0 ± 2.7 kJ/mol 30.04975 ± 0.00085 74215-21-7*0 Hydrogen fluoride HF (aq, 37 H2O) -321.14 ± 0.17 kJ/mol 20.006343 ± 0.000070 7664-39-3*890 Allylium [CH2CHCH2]+ (g) 964.11 952.56 ± 0.54 kJ/mol 41.0713 ± 0.0024 1724-44-3*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) 1234.2 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 Peroxyhypochlorite [ClOO]- (g) -249.32 -249.88 ± 0.37 kJ/mol 67.4520 ± 0.0011 224299-14-3*0 Methylaminilium [CH3NH]+ (g) 1135.2 1125.3 ± 2.5 kJ/mol 30.04865 ± 0.00085 49784-84-1*0 Hydrogen fluoride HF (aq, 55.51 H2O) -321.19 ± 0.17 kJ/mol 20.006343 ± 0.000070 7664-39-3*891 Cycloprop-2-enylium [CH(CHCH)]+ (g) 1080.9 1075.8 ± 1.4 kJ/mol 39.0554 ± 0.0024 26810-74-2*0 Nitrogen hydride oxide H3NO (g) 72.3 61.1 ± 1.7 kJ/mol 33.02996 ± 0.00037 38544-48-8*0 Methanimine cation [H2CNH]+ (g) 1055.8 1048.8 ± 2.1 kJ/mol 29.04071 ± 0.00083 65130-65-6*0 Methanimine anion [H2CNH]- (g) 228.7 221.4 ± 2.5 kJ/mol 29.04181 ± 0.00083 127593-73-1*0 Propynylidene HCCCH (g) 543.38 546.37 ± 0.63 kJ/mol 38.0480 ± 0.0024 67152-18-5*0 Bifluoride [FFH]- (g) -475.9 -476.3 ± 3.1 kJ/mol 39.005295 ± 0.000070 *18130-74-0*0 Aminomethyliumyl [HCNH2]+ (g) 1040.8 1033.1 ± 2.6 kJ/mol 29.04071 ± 0.00083 89302-94-3*0 Cyclopropyne CH2(CC) (g) 791.3 790.8 ± 1.4 kJ/mol 38.0480 ± 0.0024 60701-63-5*0 Carbon atom C (g, singlet) 833.332 838.478 ± 0.050 kJ/mol 12.01070 ± 0.00080 7440-44-0*2 Aminomethylene anion [HCNH2]- (g) 357.1 350.2 ± 2.5 kJ/mol 29.04181 ± 0.00083 207914-86-1*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 Nitroxyl anion [H2NO]- (g) 49.3 42.3 ± 1.8 kJ/mol 32.02257 ± 0.00034 51375-41-8*0 Methylaminyliumyl [H3CN]+ (g, quartet) 1478.4 1471.3 ± 2.6 kJ/mol 29.04071 ± 0.00083 56924-51-7*2 Hydrogen chloride HCl (aq, 140 H2O) -165.948 ± 0.026 kJ/mol 36.46064 ± 0.00090 7647-01-0*907 Methylimidogen anion [H3CN]- (g) 322.2 314.6 ± 1.7 kJ/mol 29.04181 ± 0.00083 82539-34-2*0 Methyleneaminylium [H2CN]+ (g, triplet) 1457.2 1453.6 ± 2.5 kJ/mol 28.03277 ± 0.00082 53518-13-1*1 Dibromine Br2 (aq) -2.16 ± 0.20 kJ/mol 159.8080 ± 0.0020 7726-95-6*800 Nitrosyl nitrite ONONO (g, t, c) 109.6 105.5 ± 1.5 kJ/mol 76.01168 ± 0.00091 122413-35-8*2 Hydrogen bromide HBr (aq, 2570 H2O) -120.54 ± 0.16 kJ/mol 80.9119 ± 0.0010 10035-10-6*952 Hydrogen chloride HCl (aq, 1500 H2O) -166.639 ± 0.025 kJ/mol 36.46064 ± 0.00090 7647-01-0*840 Cyclopentene CH2(CH2CHCHCH2) (l) 5.01 ± 0.42 kJ/mol 68.1170 ± 0.0040 142-29-0*590 Hydrogen chloride HCl (aq, 74 H2O) -165.548 ± 0.027 kJ/mol 36.46064 ± 0.00090 7647-01-0*953 Ethanol CH3CH2OH (l) -269.31 -277.07 ± 0.21 kJ/mol 46.0684 ± 0.0017 64-17-5*500 Chlorosyl chloride cation [ClClO]+ (g) 1132.6 1130.8 ± 2.0 kJ/mol 86.9043 ± 0.0018 *86825-56-1*0 Bromosyl ion [BrO]+ (g) 1139.5 1131.7 ± 1.6 kJ/mol 95.9029 ± 0.0010 142315-39-7*0 1-Hydroxyethyl anion [CH3CHOH]- (g) -19.8 -33.2 ± 2.5 kJ/mol 45.0610 ± 0.0017 88032-18-2*0 Hydrazinylium [N2H3]+ (g) 968.91 957.66 ± 0.83 kJ/mol 31.03675 ± 0.00025 37369-93-0*0 Hypochlorous acid cation [HOCl]+ (g) 998.75 995.71 ± 0.88 kJ/mol 52.45949 ± 0.00095 71606-47-8*0 Dinitrogen pentoxide O2NONO2 (cr,l) -41.06 ± 0.43 kJ/mol 108.0105 ± 0.0015 10102-03-1*500 Chlorine fluoride cation [ClF]+ (g) 1165.59 1165.77 ± 0.50 kJ/mol 54.45055 ± 0.00090 12432-44-9*0 Aminomethyliumylidene [CNH2]+ (g) 1168.9 1165.6 ± 2.5 kJ/mol 28.03277 ± 0.00082 86784-42-1*0 Trioxidanylium [HOOO]+ (g) 1070.2 1063.9 ± 1.3 kJ/mol 49.00559 ± 0.00090 74241-49-9*0 Acetaldehyde anion [CH3CHO]- (g) -59.3 -69.8 ± 2.4 kJ/mol 44.0531 ± 0.0017 60427-04-5*0 Triazirinylium ion [N(NN)]+ (g) 1608.8 1605.9 ± 1.6 kJ/mol 42.01967 ± 0.00021 92220-05-8*0 Bromine dioxide OBrO (g) 167.8 158.2 ± 2.8 kJ/mol 111.9028 ± 0.0012 21255-83-4*0 Ketene cation [CH2CO]+ (g) 882.12 879.10 ± 0.13 kJ/mol 42.0361 ± 0.0016 64999-16-2*0 Ketene anion [CH2CO]- (g) -15.4 -18.5 ± 1.9 kJ/mol 42.0372 ± 0.0016 56391-79-8*0 Hydrooxonitrate [HNO]- (g) 79.7 76.8 ± 1.1 kJ/mol 31.01463 ± 0.00032 66057-02-1*0 Oxoethenylium [HCCO]+ (g) 1139.0 1141.7 ± 2.5 kJ/mol 41.0282 ± 0.0016 92056-63-8*0 Hypofluorous acid cation [HOF]+ (g) 1142.01 1139.08 ± 0.89 kJ/mol 36.00519 ± 0.00031 90243-22-4*0 Ethynylene cation [C2]+ (g) 1967.4 1974.0 ± 1.7 kJ/mol 24.0209 ± 0.0016 12595-79-8*0 Hydrogen bromide HBr (aq, 3000 H2O) -120.56 ± 0.16 kJ/mol 80.9119 ± 0.0010 10035-10-6*842 Hypochlorous acid anion [HOCl]- (g) 196.7 196.4 ± 2.2 kJ/mol 52.46059 ± 0.00095 34524-94-2*0 Hydroxyimidogen anion [NOH]- (g) 230.8 228.3 ± 1.9 kJ/mol 31.01463 ± 0.00032 *35337-59-8*0 Triazirine HN(NN) (g) 464.1 457.7 ± 2.6 kJ/mol 43.02816 ± 0.00022 157-29-9*0 Ethynol cation [HCCOH]+ (g) 1063.0 1060.8 ± 2.5 kJ/mol 42.0361 ± 0.0016 84005-02-7*0 Methyl hydroperoxide cation [CH3OOH]+ (g) 832.3 819.6 ± 2.5 kJ/mol 48.0407 ± 0.0010 112465-88-0*0 Chlorosyl Hydride HClO (g) 141.9 139.1 ± 2.3 kJ/mol 52.46004 ± 0.00095 71572-35-5*0 Trifluorine cation [F3]+ (g) 1533.0 1531.0 ± 2.2 kJ/mol 56.9946610 ± 0.0000015 64710-22-1*0 Methoxyoxoniumylidene [CH3OO]+ (g) 1012.2 1003.8 ± 2.0 kJ/mol 47.0328 ± 0.0010 86475-50-5*0 Hypofluorous acid anion [HOF]- (g) 152.7 152.0 ± 3.8 kJ/mol 36.00629 ± 0.00031 36505-07-4*0 1,2-Propadien-1-yl-3-ylidene anion [CCC]- (g) 621.5 628.9 ± 1.2 kJ/mol 36.0326 ± 0.0024 109292-47-9*0 Chloroniumyl ion [HCl]+ (g) 1137.797 1137.731 ± 0.0051 kJ/mol 36.46009 ± 0.00090 12258-94-5*0 Dioxirane anion [CH2(OO)]- (g) -170.4 -177.3 ± 3.9 kJ/mol 46.0259 ± 0.0010 *157-26-6*0 Diazene ion [N2H]- (g) 176.5 175.0 ± 2.2 kJ/mol 29.02197 ± 0.00016 71004-29-0*0 Dioxymethyl anion [CH2OO]- (g) 55.4 50.3 ± 1.4 kJ/mol 46.0259 ± 0.0010 93207-29-5*0 Hypobromous acid cation [HOBr]+ (g) 975.16 964.58 ± 0.62 kJ/mol 96.9108 ± 0.0010 154804-02-1*0 Formyloxidanyl HC(O)O (g) -124.76 -126.12 ± 0.55 kJ/mol 45.0174 ± 0.0010 16499-21-1*0 Dioxiranyl HC(OO) (g) 216.5 213.0 ± 2.0 kJ/mol 45.0174 ± 0.0010 120595-16-6*0 2-Cyclopropyn-1-ylidene C(CC) (g, singlet) 994.2 1001.0 ± 2.2 kJ/mol 36.0321 ± 0.0024 102508-15-6*2 Propynylidyne anion [C(CC)]- (g) 664.7 672.0 ± 1.6 kJ/mol 36.0326 ± 0.0024 500574-36-7*0 2-Propanol CH3CH(OH)CH3 (cr,l) -305.49 -318.30 ± 0.35 kJ/mol 60.0950 ± 0.0025 67-63-0*500 Imidogen anion [NH]- (g) 322.61 322.66 ± 0.17 kJ/mol 15.015229 ± 0.000099 23841-33-0*0 Hydrogen bromide HBr (aq, 2000 H2O) -120.51 ± 0.16 kJ/mol 80.9119 ± 0.0010 10035-10-6*841 Hydroxyoxoammoniumyl [HONO]+ (g) 984.1 977.7 ± 1.6 kJ/mol 47.01293 ± 0.00061 80371-48-8*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) -418.38 -432.50 ± 0.54 kJ/mol 60.0520 ± 0.0017 64-19-7*0 Bicyclo[1.1.0]buta-1,3-diene-2,4-diyl C(CC)C (g) 1047.41 1055.01 ± 0.71 kJ/mol 48.0428 ± 0.0032 12184-80-4*0 Methoxycarbonyl C(O)OCH3 (g, anti-staggered) -149.8 -157.7 ± 1.9 kJ/mol 59.0440 ± 0.0017 16481-04-2*1 Hydrogen fluoride HF (aq, 22.2 H2O) -321.07 ± 0.17 kJ/mol 20.006343 ± 0.000070 7664-39-3*888 Fluorosyl fluoride FFO (g) 189.2 189.5 ± 4.8 kJ/mol 53.99621 ± 0.00030 86825-57-2*0 Oxalic acid (COOH)2 (g) -710.8 -721.4 ± 2.1 kJ/mol 90.0349 ± 0.0020 144-62-7*0 Methanol anion [CH3OH]- (g) 53.8 43.1 ± 2.6 kJ/mol 32.04241 ± 0.00090 68474-04-4*0 Isocyanogen anion [CNCN]- (g, cis) 386.7 389.6 ± 2.9 kJ/mol 52.0354 ± 0.0016 *83951-85-3*2 Hydroperoxyimidogen HOON (g, trans) 103.3 99.8 ± 2.4 kJ/mol 47.01348 ± 0.00061 877456-58-1*1 Diisocyanogen cation [CNNC]+ (g, cis) 1835.1 1837.8 ± 3.5 kJ/mol 52.0343 ± 0.0016 *78800-21-2*2 Cyanoamidogen anion [HNCN]- (g) 71.7 68.7 ± 1.7 kJ/mol 41.03267 ± 0.00082 67131-47-9*0 Cyanamide H2NCN (g) 140.9 134.7 ± 1.5 kJ/mol 42.04006 ± 0.00082 420-04-2*0 Diazomethylene CNN (g) 578.8 579.4 ± 4.0 kJ/mol 40.02418 ± 0.00081 2468-81-7*0 Hydrogen chloride HCl (aq, 2439 H2O) -166.714 ± 0.024 kJ/mol 36.46064 ± 0.00090 7647-01-0*951 Water H2O (l, eq.press.) -285.830 ± 0.027 kJ/mol 18.01528 ± 0.00033 7732-18-5*589 Nitric acid cation [HNO3]+ (g) 1029.29 1020.23 ± 0.69 kJ/mol 63.01233 ± 0.00091 272109-63-4*0 Tetranitrogen cation [N4]+ (g) 1392.8 1392.5 ± 1.5 kJ/mol 56.02641 ± 0.00028 12185-04-5*0 Fluorobromomethane CH2FBr (g) -198.0 -212.4 ± 5.5 kJ/mol 112.9290 ± 0.0013 373-52-4*0 Fluorine atom cation F+ (g) 1758.311 1760.610 ± 0.048 kJ/mol 18.99785462 ± 0.00000050 14701-13-4*0 Nirous oxide anion [NNO]- (g) 99.3 96.7 ± 1.8 kJ/mol 44.01343 ± 0.00033 12274-12-3*0 Fluorodibromomethane CHFBr2 (g) -160.0 -179.5 ± 5.5 kJ/mol 191.8250 ± 0.0022 1868-53-7*0 Acetylene anion [HCCH]- (g, cis ?) 380.5 380.7 ± 1.8 kJ/mol 26.0378 ± 0.0016 50443-89-5*2 Difluorochlorobromomethane CF2ClBr (g) -431.4 -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 Difluoromethyliumyl [CF2]+ (g) 908.37 908.80 ± 0.89 kJ/mol 50.00696 ± 0.00080 54250-40-7*0 Formaldehyde anion [H2CO]- (g) -25.9 -27.5 ± 1.8 kJ/mol 30.02653 ± 0.00087 27837-46-3*0 Dioxygen difluoride cation [FOOF]+ (g, cis) 1294.2 1290.2 ± 4.6 kJ/mol 69.99506 ± 0.00060 *7783-44-0*2 Fluoroniumyl ion [HF]+ (g) 1275.567 1275.799 ± 0.050 kJ/mol 20.005795 ± 0.000070 12381-92-9*0 Ammonium chloride (NH4)Cl (cr) -311.724 -314.886 ± 0.063 kJ/mol 53.49120 ± 0.00095 12125-02-9*510 Chlorosyl chloride anion [ClClO]- (g) -185.4 -184.8 ± 2.3 kJ/mol 86.9053 ± 0.0018 *86825-55-0*0 Ethonium [C2H7]+ (g, classical Cs I) 889.8 871.4 ± 1.6 kJ/mol 31.0764 ± 0.0017 24669-33-8*2 Difluorophosgene cation [COF2]+ (g) 653.31 650.68 ± 0.56 kJ/mol 66.00636 ± 0.00085 73256-56-1*0 Difluorophosgene anion [COF2]- (g) -603.5 -605.4 ± 2.9 kJ/mol 66.00745 ± 0.00085 474815-26-4*0 Ammonium bromide (NH4)Br (cr) -253.56 -270.14 ± 0.17 kJ/mol 97.9425 ± 0.0010 12124-97-9*510 Trioxodinitrate anion [ONNO2]- (g, non-vdW) -87.8 -94.9 ± 1.8 kJ/mol 76.01223 ± 0.00091 194856-62-7*1 Ethonium [C2H7]+ (g, classical Cs II) 896.2 878.4 ± 1.6 kJ/mol 31.0764 ± 0.0017 24669-33-8*3 Dibromophosgene COBr2 (l) -144.28 ± 0.96 kJ/mol 187.8181 ± 0.0022 593-95-3*590 Hydrogen fluoride HF (aq, 23 H2O) -321.08 ± 0.17 kJ/mol 20.006343 ± 0.000070 7664-39-3*903 2-Chloroethanol ClCH2CH2OH (l) -315.08 ± 0.54 kJ/mol 80.5132 ± 0.0019 107-07-3*590 2-Bromoethanol BrCH2CH2OH (l) -274.85 ± 0.47 kJ/mol 124.9645 ± 0.0019 540-51-2*590 Ethylene anion [C2H4]- (g, syn ?) 231.6 225.5 ± 2.0 kJ/mol 28.0537 ± 0.0016 34527-91-8*2 Phenylium [C6H5]+ (g, singlet) 1148.47 1136.57 ± 0.89 kJ/mol 77.1034 ± 0.0048 17333-73-2*2 Methylammoniumyl [CH3NH2]+ (g) 866.9 853.1 ± 2.4 kJ/mol 31.05659 ± 0.00088 34516-31-9*0 Methylamine anion [CH3NH2]- (g) 69.1 54.8 ± 4.0 kJ/mol 31.05769 ± 0.00088 81096-79-9*0 Nitrate [NO3]- (aq) -206.63 ± 0.18 kJ/mol 62.00549 ± 0.00090 14797-55-8*800 Chloryl chloride ClCl(O)O (g) 126.0 122.0 ± 1.7 kJ/mol 102.9042 ± 0.0019 117489-73-3*0 Fluorobenzene C6H5F (cr,l) -152.01 -149.59 ± 0.83 kJ/mol 96.1023 ± 0.0048 462-06-6*500 1-Ethylium-1-yl [CH3CH]+ (g) 1182.9 1175.5 ± 3.0 kJ/mol 28.0526 ± 0.0016 85944-79-2*0 Bromobenzene C6H5Br (cr,l) 59.8 ± 1.3 kJ/mol 157.0079 ± 0.0049 108-86-1*500 Acetone CH3C(O)CH3 (cr,l) -244.40 -247.52 ± 0.36 kJ/mol 58.0791 ± 0.0025 67-64-1*500 Ethylidene anion [CH3CH]- (g) 326.7 319.4 ± 1.6 kJ/mol 28.0537 ± 0.0016 35829-99-3*0 Monoammonium succinate (CH2COOH)2(NH3) (cr) -1067.97 ± 0.72 kJ/mol 135.1186 ± 0.0035 38457-08-8*510 Diammonium succinate (CH2COOH)2(NH3)2 (cr) -1182.51 ± 0.48 kJ/mol 152.1492 ± 0.0035 2226-88-2*510 1,2-Dichloroethane (CClH2)2 (cr,l) -165.33 ± 0.59 kJ/mol 98.9586 ± 0.0024 107-06-2*500 1,1-Dichloroethane CHCl2CH3 (cr,l) -158.2 ± 1.1 kJ/mol 98.9586 ± 0.0024 75-34-3*500 Dioxymethylidyne cation [(C)(OO)]+ (g, vdW quartet) 1386.6 1390.1 ± 2.9 kJ/mol 44.00895 ± 0.00100 *791121-04-5*101 Iodine monochloride ICl (cr) -36.511 -35.537 ± 0.063 kJ/mol 162.35717 ± 0.00090 7790-99-0*510 NON anion [NON]- (g) 495.9 493.3 ± 2.2 kJ/mol 44.01343 ± 0.00033 *227934-47-6*0 Dinitrogen dioxide ONNO (g, cis) 172.89 171.12 ± 0.14 kJ/mol 60.01228 ± 0.00062 16824-89-8*2 Nitrogen sesquioxide cation [ONNO2]+ (g, vdW) 1027.7 1023.8 ± 3.4 kJ/mol 76.01113 ± 0.00091 *10544-73-7*0 Dihydrogen H2 (g, ortho) 1.417 0.019 ± 0.000 kJ/mol 2.01588 ± 0.00014 1333-74-0*1 Carbon dioxide cation [CO2]+ (g, quartet) 1333.5 1334.0 ± 2.1 kJ/mol 44.00895 ± 0.00100 12181-61-2*1 Trifluorine F3 (g) 84.1 84.8 ± 2.4 kJ/mol 56.9952096 ± 0.0000015 73455-86-4*0 Carbon monoxide anion [CO]- (g) 34.3 38.0 ± 2.2 kJ/mol 28.01065 ± 0.00085 12539-63-8*0 Cycloprop-1-enylium [CH2(CHC)]+ (g) 1502.6 1498.4 ± 2.2 kJ/mol 39.0554 ± 0.0024 117067-78-4*0 Cycloprop-1-enyl anion [CH2(CHC)]- (g) 373.8 369.3 ± 2.2 kJ/mol 39.0565 ± 0.0024 80251-77-0*0 Hydroxylamine NH2OH (aq, undissoc) -97.1 ± 2.2 kJ/mol 33.02996 ± 0.00037 7803-49-8*1000 Hydraziniumyl [H2NNH2]+ (g) 887.5 873.7 ± 1.8 kJ/mol 32.04469 ± 0.00031 20771-51-1*0 Cycloprop-2-enyl anion [CH(CHCH)]- (g) 515.2 512.2 ± 2.2 kJ/mol 39.0565 ± 0.0024 20829-57-6*0 Carbide [C2]- (g) 504.83 511.41 ± 0.52 kJ/mol 24.0219 ± 0.0016 12595-78-7*0 Hydrogen fluoride HF (aq, 18.5 H2O) -321.05 ± 0.17 kJ/mol 20.006343 ± 0.000070 7664-39-3*887 Ammonia anion [NH3]- (g) 94.3 87.4 ± 2.4 kJ/mol 17.03111 ± 0.00022 37353-00-7*0 Hydrazine H2NNH2 (cr,l) 57.25 50.68 ± 0.18 kJ/mol 32.04524 ± 0.00031 302-01-2*500 Hydrazoic acid anion [HNNN]- (g, trans) 309.0 302.7 ± 2.3 kJ/mol 43.02871 ± 0.00022 203264-98-6*1 Cyclopropenylidene anion [C(CHCH)]- (g) 544.3 543.8 ± 2.2 kJ/mol 38.0485 ± 0.0024 *16165-40-5*0 Nitrosyl nitrite anion [ONONO]- (g, t, t) -102.3 -105.5 ± 2.6 kJ/mol 76.01223 ± 0.00091 *122413-35-8*1 Propane cation [CH3CH2CH3]+ (g) 974.5 954.6 ± 1.6 kJ/mol 44.0951 ± 0.0025 34479-70-4*0 Dihydrogen cation [H2]+ (g, ortho) 1489.060 1488.480 ± 0.000 kJ/mol 2.01533 ± 0.00014 12184-90-6*1 Bromoniumyl [HBr]+ (g) 1097.86 1090.01 ± 0.16 kJ/mol 80.9114 ± 0.0010 12258-64-9*0 Carbon atom C (g, triplet) 711.401 716.886 ± 0.050 kJ/mol 12.01070 ± 0.00080 7440-44-0*1 1,2-Propadien-1-ylium-1-yl-3-ylidene [CCC]+ (g, lin) 1981.7 1990.8 ± 2.1 kJ/mol 36.0316 ± 0.0024 118090-85-0*1 Formic acid HC(O)OH (cr,l) -431.60 -424.77 ± 0.20 kJ/mol 46.0254 ± 0.0010 64-18-6*500 Hydrogen peroxide H2O2 (cr,l) -193.161 -187.344 ± 0.080 kJ/mol 34.01468 ± 0.00062 7722-84-1*500 Bromosyl bromide BrBrO (g) 180.5 164.7 ± 2.3 kJ/mol 175.8074 ± 0.0020 68322-97-4*0 2-Propen-3-ylium-1-ylidyne [CHCHC]+ (g) 1791.2 1792.8 ± 2.6 kJ/mol 38.0474 ± 0.0024 161054-36-0*0 Hydroxyoxoammoniumyl [HONO]+ (g, trans) 984.1 977.7 ± 1.6 kJ/mol 47.01293 ± 0.00061 80371-48-8*1 Propenediylidene anion [CHCHC]- (g) 588.8 590.0 ± 2.3 kJ/mol 38.0485 ± 0.0024 *161054-36-0*0 Hydrochlorate ion [HCl]- (g) -25.5 -24.5 ± 3.0 kJ/mol 36.46119 ± 0.00090 63099-75-2*0 1-Propanol CH3CH2CH2OH (cr,l) -290.50 -302.69 ± 0.25 kJ/mol 60.0950 ± 0.0025 71-23-8*500 Nitrous acid anion [HONO]- (g, cis) -107.4 -112.1 ± 2.1 kJ/mol 47.01403 ± 0.00061 256393-36-9*2 Dioxygen difluoride anion [FOOF]- (g) -237.4 -237.6 ± 5.6 kJ/mol 69.99615 ± 0.00060 *7783-45-1*0 Carbon dioxide anion [CO2]- (g) -340.2 -339.7 ± 1.9 kJ/mol 44.01005 ± 0.00100 14485-07-5*0 Tetrazete N(NNN) (g, D2h) 764.9 759.0 ± 1.8 kJ/mol 56.02696 ± 0.00028 42851-09-2*0 Acetic acid CH3C(O)OH (g, anti) -397.3 -411.1 ± 1.2 kJ/mol 60.0520 ± 0.0017 64-19-7*2 Acetic acid CH3C(O)OH (aq, 1000 H2O) -484.91 ± 0.23 kJ/mol 60.0520 ± 0.0017 64-19-7*839 Hydronium radical (H2O)(H) (g, vdW) -18.5 -21.6 ± 2.1 kJ/mol 19.02322 ± 0.00037 12168-76-2*100 Methyl formate HC(O)OCH3 (l) -386.14 ± 0.58 kJ/mol 60.0520 ± 0.0017 107-31-3*500 Hydrogen chloride HCl (aq, 1000 H2O) -166.567 ± 0.024 kJ/mol 36.46064 ± 0.00090 7647-01-0*839 Hypochloritooxygen cation [ClOO]+ (g) 1202.5 1200.3 ± 3.4 kJ/mol 67.4510 ± 0.0011 64710-10-7*0 Tetraazatetrahedrane N4 (g, Td) 763.7 757.2 ± 1.7 kJ/mol 56.02696 ± 0.00028 12596-63-3*0 Ethylene glycol (CH2OH)2 (cr,l) -448.69 -455.21 ± 0.38 kJ/mol 62.0678 ± 0.0018 107-21-1*500 Oxalic acid (COOH)2 (cr) -819.29 ± 0.46 kJ/mol 90.0349 ± 0.0020 144-62-7*500 Hydrazide [N2H3]- (g) 252.8 242.9 ± 2.5 kJ/mol 31.03785 ± 0.00025 25415-88-7*0 Dimethylamine (CH3)2NH (l) -41.21 ± 0.72 kJ/mol 45.0837 ± 0.0017 124-40-3*500 Trimethylamine (CH3)3N (l) -45.80 ± 0.61 kJ/mol 59.1103 ± 0.0025 75-50-3*500 Cyanogen cation [NCCN]+ (g) 1598.28 1600.50 ± 0.44 kJ/mol 52.0343 ± 0.0016 37354-81-7*0 Cyanogen anion [NCCN]- (g) 281.5 284.5 ± 2.7 kJ/mol 52.0354 ± 0.0016 11118-88-0*0 Isocyanogen cation [CNCN]+ (g) 1652.8 1654.2 ± 1.7 kJ/mol 52.0343 ± 0.0016 133415-63-1*0 Cyclobutane CH2(CH2CH2CH2) (l) 3.80 ± 0.44 kJ/mol 56.1063 ± 0.0032 287-23-0*590 Methylcyclopropane CH3CH(CH2CH2) (l) 1.82 ± 0.59 kJ/mol 56.1063 ± 0.0032 594-11-6*590 Methanol CH3OH (l) -235.07 -238.41 ± 0.17 kJ/mol 32.04186 ± 0.00090 67-56-1*500 Hydrogen chloride HCl (aq, 200 H2O) -166.107 ± 0.024 kJ/mol 36.46064 ± 0.00090 7647-01-0*830 Diisocyanogen anion [CNNC]- (g) 456.7 463.6 ± 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) 536.1 538.6 ± 5.8 kJ/mol 52.0354 ± 0.0016 *130760-11-1*0 3H-diazirin-3-ylidene-methylene CC(NN) (g) 833.6 836.1 ± 3.6 kJ/mol 52.0349 ± 0.0016 204253-88-3*0 Oxadiazirine [O(NN)]+ (g) 1511.2 1508.8 ± 2.1 kJ/mol 44.01233 ± 0.00033 *227934-45-4*0 Isocyanomethyliumylidene [CNC]+ (g) 1612.5 1618.1 ± 6.2 kJ/mol 38.0276 ± 0.0016 78271-45-1*0 Isocyanomethylidyne anion [CNC]- (g) 478.6 482.3 ± 5.8 kJ/mol 38.0287 ± 0.0016 *53590-27-5*0 Cyanomethyliumylidene [CCN]+ (g) 1711.0 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) 722.1 726.2 ± 4.9 kJ/mol 38.0281 ± 0.0016 439586-06-8*0 Cyanoaminyliumyl [NCN]+ (g) 1671.9 1673.2 ± 2.9 kJ/mol 40.02363 ± 0.00081 316122-03-9*0 Cyanoamidogen anion [NCN]- (g) 210.87 210.88 ± 0.81 kJ/mol 40.02473 ± 0.00081 189879-95-6*0 1-Methylethenylium [CH3CCH2]+ (g) 996.1 986.6 ± 2.5 kJ/mol 41.0713 ± 0.0024 50457-57-3*0 Cyanamide H2NCN (cr) 58.91 ± 0.54 kJ/mol 42.04006 ± 0.00082 420-04-2*500 Diazomethyliumyl [CNN]+ (g) 1641.8 1643.6 ± 4.4 kJ/mol 40.02363 ± 0.00081 307495-90-5*0 Diazomethylene anion [CNN]- (g) 407.9 408.0 ± 4.0 kJ/mol 40.02473 ± 0.00081 205498-92-6*0 Trihydrogen H(HH) (g, 2p 2A2" Ry) 756.931 754.146 ± 0.015 kJ/mol 3.02382 ± 0.00021 12184-91-7*2 Dioxiranylidene cation [C(OO)]+ (g) 1409.4 1410.7 ± 2.4 kJ/mol 44.00895 ± 0.00100 *138832-57-2*0 Trioxidanyl HOOO (g) 25.31 23.22 ± 0.13 kJ/mol 49.00614 ± 0.00090 12500-78-6*0 Deuterium hydride cation [HD]+ (g) 1490.498 1490.587 ± 0.000 kJ/mol 3.021493 ± 0.000070 12181-16-7*0 1-Methylethenyl anion [CH3CCH2]- (g) 199.2 188.1 ± 2.8 kJ/mol 41.0723 ± 0.0024 65887-19-6*0 Hydrazine anion [H2NNH2]- (g) 226.6 212.7 ± 3.1 kJ/mol 32.04579 ± 0.00031 65391-88-0*0 Methanol dimer (CH3OH)2 (g) -398.1 -418.7 ± 1.4 kJ/mol 64.0837 ± 0.0018 42845-44-3*0 Methylene chloride CH2Cl2 (l) -123.30 ± 0.61 kJ/mol 84.9320 ± 0.0020 75-09-2*590 Nitrato [NO3]+ (g) 1290.55 1285.84 ± 0.86 kJ/mol 62.00439 ± 0.00090 133057-96-2*0 Tetraoxodinitrogen cation [O2NNO2]+ (g) 1030.6 1025.1 ± 2.6 kJ/mol 92.0105 ± 0.0012 64476-91-1*0 Dioxiranylidene anion [C(OO)]- (g, ?) -109.6 -109.1 ± 2.6 kJ/mol 44.01005 ± 0.00100 *138832-58-3*0 Krypton cation Kr+ (g) 1350.759 1350.759 ± 0.0011 kJ/mol 83.7995 ± 0.1000 16915-28-9*0 Difluoromethylene anion [CF2]- (g) -211.25 -210.03 ± 0.59 kJ/mol 50.00805 ± 0.00080 66212-40-6*0 Fluorosyl fluoride cation [FFO]+ (g) 1409.3 1409.6 ± 6.3 kJ/mol 53.99566 ± 0.00030 *86825-50-5*0 Fluoromethylidyne anion [CF]- (g) 200.6 204.1 ± 1.7 kJ/mol 31.00965 ± 0.00080 33412-12-3*0 1-Ethenylium-1-yl [CCH2]+ (g) 1507.6 1507.6 ± 1.9 kJ/mol 26.0367 ± 0.0016 80541-07-7*0 NON cation [NON]+ (g) 1443.2 1443.4 ± 2.4 kJ/mol 44.01233 ± 0.00033 *227934-46-5*0 n-Hexane CH3CH2CH2CH2CH2CH3 (l) -179.99 -198.64 ± 0.34 kJ/mol 86.1754 ± 0.0049 110-54-3*500 Formaldehyde H2CO (cr, paraformaldehyde) -179.2 ± 1.6 kJ/mol 30.02598 ± 0.00087 50-00-0*500 Nitrosyl nitrite ONONO (g, c, p) 125.4 120.1 ± 2.1 kJ/mol 76.01168 ± 0.00091 122413-35-8*3 Deuterium hydride HD (g) 0.328 0.319 ± 0.000 kJ/mol 3.022042 ± 0.000070 13983-20-5*0 Cyclohexane CH2(CH2CH2CH2CH2CH2) (l) -156.29 ± 0.36 kJ/mol 84.1595 ± 0.0049 110-82-7*500 Hydrofluorate ion [HF]- (g) -75.4 -74.9 ± 2.0 kJ/mol 20.006892 ± 0.000070 37249-79-9*0 Iodine atom I (g, 2P3/2) 107.157 106.757 ± 0.0021 kJ/mol 126.904470 ± 0.000030 14362-44-8*1 Nitric acid HNO3 (aq, 1 H2O) -186.84 ± 0.19 kJ/mol 63.01288 ± 0.00091 7697-37-2*801 Nitric acid HNO3 (aq, 3 H2O) -197.75 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*805 1,2-Difluoroacetylene cation [FCCF]+ (g) 1081.0 1084.0 ± 1.5 kJ/mol 62.0177 ± 0.0016 268566-70-7*0 n-Heptane CH3(CH2)5CH3 (l) -201.72 -224.17 ± 0.48 kJ/mol 100.2019 ± 0.0057 142-82-5*500 Trioxirane O(OO) (g) 274.5 271.9 ± 1.2 kJ/mol 47.99820 ± 0.00090 153851-84-4*0 n-Octane CH3(CH2)6CH3 (l) -226.67 -249.79 ± 0.67 kJ/mol 114.2285 ± 0.0065 111-65-9*500 1,5-Hexadiene CH2CHCH2CH2CHCH2 (cr,l) 54.43 ± 0.32 kJ/mol 82.1436 ± 0.0049 592-42-7*500 Trioxidane HOOOH (g) -81.43 -90.03 ± 0.70 kJ/mol 50.01408 ± 0.00091 14699-99-1*0 Nitric acid trihydrate HNO3(H2O)3 (cr,l) -1062.09 -1055.24 ± 0.21 kJ/mol 117.0587 ± 0.0019 13444-83-2*500 Deuterium atom cation D+ (g) 1532.211 1534.123 ± 0.000 kJ/mol 2.01355319809 ± 0.00000000040 14464-47-2*0 Cyclopropyl anion [CH(CH2CH2)]- (g) 263.7 250.9 ± 2.5 kJ/mol 41.0723 ± 0.0024 1724-45-4*0 Hydrogen chloride HCl (aq, 3000 H2O) -166.744 ± 0.024 kJ/mol 36.46064 ± 0.00090 7647-01-0*842 Dioxymethylidyne cation [COO]+ (g, doublet) 1435.7 1438.2 ± 2.7 kJ/mol 44.00895 ± 0.00100 *791121-04-5*2 2-Iodoethanol ICH2CH2OH (l) -207.2 ± 2.4 kJ/mol 171.9650 ± 0.0017 624-76-0*590 Azide ion [NNN]- (aq) 272.62 ± 0.47 kJ/mol 42.02077 ± 0.00021 14343-69-2*800 1,3-Butadiyne cation [HCCCCH]+ (g) 1440.60 1441.45 ± 0.88 kJ/mol 50.0581 ± 0.0032 55468-55-8*0 Tricarbon dioxide cation [OCCCO]+ (g) 927.0 930.5 ± 1.3 kJ/mol 68.0304 ± 0.0025 151528-67-5*0 Tricarbon dioxide anion [OCCCO]- (g) -133.5 -129.8 ± 2.5 kJ/mol 68.0314 ± 0.0025 109362-94-9*0 Trioxygen difluoride FOOOF (g) 116.8 111.3 ± 7.8 kJ/mol 85.99501 ± 0.00090 16829-28-0*0 Oxygen difluoride cation [FOF]+ (g) 1292.21 1289.69 ± 0.67 kJ/mol 53.99566 ± 0.00030 39432-25-2*0 Nitric acid monohydrate HNO3(H2O) (cr,l) -479.17 -472.67 ± 0.19 kJ/mol 81.0282 ± 0.0012 13444-82-1*500 o-Benzyne cation [C6H4]+ (g) 1398.9 1391.4 ± 2.9 kJ/mol 76.0954 ± 0.0048 70220-84-7*0 Nitrosyl nitrate ONONO2 (g, t) 48.2 40.3 ± 1.8 kJ/mol 92.0111 ± 0.0012 15969-55-8*1 Toluene C6H5CH3 (l) 19.99 12.23 ± 0.36 kJ/mol 92.1384 ± 0.0056 108-88-3*500 Benzaldehyde C6H5C(O)H (cr,l) -85.6 -86.7 ± 1.1 kJ/mol 106.1219 ± 0.0056 100-52-7*500 Hydrogen bromide HBr (aq, 1000 H2O) -120.41 ± 0.16 kJ/mol 80.9119 ± 0.0010 10035-10-6*839 Fluorosyl fluoride anion [FFO]- (g) -53.5 -53.0 ± 6.1 kJ/mol 53.99675 ± 0.00030 *86825-57-2*0 Dioxygen O2 (g, singlet) 94.410 94.383 ± 0.000 kJ/mol 31.99880 ± 0.00060 7782-44-7*2 Oxygen difluoride anion [FOF]- (g) -194.0 -194.4 ± 3.8 kJ/mol 53.99675 ± 0.00030 *7783-41-7*0 Iodobenzene cation [C6H5I]+ (g) 1022.6 1007.1 ± 1.0 kJ/mol 204.0078 ± 0.0048 38406-85-8*0 Peroxynitrous acid HOONO (g) -5.99 -12.62 ± 0.36 kJ/mol 63.01288 ± 0.00091 14691-52-2*0 Nitrosobenzene C6H5NO (g) 215.4 198.4 ± 1.5 kJ/mol 107.1100 ± 0.0048 586-96-9*0 2,4,5-Trioxa-1,3-diazabicyclo[1.1.1]pentane N(O3)N (g) 602.2 593.0 ± 1.8 kJ/mol 76.01168 ± 0.00091 224950-18-9*0 Hydrogen fluoride HF (aq, 400 H2O) -321.48 ± 0.17 kJ/mol 20.006343 ± 0.000070 7664-39-3*832 Nitromethane CH3N(O)O (cr,l) -114.20 -113.01 ± 0.44 kJ/mol 61.0401 ± 0.0010 75-52-5*500 2,2,4-Trimethylpentane (CH3)2CHCH2C(CH3)3 (l) -224.5 -258.9 ± 1.5 kJ/mol 114.2285 ± 0.0065 540-84-1*500 Trifluoroethylene C2HF3 (g) -482.8 -487.8 ± 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) -365.46 ± 0.54 kJ/mol 86.0892 ± 0.0033 431-03-8*500 2,3-Butanedione (CH3CO)2 (g) -309.87 -326.44 ± 0.78 kJ/mol 86.0892 ± 0.0033 431-03-8*0 Succinic acid (CH2COOH)2 (cr,l) -918.55 -940.28 ± 0.13 kJ/mol 118.0880 ± 0.0034 110-15-6*500 1-Propynylium [CH3CC]+ (g) 1545.8 1543.9 ± 2.6 kJ/mol 39.0554 ± 0.0024 24858-94-4*0 Hydrazoic acid cation [HNNN]+ (g) 1333.77 1328.10 ± 0.82 kJ/mol 43.02761 ± 0.00022 58852-14-5*0 Oxygen atom hexacation [O]+6 (g) 42035.28 42037.14 ± 0.12 kJ/mol 15.99611 ± 0.00030 14158-22-6*0 1,2-Diiodoethane (CIH2)2 (g) 87.79 73.12 ± 0.90 kJ/mol 281.8621 ± 0.0016 624-73-7*0 1,2-Diiodoethane (CIH2)2 (cr,l) 9.26 ± 0.60 kJ/mol 281.8621 ± 0.0016 624-73-7*500 Methylamine CH3NH2 (l) -44.83 ± 0.52 kJ/mol 31.05714 ± 0.00088 74-89-5*500 1,1-Dibromoethane CHBr2CH3 (g) -9.3 -36.3 ± 7.8 kJ/mol 187.8612 ± 0.0026 557-91-5*0 Xenon hydride cation [XeH]+ (g) 1038.39 1036.61 ± 0.93 kJ/mol 132.2974 ± 0.0200 37276-91-8*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) -238.930 -241.833 ± 0.027 kJ/mol 18.01528 ± 0.00033 7732-18-5*2 1,3-Butadiynyl anion [CCCC]- (g) 677.6 686.7 ± 1.1 kJ/mol 48.0433 ± 0.0032 59158-53-1*0 1,2-Propadien-1-ylium-1-yl-3-ylidene [CCC]+ (g) 1948.3 1956.2 ± 2.0 kJ/mol 36.0316 ± 0.0024 118090-85-0*0 Carbon monoxide CO (g, singlet) -113.803 -110.523 ± 0.026 kJ/mol 28.01010 ± 0.00085 630-08-0*2 Oxoniumyl ion [H2O]+ (g, ortho) 978.472 975.569 ± 0.029 kJ/mol 18.01473 ± 0.00033 56583-62-1*1 Iodine monochloride ICl (l) -24.048 ± 0.063 kJ/mol 162.35717 ± 0.00090 7790-99-0*590 Water trimer (H2O)3 (g) -762.73 -776.83 ± 0.21 kJ/mol 54.04584 ± 0.00099 31014-12-7*0 Oxygen atom octacation [O]+8 (g) 197444.7 197446.6 ± 1.2 kJ/mol 15.99501 ± 0.00030 21450-98-6*0 Nitrosyl nitrite anion [ONONO]- (g, t, c) -99.3 -102.5 ± 2.7 kJ/mol 76.01223 ± 0.00091 *122413-35-8*2 Propylene cation [CH3CHCH2]+ (g) 975.10 962.14 ± 0.35 kJ/mol 42.0792 ± 0.0024 34504-10-4*0 3H-Diazirin-3-ylidene C(NN) (g) 578.0 578.4 ± 4.0 kJ/mol 40.02418 ± 0.00081 253308-70-2*0 Oxygen atom tetracation [O]+4 (g) 17719.207 17721.064 ± 0.025 kJ/mol 15.99721 ± 0.00030 14127-65-2*0 Tetrabromomethane CBr4 (cr, monoclinic) 47.4 ± 1.3 kJ/mol 331.6267 ± 0.0041 558-13-4*500 Trihydrogen cation [H3]+ (g, para) 1110.304 1106.697 ± 0.013 kJ/mol 3.02327 ± 0.00021 28132-48-1*2 Tetraiodomethane CI4 (cr, monoclinic) 392.5 ± 8.0 kJ/mol 519.62858 ± 0.00081 507-25-5*500 Methyl bromide CH3Br (l) -56.08 -59.10 ± 0.27 kJ/mol 94.9385 ± 0.0013 74-83-9*590 Fluorine atom F (g, 2P3/2) 77.264 79.048 ± 0.048 kJ/mol 18.99840320 ± 0.00000050 14762-94-8*1 Acetylene anion [HCCH]- (g) 357.4 357.2 ± 1.8 kJ/mol 26.0378 ± 0.0016 50443-89-5*0 Water H2O (cr) -286.300 -292.741 ± 0.027 kJ/mol 18.01528 ± 0.00033 7732-18-5*510 Dinitrogen dimer (N2)2 (g) -0.88 0.84 ± 0.67 kJ/mol 56.02696 ± 0.00028 *7727-37-9*0 Trioxirane cation [O(OO)]+ (g) 1444.4 1442.3 ± 2.3 kJ/mol 47.99765 ± 0.00090 *153851-84-4*0 Dioxaziridine HN(OO) (g) 277.2 270.5 ± 2.0 kJ/mol 47.01348 ± 0.00061 67394-35-8*0 Dihydrogen H2 (g, para) -0.000 -0.058 ± 0.000 kJ/mol 2.01588 ± 0.00014 1333-74-0*2 Hydrogen peroxide H2O2 (g, para) -129.471 -135.457 ± 0.064 kJ/mol 34.01468 ± 0.00062 7722-84-1*2 Methylene CH2 (g) 390.96 391.52 ± 0.12 kJ/mol 14.02658 ± 0.00081 2465-56-7*0 Oxygen atom heptacation [O]+7 (g) 113366.4 113368.3 ± 1.2 kJ/mol 15.99556 ± 0.00030 14274-89-6*0 Tetraoxodinitrate anion [O2NNO2]- (g) -184.6 -187.8 ± 2.4 kJ/mol 92.0116 ± 0.0012 63552-02-3*0 Trihydrogen H(HH) (g, 2s 2A1' Ry) 745.878 743.094 ± 0.062 kJ/mol 3.02382 ± 0.00021 12184-91-7*1 Oxonium [H3O]+ (g, para) 605.85 599.10 ± 0.17 kJ/mol 19.02267 ± 0.00037 13968-08-6*2 Chloryl ion [OClO]+ (g) 1099.83 1097.15 ± 0.54 kJ/mol 67.4510 ± 0.0011 25052-55-5*0 Cyclopropane cation [CH2(CH2CH2)]+ (g) 1021.7 1006.3 ± 1.6 kJ/mol 42.0792 ± 0.0024 34496-93-0*0 Hydroxylamine NH2OH (g) -33.12 -43.49 ± 0.49 kJ/mol 33.02996 ± 0.00037 7803-49-8*0 1,3-Cyclopentadiene CH2(CHCHCHCH) (l) 108.76 ± 0.61 kJ/mol 66.1011 ± 0.0040 542-92-7*590 Chlorite [OClO]- (g) -105.94 -108.11 ± 0.38 kJ/mol 67.4520 ± 0.0011 14998-27-7*0 Oxygen fluoride OOF2 (g) 75.5 71.2 ± 7.8 kJ/mol 69.99561 ± 0.00060 183051-89-0*0 Ammonium hydroxide NH4OH (aq, undissoc) -366.715 ± 0.062 kJ/mol 35.04584 ± 0.00047 1336-21-6*1000 Hydrazoic acid HNNN (aq, undissoc) 257.63 ± 0.48 kJ/mol 43.02816 ± 0.00022 7782-79-8*1000 Oxygen atom pentacation [O]+5 (g) 28708.788 28710.646 ± 0.053 kJ/mol 15.99666 ± 0.00030 14127-66-3*0 Hydrazoic acid HNNN (aq) 272.62 ± 0.47 kJ/mol 43.02816 ± 0.00022 7782-79-8*800 Formaldehyde H2CO (cr, polyoxymethylene) -170.88 ± 0.21 kJ/mol 30.02598 ± 0.00087 50-00-0*501 Formaldehyde H2CO (aq) -171.16 ± 0.59 kJ/mol 30.02598 ± 0.00087 50-00-0*800 mu-Oxodichlorine cation [ClOCl]+ (g) 1130.42 1126.81 ± 0.63 kJ/mol 86.9043 ± 0.0018 51174-96-0*0 Dioxofluorine cation [OFO]+ (g) 1666.7 1664.5 ± 2.8 kJ/mol 50.99665 ± 0.00060 223566-05-0*0 Ethyl bromide CH3CH2Br (l) -55.54 -91.07 ± 0.27 kJ/mol 108.9651 ± 0.0019 74-96-4*500 Hydroxyoxoammoniumyl [HONO]+ (g, cis) 1014.8 1008.5 ± 1.8 kJ/mol 47.01293 ± 0.00061 80371-48-8*2 Nitrous acid anion [HONO]- (g, trans) -106.0 -110.0 ± 2.1 kJ/mol 47.01403 ± 0.00061 256393-36-9*1 Vinyl iodide CH2CHI (g) 139.7 130.9 ± 1.2 kJ/mol 153.9497 ± 0.0016 593-66-8*0 Iodine atom I (g, 2P1/2) 198.109 197.709 ± 0.0021 kJ/mol 126.904470 ± 0.000030 14362-44-8*2 Ethynylene C2 (g, singlet) 820.21 826.78 ± 0.27 kJ/mol 24.0214 ± 0.0016 12070-15-4*2 Hydrazine monohydrate (H2NNH2)(H2O) (l) -242.66 ± 0.19 kJ/mol 50.06052 ± 0.00053 7803-57-8*500 Diatomic bromine cation [Br2]+ (g) 1060.33 1045.38 ± 0.23 kJ/mol 159.8075 ± 0.0020 12595-71-0*0 Chlorine atom Cl (g, 2P3/2) 119.621 121.228 ± 0.0011 kJ/mol 35.45270 ± 0.00090 22537-15-1*1 Dihydrogen cation [H2]+ (g, para) 1488.364 1488.480 ± 0.000 kJ/mol 2.01533 ± 0.00014 12184-90-6*2 Hydroxymethylene HCOH (g) 112.40 108.64 ± 0.33 kJ/mol 30.02598 ± 0.00087 19710-56-6*0 1-Hydroxyethyl CH3CHOH (g) -42.17 -55.59 ± 0.61 kJ/mol 45.0605 ± 0.0017 2348-46-1*0 Acetaldehyde CH3CHO (cr,l) -186.95 -191.67 ± 0.33 kJ/mol 44.0526 ± 0.0017 75-07-0*500 Hydrogen peroxide cation [H2O2]+ (g, trans, ortho) 896.87 889.89 ± 0.57 kJ/mol 34.01413 ± 0.00062 12325-10-9*11 Tricarbon dioxide OCCCO (cr,l) -133.0 -117.9 ± 1.2 kJ/mol 68.0309 ± 0.0025 504-64-3*500 Deuteride D- (g) 146.991 148.904 ± 0.0021 kJ/mol 2.01465035791 ± 0.00000000040 14452-69-8*0 Acetic acid CH3C(O)OH (aq, 500 H2O) -484.89 ± 0.23 kJ/mol 60.0520 ± 0.0017 64-19-7*833 Oxygen atom dication [O]+2 (g) 4949.459 4953.000 ± 0.013 kJ/mol 15.99830 ± 0.00030 14127-63-0*0 Acetic acid CH3C(O)OH (aq, 10000 H2O) -484.94 ± 0.23 kJ/mol 60.0520 ± 0.0017 64-19-7*850 Hydrogen fluoride HF (aq, 45 H2O) -321.16 ± 0.17 kJ/mol 20.006343 ± 0.000070 7664-39-3*906 Dihydrogen anion [H2]- (g) 253.8 254.7 ± 1.2 kJ/mol 2.01643 ± 0.00014 12184-89-3*0 Hydrogen peroxide cation [H2O2]+ (g, cis, para) 930.91 924.05 ± 0.94 kJ/mol 34.01413 ± 0.00062 12325-10-9*22 Bicyclo[1.1.0]buta-1,3-dien-4-ylium-2-yl [C(CC)C]+ (g) 2087.3 2097.1 ± 2.7 kJ/mol 48.0423 ± 0.0032 289679-91-0*0 Bicyclo[1.1.0]buta-1,3-dien-2-yl anion [C(CC)C]- (g) 803.6 811.2 ± 2.1 kJ/mol 48.0433 ± 0.0032 289679-89-6*0 Tetroxidane HOOOOH (g) -33.5 -44.0 ± 2.4 kJ/mol 66.0135 ± 0.0012 29683-94-1*0 Bromine atom Br (g, 2P3/2) 117.917 111.854 ± 0.056 kJ/mol 79.90400 ± 0.00100 10097-32-2*1 Methyl formate HC(O)OCH3 (g) -344.75 -357.79 ± 0.58 kJ/mol 60.0520 ± 0.0017 107-31-3*0 Difluorine cation [F2]+ (g) 1514.301 1514.475 ± 0.013 kJ/mol 37.9962578 ± 0.0000010 12184-86-0*0 Hydrogen iodide HI (aq) -56.829 ± 0.089 kJ/mol 127.912410 ± 0.000076 10034-85-2*800 Bromodioxy BrOO (g) 119.2 110.2 ± 4.0 kJ/mol 111.9028 ± 0.0012 67177-47-3*0 mu-Oxodichlorate anion [ClOCl]- (g) -147.8 -147.7 ± 2.5 kJ/mol 86.9053 ± 0.0018 365546-30-1*0 Oxygen atom trication [O]+3 (g) 10249.929 10252.880 ± 0.018 kJ/mol 15.99775 ± 0.00030 14127-64-1*0 Dioxofluorine anion [OFO]- (g) 156.0 154.4 ± 2.5 kJ/mol 50.99775 ± 0.00060 *175861-93-5*0 Deuterium molecule cation [D2]+ (g) 1492.286 1492.361 ± 0.000 kJ/mol 4.02765497609 ± 0.00000000080 12184-84-8*0 (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 1,3-Butadiyn-4-ylium-1-yl [CCCC]+ (g) 2109.8 2120.4 ± 2.9 kJ/mol 48.0423 ± 0.0032 124708-46-9*0 Nitrosyl nitrate ONONO2 (g, cis-perp) 60.4 52.5 ± 1.9 kJ/mol 92.0111 ± 0.0012 15969-55-8*2 Tribromide ion [Br3]- (aq) -129.38 ± 0.26 kJ/mol 239.7125 ± 0.0030 14522-80-6*800 1,2-Dibromoethane (CBrH2)2 (cr,l) -79.4 ± 1.3 kJ/mol 187.8612 ± 0.0026 106-93-4*500 Hydroxylamine NH2OH (cr,l) -107.50 ± 0.65 kJ/mol 33.02996 ± 0.00037 7803-49-8*500 Trihydrogen (H)(HH) (g, vdW) 215.9 218.3 ± 1.1 kJ/mol 3.02382 ± 0.00021 12184-91-7*100 Krypton hydride cation [KrH]+ (g) 1106.49 1104.71 ± 0.70 kJ/mol 84.8074 ± 0.1000 37276-90-7*0 Dioxymethylene HCOO (g, cis-trans equilib) 339.6 337.4 ± 3.1 kJ/mol 45.0174 ± 0.0010 438586-67-5*0 Nitrosyl nitrite ONONO (g) 92.7 87.8 ± 1.2 kJ/mol 76.01168 ± 0.00091 122413-35-8*0 Cyanogen fluoride cation [FCN]+ (g) 1294.6 1295.3 ± 1.1 kJ/mol 45.01529 ± 0.00080 62532-69-8*0 Hydrogen peroxide H2O2 (g, ortho) -129.451 -135.457 ± 0.064 kJ/mol 34.01468 ± 0.00062 7722-84-1*1 Isoformyl anion [COH]- (g) 55.8 58.4 ± 1.8 kJ/mol 29.01859 ± 0.00086 81747-63-9*0 Diazene HNNH (g, trans-cis-iso equilib) 207.35 200.21 ± 0.44 kJ/mol 30.02936 ± 0.00020 3618-05-1*0 Hydrogen difluoride cation [FHF]+ (g) 1253. 1249. ± 20. kJ/mol 39.004198 ± 0.000070 126950-54-7*0 Methyl fluoride cation [CH3F]+ (g) 981.49 973.98 ± 0.62 kJ/mol 34.03237 ± 0.00083 59122-96-2*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 Hydroperoxonium [H2OOH]+ (g) 738.17 727.91 ± 0.98 kJ/mol 35.02207 ± 0.00064 70850-26-9*0 Water H2O (g, ortho) -238.646 -241.833 ± 0.027 kJ/mol 18.01528 ± 0.00033 7732-18-5*1 Cyanogen fluoride anion [FCN]- (g) -21.3 -19.4 ± 3.3 kJ/mol 45.01639 ± 0.00080 34507-50-1*0 Methyl fluoride CH3F (l) -246.07 ± 0.45 kJ/mol 34.03292 ± 0.00083 593-53-3*590 Methyl chloride cation [CH3Cl]+ (g) 1015.03 1007.58 ± 0.25 kJ/mol 50.4867 ± 0.0012 12538-71-5*0 Dicarbon monoxide CCO (g) 376.30 380.34 ± 0.97 kJ/mol 40.0208 ± 0.0016 12071-23-7*0 Methyl chloride CH3Cl (l) -106.05 -102.08 ± 0.25 kJ/mol 50.4872 ± 0.0012 74-87-3*590 Ethyl chloride CH3CH2Cl (cr,l) -134.15 -135.77 ± 0.21 kJ/mol 64.5138 ± 0.0019 75-00-3*500 Hydrazoic acid HNNN (cr,l) 261.50 ± 0.64 kJ/mol 43.02816 ± 0.00022 7782-79-8*500 Methyl bromide cation [CH3Br]+ (g) 996.75 981.84 ± 0.27 kJ/mol 94.9380 ± 0.0013 12538-70-4*0 Ethane anion [C2H6]- (g) 41.9 26.7 ± 4.4 kJ/mol 30.0696 ± 0.0017 54064-82-3*0 Iodine monochloride ICl (cr,l) -36.511 -35.537 ± 0.063 kJ/mol 162.35717 ± 0.00090 7790-99-0*500 Nitrogen atom anion N- (g) 487.6 489.9 ± 2.5 kJ/mol 14.007289 ± 0.000070 17778-87-9*0 2-Cyclopropyn-1-ylidene C(CC) (g) 899.2 906.1 ± 1.5 kJ/mol 36.0321 ± 0.0024 102508-15-6*0 3-Chloro-3-methyl-3H-diazirine (NNC)ClCH3 (g) 230. 218. ± 40. kJ/mol 90.5114 ± 0.0019 4222-21-3*0 Methyl iodide cation [CH3I]+ (g) 944.77 935.37 ± 0.17 kJ/mol 141.93844 ± 0.00083 12538-72-6*0 Imidogen NH (g, singlet) 509.32 509.37 ± 0.18 kJ/mol 15.014680 ± 0.000099 13774-92-0*2 Fluoroform CF3H (l) -704.33 ± 0.46 kJ/mol 70.01385 ± 0.00080 75-46-7*590 Oxonium [H3O]+ (g, ortho) 605.91 599.10 ± 0.17 kJ/mol 19.02267 ± 0.00037 13968-08-6*1 Nitrosyl nitrite anion [ONONO]- (g) -102.3 -105.4 ± 2.6 kJ/mol 76.01223 ± 0.00091 *122413-35-8*0 Trihydrogen HHH (g, TS) 254.5 250.7 ± 1.2 kJ/mol 3.02382 ± 0.00021 12184-91-7*200 1,2-Propadien-1-yl-3-ylidene anion [CCC]- (g, lin) 621.5 628.9 ± 1.2 kJ/mol 36.0326 ± 0.0024 109292-47-9*1 Dinitrogen dioxide ONNO (g) 172.89 171.12 ± 0.14 kJ/mol 60.01228 ± 0.00062 16824-89-8*0 Iminomethyl HCNH (g, trans-cis equilib) 275.92 272.32 ± 0.84 kJ/mol 28.03332 ± 0.00082 15691-95-9*0 Cyclopropane CH2(CH2CH2) (l) 35.55 ± 0.58 kJ/mol 42.0797 ± 0.0024 75-19-4*500 Isocyanogen fluoride FNC (g) 300.3 302.2 ± 2.0 kJ/mol 45.01584 ± 0.00080 16992-26-0*0 Iminomethyl anion [HCNH]- (g) 238.9 235.2 ± 1.9 kJ/mol 28.03387 ± 0.00082 90623-30-6*0 Trihydrogen H(HH) (g, Ry) 745.878 743.199 ± 0.062 kJ/mol 3.02382 ± 0.00021 12184-91-7*0 Hydrazoic acid anion [HNNN]- (g) 309.0 303.2 ± 2.3 kJ/mol 43.02871 ± 0.00022 203264-98-6*0 Formic acid cation [HC(O)OH]+ (g) 721.86 715.32 ± 0.26 kJ/mol 46.0248 ± 0.0010 50614-05-6*0 Fluoro(fluorooxy)methylene FCOF (g) -135.8 -137.0 ± 2.0 kJ/mol 66.00691 ± 0.00085 479587-30-9*0 Formic acid anion [HC(O)OH]- (g) -255.6 -261.7 ± 1.7 kJ/mol 46.0259 ± 0.0010 19066-82-1*0 COC vdW (CO)(C) (g) 589.8 598.6 ± 1.8 kJ/mol 40.0208 ± 0.0016 *12071-24-8*0 Hydroxyamidogen HNOH (g) 101.5 94.7 ± 1.0 kJ/mol 32.02202 ± 0.00034 13940-32-4*0 Oxonium [H3O]+ (aq) -285.828 ± 0.027 kJ/mol 19.02267 ± 0.00037 13968-08-6*800 Trioxodinitrate anion [ONNO2]- (g) -104.4 -108.4 ± 2.3 kJ/mol 76.01223 ± 0.00091 194856-62-7*0 Hydroperoxyimidogen HOON (g, cis) 111.8 108.9 ± 2.8 kJ/mol 47.01348 ± 0.00061 877456-58-1*2 Propynylidene HCCCH (g, singlet) 597.6 599.4 ± 1.2 kJ/mol 38.0480 ± 0.0024 67152-18-5*2 Phosgene COCl2 (cr, l, I+liquid) -242.72 ± 0.27 kJ/mol 98.9155 ± 0.0020 75-44-5*501 Phosgene COCl2 (cr, l, II+liquid) -255.42 -242.72 ± 0.27 kJ/mol 98.9155 ± 0.0020 75-44-5*502 Hydroxymethylene cation [HCOH]+ (g) 971.9 968.3 ± 1.3 kJ/mol 30.02543 ± 0.00087 135395-06-1*0 Cyanogen chloride cation [ClCN]+ (g) 1325.97 1327.30 ± 0.94 kJ/mol 61.4696 ± 0.0012 37612-72-9*0 Isocyanogen chloride ClNC (g) 314.8 316.6 ± 2.1 kJ/mol 61.4701 ± 0.0012 75754-69-7*0 Dioxyamidogen HNOO (g, trans) 251.1 244.5 ± 2.5 kJ/mol 47.01348 ± 0.00061 71843-95-3*1 Hydroperoxonium [H2OOH]+ (g, cis) 762.6 752.7 ± 1.9 kJ/mol 35.02207 ± 0.00064 70850-26-9*2 Cyclopropylium [CH(CH2CH2)]+ (g) 1104.9 1093.4 ± 4.1 kJ/mol 41.0713 ± 0.0024 1724-43-2*0 Nitrous acid anion [HONO]- (g) -107.4 -110.9 ± 2.1 kJ/mol 47.01403 ± 0.00061 256393-36-9*0 Dioxygen O2 (g, triplet) 0.000 0.000 ± 0.000 kJ/mol 31.99880 ± 0.00060 7782-44-7*1 Diazene anion [HNNH]- (g, trans-cis-iso equilib) 269.3 262.4 ± 1.7 kJ/mol 30.02991 ± 0.00020 100429-75-2*0 Allyl anion [CH2CHCH2]- (g) 133.26 123.51 ± 0.92 kJ/mol 41.0723 ± 0.0024 1724-46-5*0 2-Iodoethanol ICH2CH2OH (g) -132.0 -150.2 ± 2.5 kJ/mol 171.9650 ± 0.0017 624-76-0*0 Diazene HNNH (g, trans-cis equilib) 207.35 200.21 ± 0.44 kJ/mol 30.02936 ± 0.00020 3618-05-1*1 Ethynylene C2 (g, triplet) 827.38 834.08 ± 0.27 kJ/mol 24.0214 ± 0.0016 12070-15-4*1 Hydrogen peroxide cation [H2O2]+ (g) 896.87 889.89 ± 0.57 kJ/mol 34.01413 ± 0.00062 12325-10-9*0 Hydroxyformyl HOCO (g, trans-cis equilib) -180.96 -183.53 ± 0.48 kJ/mol 45.0174 ± 0.0010 2564-86-5*0 Cyanogen bromide cation [BrCN]+ (g) 1330.2 1323.9 ± 1.1 kJ/mol 105.9209 ± 0.0013 34749-77-4*0 Bromoform CBr3H (l) 2.1 ± 1.3 kJ/mol 252.7306 ± 0.0031 75-25-2*590 Hydroxyformyl anion [HOCO]- (g, trans-cis equilib) -319.36 -321.43 ± 0.58 kJ/mol 45.0180 ± 0.0010 78944-70-4*0 Hydroxymethylene anion [HCOH]- (g) 147.4 144.5 ± 1.4 kJ/mol 30.02653 ± 0.00087 207914-87-2*0 Benzene anion [C6H6]- (g) 208.3 196.0 ± 3.0 kJ/mol 78.1124 ± 0.0048 34562-85-1*0 Dichlorine cation [Cl2]+ (g) 1108.287 1108.266 ± 0.013 kJ/mol 70.9049 ± 0.0018 12595-90-3*0 Water dimer cation [(H2O)2]+ (g) 556.8 546.4 ± 3.0 kJ/mol 36.03001 ± 0.00066 158061-35-9*0 Hydrogen peroxide cation [H2O2]+ (g, trans, para) 896.89 889.89 ± 0.57 kJ/mol 34.01413 ± 0.00062 12325-10-9*12 Vinyl alcohol CH2CHOH (g, syn-anti equilib) -112.55 -122.93 ± 0.84 kJ/mol 44.0526 ± 0.0017 557-75-5*0 O--HH Complex (H2)(O) (g, vdW C2v ?) 247.2 248.2 ± 2.0 kJ/mol 18.01528 ± 0.00033 *7732-18-5*102 Methylene fluoride CH2F2 (l) -467.00 ± 0.38 kJ/mol 52.02339 ± 0.00081 75-10-5*590 Ethylene anion [C2H4]- (g) 232.1 225.6 ± 2.0 kJ/mol 28.0537 ± 0.0016 34527-91-8*0 Trihydrogen H(HH) (g, TS) 477.4 474.7 ± 2.3 kJ/mol 3.02382 ± 0.00021 12184-91-7*201 Hydrogen cyanide anion [HCN]- (g) 129.508 129.030 ± 0.091 kJ/mol 27.02593 ± 0.00081 12334-27-9*0 2-Hydroxyethyl CH2CH2OH (g) -12.79 -26.06 ± 0.61 kJ/mol 45.0605 ± 0.0017 4422-54-2*0 Methane anion [CH4]- (g) 10.6 2.6 ± 4.8 kJ/mol 16.04301 ± 0.00085 27680-53-1*0 Chlorine atom Cl (g, 2P1/2) 130.176 131.783 ± 0.0011 kJ/mol 35.45270 ± 0.00090 22537-15-1*2 Isocyanogen bromide BrNC (g) 343.3 337.6 ± 3.1 kJ/mol 105.9214 ± 0.0013 65997-98-0*0 Hydroxyaminylium [HNOH]+ (g) 1020.2 1013.0 ± 2.0 kJ/mol 32.02147 ± 0.00034 66097-71-0*0 Diazene anion [HNNH]- (g, trans-cis equilib) 269.3 262.4 ± 1.7 kJ/mol 30.02991 ± 0.00020 100429-75-2*1 Iodosyl ion [IO]+ (g) 1066.1 1064.1 ± 2.0 kJ/mol 142.90332 ± 0.00030 81182-81-2*0 Diisocyanogen cation [CNNC]+ (g, trans-cis equilib) 1823.0 1826.0 ± 3.5 kJ/mol 52.0343 ± 0.0016 *78800-21-2*0 Oxide [O]-2 (g) 651. 653. ± 15. kJ/mol 16.00050 ± 0.00030 16833-27-5*0 Diazene cation [HNNH]+ (g, trans-iso-cis equilib) 1132.58 1125.91 ± 0.67 kJ/mol 30.02881 ± 0.00020 76986-17-9*0 Imidogen NH (g, triplet) 358.73 358.77 ± 0.17 kJ/mol 15.014680 ± 0.000099 13774-92-0*1 Propargylenide [HCCCH]- (g) 434.6 437.8 ± 1.1 kJ/mol 38.0485 ± 0.0024 82906-05-6*0 Bromine atom Br (g, 2P1/2) 162.001 155.938 ± 0.056 kJ/mol 79.90400 ± 0.00100 10097-32-2*2 Carbon monoxide CO (g, triplet) 465.579 469.286 ± 0.026 kJ/mol 28.01010 ± 0.00085 630-08-0*1 Dinitrogen dioxide ONNO (g, trans) 192.2 188.7 ± 1.8 kJ/mol 60.01228 ± 0.00062 16824-89-8*1 C=O-C cation [COC]+ (g) 1576.2 1583.3 ± 2.3 kJ/mol 40.0203 ± 0.0016 83483-98-1*0 Dinitrogen tetraoxide O2NNO2 (cr,l) -37.87 -27.02 ± 0.19 kJ/mol 92.0111 ± 0.0012 10544-72-6*500 Methoxycarbonyl C(O)OCH3 (g) -149.8 -157.5 ± 1.9 kJ/mol 59.0440 ± 0.0017 16481-04-2*0 Diazene cation [HNNH]+ (g, trans-cis equilib) 1132.58 1125.67 ± 0.67 kJ/mol 30.02881 ± 0.00020 76986-17-9*1 2-Hydroxyethylium [CH2CH2OH]+ (g) 1019.6 1007.5 ± 1.6 kJ/mol 45.0600 ± 0.0017 38607-31-7*0 Dinitrogen anion [N2]- (g) 193.6 193.6 ± 1.6 kJ/mol 28.01403 ± 0.00014 12185-02-3*0 (Formyloxy)methyl HC(O)OCH2 (g) -148.7 -156.8 ± 1.5 kJ/mol 59.0440 ± 0.0017 3122-12-1*0 Fluorine atom F (g, 2P1/2) 82.098 83.883 ± 0.048 kJ/mol 18.99840320 ± 0.00000050 14762-94-8*2 Hydrogen peroxide H2O2 (aq) -190.75 ± 0.30 kJ/mol 34.01468 ± 0.00062 7722-84-1*800 Carbon atom C (diamond) 2.391 1.863 ± 0.044 kJ/mol 12.01070 ± 0.00080 7440-44-0*501 Methyl nitrite CH3ONO (g, trans) -52.35 -64.30 ± 0.89 kJ/mol 61.0401 ± 0.0010 624-91-9*1 Methyl nitrite CH3ONO (cr,l) -88.69 ± 0.56 kJ/mol 61.0401 ± 0.0010 624-91-9*500 Carbonic acid C(O)(OH)2 (g) -602.78 -612.09 ± 0.79 kJ/mol 62.0248 ± 0.0012 463-79-6*0 2,2,4-Trimethylpentane (CH3)2CHCH2C(CH3)3 (g) -171.3 -223.7 ± 1.5 kJ/mol 114.2285 ± 0.0065 540-84-1*0 Water H2O (cr, l, eq.press.) -286.302 -285.830 ± 0.027 kJ/mol 18.01528 ± 0.00033 7732-18-5*499 Isocyanogen anion [CNCN]- (g, trans-cis equilib) 383.9 388.0 ± 2.5 kJ/mol 52.0354 ± 0.0016 *83951-85-3*0 Trihydrogen cation [H3]+ (g, ortho) 1110.577 1106.695 ± 0.013 kJ/mol 3.02327 ± 0.00021 28132-48-1*1 Water anion [H2O]- (g) -50.1 -53.0 ± 4.3 kJ/mol 18.01583 ± 0.00033 12259-30-2*0 Water H2O (cr, eq.press.) -286.302 -292.743 ± 0.027 kJ/mol 18.01528 ± 0.00033 7732-18-5*509 Dioxygen difluoride cation [FOOF]+ (g) 1291.4 1288.2 ± 4.6 kJ/mol 69.99506 ± 0.00060 *7783-44-0*0 Peroxyformic acid HC(O)OOH (g) -279.8 -288.9 ± 1.1 kJ/mol 62.0248 ± 0.0012 107-32-4*0 Hydrogen isocyanide anion [HNC]- (g) 191.56 191.74 ± 0.38 kJ/mol 27.02593 ± 0.00081 96913-22-3*0 Succinic acid (CH2COOH)2 (g) -795.63 -817.77 ± 0.61 kJ/mol 118.0880 ± 0.0034 110-15-6*0 Diiodine cation [I2]+ (g) 963.523 960.408 ± 0.018 kJ/mol 253.808391 ± 0.000060 28712-14-3*0 Oxirene O(CHCH) (g) 272.81 272.12 ± 0.98 kJ/mol 42.0367 ± 0.0016 157-18-6*0 Oxirene O(CHCH) (g, triplet) 388.7 385.4 ± 2.6 kJ/mol 42.0367 ± 0.0016 157-18-6*1 Hydrodioxonitrogen cation [HN(O)O]+ (g) 1129.6 1123.0 ± 3.2 kJ/mol 47.01293 ± 0.00061 252986-76-8*0 Ethylidene CH3CH (g) 361.45 354.47 ± 0.82 kJ/mol 28.0532 ± 0.0016 4218-50-2*0 Oxoniumyl ion [H2O]+ (g, para) 978.722 975.571 ± 0.029 kJ/mol 18.01473 ± 0.00033 56583-62-1*2 Hydrogen peroxide cation [H2O2]+ (g, cis, ortho) 930.94 924.05 ± 0.94 kJ/mol 34.01413 ± 0.00062 12325-10-9*21 Vinyl alcohol cation [CH2CHOH]+ (g, anti-syn equilib) 779.2 768.3 ± 1.2 kJ/mol 44.0520 ± 0.0017 57239-63-1*0 Methanediol CH2(OH)2 (g) -379.05 -392.44 ± 0.95 kJ/mol 48.0413 ± 0.0010 463-57-0*0 Trioxidanyl HOOO (g, cis) 26.29 23.01 ± 0.19 kJ/mol 49.00614 ± 0.00090 12500-78-6*2 Cyanogen NCCN (cr,l) 273.93 289.18 ± 0.43 kJ/mol 52.0349 ± 0.0016 460-19-5*500 1,1-Dibromoethane CHBr2CH3 (cr,l) -66.4 ± 1.4 kJ/mol 187.8612 ± 0.0026 557-91-5*500 Xenon dication [Xe]+2 (g) 3194.14 3194.14 ± 0.36 kJ/mol 131.2889 ± 0.0200 14066-95-6*0 Trioxidaniumyl [HOOOH]+ (g) 927.1 918.2 ± 1.3 kJ/mol 50.01353 ± 0.00091 161321-37-5*0 Hydrodioxonitrate [HN(O)O]- (g) -62.4 -68.8 ± 3.3 kJ/mol 47.01403 ± 0.00061 61508-71-2*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. ± 76. kJ/mol 39.94855 ± 0.00100 16544-90-4*1 Argon anion Ar- (g) 23. 23. ± 76. kJ/mol 39.94855 ± 0.00100 16544-90-4*0 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 Neon cation Ne+ (g) 2080.662 2080.769 ± 0.0011 kJ/mol 20.17915 ± 0.00060 14782-23-1*0 Argon cation Ar+ (g) 1520.571 1520.580 ± 0.0011 kJ/mol 39.94745 ± 0.00100 14791-69-6*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 Argon anion Ar- (g, 4S3/2) 1111.116 1111.116 ± 0.099 kJ/mol 39.94855 ± 0.00100 16544-90-4*2 Argon dimer Ar2 (g) -1.012 -6.346 ± 0.0092 kJ/mol 79.8960 ± 0.0020 12595-59-4*0 Hydron H+ (aq) 0 0 exact 1.007391 ± 0.000070 12408-02-5*800