ATcT [1 , 2 ] enthalpies of formation based on version 1.122x of the Thermochemical Network [3 ]
Below is a list of 0 K and 298.15 K enthalpies of formation
for all 2379 species included in version 1.122x (as of 09/01/2022). This version of ATcT results was generated from an expansion of version 1.122v [4 ] to include species relevant to the study of bond dissociation enthalpies of representative aromatic aldehydes [5 ].
The elements in their standard states are listed first; the listing order of the other species follows the actual order from the ATcT solution file,
which roughly reflects the number of thermochemically-relevant determinations that include the species in question (highest first).
The intent is to convey a very approximate indication of the robustness of the listed values, which is generally higher toward the top of the list
and lower toward the bottom.
For species other than elements in their standard states, the Species Name acts as a link to the page
itemizing the most important contributors to the provenance of its ATcT enthalpy of formation, other highly correlated chemical species, and high-leverage reactions in the Thermochemical Network.
(Please note that, as opposed to traditional sequential thermochemistry where the provenance of a given enthalpy of formation is typically a single measurement,
the provenances of ATcT enthalpies of formation, which are obtained by analysing and solving a large Thermochemical Network, are normally quite distributed.)
Reaction Search
The stoichiometry represents fractions as decimals, e.g. 0.5 O2, 1 H2, 1 H2O would represent 1/2 O2 + H2 → H2O
Species Name
Preferred Formula
Image
Δf H°(0 K)
Δf H°(298.15 K)
Uncertainty
Units
Relative Molecular Mass
ATcT ID
Dihydrogen H2 (g) 0 0 exact 2.01588 ± 0.00014 1333-74-0*0 Helium He (g) 0 0 exact 4.0026020 ± 0.0000020 7440-59-7*0 Carbon C (graphite) 0 0 exact 12.01070 ± 0.00080 7440-44-0*500 Dinitrogen N2 (g) 0 0 exact 28.01348 ± 0.00014 7727-37-9*0 Dioxygen O2 (g) 0 0 exact 31.99880 ± 0.00060 7782-44-7*0 Difluorine F2 (g) 0 0 exact 37.9968064 ± 0.0000010 7782-41-4*0 Neon Ne (g) 0 0 exact 20.17970 ± 0.00060 7440-01-9*0 Silicon Si (cr,l) 0 0 exact 28.08550 ± 0.00030 7440-21-3*500 Sulfur S (cr,l) 0 0 exact 32.0660 ± 0.0060 7704-34-9*500 Dichlorine Cl2 (g) 0 0 exact 70.9054 ± 0.0018 7782-50-5*0 Argon Ar (g) 0 0 exact 39.94800 ± 0.00100 7440-37-1*0 Dibromine Br2 (cr,l) 0 0 exact 159.8080 ± 0.0020 7726-95-6*500 Krypton Kr (g) 0 0 exact 83.8000 ± 0.1000 7439-90-9*0 Diiodine I2 (cr,l) 0 0 exact 253.808940 ± 0.000060 7553-56-2*500 Xenon Xe (g) 0 0 exact 131.2900 ± 0.0200 7440-63-3*0 Platinum Pt (cr,l) 0 0 exact 195.0780 ± 0.0020 7440-06-4*500 Radon Rn (g) 0 0 exact 222.0000 ± 0.1000 10043-92-2*0 Deuterium molecule D2 (g) 0 0 exact 4.02820355600 ± 0.00000000080 7782-39-0*0 Hydrogen atom H (g) 216.034 217.998 ± 0.000 kJ/mol 1.007940 ± 0.000070 12385-13-6*0 Carbon C (g) 711.411 716.896 ± 0.044 kJ/mol 12.01070 ± 0.00080 7440-44-0*0 Oxygen atom O (g) 246.844 249.229 ± 0.0021 kJ/mol 15.99940 ± 0.00030 17778-80-2*0 Methane CH4 (g) -66.546 -74.515 ± 0.048 kJ/mol 16.04246 ± 0.00085 74-82-8*0 Nitrogen atom N (g) 470.580 472.442 ± 0.024 kJ/mol 14.006740 ± 0.000070 17778-88-0*0 Carbon dioxide CO2 (g) -393.110 -393.476 ± 0.015 kJ/mol 44.00950 ± 0.00100 124-38-9*0 Ethane CH3CH3 (g) -68.39 -84.01 ± 0.12 kJ/mol 30.0690 ± 0.0017 74-84-0*0 Water H2O (cr,l) -286.267 -285.795 ± 0.025 kJ/mol 18.01528 ± 0.00033 7732-18-5*500 Water H2O (g) -238.898 -241.801 ± 0.025 kJ/mol 18.01528 ± 0.00033 7732-18-5*0 Hydron H+ (g) 1528.084 1530.047 ± 0.000 kJ/mol 1.007391 ± 0.000070 12408-02-5*0 Chlorine atom Cl (g) 119.621 121.302 ± 0.0011 kJ/mol 35.45270 ± 0.00090 22537-15-1*0 Fluorine atom F (g) 77.253 79.359 ± 0.017 kJ/mol 18.99840320 ± 0.00000050 14762-94-8*0 Ethylene CH2CH2 (g) 60.89 52.38 ± 0.12 kJ/mol 28.0532 ± 0.0016 74-85-1*0 Propane CH3CH2CH3 (g) -82.72 -105.00 ± 0.16 kJ/mol 44.0956 ± 0.0025 74-98-6*0 Methyl CH3 (g) 149.878 146.464 ± 0.053 kJ/mol 15.03452 ± 0.00083 2229-07-4*0 Methanol CH3OH (g) -190.03 -200.91 ± 0.15 kJ/mol 32.04186 ± 0.00090 67-56-1*0 Bromine atom Br (g) 117.910 111.848 ± 0.056 kJ/mol 79.90400 ± 0.00100 10097-32-2*0 Formaldehyde CH2O (g) -105.386 -109.226 ± 0.096 kJ/mol 30.02598 ± 0.00087 50-00-0*0 Hydroxyl OH (g) 37.283 37.523 ± 0.025 kJ/mol 17.00734 ± 0.00031 3352-57-6*0 Ammonia NH3 (g) -38.562 -45.555 ± 0.029 kJ/mol 17.03056 ± 0.00022 7664-41-7*0 Carbon monoxide CO (g) -113.804 -110.524 ± 0.026 kJ/mol 28.01010 ± 0.00085 630-08-0*0 Ethanol CH3CH2OH (g) -217.32 -235.04 ± 0.21 kJ/mol 46.0684 ± 0.0017 64-17-5*0 Acetylene HCCH (g) 228.84 228.28 ± 0.12 kJ/mol 26.0373 ± 0.0016 74-86-2*0 Hydrogen chloride HCl (g) -91.988 -92.172 ± 0.0062 kJ/mol 36.46064 ± 0.00090 7647-01-0*0 Benzene C6H6 (g) 100.75 83.24 ± 0.22 kJ/mol 78.1118 ± 0.0048 71-43-2*0 Ethyl CH3CH2 (g) 131.39 120.64 ± 0.22 kJ/mol 29.0611 ± 0.0016 2025-56-1*0 Hydrogen fluoride HF (g) -272.679 -272.726 ± 0.018 kJ/mol 20.006343 ± 0.000070 7664-39-3*0 Propene CH3CHCH2 (g) 34.85 20.01 ± 0.19 kJ/mol 42.0797 ± 0.0024 115-07-1*0 Iodine I (g) 107.157 106.757 ± 0.0021 kJ/mol 126.904470 ± 0.000030 14362-44-8*0 Hydrogen bromide HBr (g) -27.89 -35.73 ± 0.13 kJ/mol 80.9119 ± 0.0010 10035-10-6*0 Hydrogen cyanide HCN (g) 129.666 129.282 ± 0.088 kJ/mol 27.02538 ± 0.00081 74-90-8*0 Nitric oxide NO (g) 90.642 91.145 ± 0.067 kJ/mol 30.00614 ± 0.00031 10102-43-9*0 Chloromethane CH3Cl (g) -74.72 -82.65 ± 0.16 kJ/mol 50.4872 ± 0.0012 74-87-3*0 Propyne CH3CCH (g) 192.66 185.51 ± 0.22 kJ/mol 40.0639 ± 0.0024 74-99-7*0 Acetaldehyde CH3CHO (g) -155.02 -165.55 ± 0.23 kJ/mol 44.0526 ± 0.0017 75-07-0*0 Nitrogen dioxide ONO (g) 36.881 34.074 ± 0.067 kJ/mol 46.00554 ± 0.00060 10102-44-0*0 Acetone CH3C(O)CH3 (g) -199.99 -216.93 ± 0.27 kJ/mol 58.0791 ± 0.0025 67-64-1*0 Hydroxyde [OH]- (g) -139.059 -139.025 ± 0.025 kJ/mol 17.00789 ± 0.00031 14280-30-9*0 Fluoromethane CH3F (g) -227.43 -235.46 ± 0.23 kJ/mol 34.03292 ± 0.00083 593-53-3*0 Dioxidanyl HO2 (g) 15.14 12.23 ± 0.15 kJ/mol 33.00674 ± 0.00060 3170-83-0*0 Hydrogen iodide HI (g) 28.643 26.467 ± 0.036 kJ/mol 127.912410 ± 0.000076 10034-85-2*0 Methylamine CH3NH2 (g) -6.48 -21.18 ± 0.23 kJ/mol 31.05714 ± 0.00088 74-89-5*0 Hydrogen peroxide H2O2 (g) -129.411 -135.396 ± 0.061 kJ/mol 34.01468 ± 0.00062 7722-84-1*0 n-Butane CH3CH2CH2CH3 (g) -98.33 -125.64 ± 0.24 kJ/mol 58.1222 ± 0.0033 106-97-8*0 Toluene C6H5CH3 (g) 73.37 50.08 ± 0.32 kJ/mol 92.1384 ± 0.0056 108-88-3*0 Allene CH2CCH2 (g) 197.40 189.94 ± 0.23 kJ/mol 40.0639 ± 0.0024 463-49-0*0 Methylene CH2 (g, triplet) 391.060 391.618 ± 0.096 kJ/mol 14.02658 ± 0.00081 2465-56-7*1 Vinyl CH2CH (g) 301.26 297.22 ± 0.30 kJ/mol 27.0452 ± 0.0016 2669-89-8*0 Methylene CH2 (g, singlet) 428.72 429.13 ± 0.11 kJ/mol 14.02658 ± 0.00081 2465-56-7*2 Silicon Si (g) 449.73 454.07 ± 0.57 kJ/mol 28.08550 ± 0.00030 7440-21-3*0 Bromomethane CH3Br (g) -20.90 -36.30 ± 0.16 kJ/mol 94.9385 ± 0.0013 74-83-9*0 1,3-Butadiene CH2CHCHCH2 (g) 125.55 111.07 ± 0.32 kJ/mol 54.0904 ± 0.0032 106-99-0*0 Ozone OOO (g) 144.406 141.744 ± 0.039 kJ/mol 47.99820 ± 0.00090 10028-15-6*0 Acetonitrile CH3CN (g) 81.12 74.06 ± 0.24 kJ/mol 41.0520 ± 0.0016 75-05-8*0 Methoxy CH3O (g) 28.93 21.56 ± 0.27 kJ/mol 31.03392 ± 0.00088 2143-68-2*0 Formic acid HC(O)OH (g, syn) -371.05 -378.36 ± 0.22 kJ/mol 46.0254 ± 0.0010 64-18-6*1 Fluoride F- (g) -250.912 -249.127 ± 0.017 kJ/mol 18.99895178 ± 0.00000050 16984-48-8*0 iso-Butane CH(CH3)3 (g) -105.88 -134.48 ± 0.28 kJ/mol 58.1222 ± 0.0033 75-28-5*0 Hypochlorous acid HOCl (g) -73.835 -76.774 ± 0.026 kJ/mol 52.46004 ± 0.00095 7790-92-3*0 Phenyl C6H5 (g) 352.19 338.83 ± 0.63 kJ/mol 77.1039 ± 0.0048 2396-01-2*0 Silane SiH4 (g) 42.11 32.50 ± 0.66 kJ/mol 32.11726 ± 0.00041 7803-62-5*0 Dibromine Br2 (g) 45.67 30.87 ± 0.11 kJ/mol 159.8080 ± 0.0020 7726-95-6*0 Ketene CH2CO (g) -45.35 -48.41 ± 0.11 kJ/mol 42.0367 ± 0.0016 463-51-4*0 Acetic acid CH3C(O)OH (g, syn) -418.53 -432.69 ± 0.36 kJ/mol 60.0520 ± 0.0017 64-19-7*1 Tetrafluoromethane CF4 (g) -927.63 -933.60 ± 0.23 kJ/mol 88.00431 ± 0.00080 75-73-0*0 Diiodine I2 (g) 65.497 62.417 ± 0.0041 kJ/mol 253.808940 ± 0.000060 7553-56-2*0 Methoxide [CH3O]- (g) -122.46 -130.19 ± 0.27 kJ/mol 31.03447 ± 0.00088 3315-60-4*0 Propargyl CH2CCH (g) 354.06 351.47 ± 0.32 kJ/mol 39.0559 ± 0.0024 2932-78-7*0 Formyl HCO (g) 41.384 41.758 ± 0.096 kJ/mol 29.01804 ± 0.00086 2597-44-6*0 Hydroxymethyl CH2OH (g) -10.36 -16.66 ± 0.28 kJ/mol 31.03392 ± 0.00088 2597-43-5*0 Chloroethane CH3CH2Cl (g) -96.95 -111.53 ± 0.25 kJ/mol 64.5138 ± 0.0019 75-00-3*0 Methylidyne CH (g) 592.840 596.175 ± 0.097 kJ/mol 13.01864 ± 0.00080 3315-37-5*0 Nitrilomethyl CN (g) 436.77 440.05 ± 0.14 kJ/mol 26.01744 ± 0.00080 2074-87-5*0 Fluoroform CHF3 (g) -689.18 -696.13 ± 0.38 kJ/mol 70.01385 ± 0.00080 75-46-7*0 Chloride Cl- (g) -228.953 -227.346 ± 0.0021 kJ/mol 35.45325 ± 0.00090 16887-00-6*0 Trifluoromethyl CF3 (g) -464.86 -467.66 ± 0.43 kJ/mol 69.00591 ± 0.00080 2264-21-3*0 Ethylium [CH3CH2]+ (g) 914.95 902.88 ± 0.30 kJ/mol 29.0606 ± 0.0016 14936-94-8*0 Allyl CH2CHCH2 (g) 180.01 168.29 ± 0.40 kJ/mol 41.0718 ± 0.0024 1981-80-2*0 Phenol C6H5OH (g) -74.66 -93.26 ± 0.63 kJ/mol 94.1112 ± 0.0048 108-95-2*0 Tetrachloromethane CCl4 (g) -89.34 -91.51 ± 0.41 kJ/mol 153.8215 ± 0.0037 56-23-5*0 Sulfur dioxide OSO (g) -294.13 -296.68 ± 0.13 kJ/mol 64.0648 ± 0.0060 7446-09-5*0 Bromide Br- (g) -206.627 -212.689 ± 0.056 kJ/mol 79.90455 ± 0.00100 24959-67-9*0 Oxomethylium [HCO]+ (g) 827.760 827.176 ± 0.096 kJ/mol 29.01749 ± 0.00086 17030-74-9*0 Hypobromous acid HOBr (g) -51.36 -61.84 ± 0.48 kJ/mol 96.9113 ± 0.0010 13517-11-8*0 Amidogen NH2 (g) 188.91 186.02 ± 0.11 kJ/mol 16.02262 ± 0.00016 13770-40-6*0 Ethenol CH2CHOH (g, syn) -113.37 -124.49 ± 0.38 kJ/mol 44.0526 ± 0.0017 557-75-5*1 Oxonium [H3O]+ (g) 605.88 599.13 ± 0.17 kJ/mol 19.02267 ± 0.00037 13968-08-6*0 Benzaldehyde C6H5C(O)H (g) -19.76 -37.56 ± 0.77 kJ/mol 106.1219 ± 0.0056 100-52-7*0 Chlorooxidanyl ClO (g) 101.124 101.716 ± 0.035 kJ/mol 51.45210 ± 0.00095 14989-30-1*0 Iodide I- (g) -187.995 -188.396 ± 0.0021 kJ/mol 126.905019 ± 0.000030 20461-54-5*0 Methyl hydroperoxide CH3OOH (g) -114.88 -127.70 ± 0.46 kJ/mol 48.0413 ± 0.0010 3031-73-0*0 Acetyl CH3CO (g) -3.45 -10.02 ± 0.30 kJ/mol 43.0446 ± 0.0016 3170-69-2*0 Formamide CH(O)NH2 (g) -178.58 -188.95 ± 0.35 kJ/mol 45.04066 ± 0.00088 75-12-7*0 Hydroxyformyl HOCO (g, trans) -181.18 -184.15 ± 0.42 kJ/mol 45.0174 ± 0.0010 2564-86-5*1 Vinyl chloride CH2CHCl (g) 29.38 21.80 ± 0.28 kJ/mol 62.4979 ± 0.0018 75-01-4*0 Imidogen NH (g) 358.74 358.79 ± 0.16 kJ/mol 15.014680 ± 0.000099 13774-92-0*0 iso-Propyl CH3CHCH3 (g) 105.61 88.74 ± 0.45 kJ/mol 43.0877 ± 0.0024 2025-55-0*0 Dioxymethyl CH2OO (g) 111.95 104.94 ± 0.62 kJ/mol 46.0254 ± 0.0010 56077-92-0*0 Cyanoacetylene HCCCN (g) 372.13 373.87 ± 0.62 kJ/mol 51.0468 ± 0.0024 1070-71-9*0 Vinylacetylene CH2CHCCH (g) 296.26 289.50 ± 0.56 kJ/mol 52.0746 ± 0.0032 689-97-4*0 Nitric acid HON(O)O (g) -124.44 -134.15 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*0 Ethoxide [CH3CH2O]- (g) -163.87 -178.81 ± 0.45 kJ/mol 45.0610 ± 0.0017 16331-64-9*0 n-Propyl CH3CH2CH2 (g) 118.42 101.02 ± 0.48 kJ/mol 43.0877 ± 0.0024 2143-61-5*0 Methoxymethane CH3OCH3 (g) -166.50 -184.01 ± 0.37 kJ/mol 46.0684 ± 0.0017 115-10-6*0 Methanimine CH2NH (g) 96.46 88.55 ± 0.37 kJ/mol 29.04126 ± 0.00083 2053-29-4*0 Methylium [CH3]+ (g) 1099.350 1095.407 ± 0.049 kJ/mol 15.03397 ± 0.00083 14531-53-4*0 Hydrogen chloride HCl (aq, 600 H2O) -166.450 ± 0.024 kJ/mol 36.46064 ± 0.00090 7647-01-0*834 Methylperoxy CH3OO (g) 22.51 13.06 ± 0.37 kJ/mol 47.0333 ± 0.0010 2143-58-0*0 1-Hydroxyethyl CH3CHOH (g, gauche-anti) -42.86 -56.29 ± 0.47 kJ/mol 45.0605 ± 0.0017 2348-46-1*1 Isocyanic acid HNCO (g) -115.96 -118.95 ± 0.28 kJ/mol 43.02478 ± 0.00086 75-13-8*0 Difluorophosgene CF2O (g) -603.33 -606.43 ± 0.40 kJ/mol 66.00691 ± 0.00085 353-50-4*0 Hypofluorous acid HOF (g) -84.37 -87.27 ± 0.19 kJ/mol 36.00574 ± 0.00031 14034-79-8*0 Oxygen atom anion O- (g) 105.868 108.097 ± 0.0021 kJ/mol 15.99995 ± 0.00030 14337-01-0*0 Iodomethane CH3I (g) 24.40 14.86 ± 0.18 kJ/mol 141.93899 ± 0.00083 74-88-4*0 Dichloromethane CH2Cl2 (g) -86.90 -93.76 ± 0.33 kJ/mol 84.9320 ± 0.0020 75-09-2*0 1,3-Butadiyne HCCCCH (g) 458.33 460.06 ± 0.58 kJ/mol 50.0587 ± 0.0032 460-12-8*0 Chlorobenzene C6H5Cl (g) 67.28 52.32 ± 0.61 kJ/mol 112.5566 ± 0.0049 108-90-7*0 Ethynyl CCH (g) 563.89 568.00 ± 0.14 kJ/mol 25.0293 ± 0.0016 2122-48-7*0 Ethynide [CCH]- (g) 277.44 280.85 ± 0.18 kJ/mol 25.0299 ± 0.0016 29075-95-4*0 1,2-Butadiene CH3CHCCH2 (g) 176.02 162.53 ± 0.43 kJ/mol 54.0904 ± 0.0032 590-19-2*0 Trihydrogen cation [H3]+ (g) 1110.304 1106.696 ± 0.013 kJ/mol 3.02327 ± 0.00021 28132-48-1*0 Cyanogen chloride ClCN (g) 135.18 135.88 ± 0.46 kJ/mol 61.4701 ± 0.0012 506-77-4*0 Isocyanomethane CH3NC (g) 183.83 177.29 ± 0.48 kJ/mol 41.0520 ± 0.0016 593-75-9*0 2-Hydroxyethyl CH2CH2OH (g, gauche-syn) -13.07 -26.33 ± 0.49 kJ/mol 45.0605 ± 0.0017 4422-54-2*1 Methyl formate HC(O)OCH3 (g, syn) -346.94 -359.98 ± 0.65 kJ/mol 60.0520 ± 0.0017 107-31-3*1 Dimethylamine (CH3)2NH (g) 4.20 -17.43 ± 0.41 kJ/mol 45.0837 ± 0.0017 124-40-3*0 Sulfur trioxide OS(O)O (g) -389.75 -395.49 ± 0.24 kJ/mol 80.0642 ± 0.0061 7446-11-9*0 Ammonium [NH4]+ (g) 643.01 631.70 ± 0.20 kJ/mol 18.03795 ± 0.00029 14798-03-9*0 2-Butyne CH3CCCH3 (g) 159.42 146.46 ± 0.46 kJ/mol 54.0904 ± 0.0032 503-17-3*0 Cyclopropene CH2(CHCH) (g) 292.36 283.63 ± 0.45 kJ/mol 40.0639 ± 0.0024 2781-85-3*0 Cyclopentadiene CH2(CHCHCHCH) (g) 151.46 134.34 ± 0.61 kJ/mol 66.1011 ± 0.0040 542-92-7*0 Difluoromethane CH2F2 (g) -443.19 -450.80 ± 0.32 kJ/mol 52.02339 ± 0.00081 75-10-5*0 Oxygen difluoride FOF (g) 26.82 24.57 ± 0.22 kJ/mol 53.99621 ± 0.00030 7783-41-7*0 Hypochlorite [ClO]- (g) -118.60 -118.33 ± 0.13 kJ/mol 51.45265 ± 0.00095 14380-61-1*0 Hydride H- (g) 143.264 145.228 ± 0.000 kJ/mol 1.008489 ± 0.000070 12184-88-2*0 Nitrosyl hydride HNO (g) 109.95 106.98 ± 0.11 kJ/mol 31.01408 ± 0.00032 14332-28-6*0 Cyclopropane CH2(CH2CH2) (g) 71.01 53.88 ± 0.38 kJ/mol 42.0797 ± 0.0024 75-19-4*0 Propynylidene HCCCH (g, triplet) 543.51 546.51 ± 0.65 kJ/mol 38.0480 ± 0.0024 67152-18-5*1 Isobutene CH2C(CH3)2 (g) 4.18 -16.89 ± 0.38 kJ/mol 56.1063 ± 0.0032 115-11-7*0 Butatriene CH2CCCH2 (g) 328.33 322.07 ± 0.62 kJ/mol 52.0746 ± 0.0032 2873-50-9*0 Ethoxy CH3CH2O (g, X 2A") 1.26 -12.65 ± 0.43 kJ/mol 45.0605 ± 0.0017 2154-50-9*51 Phosgene CCl2O (g) -217.50 -219.19 ± 0.24 kJ/mol 98.9155 ± 0.0020 75-44-5*0 1-Hydroxy-2-propanone CH3C(O)CH2OH (g, syn-syn) -354.56 -373.94 ± 0.84 kJ/mol 74.0785 ± 0.0025 116-09-6*11 Chloroform CHCl3 (g) -94.63 -99.53 ± 0.39 kJ/mol 119.3767 ± 0.0028 67-66-3*0 Tetrafluoroethylene CF2CF2 (g) -670.71 -674.11 ± 0.49 kJ/mol 100.0150 ± 0.0016 116-14-3*0 Fluoromethylidyne CF (g) 243.14 246.74 ± 0.12 kJ/mol 31.00910 ± 0.00080 3889-75-6*0 Phenide [C6H5]- (g) 244.35 230.92 ± 0.39 kJ/mol 77.1044 ± 0.0048 30922-78-2*0 Acrylonitrile CH2CHCN (g, singlet) 193.83 187.06 ± 0.66 kJ/mol 53.0627 ± 0.0024 107-13-1*1 Silanol SiH3OH (g) -271.8 -283.4 ± 1.3 kJ/mol 48.11666 ± 0.00051 14475-38-8*0 Oxygen atom cation O+ (g) 1560.786 1562.643 ± 0.0021 kJ/mol 15.99885 ± 0.00030 14581-93-2*0 Nitrous acid HONO (g, trans) -72.966 -79.109 ± 0.080 kJ/mol 47.01348 ± 0.00061 7782-77-6*1 1,2-Propadiene-1,3-diylidene CCC (g) 814.55 823.51 ± 0.53 kJ/mol 36.0321 ± 0.0024 12075-35-3*0 Oxirane O(CH2CH2) (g) -39.97 -52.50 ± 0.35 kJ/mol 44.0526 ± 0.0017 75-21-8*0 Vinyl anion [CH2CH]- (g) 237.00 232.58 ± 0.68 kJ/mol 27.0458 ± 0.0016 25012-81-1*0 Cyanide [CN]- (g) 63.962 67.248 ± 0.093 kJ/mol 26.01799 ± 0.00080 57-12-5*0 Cyanogen bromide BrCN (g) 186.6 180.0 ± 1.4 kJ/mol 105.9214 ± 0.0013 506-68-3*0 1-Butene CH2CHCH2CH3 (g) 21.15 0.20 ± 0.35 kJ/mol 56.1063 ± 0.0032 106-98-9*0 Formate [HC(O)O]- (g) -463.15 -466.80 ± 0.55 kJ/mol 45.0180 ± 0.0010 71-47-6*0 Methyl acetate CH3C(O)OCH3 (g, syn) -394.15 -413.02 ± 0.57 kJ/mol 74.0785 ± 0.0025 79-20-9*1 Ethyl bromide CH3CH2Br (g) -41.33 -63.28 ± 0.24 kJ/mol 108.9651 ± 0.0019 74-96-4*0 Vinyl bromide CH2CHBr (g) 88.69 73.89 ± 0.56 kJ/mol 106.9492 ± 0.0019 593-60-2*0 Benzoyl C6H5CO (g) 138.3 124.7 ± 1.1 kJ/mol 105.1140 ± 0.0056 2652-65-5*0 Methyl nitrite CH3ONO (g, cis) -55.55 -67.33 ± 0.45 kJ/mol 61.0401 ± 0.0010 624-91-9*2 Silyl SiH3 (g) 204.09 198.61 ± 0.90 kJ/mol 31.10932 ± 0.00037 13765-44-1*0 Naphthalene C6H4(C4H4) (g) 171.07 147.60 ± 0.59 kJ/mol 128.1705 ± 0.0080 91-20-3*0 Chlorine fluoride ClF (g) -55.622 -55.717 ± 0.030 kJ/mol 54.45110 ± 0.00090 7790-89-8*0 Diazynium [NNH]+ (g) 1042.53 1038.91 ± 0.68 kJ/mol 29.02087 ± 0.00016 12357-66-3*0 Nitrite [ONO]- (g) -182.61 -185.42 ± 0.46 kJ/mol 46.00609 ± 0.00060 14797-65-0*0 Hydroxylamine NH2OH (g, trans) -33.07 -43.45 ± 0.42 kJ/mol 33.02996 ± 0.00037 7803-49-8*1 n-Butyl CH3CH2CH2CH2 (g) 103.02 80.51 ± 0.70 kJ/mol 57.1143 ± 0.0033 2492-36-6*0 cis-2-Butene CH3CHCHCH3 (g, cis) 14.32 -6.95 ± 0.40 kJ/mol 56.1063 ± 0.0032 590-18-1*0 1-Butyne CH3CH2CCH (g) 180.35 166.77 ± 0.56 kJ/mol 54.0904 ± 0.0032 107-00-6*0 n-Hexane CH3CH2CH2CH2CH2CH3 (g) -129.88 -166.75 ± 0.33 kJ/mol 86.1754 ± 0.0049 110-54-3*0 Acetone enol CH3C(OH)CH2 (g, syn) -151.35 -168.64 ± 0.69 kJ/mol 58.0791 ± 0.0025 29456-04-0*1 Tetrabromomethane CBr4 (g) 142.9 113.2 ± 1.1 kJ/mol 331.6267 ± 0.0041 558-13-4*0 Vinyl fluoride CH2CHF (g) -134.52 -142.32 ± 0.45 kJ/mol 46.0436 ± 0.0016 75-02-5*0 Phenylium [C6H5]+ (g) 1149.17 1136.39 ± 0.85 kJ/mol 77.1034 ± 0.0048 17333-73-2*0 Fluorooxidanyl FO (g) 110.28 110.90 ± 0.14 kJ/mol 34.99780 ± 0.00030 12061-70-0*0 Hypoiodous acid HOI (g) -54.1 -58.9 ± 3.1 kJ/mol 143.91181 ± 0.00031 14332-21-9*0 Methanium [CH5]+ (g) 921.98 911.74 ± 0.44 kJ/mol 17.04985 ± 0.00087 15135-49-6*0 Ethylidene CH3CH (g, triplet) 361.27 354.27 ± 0.46 kJ/mol 28.0532 ± 0.0016 4218-50-2*1 Cyanomethyl CH2CN (g) 263.31 260.43 ± 0.59 kJ/mol 40.0440 ± 0.0016 2932-82-3*0 Cyanic fluoride FCN (g) 8.61 8.94 ± 0.71 kJ/mol 45.01584 ± 0.00080 1495-50-7*0 n-Pentane CH3CH2CH2CH2CH3 (g) -114.17 -146.04 ± 0.30 kJ/mol 72.1488 ± 0.0041 109-66-0*0 Formic acid HC(O)OH (g, anti) -354.72 -361.82 ± 0.38 kJ/mol 46.0254 ± 0.0010 64-18-6*2 Cyanooxidanyl NCO (g) 126.94 127.42 ± 0.33 kJ/mol 42.01684 ± 0.00086 22400-26-6*0 Methanetetraylbisamidogen NCN (g) 451.24 451.65 ± 0.44 kJ/mol 40.02418 ± 0.00081 2669-76-3*0 Fluoroethane CH3CH2F (g) -257.22 -272.08 ± 0.36 kJ/mol 48.0595 ± 0.0016 353-36-6*0 Chlorotrifluoromethane CF3Cl (g) -704.26 -709.37 ± 0.56 kJ/mol 104.4586 ± 0.0012 75-72-9*0 Fluorobenzene C6H5F (g) -99.00 -114.67 ± 0.89 kJ/mol 96.1023 ± 0.0048 462-06-6*0 Nitromethane CH3N(O)O (g) -60.74 -74.64 ± 0.46 kJ/mol 61.0401 ± 0.0010 75-52-5*0 Pyridine N(CHCHCHCHCH) (g) 157.36 140.56 ± 0.40 kJ/mol 79.0999 ± 0.0040 110-86-1*0 Acrylonitrile CH2CHCN (g) 193.83 187.06 ± 0.66 kJ/mol 53.0627 ± 0.0024 107-13-1*0 1,2,3-Butatrien-1-yl CH2CCCH (g) 497.44 497.45 ± 0.69 kJ/mol 51.0666 ± 0.0032 22112-56-7*0 Disilane SiH3SiH3 (g) 90.9 74.8 ± 1.4 kJ/mol 62.21864 ± 0.00073 1590-87-0*0 2,4-Hexadiyne CH3CCCCCH3 (g) 380.24 370.21 ± 0.87 kJ/mol 78.1118 ± 0.0048 2809-69-0*0 Bromooxidanyl BrO (g) 131.20 123.66 ± 0.28 kJ/mol 95.9034 ± 0.0010 15656-19-6*0 Dioxygen cation [O2]+ (g) 1164.585 1165.221 ± 0.0092 kJ/mol 31.99825 ± 0.00060 12185-07-8*0 Ethynylene C2 (g) 820.017 828.483 ± 0.092 kJ/mol 24.0214 ± 0.0016 12070-15-4*0 Methylidyne CH (g, quartet) 664.60 667.93 ± 0.54 kJ/mol 13.01864 ± 0.00080 3315-37-5*2 Ethanide [CH3CH2]- (g) 155.45 144.37 ± 0.87 kJ/mol 29.0616 ± 0.0016 25013-41-6*0 Vinylium [CH2CH]+ (g) 1119.07 1115.63 ± 0.55 kJ/mol 27.0447 ± 0.0016 14604-48-9*0 Aminomethyl CH2NH2 (g) 159.34 149.50 ± 0.37 kJ/mol 30.04920 ± 0.00085 10507-29-6*0 Hydroxymethylium [CH2OH]+ (g) 717.68 709.74 ± 0.19 kJ/mol 31.03337 ± 0.00088 18682-95-6*0 Hydroxymethylene HCOH (g, trans) 112.69 108.92 ± 0.27 kJ/mol 30.02598 ± 0.00087 19710-56-6*1 Peroxyformic acid HC(O)OOH (g, cis) -279.23 -288.58 ± 0.88 kJ/mol 62.0248 ± 0.0012 107-32-4*1 1,2-Propadienyl anion [CH2CCH]- (g) 266.07 263.01 ± 0.64 kJ/mol 39.0565 ± 0.0024 64066-06-4*0 Propadienylidene CH2CC (g) 554.44 555.59 ± 0.40 kJ/mol 38.0480 ± 0.0024 60731-10-4*0 trans-2-Butene CH3CHCHCH3 (g, trans) 9.46 -11.10 ± 0.37 kJ/mol 56.1063 ± 0.0032 624-64-6*0 Cyclopentane CH2(CH2CH2CH2CH2) (g) -43.67 -76.24 ± 0.41 kJ/mol 70.1329 ± 0.0041 287-92-3*0 Propionaldehyde CH3CH2CHO (g) -171.22 -186.62 ± 0.24 kJ/mol 58.0791 ± 0.0025 123-38-6*0 Phenolate [C6H5O]- (g) -146.42 -161.89 ± 0.84 kJ/mol 93.1038 ± 0.0048 3229-70-7*0 Bromotrifluoromethane CF3Br (g) -638.68 -650.79 ± 0.40 kJ/mol 148.9099 ± 0.0013 75-63-8*0 Bromoform CHBr3 (g) 79.7 53.5 ± 1.0 kJ/mol 252.7306 ± 0.0031 75-25-2*0 Cyclopentadienyl CH(CHCHCHCH) (g) 275.26 262.15 ± 0.92 kJ/mol 65.0932 ± 0.0040 2143-53-5*0 Carbamoyl NH2CO (g) -7.77 -14.17 ± 0.74 kJ/mol 44.03272 ± 0.00087 2858-51-7*0 Tetrahedrane CH(CH(CHCH)) (g) 547.72 539.31 ± 0.91 kJ/mol 52.0746 ± 0.0032 157-39-1*0 Silylene SiH2 (g, singlet) 270.79 269.12 ± 0.86 kJ/mol 30.10138 ± 0.00033 13825-90-6*2 Ethylamine CH3CH2NH2 (g) -28.20 -49.97 ± 0.53 kJ/mol 45.0837 ± 0.0017 75-04-7*0 Hydrogen sulfide H2S (g) -17.35 -20.27 ± 0.19 kJ/mol 34.0819 ± 0.0060 7783-06-4*0 Chlorine dioxide OClO (g) 101.41 98.94 ± 0.29 kJ/mol 67.4515 ± 0.0011 10049-04-4*0 Azanide [NH2]- (g) 114.66 111.78 ± 0.30 kJ/mol 16.02317 ± 0.00016 17655-31-1*0 (E)-Diazene HNNH (g, trans) 207.12 199.98 ± 0.41 kJ/mol 30.02936 ± 0.00020 15626-43-4*0 Peroxynitrous acid HOONO (g, cis, cis) -5.76 -14.20 ± 0.36 kJ/mol 63.01288 ± 0.00091 14691-52-2*3 Ethylidene CH3CH (g, singlet) 373.61 366.38 ± 0.57 kJ/mol 28.0532 ± 0.0016 4218-50-2*2 Cyanogen NCCN (g) 308.18 310.13 ± 0.41 kJ/mol 52.0349 ± 0.0016 460-19-5*0 1-Methylethenyl CH3CCH2 (g) 263.03 252.63 ± 0.62 kJ/mol 41.0718 ± 0.0024 15552-77-9*0 neo-Pentane C(CH3)4 (g) -134.22 -167.10 ± 0.38 kJ/mol 72.1488 ± 0.0041 463-82-1*0 Hydrogen fluoride HF (aq) -334.51 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*800 Trimethylamine (CH3)3N (g) 2.26 -26.60 ± 0.76 kJ/mol 59.1103 ± 0.0025 75-50-3*0 Dichloromethylene CCl2 (g, singlet) 229.89 231.07 ± 0.64 kJ/mol 82.9161 ± 0.0020 1605-72-7*2 Trifluoromethylium [CF3]+ (g) 409.77 406.56 ± 0.42 kJ/mol 69.00536 ± 0.00080 18851-76-8*0 Trioxidane HOOOH (g, trans) -81.95 -90.79 ± 0.62 kJ/mol 50.01408 ± 0.00091 14699-99-1*1 Ethyl nitrite CH3CH2ONO (g, trans-cis) -81.30 -100.04 ± 0.87 kJ/mol 75.0666 ± 0.0017 109-95-5*1 Hypobromite [BrO]- (g) -96.04 -103.53 ± 0.54 kJ/mol 95.9039 ± 0.0010 14380-62-2*0 Azido radical NNN (g) 452.24 449.66 ± 0.60 kJ/mol 42.02022 ± 0.00021 12596-60-0*0 Nitrous oxide NNO (g) 86.024 82.595 ± 0.096 kJ/mol 44.01288 ± 0.00033 10024-97-2*0 Dioxidanide [HO2]- (g) -88.85 -91.52 ± 0.35 kJ/mol 33.00729 ± 0.00060 14691-59-9*0 Ozonide [OOO]- (g) -58.47 -60.82 ± 0.21 kJ/mol 47.99875 ± 0.00090 12596-80-4*0 Hydroxyoxomethylium [HOCO]+ (g) 600.68 597.59 ± 0.44 kJ/mol 45.0169 ± 0.0010 638-71-1*0 Hydroxyamidogen HNOH (g, trans) 101.26 94.42 ± 0.80 kJ/mol 32.02202 ± 0.00034 13940-32-4*1 Hydrazoic acid HNNN (g) 297.88 291.58 ± 0.49 kJ/mol 43.02816 ± 0.00022 7782-79-8*0 Vinylidene CCH2 (g) 411.23 412.14 ± 0.30 kJ/mol 26.0373 ± 0.0016 2143-69-3*0 Acetylium [CH3CO]+ (g) 666.65 659.36 ± 0.42 kJ/mol 43.0441 ± 0.0016 15762-07-9*0 Chloroacetylene HCCCl (g) 229.30 230.16 ± 0.45 kJ/mol 60.4820 ± 0.0018 593-63-5*0 Fluoroacetylene HCCF (g) 104.97 105.69 ± 0.40 kJ/mol 44.0277 ± 0.0016 2713-09-9*0 Peroxyformyl HC(O)OO (g, syn) -100.65 -105.95 ± 0.93 kJ/mol 61.0168 ± 0.0012 56240-83-6*1 1-Propenyl CH3CHCH (g, cis) 278.22 267.37 ± 0.63 kJ/mol 41.0718 ± 0.0024 6067-68-1*2 Water H2O (l) -285.795 ± 0.025 kJ/mol 18.01528 ± 0.00033 7732-18-5*590 Ketenyl HCCO (g) 177.08 178.18 ± 0.54 kJ/mol 41.0287 ± 0.0016 51095-15-9*0 Formic acid HC(O)OH (g) -371.05 -378.34 ± 0.22 kJ/mol 46.0254 ± 0.0010 64-18-6*0 Acetic acid CH3C(O)OH (g, anti) -397.72 -412.13 ± 0.52 kJ/mol 60.0520 ± 0.0017 64-19-7*2 Glycolaldehyde HC(O)CH2OH (g, syn-syn) -304.46 -317.73 ± 0.90 kJ/mol 60.0520 ± 0.0017 141-46-8*11 Methyl formate HC(O)OCH3 (g, anti) -326.6 -339.1 ± 1.1 kJ/mol 60.0520 ± 0.0017 107-31-3*2 Glyoxal OCHCHO (g, trans) -207.77 -213.41 ± 0.57 kJ/mol 58.0361 ± 0.0017 107-22-2*1 Trichloromethyl CCl3 (g) 73.78 73.31 ± 0.84 kJ/mol 118.3688 ± 0.0028 3170-80-7*0 1,1-Dichloroethane CH3CHCl2 (g) -120.17 -132.94 ± 0.43 kJ/mol 98.9586 ± 0.0024 75-34-3*0 Bromobenzene C6H5Br (g) 127.0 104.9 ± 1.3 kJ/mol 157.0079 ± 0.0049 108-86-1*0 Acetophenone C6H5C(O)CH3 (g) -61.5 -84.7 ± 1.0 kJ/mol 120.1485 ± 0.0064 98-86-2*0 Difluorodioxidane FOOF (g) 35.33 31.60 ± 0.40 kJ/mol 69.99561 ± 0.00060 7783-44-0*0 Nitrosomethane CH3NO (g) 80.79 70.88 ± 0.91 kJ/mol 45.04066 ± 0.00088 865-40-7*0 Isocyanoacetylene HCCNC (g) 484.7 486.9 ± 1.0 kJ/mol 51.0468 ± 0.0024 66723-45-3*0 Cyclobutadiene CH(CHCHCH) (g) 436.65 428.20 ± 0.69 kJ/mol 52.0746 ± 0.0032 1120-53-2*0 Silanone SiH2O (g) -94.3 -99.7 ± 1.0 kJ/mol 46.10078 ± 0.00045 22755-01-7*0 Silyloxy SiH3O (g) 7.8 -0.2 ± 1.4 kJ/mol 47.10872 ± 0.00047 81429-20-1*0 Sulfur S (g) 276.89 279.14 ± 0.14 kJ/mol 32.0660 ± 0.0060 7704-34-9*0 Chlorous acid HOClO (g) 25.77 20.71 ± 0.63 kJ/mol 68.4594 ± 0.0011 13898-47-0*0 Iodooxidanyl IO (g) 127.00 125.07 ± 0.82 kJ/mol 142.90387 ± 0.00030 14696-98-1*0 Carbon monoxide cation [CO]+ (g) 1238.305 1241.585 ± 0.026 kJ/mol 28.00955 ± 0.00085 12144-04-6*0 Hydrazine NH2NH2 (g) 111.72 97.57 ± 0.42 kJ/mol 32.04524 ± 0.00031 302-01-2*0 Aminooxy NH2O (g) 70.69 64.08 ± 0.66 kJ/mol 32.02202 ± 0.00034 13408-29-2*0 Nitrate [ON(O)O]- (g) -299.70 -306.25 ± 0.22 kJ/mol 62.00549 ± 0.00090 14797-55-8*0 Methylamidogen CH3NH (g) 187.71 177.06 ± 0.45 kJ/mol 30.04920 ± 0.00085 15622-51-2*0 Cyanogen iodide ICN (g) 222.6 222.1 ± 1.7 kJ/mol 152.92191 ± 0.00080 506-78-5*0 Formyl anion [HCO]- (g) 11.59 11.98 ± 0.44 kJ/mol 29.01859 ± 0.00086 57340-31-5*0 2-Propynylidyne CCCH (g) 718.09 722.44 ± 0.79 kJ/mol 37.0400 ± 0.0024 53590-28-6*0 iso-Pentane CH3CH2CH(CH3)2 (g) -118.90 -152.95 ± 0.39 kJ/mol 72.1488 ± 0.0041 78-78-4*0 1-Hydroxyethylidene CH3COH (g, anti singlet) 57.35 46.98 ± 0.77 kJ/mol 44.0526 ± 0.0017 30967-49-8*21 Dicarbon monoxide CCO (g, triplet) 377.13 381.17 ± 0.83 kJ/mol 40.0208 ± 0.0016 12071-23-7*1 1-Propanol CH3CH2CH2OH (g) -231.26 -255.10 ± 0.24 kJ/mol 60.0950 ± 0.0025 71-23-8*0 Fluorodioxidanyl FOO (g) 26.89 25.18 ± 0.26 kJ/mol 50.99720 ± 0.00060 15499-23-7*0 N-Methylenemethanamine CH3NCH2 (g) 94.55 79.63 ± 0.70 kJ/mol 43.0678 ± 0.0016 1761-67-7*0 Chloromethylene CHCl (g, singlet) 320.37 320.65 ± 0.89 kJ/mol 48.4713 ± 0.0012 2108-20-5*2 Dibromomethane CH2Br2 (g) 26.9 5.5 ± 1.1 kJ/mol 173.8346 ± 0.0022 74-95-3*0 1,1-Difluoroethene CH2CF2 (g) -343.47 -350.53 ± 0.77 kJ/mol 64.0341 ± 0.0016 75-38-7*0 Phenylacetylene C6H5CCH (g) 332.89 317.73 ± 0.72 kJ/mol 102.1332 ± 0.0064 536-74-3*0 o-Tolualdehyde CH3C6H4C(O)H (g, ortho) -44.7 -66.9 ± 1.1 kJ/mol 120.1485 ± 0.0064 529-20-4*0 Acetonyl CH3C(O)CH2 (g) -18.48 -32.08 ± 0.69 kJ/mol 57.0712 ± 0.0024 3122-07-4*0 3-Buten-2-one CH3C(O)CHCH2 (g, trans) -95.40 -111.64 ± 0.85 kJ/mol 70.0898 ± 0.0032 78-94-4*1 Urea NH2C(O)NH2 (g) -218.17 -234.57 ± 0.42 kJ/mol 60.05534 ± 0.00091 57-13-6*0 Oxomethaniminium [NH2CO]+ (g) 695.32 688.76 ± 0.90 kJ/mol 44.03217 ± 0.00087 59348-22-0*0 Acetamide CH3C(O)NH2 (g) -219.59 -237.10 ± 0.56 kJ/mol 59.0672 ± 0.0017 60-35-5*0 1-Cyanovinyl CH2CCN (g) 419.0 418.9 ± 1.1 kJ/mol 52.0547 ± 0.0024 15091-87-9*0 Disilanyl SiH3SiH2 (g) 241.3 229.3 ± 1.6 kJ/mol 61.21070 ± 0.00069 73151-72-1*0 Disilene SiH2SiH2 (g, singlet) 287.4 278.7 ± 1.9 kJ/mol 60.20276 ± 0.00066 15435-77-5*2 Hypofluorite [FO]- (g) -108.84 -108.67 ± 0.48 kJ/mol 34.99835 ± 0.00030 12763-66-5*0 1,3-Hexadiyne HCCCCCH2CH3 (g) 405.15 393.46 ± 0.98 kJ/mol 78.1118 ± 0.0048 4447-21-6*0 (E)-1-Methylallyl CH3CHCHCH2 (g, trans) 152.61 135.29 ± 0.80 kJ/mol 55.0984 ± 0.0032 17787-86-9*0 Iodine monochloride ICl (g) 19.024 17.391 ± 0.013 kJ/mol 162.35717 ± 0.00090 7790-99-0*0 Iodotrifluoromethane CF3I (g) -583.25 -589.13 ± 0.45 kJ/mol 195.91038 ± 0.00080 2314-97-8*0 Trinitrogen cation [NNN]+ (g) 1519.41 1516.78 ± 0.89 kJ/mol 42.01967 ± 0.00021 12185-03-4*0 Oxonitrate anion [NO]- (g) 88.12 88.15 ± 0.25 kJ/mol 30.00669 ± 0.00031 14967-78-3*0 Nitrosyl ion [NO]+ (g) 984.509 984.504 ± 0.067 kJ/mol 30.00559 ± 0.00031 14452-93-8*0 Nitrogen sesquioxide ONN(O)O (g) 90.77 86.20 ± 0.15 kJ/mol 76.01168 ± 0.00091 10544-73-7*0 Methylene anion [CH2]- (g) 328.17 328.60 ± 0.18 kJ/mol 14.02713 ± 0.00081 50928-07-9*0 Methylidyne anion [CH]- (g) 475.75 479.08 ± 0.22 kJ/mol 13.01919 ± 0.00080 28604-54-8*0 Ethanium [C2H7]+ (g, bridged C2) 874.33 858.07 ± 0.62 kJ/mol 31.0764 ± 0.0017 24669-33-8*1 Hydrogen bromide HBr (aq) -120.88 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*800 Chloronium [HClH]+ (g) 881.5 878.4 ± 1.1 kJ/mol 37.46803 ± 0.00091 36658-55-6*0 Chlorine trifluoride FCl(F)F (g) -158.58 -162.68 ± 0.86 kJ/mol 92.44791 ± 0.00090 7790-91-2*0 Hydrogen isocyanide HNC (g) 192.04 192.43 ± 0.33 kJ/mol 27.02538 ± 0.00081 6914-07-4*0 iso-Propylium [CH3CHCH3]+ (g) 822.95 805.87 ± 0.23 kJ/mol 43.0871 ± 0.0024 19252-53-0*0 Carbonic acid C(O)(OH)2 (g, cis-cis) -602.53 -612.70 ± 0.75 kJ/mol 62.0248 ± 0.0012 463-79-6*1 Cyclobutane CH2(CH2CH2CH2) (g) 52.29 27.75 ± 0.38 kJ/mol 56.1063 ± 0.0032 287-23-0*0 2-Butynyl CH3CCCH2 (g) 318.10 310.73 ± 0.67 kJ/mol 53.0825 ± 0.0032 82252-88-8*0 1,2-Butadienyl CH3CHCCH (g) 328.93 320.21 ± 0.64 kJ/mol 53.0825 ± 0.0032 4777-46-2*0 Isoprene CH2C(CH3)CHCH2 (g) 96.25 75.73 ± 0.66 kJ/mol 68.1170 ± 0.0040 78-79-5*0 Dioxygen anion [O2]- (g) -43.36 -42.72 ± 0.17 kJ/mol 31.99935 ± 0.00060 11062-77-4*0 1-Hydroxyethylium [CH3CHOH]+ (g, anti) 608.73 594.31 ± 0.38 kJ/mol 45.0600 ± 0.0017 18682-96-7*1 Vinoxy CH2CHO (g) 23.11 16.31 ± 0.59 kJ/mol 43.0446 ± 0.0016 6912-06-7*0 Ethynol HCCOH (g, singlet) 95.29 92.81 ± 0.78 kJ/mol 42.0367 ± 0.0016 32038-79-2*2 Formyloxidanyl HC(O)O (g, 2A1) -125.82 -127.48 ± 0.55 kJ/mol 45.0174 ± 0.0010 16499-21-1*1 Methoxyethane CH3CH2OCH3 (g) -194.77 -217.66 ± 0.57 kJ/mol 60.0950 ± 0.0025 540-67-0*0 1,1,1-Trichloroethane CH3CCl3 (g) -133.97 -144.55 ± 0.52 kJ/mol 133.4033 ± 0.0031 71-55-6*0 Tetrachloroethene CCl2CCl2 (g) -20.53 -21.40 ± 0.99 kJ/mol 165.8322 ± 0.0039 127-18-4*0 Chlorodifluoromethane CHClF2 (g) -475.56 -481.75 ± 0.99 kJ/mol 86.4681 ± 0.0012 75-45-6*0 Fluoromethylene CHF (g, singlet) 148.40 148.69 ± 0.43 kJ/mol 32.01704 ± 0.00080 13453-52-6*2 Fluoroformyl FCO (g) -176.61 -176.03 ± 0.37 kJ/mol 47.00850 ± 0.00085 1871-24-5*0 2-Bromoethanol BrCH2CH2OH (g) -196.34 -220.40 ± 0.53 kJ/mol 124.9645 ± 0.0019 540-51-2*0 Carbon suboxide OCCCO (g) -94.5 -92.4 ± 1.1 kJ/mol 68.0309 ± 0.0025 504-64-3*0 Benzyl C6H5CH2 (g) 230.27 211.45 ± 0.55 kJ/mol 91.1305 ± 0.0056 2154-56-5*0 Phenoxy C6H5O (g) 71.04 55.75 ± 0.84 kJ/mol 93.1033 ± 0.0048 2122-46-5*0 m-Tolualdehyde CH3C6H4C(O)H (g, meta) -49.1 -72.0 ± 1.2 kJ/mol 120.1485 ± 0.0064 620-23-5*0 Propadienone CH2CCO (g) 132.14 130.50 ± 0.72 kJ/mol 54.0474 ± 0.0024 61244-93-7*0 2-Propynal CHCCHO (g) 135.38 133.21 ± 0.91 kJ/mol 54.0474 ± 0.0024 624-67-9*0 Cyanomethylene HCCN (g, triplet) 479.9 483.2 ± 1.1 kJ/mol 39.0361 ± 0.0016 2612-62-6*1 3-Methylenecyclopropene CH2C(CHCH) (g) 395.97 388.04 ± 0.83 kJ/mol 52.0746 ± 0.0032 4095-06-1*0 Phenylperoxy C6H5OO (g) 153.5 136.5 ± 1.4 kJ/mol 109.1027 ± 0.0049 91422-02-5*0 Trimethylsilane SiH(CH3)3 (g) -125.3 -151.4 ± 1.6 kJ/mol 74.1970 ± 0.0025 993-07-7*0 1-Methyl-1-propenyl CH3CCHCH3 (g, trans) 240.00 223.82 ± 0.67 kJ/mol 55.0984 ± 0.0032 71790-71-1*1 1-Butenyl CH3CH2CHCH (g, cis) 263.41 246.07 ± 0.69 kJ/mol 55.0984 ± 0.0032 2669-61-6*2 Methanide [CH3]- (g) 141.12 137.67 ± 0.24 kJ/mol 15.03507 ± 0.00083 15194-58-8*0 Methyliumyl [CH2]+ (g) 1393.19 1394.05 ± 0.11 kJ/mol 14.02603 ± 0.00081 15091-72-2*0 Ethylidyne CH3C (g, quartet) 640.8 636.2 ± 1.1 kJ/mol 27.0452 ± 0.0016 67624-57-1*2 Aminomethylium [CH2NH2]+ (g) 764.04 752.07 ± 0.64 kJ/mol 30.04865 ± 0.00085 488821-23-4*0 Hydrogen chloride HCl (aq) -166.990 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*800 Isocyanomethanide [CH2NC]- (g) 254.07 251.03 ± 0.95 kJ/mol 40.0446 ± 0.0016 81704-80-5*0 Peroxyformate [HC(O)OO]- (g, syn) -341.15 -346.60 ± 0.98 kJ/mol 61.0174 ± 0.0012 104960-05-6*1 n-Propylium [CH3CH2CH2]+ (g) 856.78 838.50 ± 0.80 kJ/mol 43.0871 ± 0.0024 19252-52-9*0 1-Methylethylidene CH3CCH3 (g, singlet) 316.03 302.13 ± 0.98 kJ/mol 42.0797 ± 0.0024 40852-89-9*2 Cycloprop-2-enylium [CH(CHCH)]+ (g) 1080.4 1075.3 ± 1.0 kJ/mol 39.0554 ± 0.0024 26810-74-2*0 Trioxidanide [HOOO]- (g, gauche) -120.0 -123.1 ± 1.6 kJ/mol 49.00669 ± 0.00090 89965-38-8*2 Cyclobutene CH2(CH2CHCH) (g) 178.02 160.97 ± 0.61 kJ/mol 54.0904 ± 0.0032 822-35-5*0 1,3-Butadienyl CH2CHCHCH (g, trans-trans) 372.23 361.74 ± 0.87 kJ/mol 53.0825 ± 0.0032 86181-68-2*11 Cyclohexane CH2(CH2CH2CH2CH2CH2) (g) -83.20 -122.76 ± 0.29 kJ/mol 84.1595 ± 0.0049 110-82-7*0 Protonated oxirane [(CH2CH2)OH]+ (g) 725.43 709.26 ± 0.61 kJ/mol 45.0600 ± 0.0017 *38607-31-7*0 Methoxymethylene CH3OCH (g, anti singlet) 129.13 118.60 ± 0.78 kJ/mol 44.0526 ± 0.0017 19527-10-7*21 Methanediol CH2(OH)2 (g, conrot gauche) -379.16 -393.36 ± 0.74 kJ/mol 48.0413 ± 0.0010 463-57-0*1 Cyanic acid HOCN (g) -12.33 -15.04 ± 0.43 kJ/mol 43.02478 ± 0.00086 420-05-3*0 Fulminic acid HCNO (g) 170.72 169.26 ± 0.44 kJ/mol 43.02478 ± 0.00086 51060-05-0*0 Isofulminic acid HONC (g) 235.24 233.53 ± 0.43 kJ/mol 43.02478 ± 0.00086 506-85-4*0 Nitrosomethylidyne CNO (g) 389.3 390.7 ± 1.1 kJ/mol 42.01684 ± 0.00086 82267-15-0*0 Acetic acid CH3C(O)OH (g) -418.53 -432.69 ± 0.36 kJ/mol 60.0520 ± 0.0017 64-19-7*0 Acetyl chloride CH3C(O)Cl (g) -232.55 -241.55 ± 0.33 kJ/mol 78.4973 ± 0.0019 75-36-5*0 Dioxoethyl OCHCO (g) -63.13 -64.55 ± 0.87 kJ/mol 57.0281 ± 0.0017 702699-38-5*0 (Methylamino)methyl CH3NHCH2 (g) 168.31 151.86 ± 0.81 kJ/mol 44.0758 ± 0.0017 31277-24-4*0 Chlorine atom cation Cl+ (g) 1370.807 1372.603 ± 0.0021 kJ/mol 35.45215 ± 0.00090 24203-47-2*0 Hydrogen peroxide cation [H2O2]+ (g, trans) 897.29 890.31 ± 0.51 kJ/mol 34.01413 ± 0.00062 12325-10-9*1 Chlorohydroxymethyl CH(Cl)OH (g, syn-gauche) -54.9 -60.9 ± 1.1 kJ/mol 65.4787 ± 0.0012 147139-06-8*1 1,1-Dichloroethene CH2CCl2 (g) 9.30 3.32 ± 0.50 kJ/mol 96.9427 ± 0.0024 75-35-4*0 Dichlorodifluoromethane CF2Cl2 (g) -488.89 -493.08 ± 0.44 kJ/mol 120.9129 ± 0.0020 75-71-8*0 Fluorodichloromethane CHFCl2 (g) -277.65 -283.10 ± 0.90 kJ/mol 102.9224 ± 0.0020 75-43-4*0 Difluoromethylene CF2 (g, singlet) -193.86 -193.39 ± 0.35 kJ/mol 50.00751 ± 0.00080 2154-59-8*2 Fluoromethylene CHF (g, triplet) 210.38 210.72 ± 0.66 kJ/mol 32.01704 ± 0.00080 13453-52-6*1 Formyl fluoride CHFO (g) -378.63 -382.22 ± 0.31 kJ/mol 48.01644 ± 0.00086 1493-02-3*0 p-Tolualdehyde CH3C6H4C(O)H (g, para) -49.9 -72.9 ± 1.2 kJ/mol 120.1485 ± 0.0064 104-87-0*0 o-Toluoyl CH3C6H4CO (g, ortho) 109.8 91.4 ± 1.4 kJ/mol 119.1406 ± 0.0064 104680-89-9*0 1-Propen-2-ol-1-yl CH3C(OH)CH (g, trans-cis) 101.57 89.35 ± 0.87 kJ/mol 57.0712 ± 0.0024 1976041-84-5*11 Propyl nitrite CH3CH2CH2ONO (g, gauche-trans-cis) -95.9 -120.8 ± 1.8 kJ/mol 89.0932 ± 0.0025 543-67-9*1 2-Cyanovinyl CHCHCN (g, syn) 447.80 445.32 ± 0.99 kJ/mol 52.0547 ± 0.0024 189141-20-6*2 1,2,3-Butatrien-1-ylium [CH2CCCH]+ (g, singlet) 1271.8 1270.0 ± 1.1 kJ/mol 51.0661 ± 0.0032 81932-79-8*2 1-Buten-3-yn-1-yl HCCCHCH (g, trans) 547.27 544.60 ± 0.87 kJ/mol 51.0666 ± 0.0032 2810-61-9*1 3-Buten-1-ynyl CH2CHCC (g) 628.5 626.4 ± 1.0 kJ/mol 51.0666 ± 0.0032 108179-98-2*0 Hydroxysilyl SiH2OH (g) -104.9 -112.8 ± 1.5 kJ/mol 47.10872 ± 0.00047 113648-09-2*0 Trimethylsilanol (CH3)3SiOH (g) -465.3 -491.5 ± 1.9 kJ/mol 90.1964 ± 0.0025 1066-40-6*0 2-Propanamine CH3CH(CH3)NH2 (g) -56.66 -83.45 ± 0.52 kJ/mol 59.1103 ± 0.0025 75-31-0*0 Sulfur monoxide SO (g) 6.02 6.07 ± 0.13 kJ/mol 48.0654 ± 0.0060 13827-32-2*0 Hypoiodite [IO]- (g) -102.44 -104.25 ± 0.88 kJ/mol 142.90442 ± 0.00030 15065-65-3*0 Dinitrogen cation [N2]+ (g) 1503.311 1503.312 ± 0.000 kJ/mol 28.01293 ± 0.00014 13966-04-6*0 Nitrogen atom cation N+ (g) 1872.908 1875.689 ± 0.024 kJ/mol 14.006191 ± 0.000070 14158-23-7*0 Chloro hypochlorite ClOCl (g) 79.79 77.98 ± 0.36 kJ/mol 86.9048 ± 0.0018 7791-21-1*0 Carbon dioxide cation [CO2]+ (g) 936.091 936.925 ± 0.017 kJ/mol 44.00895 ± 0.00100 12181-61-2*0 Hydroperoxonium [H2OOH]+ (g, trans) 738.2 727.9 ± 1.2 kJ/mol 35.02207 ± 0.00064 70850-26-9*1 Ammonium [NH4]+ (aq) -133.070 ± 0.056 kJ/mol 18.03795 ± 0.00029 14798-03-9*800 Hydrazino NH2NH (g) 234.76 224.24 ± 0.69 kJ/mol 31.03730 ± 0.00025 13598-46-4*0 Carbon anion C- (g) 589.634 594.781 ± 0.044 kJ/mol 12.01125 ± 0.00080 14337-00-9*0 Chlorooxy hypochlorite ClOOCl (g) 134.57 131.34 ± 0.56 kJ/mol 102.9042 ± 0.0019 12292-23-8*0 Methyleneamidogen CH2N (g) 242.01 238.36 ± 0.58 kJ/mol 28.03332 ± 0.00082 15845-29-1*0 (E)-Iminomethyl HCNH (g, trans) 275.80 272.19 ± 0.61 kJ/mol 28.03332 ± 0.00082 54980-10-8*0 Hydrogen isocyanide cation [HNC]+ (g) 1351.51 1351.47 ± 0.84 kJ/mol 27.02483 ± 0.00081 74158-11-5*0 Methyloxonium [CH3OH2]+ (g) 589.1 574.9 ± 1.1 kJ/mol 33.04925 ± 0.00092 17836-08-7*0 n-Propylide [CH3CH2CH2]- (g) 123.1 105.5 ± 1.2 kJ/mol 43.0882 ± 0.0024 59513-13-2*0 Hydroxyde [OH]- (aq) -229.979 ± 0.027 kJ/mol 17.00789 ± 0.00031 14280-30-9*800 Propargylenide [HCCCH]- (g, transoid 2B) 434.5 437.0 ± 1.1 kJ/mol 38.0485 ± 0.0024 82906-05-6*1 Chlorine pentafluoride FCl(F)(F)(F)F (g) -226.0 -234.1 ± 1.2 kJ/mol 130.44472 ± 0.00090 13637-63-3*0 t-Butyl (CH3)3C (g) 75.34 50.04 ± 0.76 kJ/mol 57.1143 ± 0.0033 1605-73-8*0 Dichloride [Cl2]- (g) -229.8 -228.7 ± 1.4 kJ/mol 70.9059 ± 0.0018 12595-89-0*0 2-Butyn-1-yl anion [CH3CCCH2]- (g) 253.7 244.8 ± 1.1 kJ/mol 53.0830 ± 0.0032 65114-66-1*0 Peroxyhypochlorous acid HOOCl (g) 3.98 -1.29 ± 0.95 kJ/mol 68.4594 ± 0.0011 67952-07-2*0 Ethoxy CH3CH2O (g, A 2A') 5.52 -8.91 ± 0.43 kJ/mol 45.0605 ± 0.0017 2154-50-9*52 Ethenol CH2CHOH (g, anti) -108.95 -119.66 ± 0.50 kJ/mol 44.0526 ± 0.0017 557-75-5*2 Oxiranyl CH2(CHO) (g) 172.87 164.59 ± 0.98 kJ/mol 43.0446 ± 0.0016 31586-84-2*0 Ketene CH2CO (g, triplet) 182.0 179.0 ± 1.1 kJ/mol 42.0367 ± 0.0016 463-51-4*1 Oxoethylidene HCC(O)H (g, syn-triplet) 261.1 257.6 ± 1.1 kJ/mol 42.0367 ± 0.0016 39920-84-8*12 Methanediol CH2(OH)2 (g, disrot gauche) -369.01 -382.16 ± 0.94 kJ/mol 48.0413 ± 0.0010 463-57-0*2 Dioxirane CH2(OO) (g) 9.41 1.74 ± 0.53 kJ/mol 46.0254 ± 0.0010 157-26-6*0 Methoxyethene CH2CHOCH3 (g, cis) -89.5 -107.4 ± 1.1 kJ/mol 58.0791 ± 0.0025 107-25-5*2 2-Propanol CH3CH(OH)CH3 (g) -248.67 -272.76 ± 0.27 kJ/mol 60.0950 ± 0.0025 67-63-0*0 Methyl acetate CH3C(O)OCH3 (g, anti) -363.3 -382.1 ± 1.2 kJ/mol 74.0785 ± 0.0025 79-20-9*2 Carboxymethyl CH2C(O)OH (g, syn) -226.7 -236.6 ± 1.1 kJ/mol 59.0440 ± 0.0017 2887-46-9*1 Dimethylamidogen (CH3)2N (g) 174.1 156.8 ± 1.4 kJ/mol 44.0758 ± 0.0017 15337-44-7*0 Cyanoamidogen HNCN (g) 322.95 320.46 ± 0.84 kJ/mol 41.03212 ± 0.00082 12347-01-2*0 Chloromethylidyne CCl (g) 430.64 434.40 ± 0.67 kJ/mol 47.4634 ± 0.0012 3889-76-7*0 Chloromethanol CH2(Cl)OH (g) -232.4 -242.7 ± 1.2 kJ/mol 66.4866 ± 0.0013 15454-33-8*0 Chloromethoxy CH2(Cl)O (g) -12.0 -18.8 ± 1.1 kJ/mol 65.4787 ± 0.0012 114282-89-2*0 Fluorotrichloromethane CCl3F (g) -283.26 -286.42 ± 0.76 kJ/mol 137.3672 ± 0.0028 75-69-4*0 Hexafluoroethane CF3CF3 (g) -1334.01 -1342.31 ± 0.82 kJ/mol 138.0118 ± 0.0016 76-16-4*0 Formyl chloride CHClO (g) -179.87 -183.07 ± 0.67 kJ/mol 64.4707 ± 0.0012 2565-30-2*0 2-Chloroethanol ClCH2CH2OH (g) -249.81 -266.53 ± 0.59 kJ/mol 80.5132 ± 0.0019 107-07-3*0 o-Benzyne C6H4 (g, singlet) 468.21 459.29 ± 0.86 kJ/mol 76.0960 ± 0.0048 462-80-6*2 Tropyl CH(CHCHCHCHCHCH) (g) 296.6 279.1 ± 1.1 kJ/mol 91.1305 ± 0.0056 3551-27-7*0 m-Toluoyl CH3C6H4CO (g, meta) 108.7 90.1 ± 1.5 kJ/mol 119.1406 ± 0.0064 67958-04-7*0 Iodobenzene C6H5I (g) 178.48 162.49 ± 0.99 kJ/mol 204.0084 ± 0.0048 591-50-4*0 1-Hydroxy-1-methylethyl CH3C(OH)CH3 (g) -78.28 -96.53 ± 0.79 kJ/mol 59.0871 ± 0.0025 5131-95-3*0 Trifluoroethene CF2CHF (g) -493.0 -498.0 ± 1.6 kJ/mol 82.0245 ± 0.0016 359-11-5*0 Isocyanoethene CH2CHNC (g) 285.20 278.70 ± 0.94 kJ/mol 53.0627 ± 0.0024 14668-82-7*0 1-Isocyanoethylidene CH3CNC (g, singlet) 527.9 523.2 ± 1.1 kJ/mol 53.0627 ± 0.0024 *498544-34-6*2 2-Cyanovinyl CHCHCN (g, anti) 448.22 445.76 ± 0.97 kJ/mol 52.0547 ± 0.0024 189141-20-6*1 3-Methylene-1-cyclopropen-1-yl CH2C(CHC) (g) 628.2 625.6 ± 1.1 kJ/mol 51.0666 ± 0.0032 127611-24-9*0 Fulvene CH2C(CHCHCHCH) (g) 232.0 216.0 ± 1.1 kJ/mol 78.1118 ± 0.0048 497-20-1*0 Oxosilylene SiO (g) -98.70 -97.55 ± 0.62 kJ/mol 44.08490 ± 0.00042 10097-28-6*0 Silyloxy anion [SiH3O]- (g) -312.5 -321.8 ± 1.6 kJ/mol 47.10927 ± 0.00047 43336-62-5*0 Cyclobutyl CH(CH2CH2CH2) (g) 246.52 227.62 ± 0.73 kJ/mol 55.0984 ± 0.0032 4548-06-5*0 1-Propanamine CH3CH2CH2NH2 (g) -42.22 -69.96 ± 0.42 kJ/mol 59.1103 ± 0.0025 107-10-8*0 Disulfur S2 (g) 127.49 127.80 ± 0.27 kJ/mol 64.1320 ± 0.0120 23550-45-0*0 Sulfuric acid OS(O)(OH)2 (g) -715.0 -729.1 ± 1.2 kJ/mol 98.0795 ± 0.0061 7664-93-9*0 Sulfuric acid OS(O)(OH)2 (aq, 100 H2O) -887.45 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*828 Sulfurous acid S(O)(OH)2 (g, cis) -511.14 -521.35 ± 0.89 kJ/mol 82.0801 ± 0.0061 7782-99-2*2 Sulfo OS(OH)O (g) -366.5 -374.3 ± 1.1 kJ/mol 81.0721 ± 0.0061 32750-86-0*0 Dioxodiazoxane ONONO (g, t, t) 93.0 87.9 ± 1.3 kJ/mol 76.01168 ± 0.00091 122413-35-8*1 Nitric acid HON(O)O (aq) -206.58 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*800 Isodiazene NNH2 (g) 307.54 300.46 ± 0.63 kJ/mol 30.02936 ± 0.00020 28647-38-3*0 Oxoammoniumyl [HNO]+ (g) 1092.48 1089.55 ± 0.67 kJ/mol 31.01353 ± 0.00032 63559-87-5*0 Nitryl hydride HN(O)O (g) -36.5 -43.5 ± 1.0 kJ/mol 47.01348 ± 0.00061 90266-90-3*0 Peroxynitrous acid HOONO (g, trans, perp) 7.83 0.75 ± 0.41 kJ/mol 63.01288 ± 0.00091 14691-52-2*1 Carbon cation C+ (g) 1797.864 1803.462 ± 0.044 kJ/mol 12.01015 ± 0.00080 14067-05-1*0 Bromanylium Br+ (g) 1257.771 1251.708 ± 0.056 kJ/mol 79.90345 ± 0.00100 22541-56-6*0 Oxoniumyl ion [H2O]+ (g) 978.501 975.598 ± 0.026 kJ/mol 18.01473 ± 0.00033 56583-62-1*0 Ethylidyne CH3C (g) 508.61 504.91 ± 0.80 kJ/mol 27.0452 ± 0.0016 67624-57-1*0 Fluoronium [HFH]+ (g, singlet) 774.04 771.10 ± 0.91 kJ/mol 21.01373 ± 0.00014 12206-67-6*2 Ethynylium [CCH]+ (g) 1687.60 1690.94 ± 0.15 kJ/mol 25.0288 ± 0.0016 16456-59-0*0 Methylamidogen anion [CH3NH]- (g) 145.33 134.50 ± 0.64 kJ/mol 30.04975 ± 0.00085 54448-39-4*0 Methylimidogen CH3N (g) 323.1 315.3 ± 1.1 kJ/mol 29.04126 ± 0.00083 27770-42-9*0 Iminomethylium [HCNH]+ (g) 953.3 949.3 ± 1.4 kJ/mol 28.03277 ± 0.00082 196216-36-1*0 Oxygen atom O (g, triplet) 246.844 249.229 ± 0.0021 kJ/mol 15.99940 ± 0.00030 17778-80-2*1 Methylperoxy anion [CH3OO]- (g) -89.78 -99.92 ± 0.57 kJ/mol 47.0339 ± 0.0010 35683-44-4*0 Propylidyne CH3CH2C (g, doublet) 492.6 483.0 ± 1.2 kJ/mol 41.0718 ± 0.0024 85056-54-8*1 Cyclopropylidene C(CH2CH2) (g, singlet) 474.94 466.91 ± 0.85 kJ/mol 40.0639 ± 0.0024 2143-70-6*1 Propargylium [CH2CCH]+ (g) 1193.54 1190.72 ± 0.32 kJ/mol 39.0554 ± 0.0024 21540-27-2*0 Cycloprop-1-enyl CH2(CHC) (g) 527.46 523.07 ± 0.58 kJ/mol 39.0559 ± 0.0024 19528-44-0*0 Cyclopropenylidene C(CHCH) (g) 497.09 496.12 ± 0.45 kJ/mol 38.0480 ± 0.0024 16165-40-5*0 Propargylenide [HCCCH]- (g, cisoid 2A) 436.9 439.5 ± 1.1 kJ/mol 38.0485 ± 0.0024 82906-05-6*2 2-Propyn-1-ylium-1-ylidene [CCCH]+ (g) 1598.2 1602.5 ± 1.3 kJ/mol 37.0395 ± 0.0024 75104-46-0*0 Difluoride [F2]- (g) -291.0 -290.2 ± 1.5 kJ/mol 37.9973550 ± 0.0000010 12184-85-9*0 1-Methylene-2-propenyl CH2CHCCH2 (g) 327.12 317.12 ± 0.75 kJ/mol 53.0825 ± 0.0032 1204515-52-5*0 Cyclopentene CH2(CH2CHCHCH2) (g) 59.61 35.34 ± 0.46 kJ/mol 68.1170 ± 0.0040 142-29-0*0 2-Hydrotrioxy OO(H)O (g) 299.6 293.9 ± 1.2 kJ/mol 49.00614 ± 0.00090 *12500-78-6*0 n-Heptane CH3(CH2)5CH3 (g) -145.36 -187.23 ± 0.46 kJ/mol 100.2019 ± 0.0057 142-82-5*0 n-Octane CH3(CH2)6CH3 (g) -160.99 -207.82 ± 0.54 kJ/mol 114.2285 ± 0.0065 111-65-9*0 Methoxymethyl CH3OCH2 (g) 13.20 0.63 ± 0.91 kJ/mol 45.0605 ± 0.0017 16520-04-0*0 Oxoethanide [CH3CO]- (g) -43.8 -49.4 ± 1.3 kJ/mol 43.0452 ± 0.0016 78944-68-0*0 Oxirene O(CHCH) (g, singlet) 273.20 271.04 ± 0.92 kJ/mol 42.0367 ± 0.0016 157-18-6*2 Hydroxyformyl HOCO (g, cis) -174.33 -177.36 ± 0.50 kJ/mol 45.0174 ± 0.0010 2564-86-5*2 Hydroxyformyl anion [HOCO]- (g, cis) -319.54 -322.13 ± 0.57 kJ/mol 45.0180 ± 0.0010 78944-70-4*2 Ethoxyethane CH3CH2OCH2CH3 (g) -223.70 -251.12 ± 0.61 kJ/mol 74.1216 ± 0.0033 60-29-7*0 Ethyl formate HC(O)OCH2CH3 (g, syn) -375.1 -393.9 ± 1.0 kJ/mol 74.0785 ± 0.0025 109-94-4*1 Propionic acid CH3CH2C(O)OH (g, syn) -435.93 -453.82 ± 0.59 kJ/mol 74.0785 ± 0.0025 79-09-4*1 Acetate [CH3C(O)O]- (g) -496.05 -505.18 ± 0.85 kJ/mol 59.0446 ± 0.0017 71-50-1*0 (1E)-Ethanimine CH3CHNH (g, trans) 55.82 39.61 ± 0.79 kJ/mol 43.0678 ± 0.0016 56003-81-7*0 Ethenamine CH2CHNH2 (g) 69.13 54.57 ± 0.75 kJ/mol 43.0678 ± 0.0016 593-67-9*0 (Dimethylamino)methyl (CH3)2NCH2 (g) 166.1 143.0 ± 1.3 kJ/mol 58.1024 ± 0.0025 30208-47-0*0 Water dimer (H2O)2 (g) -491.016 -499.055 ± 0.048 kJ/mol 36.03056 ± 0.00066 25655-83-8*0 Chloromethide [CH2Cl]- (g) 56.3 53.0 ± 2.0 kJ/mol 49.4798 ± 0.0012 60291-29-4*0 Hexachloroethane CCl3CCl3 (g) -144.2 -146.5 ± 1.3 kJ/mol 236.7376 ± 0.0056 67-72-1*0 cis-1,2-Dichloroethene CHClCHCl (g, cis) 3.82 -2.18 ± 0.55 kJ/mol 96.9427 ± 0.0024 156-59-2*0 Dichloroacetylene ClCCCl (g) 232.74 236.05 ± 0.73 kJ/mol 94.9268 ± 0.0024 7572-29-4*0 Difluoromethylene CF2 (g) -193.86 -193.39 ± 0.35 kJ/mol 50.00751 ± 0.00080 2154-59-8*0 1,1-Difluoroethane CH3CHF2 (g) -488.96 -502.68 ± 0.53 kJ/mol 66.0500 ± 0.0016 75-37-6*0 Chloric acid HOCl(O)O (g) 0.6 -6.5 ± 1.1 kJ/mol 84.4588 ± 0.0013 7790-93-4*0 2-Fluoroethanol FCH2CH2OH (g) -405.70 -422.94 ± 0.99 kJ/mol 64.0589 ± 0.0017 371-62-0*0 Trioxidane HOOOH (g, cis) -72.68 -81.17 ± 0.82 kJ/mol 50.01408 ± 0.00091 14699-99-1*2 Benzylide [C6H5CH2]- (g) 142.03 123.12 ± 0.41 kJ/mol 91.1310 ± 0.0056 18860-15-6*0 Cycloheptatriene CH2(CHCHCHCHCHCH) (g) 207.47 184.04 ± 0.94 kJ/mol 92.1384 ± 0.0056 544-25-2*0 Ethylbenzene C6H5CH2CH3 (g) 58.37 29.91 ± 0.54 kJ/mol 106.1650 ± 0.0064 100-41-4*0 Phenylethene C6H5CHCH2 (g) 169.83 148.50 ± 0.54 kJ/mol 104.1491 ± 0.0064 100-42-5*0 Benzonitrile C6H5CN (g) 230.06 215.86 ± 0.93 kJ/mol 103.1213 ± 0.0056 100-47-0*0 p-Toluoyl CH3C6H4CO (g, para) 107.8 89.2 ± 1.5 kJ/mol 119.1406 ± 0.0064 67958-03-6*0 Acetonate [CH3C(O)CH2]- (g) -187.57 -201.12 ± 0.92 kJ/mol 57.0717 ± 0.0024 24262-31-5*0 Hydrogen fluoride HF (aq, 20 H2O) -321.06 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*818 Methyl nitrite CH3ONO (g) -55.55 -66.22 ± 0.45 kJ/mol 61.0401 ± 0.0010 624-91-9*0 Perchloryl OCl(O)O (g) 191.76 186.09 ± 0.62 kJ/mol 83.4509 ± 0.0013 13932-10-0*0 3-Oxo-1,2-propadien-1-yl HCCCO (g) 290.3 292.8 ± 1.0 kJ/mol 53.0394 ± 0.0024 1198096-74-0*0 Chlorate [OCl(O)O]- (g) -208.2 -213.7 ± 1.5 kJ/mol 83.4514 ± 0.0013 14866-68-3*0 1-Cyanoethylidene CH3CCN (g, singlet) 475.7 470.5 ± 1.1 kJ/mol 53.0627 ± 0.0024 498544-34-6*2 3-Imino-2-propen-1-ylidene CHCHCNH (g, syn-singlet) 530.7 525.9 ± 1.2 kJ/mol 53.0627 ± 0.0024 916765-05-4*11 2-(Methylidyneamino)ethenyl CHCHNCH (g, anti-singlet) 600.7 595.6 ± 1.2 kJ/mol 53.0627 ± 0.0024 123416-74-0*11 1-Cyanovinyl anion [CH2CCN]- (g) 224.4 221.6 ± 1.3 kJ/mol 52.0553 ± 0.0024 36259-97-9*0 1,2,3-Butatrien-1-yl anion [CH2CCCH]- (g) 388.4 386.5 ± 1.1 kJ/mol 51.0672 ± 0.0032 102275-54-7*0 Silylene SiH2 (g, triplet) 361.3 359.7 ± 1.1 kJ/mol 30.10138 ± 0.00033 13825-90-6*1 Di-mu-hydrodihydrodisilicon HSi(HSiHH) (g, trans-singlet) 373.3 362.9 ± 2.4 kJ/mol 60.20276 ± 0.00066 129970-82-7*12 Methylsilane CH3SiH3 (g) -10.20 -26.38 ± 0.93 kJ/mol 46.14384 ± 0.00095 992-94-9*0 Trimethylsiloxy (CH3)3SiO (g) -188.1 -211.1 ± 2.0 kJ/mol 89.1885 ± 0.0025 54572-10-0*0 1,5-Hexadiyne HCCCH2CH2CCH (g) 431.6 421.1 ± 1.2 kJ/mol 78.1118 ± 0.0048 628-16-0*0 2-Methylallyl CH3C(CH2)CH2 (g) 155.89 138.77 ± 0.78 kJ/mol 55.0984 ± 0.0032 15157-95-6*0 3-Butenyl CH2CHCH2CH2 (g) 223.17 206.66 ± 0.91 kJ/mol 55.0984 ± 0.0032 2154-62-3*0 2-Methyl-1-propenyl CH3C(CH3)CH (g) 251.17 234.15 ± 0.73 kJ/mol 55.0984 ± 0.0032 33825-33-1*0 N-Methylethanamine CH3CH2NHCH3 (g) -17.7 -45.8 ± 1.1 kJ/mol 59.1103 ± 0.0025 624-78-2*0 Disulfene oxide SSO (g) -50.48 -52.50 ± 0.43 kJ/mol 80.1314 ± 0.0120 20901-21-7*0 Sulfur hydroxide oxide OHS(O)(O)O (g, staggered) -473.9 -483.4 ± 1.7 kJ/mol 97.0715 ± 0.0061 12337-07-4*1 Oxygen atom O (g, singlet) 436.665 438.523 ± 0.0021 kJ/mol 15.99940 ± 0.00030 17778-80-2*2 Methyliumylidene [CH]+ (g) 1619.768 1623.112 ± 0.051 kJ/mol 13.01809 ± 0.00080 24361-82-8*0 Ethylidyne CH3C (g, doublet) 508.61 504.91 ± 0.80 kJ/mol 27.0452 ± 0.0016 67624-57-1*1 Vinylidene anion [CCH2]- (g) 364.03 363.84 ± 0.50 kJ/mol 26.0378 ± 0.0016 66295-36-1*0 Trioxidanyl HOOO (g, trans) 25.36 23.38 ± 0.13 kJ/mol 49.00614 ± 0.00090 12500-78-6*1 Cyanomethanide [CH2CN]- (g) 114.16 111.34 ± 0.59 kJ/mol 40.0446 ± 0.0016 21438-99-3*0 Methanol cation [CH3OH]+ (g) 856.83 846.50 ± 0.32 kJ/mol 32.04131 ± 0.00090 12538-91-9*0 Hydroxymethylene HCOH (g, gauche triplet) 219.3 216.4 ± 1.1 kJ/mol 30.02598 ± 0.00087 19710-56-6*3 Aquacarbon H2OC (g, triplet) 442.7 441.1 ± 1.3 kJ/mol 30.02598 ± 0.00087 81434-73-3*1 Oxidanylium [OH]+ (g) 1293.361 1293.391 ± 0.025 kJ/mol 17.00679 ± 0.00031 12259-29-9*0 Carbonic acid C(O)(OH)2 (g, cis-trans) -596.69 -606.80 ± 0.83 kJ/mol 62.0248 ± 0.0012 463-79-6*2 Carbonic acid C(O)(OH)2 (g, trans-trans) -561.44 -570.29 ± 0.95 kJ/mol 62.0248 ± 0.0012 463-79-6*3 Propylidene CH3CH2CH (g, triplet) 349.53 335.84 ± 0.95 kJ/mol 42.0797 ± 0.0024 6700-78-3*1 Allyl anion [CH2CHCH2]- (g) 133.96 122.95 ± 0.22 kJ/mol 41.0723 ± 0.0024 1724-46-5*0 Cyclopropyl CH(CH2CH2) (g) 303.86 291.24 ± 0.94 kJ/mol 41.0718 ± 0.0024 2417-82-5*0 Propylidyne CH3CH2C (g, quartet) 624.8 613.2 ± 1.3 kJ/mol 41.0718 ± 0.0024 85056-54-8*2 Dinitrogen tetraoxide O2NNO2 (g) 20.20 10.91 ± 0.14 kJ/mol 92.0111 ± 0.0012 10544-72-6*0 1-Propynyl CH3CC (g) 528.54 526.37 ± 0.65 kJ/mol 39.0559 ± 0.0024 89342-91-6*0 1-Propynylide [CH3CC]- (g) 264.60 261.02 ± 0.66 kJ/mol 39.0565 ± 0.0024 36147-87-2*0 1-Propen-1-yl-3-ylidene CHCHCH (g, c-c quartet) 656.7 653.3 ± 1.1 kJ/mol 39.0559 ± 0.0024 84654-90-0*11 sec-Butyl CH3CH2CHCH3 (g) 91.30 66.53 ± 0.85 kJ/mol 57.1143 ± 0.0033 2348-55-2*0 t-Butyl anion [(CH3)3C]- (g) 76.9 52.1 ± 1.3 kJ/mol 57.1148 ± 0.0033 65114-21-8*0 Nitroxyl ON(O)O (g) 79.40 74.15 ± 0.19 kJ/mol 62.00494 ± 0.00090 12033-49-7*0 2-Hydroxyethenyl CHCHOH (g, trans-cis) 138.01 131.27 ± 0.72 kJ/mol 43.0446 ± 0.0016 108665-16-3*21 Oxirene O(CHCH) (g, t-triplet) 387.9 383.7 ± 1.4 kJ/mol 42.0367 ± 0.0016 157-18-6*11 Oxiranylidene CH2(CO) (g, singlet) 213.5 209.3 ± 1.4 kJ/mol 42.0367 ± 0.0016 50983-85-2*2 Azanylium [NH3]+ (g) 944.274 937.320 ± 0.029 kJ/mol 17.03001 ± 0.00022 19496-55-0*0 Hydroxyformyl anion [HOCO]- (g, trans) -313.66 -315.46 ± 0.57 kJ/mol 45.0180 ± 0.0010 78944-70-4*1 Ethoxyethene CH2CHOCH2CH3 (g, cis-trans) -118.0 -141.8 ± 1.5 kJ/mol 72.1057 ± 0.0033 109-92-2*2 1,1-Ethenediol CH2C(OH)2 (g, syn-anti Cs) -307.66 -320.61 ± 0.83 kJ/mol 60.0520 ± 0.0017 10375-04-9*1 1,2-Ethenediol HOCHCHOH (g, cis) -272.81 -285.13 ± 0.90 kJ/mol 60.0520 ± 0.0017 1571-60-4*1 Methoxyoxomethyl CH3OCO (g, anti-staggered) -152.6 -160.7 ± 1.2 kJ/mol 59.0440 ± 0.0017 16481-04-2*1 (Formyloxy)methyl HC(O)OCH2 (g, syn) -151.5 -159.6 ± 1.1 kJ/mol 59.0440 ± 0.0017 3122-12-1*1 Ethylene glycol (CH2OH)2 (g) -369.65 -389.28 ± 0.40 kJ/mol 62.0678 ± 0.0018 107-21-1*0 Oxalic acid (C(O)OH)2 (g) -721.1 -731.7 ± 1.2 kJ/mol 90.0349 ± 0.0020 144-62-7*0 (Methylamino)methyl cation [CH3NHCH2]+ (g) 729.42 710.80 ± 0.96 kJ/mol 44.0752 ± 0.0017 *31277-24-4*0 Trioxygen difluoride FOOOF (g, trans) 112.3 106.6 ± 1.1 kJ/mol 85.99501 ± 0.00090 16829-28-0*1 Bromochlorane BrCl (g) 21.875 14.432 ± 0.060 kJ/mol 115.3567 ± 0.0013 13863-41-7*0 Iodine monobromide IBr (g) 49.712 40.765 ± 0.067 kJ/mol 206.8085 ± 0.0010 7789-33-5*0 Diazomethyl HCNN (g) 468.18 465.63 ± 0.98 kJ/mol 41.03212 ± 0.00082 20813-32-5*0 Isocyanoamidogen HNNC (g) 490.3 488.3 ± 1.5 kJ/mol 41.03212 ± 0.00082 947408-73-3*0 Bromotrichloromethane CCl3Br (g) -29.68 -38.83 ± 0.54 kJ/mol 198.2728 ± 0.0030 75-62-7*0 Dichloromethyl CHCl2 (g) 92.90 90.98 ± 0.88 kJ/mol 83.9240 ± 0.0020 3474-12-2*0 Chloromethyl CH2Cl (g) 118.45 115.38 ± 0.87 kJ/mol 49.4793 ± 0.0012 6806-86-6*0 Methyl hypochlorite CH3OCl (g) -53.1 -63.0 ± 1.4 kJ/mol 66.4866 ± 0.0013 593-78-2*0 1,2-Dichloroethane CH2ClCH2Cl (g) -118.51 -130.45 ± 0.54 kJ/mol 98.9586 ± 0.0024 107-06-2*0 Tetraiodomethane CI4 (g) 320.9 315.8 ± 2.0 kJ/mol 519.62858 ± 0.00081 507-25-5*0 Chlorofluoromethane CH2FCl (g) -256.42 -263.61 ± 0.85 kJ/mol 68.4777 ± 0.0012 593-70-4*0 Difluoromethyliumyl [CF2]+ (g) 908.28 908.70 ± 0.77 kJ/mol 50.00696 ± 0.00080 54250-40-7*0 Fluoromethyliumylidene [CF]+ (g) 1123.08 1126.30 ± 0.45 kJ/mol 31.00855 ± 0.00080 33412-11-2*0 1,2-Difluoroacetylene FCCF (g) 2.89 5.71 ± 0.64 kJ/mol 62.0182 ± 0.0016 689-99-6*0 Chloroformyl ClCO (g) -21.93 -20.53 ± 0.49 kJ/mol 63.4628 ± 0.0012 2602-42-8*0 Hypochloroperoxoous acid, hydroxy ester HOOOCl (g, syn) 48.5 41.5 ± 1.8 kJ/mol 84.4588 ± 0.0013 928652-99-7*1 o-Benzyne anion [C6H4]- (g) 413.82 404.71 ± 0.96 kJ/mol 76.0965 ± 0.0048 100569-88-8*0 Cycloheptene CH2(CHCHCH2CH2CH2CH2 (g) 28.44 -8.79 ± 0.75 kJ/mol 96.1702 ± 0.0057 628-92-2*0 Benzoylium [C6H5CO]+ (g) 763.5 749.4 ± 1.3 kJ/mol 105.1135 ± 0.0056 19270-10-1*0 Benzoyl fluoride C6H5C(O)F (g) -288.4 -304.9 ± 1.3 kJ/mol 124.1124 ± 0.0056 455-32-3*0 Fluorobenzene cation [C6H5F]+ (g) 788.98 773.96 ± 0.89 kJ/mol 96.1018 ± 0.0048 34468-25-2*0 Nitrosobenzene C6H5NO (g) 216.7 199.8 ± 1.2 kJ/mol 107.1100 ± 0.0048 586-96-9*0 1-Methylethoxy CH3CH(O)CH3 (g) -25.12 -43.88 ± 0.75 kJ/mol 59.0871 ± 0.0025 3958-66-5*0 Nitromethyl CH2N(O)O (g) 139.2 129.8 ± 1.2 kJ/mol 60.0321 ± 0.0010 16787-85-2*0 Dioxaziridinyl N(OO) (g) 355.1 352.6 ± 1.4 kJ/mol 46.00554 ± 0.00060 66252-29-7*0 2-Butanone CH3CH2C(O)CH3 (g) -216.87 -238.33 ± 0.79 kJ/mol 72.1057 ± 0.0033 78-93-3*0 Methylketene CH3CHCO (g) -54.7 -64.2 ± 1.1 kJ/mol 56.0633 ± 0.0024 6004-44-0*0 Acrolein CH2CHCHO (g, trans) -55.2 -65.6 ± 1.2 kJ/mol 56.0633 ± 0.0024 107-02-8*1 Formaldoxime CH2NOH (g, trans) 30.5 19.9 ± 1.3 kJ/mol 45.04066 ± 0.00088 75-17-2*1 Iodine I (g, 2P3/2) 107.157 106.757 ± 0.0021 kJ/mol 126.904470 ± 0.000030 14362-44-8*1 1,3-Cyclobutadien-1-yl C(CHCHCH) (g) 653.8 649.3 ± 1.1 kJ/mol 51.0666 ± 0.0032 127611-22-7*0 Silylsilylene SiH3SiH (g, singlet) 315.9 308.0 ± 2.0 kJ/mol 60.20276 ± 0.00066 50420-90-1*2 Trimethylsiloxide [(CH3)3SiO]- (g) -486.7 -510.5 ± 2.1 kJ/mol 89.1890 ± 0.0025 41866-81-3*0 1,3-Pentadiyne HCCCCCH3 (g) 418.02 413.81 ± 0.84 kJ/mol 64.0853 ± 0.0040 4911-55-1*0 1,4-Hexadiyne HCCCH2CCCH3 (g) 424.7 414.7 ± 1.3 kJ/mol 78.1118 ± 0.0048 10420-91-4*0 Biallenyl CH2CCHCHCCH2 (g, trans) 410.6 399.0 ± 1.5 kJ/mol 78.1118 ± 0.0048 29776-96-3*1 1,2,3,4-Hexatetraene CH2CCCCHCH3 (g) 429.9 420.1 ± 1.6 kJ/mol 78.1118 ± 0.0048 177856-38-1*0 2-Naphthyl anion [C6H4(CHCCHCH)]- (g) 288.6 269.2 ± 1.3 kJ/mol 127.1631 ± 0.0080 88760-89-8*0 1-Naphthyl anion [C6H4(CCHCHCH)]- (g) 283.4 264.0 ± 1.2 kJ/mol 127.1631 ± 0.0080 125254-29-7*0 Nitrosamine NH2NO (g) 85.00 76.11 ± 0.96 kJ/mol 46.02876 ± 0.00036 35576-91-1*0 Butadiynyl CCCCH (g) 801.8 808.4 ± 1.0 kJ/mol 49.0507 ± 0.0032 53561-65-2*0 Sulfur dioxide anion [OSO]- (g) -401.06 -403.32 ± 0.75 kJ/mol 64.0653 ± 0.0060 12143-17-8*0 Sulfanyl SH (g) 142.93 143.39 ± 0.20 kJ/mol 33.0739 ± 0.0060 13940-21-1*0 Carbide [C2]- (g) 504.43 511.00 ± 0.31 kJ/mol 24.0219 ± 0.0016 12595-78-7*0 Carbon dioxide CO2 (g, triplet) 49.8 50.6 ± 1.1 kJ/mol 44.00950 ± 0.00100 124-38-9*1 Bicyclo[1.1.0]buta-1,3-diene-2,4-diyl C(CC)C (g) 1047.22 1054.81 ± 0.68 kJ/mol 48.0428 ± 0.0032 12184-80-4*0 Methane cation [CH4]+ (g) 1150.684 1144.301 ± 0.060 kJ/mol 16.04191 ± 0.00085 20741-88-2*0 Iodide I- (aq) -56.828 ± 0.089 kJ/mol 126.905019 ± 0.000030 20461-54-5*800 Ethanium [C2H7]+ (g) 874.33 858.09 ± 0.62 kJ/mol 31.0764 ± 0.0017 24669-33-8*0 Acetylene cation [HCCH]+ (g) 1328.86 1328.19 ± 0.12 kJ/mol 26.0367 ± 0.0016 25641-79-6*0 1-Ethylium-1-ylidene [CH3C]+ (g) 1329.7 1328.3 ± 1.2 kJ/mol 27.0447 ± 0.0016 78949-84-5*0 Ethylidyne anion [CH3C]- (g) 457.1 453.1 ± 1.2 kJ/mol 27.0458 ± 0.0016 117768-70-4*0 Isocyanomethyl CH2NC (g) 363.7 361.3 ± 1.2 kJ/mol 40.0440 ± 0.0016 70971-59-4*0 Methyloxoniumylidene [CH3O]+ (g) 1062.69 1054.87 ± 0.57 kJ/mol 31.03337 ± 0.00088 58157-09-8*0 Hydroxymethylene HCOH (g, cis) 131.11 127.36 ± 0.29 kJ/mol 30.02598 ± 0.00087 19710-56-6*2 Hydroxymethylene cation [HCOH]+ (g, trans) 971.9 968.2 ± 1.4 kJ/mol 30.02543 ± 0.00087 135395-06-1*1 Isoformyl COH (g) 217.25 217.63 ± 0.69 kJ/mol 29.01804 ± 0.00086 71080-92-7*0 Hydroxyoxomethoxy HOC(O)O (g) -360.80 -366.88 ± 0.98 kJ/mol 61.0168 ± 0.0012 38330-85-7*0 Hydrogen chloride HCl (aq, 100 H2O) -165.755 ± 0.025 kJ/mol 36.46064 ± 0.00090 7647-01-0*828 Bromide Br- (aq) -120.88 ± 0.14 kJ/mol 79.90455 ± 0.00100 24959-67-9*800 3-Dioxiranone OC(OO) (g) -159.7 -162.4 ± 1.7 kJ/mol 60.0089 ± 0.0012 94660-13-6*0 Carbonylbis(oxy) anion [OC(O)O]- (g) -549.9 -551.9 ± 1.4 kJ/mol 60.0094 ± 0.0012 16518-46-0*0 1-Methylethylidene CH3CCH3 (g, triplet) 326.9 313.7 ± 1.2 kJ/mol 42.0797 ± 0.0024 40852-89-9*1 Allylium [CH2CHCH2]+ (g) 964.57 953.01 ± 0.40 kJ/mol 41.0713 ± 0.0024 1724-44-3*0 1-Propenyl CH3CHCH (g, trans) 280.30 269.47 ± 0.77 kJ/mol 41.0718 ± 0.0024 6067-68-1*1 Cyclopropynyl CH(CC) (g) 711.01 715.13 ± 0.85 kJ/mol 37.0400 ± 0.0024 119178-99-3*0 n-Butyl anion [CH3CH2CH2CH2]- (g) 106.1 81.2 ± 1.3 kJ/mol 57.1148 ± 0.0033 79431-01-9*0 sec-Butyl anion [CH3CH2CHCH3]- (g) 103.3 78.8 ± 1.3 kJ/mol 57.1148 ± 0.0033 79431-00-8*0 1,2-Butadienyl anion [CH3CHCCH]- (g) 255.7 246.2 ± 1.1 kJ/mol 53.0830 ± 0.0032 65114-67-2*0 Dinitrogen pentoxide O2NONO2 (g) 24.35 14.78 ± 0.30 kJ/mol 108.0105 ± 0.0015 10102-03-1*0 n-Hexane CH3CH2CH2CH2CH2CH3 (cr,l) -179.81 -198.47 ± 0.33 kJ/mol 86.1754 ± 0.0049 110-54-3*500 1-Hydroxyethylium [CH3CHOH]+ (g, syn) 610.8 596.3 ± 1.1 kJ/mol 45.0600 ± 0.0017 18682-96-7*2 2-Hydroxyethyl CH2CH2OH (g, gauche-anti) -11.00 -23.64 ± 0.93 kJ/mol 45.0605 ± 0.0017 4422-54-2*2 Vinyl alcohol cation [CH2CHOH]+ (g, anti) 778.6 767.3 ± 1.3 kJ/mol 44.0520 ± 0.0017 57239-63-1*2 1-Hydroxyethylidene CH3COH (g, syn singlet) 69.98 59.47 ± 0.86 kJ/mol 44.0526 ± 0.0017 30967-49-8*22 Oxiranylium [CH2(CHO)]+ (g, singlet) 901.3 893.3 ± 1.4 kJ/mol 43.0441 ± 0.0016 57789-76-1*2 C=O=C COC (g, triplet) 653.0 657.3 ± 1.5 kJ/mol 40.0208 ± 0.0016 *12071-23-7*1 C=O=C COC (g, singlet) 721.9 726.3 ± 1.6 kJ/mol 40.0208 ± 0.0016 *12071-23-7*2 Hydroxyimidogen NOH (g) 217.87 214.98 ± 0.77 kJ/mol 31.01408 ± 0.00032 35337-59-8*0 Oxoethylidene HCC(O)H (g, singlet) 275.5 272.6 ± 1.7 kJ/mol 42.0367 ± 0.0016 39920-84-8*2 Ethyl hydroperoxide CH3CH2OOH (g) -143.0 -161.4 ± 1.2 kJ/mol 62.0678 ± 0.0018 3031-74-1*0 Hydrogen difluoride (F)(HF) (g, lin) -198.5 -198.4 ± 1.2 kJ/mol 39.004746 ± 0.000070 12528-21-1*1 Formic acid cation [HC(O)OH]+ (g, syn) 721.93 714.84 ± 0.25 kJ/mol 46.0248 ± 0.0010 50614-05-6*1 Formyloxidanyl HC(O)O (g, 2B2) -122.01 -125.36 ± 0.55 kJ/mol 45.0174 ± 0.0010 16499-21-1*2 Fluoride F- (aq) -334.51 ± 0.16 kJ/mol 18.99895178 ± 0.00000050 16984-48-8*800 Azide [NNN]- (g) 193.53 190.02 ± 0.91 kJ/mol 42.02077 ± 0.00021 14343-69-2*0 1-Methoxyethenol CH2C(OH)OCH3 (g, anti-syn) -284.3 -303.7 ± 1.2 kJ/mol 74.0785 ± 0.0025 4453-91-2*1 Bromonium [HBrH]+ (g) 924.2 913.4 ± 3.0 kJ/mol 81.9193 ± 0.0010 36658-54-5*0 Trioxidanylium [HOOO]+ (g, trans) 1070.4 1064.1 ± 1.4 kJ/mol 49.00559 ± 0.00090 74241-49-9*1 1-Propene-1,2-diol CH3C(OH)CHOH (g, cis) -311.4 -329.8 ± 1.2 kJ/mol 74.0785 ± 0.0025 7333-03-1*1 1-Propene-1,2-diol CH3C(OH)CHOH (g, trans) -293.2 -309.8 ± 1.3 kJ/mol 74.0785 ± 0.0025 7333-03-1*2 (Formyloxy)methyl HC(O)OCH2 (g, anti) -135.9 -144.0 ± 1.3 kJ/mol 59.0440 ± 0.0017 3122-12-1*2 Carboxymethyl CH2C(O)OH (g, anti) -206.1 -215.5 ± 1.2 kJ/mol 59.0440 ± 0.0017 2887-46-9*2 Dimethylamide [(CH3)2N]- (g) 122.4 104.0 ± 1.7 kJ/mol 44.0763 ± 0.0017 34285-60-4*0 1H-Triazirin-1-yl N(NN) (g) 585.9 584.1 ± 2.0 kJ/mol 42.02022 ± 0.00021 912535-95-6*0 Chlorine difluoride FClF (g) -47.0 -48.2 ± 1.3 kJ/mol 73.44951 ± 0.00090 24801-48-7*0 1,1,2-Trichloroethane CH2ClCHCl2 (g) -135.6 -147.3 ± 1.1 kJ/mol 133.4033 ± 0.0031 79-00-5*0 1,1,1,2-Tetrachloroethane CH2ClCCl3 (g) -144.4 -152.9 ± 1.3 kJ/mol 167.8481 ± 0.0039 630-20-6*0 Pentachloroethyl CCl3CCl2 (g) 28.9 27.0 ± 1.3 kJ/mol 201.2849 ± 0.0048 7094-17-9*0 Chloryl hydride HCl(O)O (g) 197.7 191.2 ± 1.6 kJ/mol 68.4594 ± 0.0011 174365-32-3*0 Iodomethane CH3I (l) -12.28 ± 0.20 kJ/mol 141.93899 ± 0.00083 74-88-4*590 Bromo hypobromite BrOBr (g) 120.9 104.4 ± 1.2 kJ/mol 175.8074 ± 0.0020 21308-80-5*0 Difluoromethylene CF2 (g, triplet) 43.33 44.05 ± 0.36 kJ/mol 50.00751 ± 0.00080 2154-59-8*1 Ethyl iodide CH3CH2I (l) -9.38 -39.25 ± 0.49 kJ/mol 155.9656 ± 0.0016 75-03-6*500 cis-1,2-Difluoroethene CHFCHF (g, cis) -302.82 -309.58 ± 0.89 kJ/mol 64.0341 ± 0.0016 1630-77-9*0 Fluoroethynyl CCF (g) 445.3 449.8 ± 1.6 kJ/mol 43.0198 ± 0.0016 22533-50-2*0 Fluoro(fluorooxy)methylene FCOF (g, cis) -134.8 -136.0 ± 1.3 kJ/mol 66.00691 ± 0.00085 479587-30-9*2 Dibromophosgene CBr2O (g) -97.99 -113.92 ± 0.37 kJ/mol 187.8181 ± 0.0022 593-95-3*0 Benzene C6H6 (cr,l) 50.85 49.30 ± 0.22 kJ/mol 78.1118 ± 0.0048 71-43-2*500 o-Benzyne C6H4 (g) 468.21 459.29 ± 0.86 kJ/mol 76.0960 ± 0.0048 462-80-6*0 m-Benzyne C6H4 (g, singlet) 527.0 518.6 ± 1.2 kJ/mol 76.0960 ± 0.0048 1828-89-3*2 p-Benzyne C6H4 (g, singlet) 587.1 577.6 ± 1.2 kJ/mol 76.0960 ± 0.0048 3355-34-8*2 Cycloheptane CH2(CH2CH2CH2CH2CH2C (g) -72.49 -117.99 ± 0.53 kJ/mol 98.1861 ± 0.0057 291-64-5*0 Peroxynitric acid HOON(O)O (g) -42.6 -52.9 ± 1.3 kJ/mol 79.0123 ± 0.0012 26404-66-0*0 Bifluoride [(HF)(F)]- (g, singlet) -481.8 -480.6 ± 1.9 kJ/mol 39.005295 ± 0.000070 *18130-74-0*2 Formylethynyl CCCHO (g) 468.4 470.3 ± 1.3 kJ/mol 53.0394 ± 0.0024 277743-00-7*0 2-Cyclopropen-1-one OC(CHCH) (g) 163.8 159.9 ± 1.2 kJ/mol 54.0474 ± 0.0024 2961-80-0*0 Cyanovinylidene CCHCN (g) 581.7 584.2 ± 1.2 kJ/mol 51.0468 ± 0.0024 70277-81-5*0 Isocyanovinylidene CCHNC (g) 697.0 700.4 ± 1.4 kJ/mol 51.0468 ± 0.0024 737788-76-0*0 Cyanoacetylide [CCCN]- (g) 300.3 305.6 ± 1.2 kJ/mol 50.0394 ± 0.0024 12373-53-4*0 Isocyanoethene CH2CHNC (g, singlet) 285.20 278.70 ± 0.94 kJ/mol 53.0627 ± 0.0024 14668-82-7*1 1-Cyanoethylidene CH3CCN (g, triplet) 437.6 433.8 ± 1.5 kJ/mol 53.0627 ± 0.0024 498544-34-6*1 Isocyanomethylene HCNC (g, singlet) 582.3 583.6 ± 1.7 kJ/mol 39.0361 ± 0.0016 78694-65-2*1 Dioxidenium [HO2]+ (g) 1110.88 1107.99 ± 0.11 kJ/mol 33.00619 ± 0.00060 12207-52-2*0 2-Methyl-2-cyclopropen-1-ylidene CH3C(CHC) (g, singlet) 448.0 441.8 ± 1.2 kJ/mol 52.0746 ± 0.0032 185841-59-2*2 Iodine cation I+ (g) 1115.549 1115.149 ± 0.0062 kJ/mol 126.903921 ± 0.000030 22541-93-1*0 1,2,3-Butatrien-1-ylium [CH2CCCH]+ (g, triplet) 1425.8 1426.1 ± 1.3 kJ/mol 51.0661 ± 0.0032 81932-79-8*1 But-1-en-3-yn-1-ide [HCCCHCH]- (g, cis) 419.7 418.5 ± 1.2 kJ/mol 51.0672 ± 0.0032 119611-65-3*2 But-3-en-1-yn-1-ide [CH2CHCC]- (g, singlet) 326.7 323.6 ± 1.4 kJ/mol 51.0672 ± 0.0032 58870-47-6*2 Cyclobutenyl CH2(CHCHCH) (g) 337.3 324.8 ± 1.2 kJ/mol 53.0825 ± 0.0032 24669-29-2*0 Propargyl chloride HCCCH2Cl (g) 186.6 180.7 ± 1.3 kJ/mol 74.5086 ± 0.0026 624-65-7*0 Dioxosilane SiO2 (g) -278.5 -279.9 ± 2.0 kJ/mol 60.08430 ± 0.00067 7631-86-9*0 Tetrafluorosilane SiF4 (g) -1609.84 -1615.35 ± 0.37 kJ/mol 104.07911 ± 0.00030 7783-61-1*0 Water anion [(H)(OH)]- (g, vdW ?) 31.3 29.8 ± 3.1 kJ/mol 18.01583 ± 0.00033 12259-30-2*100 Hydrogen fluoride HF (aq, 30 H2O) -321.11 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*820 Silylidyne SiH (g) 370.68 372.47 ± 0.75 kJ/mol 29.09344 ± 0.00031 13774-94-2*0 Nitrosyl chloride ClNO (g) 54.476 52.574 ± 0.069 kJ/mol 65.45884 ± 0.00095 2696-92-6*0 Benzvalene ((CHCH)(CH(CHCH)CH)) (g) 404.4 386.7 ± 1.2 kJ/mol 78.1118 ± 0.0048 659-85-8*0 Diazenyl NNH (g) 252.14 249.23 ± 0.45 kJ/mol 29.02142 ± 0.00016 36882-13-0*0 2-Naphthalenyl C6H4(CHCCHCH) (g) 416.7 397.1 ± 1.3 kJ/mol 127.1626 ± 0.0080 10237-50-0*0 1-Naphthalenyl C6H4(CCHCHCH) (g) 418.0 398.4 ± 1.3 kJ/mol 127.1626 ± 0.0080 2510-51-2*0 Phenanthrene C6H4(C2H2(CC(C4H4))) (g) 231.88 203.06 ± 0.80 kJ/mol 178.2292 ± 0.0112 85-01-8*0 Aniline C6H5NH2 (g) 108.82 86.80 ± 0.73 kJ/mol 93.1265 ± 0.0048 62-53-3*0 Pyruvic acid CH3C(O)C(O)OH (g) -521.1 -535.5 ± 1.1 kJ/mol 88.0621 ± 0.0026 127-17-3*0 Sulfurous acid S(O)(OH)2 (aq, 100 H2O) -612.21 ± 0.14 kJ/mol 82.0801 ± 0.0061 7782-99-2*828 Methylammonium [CH3NH3]+ (g) 628.5 609.6 ± 1.4 kJ/mol 32.06453 ± 0.00091 17000-00-9*0 Chlorine chlorite ClOClO (g, gauche) 168.6 166.2 ± 1.3 kJ/mol 102.9042 ± 0.0019 105206-44-8*3 Aminomethylene CHNH2 (g) 245.9 238.2 ± 1.5 kJ/mol 29.04126 ± 0.00083 35430-17-2*0 Nitrosodioxaziridine ONN(OO) (g, trans) 413.7 407.7 ± 1.8 kJ/mol 76.01168 ± 0.00091 132871-99-9*1 Methyleneamidogen anion [CH2N]- (g) 192.78 189.03 ± 0.91 kJ/mol 28.03387 ± 0.00082 28892-56-0*0 (Z)-Iminomethyl HCNH (g, cis) 294.51 291.02 ± 0.90 kJ/mol 28.03332 ± 0.00082 54980-11-9*0 Aminomethylidyne CNH2 (g) 371.9 368.4 ± 1.1 kJ/mol 28.03332 ± 0.00082 84654-89-7*0 Ethynylamidogen HCCNH (g) 395.40 393.37 ± 0.97 kJ/mol 40.0440 ± 0.0016 73456-14-1*0 Methyleneoxonium CH2OH2 (g) 152.47 144.16 ± 0.49 kJ/mol 32.04186 ± 0.00090 177788-17-9*0 Hydroxymethylene anion [HCOH]- (g, trans) 147.2 144.1 ± 1.6 kJ/mol 30.02653 ± 0.00087 207914-87-2*1 Hydroxyaminiumyl [NOH]+ (g) 1161.1 1158.2 ± 1.4 kJ/mol 31.01353 ± 0.00032 63559-88-6*0 Hydroxymethyliumylidene [COH]+ (g) 986.01 987.65 ± 0.83 kJ/mol 29.01749 ± 0.00086 60528-75-8*0 Isoformyl anion [(CO)(H)]- (g, vdW singlet ?) 55.7 58.4 ± 1.8 kJ/mol 29.01859 ± 0.00086 81747-63-9*1 Oxywater (H2O)O (g) 64.9 58.4 ± 1.3 kJ/mol 34.01468 ± 0.00062 171363-09-0*0 Peroxyformic acid HC(O)OOH (g, trans) -265.2 -273.2 ± 1.6 kJ/mol 62.0248 ± 0.0012 107-32-4*2 Hydrogen carbonate [HOC(O)O]- (g) -716.9 -723.3 ± 1.4 kJ/mol 61.0174 ± 0.0012 71-52-3*0 Trioxidaniumyl [HOOOH]+ (g, t, t) 925.5 916.3 ± 1.5 kJ/mol 50.01353 ± 0.00091 161321-37-5*2 Hydroperoxycarbonyl HOOCO (g) -73.5 -77.3 ± 1.7 kJ/mol 61.0168 ± 0.0012 153751-35-0*0 Propan-1-yl-3-ylidene CH2CH2CH (g, quartet) 554.4 545.7 ± 1.3 kJ/mol 41.0718 ± 0.0024 *50457-59-5*2 1-Propenylidene CH3CHC (g, singlet) 392.3 388.0 ± 1.1 kJ/mol 40.0639 ± 0.0024 70277-78-0*1 Hydroxyamidogen HNOH (g, cis) 123.3 116.7 ± 1.7 kJ/mol 32.02202 ± 0.00034 13940-32-4*2 Hydroxyaminylium [HNOH]+ (g, trans) 1019.5 1012.3 ± 2.5 kJ/mol 32.02147 ± 0.00034 66097-71-0*1 Cycloprop-2-enyl CH(CHCH) (g) 490.30 485.75 ± 0.58 kJ/mol 39.0559 ± 0.0024 28933-84-8*0 2-Propen-1-yl-3-ylidene CH2CHC (g) 556.64 554.38 ± 0.89 kJ/mol 39.0559 ± 0.0024 202744-74-9*0 2-Propynylidyne anion [CCCH]- (g) 540.10 544.88 ± 0.82 kJ/mol 37.0406 ± 0.0024 82893-67-2*0 t-Butylium [(CH3)3C]+ (g) 734.02 710.74 ± 0.98 kJ/mol 57.1137 ± 0.0033 14804-25-2*0 iso-Butyl (CH3)2CHCH2 (g) 97.23 73.24 ± 0.91 kJ/mol 57.1143 ± 0.0033 4630-45-9*0 Methylcyclopropane CH3CH(CH2CH2) (g) 47.8 24.6 ± 1.3 kJ/mol 56.1063 ± 0.0032 594-11-6*0 Chlorosyl hydride HClO (g) 141.9 139.0 ± 1.7 kJ/mol 52.46004 ± 0.00095 71572-35-5*0 Aquachlorine cation [ClOH2]+ (g) 822.0 815.1 ± 1.8 kJ/mol 53.46743 ± 0.00096 142599-65-3*0 1,2-Butadienylium [CH3CHCCH]+ (g, singlet) 1099.2 1089.9 ± 1.2 kJ/mol 53.0820 ± 0.0032 *65114-67-2*2 Dihydrogen fluoride anion [HFH]- (g, triplet) 133.2 131.9 ± 1.6 kJ/mol 21.01483 ± 0.00014 117339-92-1*1 2,2-Dimethylbutane CH3CH2C(CH3)3 (g) -145.27 -185.69 ± 0.75 kJ/mol 86.1754 ± 0.0049 75-83-2*0 n-Nonane CH3(CH2)7CH3 (g) -176.16 -227.94 ± 0.50 kJ/mol 128.2551 ± 0.0073 111-84-2*0 Ethanol CH3CH2OH (l) -269.75 -277.51 ± 0.21 kJ/mol 46.0684 ± 0.0017 64-17-5*500 Vinyl alcohol cation [CH2CHOH]+ (g, syn) 786.57 775.34 ± 0.80 kJ/mol 44.0520 ± 0.0017 57239-63-1*1 Vinoxy cation [CH2CHO]+ (g, triplet) 1020.3 1013.2 ± 1.5 kJ/mol 43.0441 ± 0.0016 *35731-40-9*1 Vinoxide [CH2CHO]- (g) -152.89 -159.94 ± 0.59 kJ/mol 43.0452 ± 0.0016 35731-40-9*0 Oxiranyl anion [CH2(CHO)]- (g, singlet) 121.4 113.4 ± 1.5 kJ/mol 43.0452 ± 0.0016 72722-59-9*2 Acetic acid CH3C(O)OH (aq) -485.10 ± 0.23 kJ/mol 60.0520 ± 0.0017 64-19-7*800 Ketene CH2CO (g, singlet) -45.35 -48.41 ± 0.11 kJ/mol 42.0367 ± 0.0016 463-51-4*2 COC vdW (CO)(C) (g, triplet) 589.8 598.5 ± 1.5 kJ/mol 40.0208 ± 0.0016 *12071-24-8*1 Oxirene O(CHCH) (g, c-triplet) 389.9 385.7 ± 1.4 kJ/mol 42.0367 ± 0.0016 157-18-6*12 Hydroperoxymethyl CH2OOH (g) 72.9 65.6 ± 1.2 kJ/mol 47.0333 ± 0.0010 74087-87-9*0 Oxygen cation monohydrate [(HOH)O]+ (g) 1153.3 1147.8 ± 3.3 kJ/mol 34.01413 ± 0.00062 *31748-17-1*0 Formyloxoniumylidene [HC(O)O]+ (g) 1017.4 1014.0 ± 1.4 kJ/mol 45.0169 ± 0.0010 54375-27-8*0 Dioxymethylene HCOO (g, trans) 364.0 361.7 ± 2.4 kJ/mol 45.0174 ± 0.0010 438586-67-5*1 Cyanate [NCO]- (g) -221.18 -221.40 ± 0.53 kJ/mol 42.01739 ± 0.00086 661-20-1*0 Oxazirinyl C(NO) (g) 450.1 450.9 ± 1.5 kJ/mol 42.01684 ± 0.00086 228850-18-8*0 Hydrogen chloride HCl (aq, 1000 H2O) -166.563 ± 0.024 kJ/mol 36.46064 ± 0.00090 7647-01-0*839 2-Propene-1,2-diol CH2C(OH)CH2OH (g, anti-gauche-gauche) -295.5 -315.0 ± 1.2 kJ/mol 74.0785 ± 0.0025 44169-27-9*11 2-Methoxy-2-oxoethyl CH2C(O)OCH3 (g, syn) -203.0 -218.2 ± 1.5 kJ/mol 73.0706 ± 0.0025 54668-31-4*1 (Acetyloxy)methyl CH3C(O)OCH2 (g, syn) -200.2 -213.9 ± 1.5 kJ/mol 73.0706 ± 0.0025 2887-49-2*1 Aziridine NH(CH2CH2) (g) 143.25 126.72 ± 0.89 kJ/mol 43.0678 ± 0.0016 151-56-4*0 Dimethylmethyleneammonium [(CH3)2NCH2]+ (g) 696.9 671.9 ± 1.3 kJ/mol 58.1018 ± 0.0025 28149-27-1*0 Dioxyamidogen HNOO (g, cis) 240.5 233.8 ± 1.8 kJ/mol 47.01348 ± 0.00061 71843-95-3*2 Trichloromethide [CCl3]- (g) -123.2 -122.7 ± 2.0 kJ/mol 118.3693 ± 0.0028 14478-07-0*0 Xenon cation Xe+ (g) 1170.354 1170.354 ± 0.0062 kJ/mol 131.2895 ± 0.0200 24203-25-6*0 1,1,2,2-Tetrachloroethane CHCl2CHCl2 (g) -146.7 -156.1 ± 1.5 kJ/mol 167.8481 ± 0.0039 79-34-5*0 1,1,2,2-Tetrachloroethane CHCl2CHCl2 (cr,l) -172.9 -201.8 ± 1.5 kJ/mol 167.8481 ± 0.0039 79-34-5*500 Pentachloroethane CHCl2CCl3 (cr,l) -201.9 ± 2.5 kJ/mol 202.2928 ± 0.0048 76-01-7*500 Trichloroethene CHClCCl2 (l) -48.8 ± 1.5 kJ/mol 131.3874 ± 0.0031 79-01-6*590 Tetrachloroethene CCl2CCl2 (l) -61.12 ± 0.99 kJ/mol 165.8322 ± 0.0039 127-18-4*500 Oxygen anion monohydrate [(HOH)O]- (g) -239.0 -244.3 ± 3.0 kJ/mol 34.01523 ± 0.00062 31748-17-1*0 Trichloroethene CHClCCl2 (g) -10.9 -14.2 ± 1.5 kJ/mol 131.3874 ± 0.0031 79-01-6*0 Hydrogen difluoride cation [FFH]+ (g) 1174.3 1171.3 ± 1.5 kJ/mol 39.004198 ± 0.000070 *126950-54-7*0 Bromodichloromethane CHCl2Br (g) -35.0 -46.7 ± 1.2 kJ/mol 163.8280 ± 0.0022 75-27-4*0 2-Hydrotrioxy cation [OO(H)O]+ (g) 1298.2 1291.5 ± 1.5 kJ/mol 49.00559 ± 0.00090 *74241-49-9*0 Difluorodibromomethane CF2Br2 (g) -360.4 -378.4 ± 1.3 kJ/mol 209.8155 ± 0.0022 75-61-6*0 Dichlorodibromomethane CCl2Br2 (g) 27.5 11.6 ± 1.3 kJ/mol 242.7241 ± 0.0028 594-18-3*0 Difluorobromomethane CHF2Br (g) -410.92 -424.12 ± 0.46 kJ/mol 130.9194 ± 0.0013 1511-62-2*0 1,2-Difluoroethane CH2FCH2F (g) -434.36 -447.78 ± 0.80 kJ/mol 66.0500 ± 0.0016 624-72-6*0 2-Hydrotrioxy anion [OO(H)O]- (g) 27.5 21.8 ± 1.4 kJ/mol 49.00669 ± 0.00090 *89965-38-8*0 Methylidyne CH (g, doublet) 592.840 596.175 ± 0.097 kJ/mol 13.01864 ± 0.00080 3315-37-5*1 Fluoro(fluorooxy)methylene FCOF (g, trans) -37.5 -39.1 ± 1.4 kJ/mol 66.00691 ± 0.00085 479587-30-9*1 Benzenium [CH2(CHCHCHCHCH)]+ (g) 887.7 867.7 ± 1.1 kJ/mol 79.1192 ± 0.0048 26812-57-7*0 Phenylium [C6H5]+ (g, triplet) 1251.2 1238.1 ± 1.6 kJ/mol 77.1034 ± 0.0048 17333-73-2*1 Chlorine difluoride cation [FClF]+ (g) 998.9 996.7 ± 1.7 kJ/mol 73.44896 ± 0.00090 32629-46-2*0 Benzylium [C6H5CH2]+ (g) 929.69 910.19 ± 0.55 kJ/mol 91.1299 ± 0.0056 6711-19-9*0 Triiodide [I3]- (aq) -51.30 ± 0.80 kJ/mol 380.713959 ± 0.000090 14900-04-0*800 Peroxynitrous acid HOONO (g, cis, perp) -0.13 -7.18 ± 0.53 kJ/mol 63.01288 ± 0.00091 14691-52-2*2 Peroxychlorous acid HOOClO (g, syn) 95.4 89.4 ± 2.0 kJ/mol 84.4588 ± 0.0013 177778-92-6*1 Benzoyl chloride C6H5C(O)Cl (cr,l) -157.08 ± 0.26 kJ/mol 140.5667 ± 0.0057 98-88-4*500 Benzoyl chloride C6H5C(O)Cl (g) -90.1 -105.4 ± 1.3 kJ/mol 140.5667 ± 0.0057 98-88-4*0 Chlorobenzene cation [C6H5Cl]+ (g) 942.61 928.68 ± 0.61 kJ/mol 112.5561 ± 0.0049 55450-32-3*0 Chlorobenzene C6H5Cl (cr,l) 11.36 ± 0.59 kJ/mol 112.5566 ± 0.0049 108-90-7*500 m-Chlorophenyl C6H4Cl (g) 321.4 310.6 ± 1.6 kJ/mol 111.5487 ± 0.0049 3474-40-6*0 p-Chlorophenyl C6H4Cl (g) 324.3 313.5 ± 1.6 kJ/mol 111.5487 ± 0.0049 2396-00-1*0 o-Chlorophenyl C6H4Cl (g) 328.6 317.8 ± 1.6 kJ/mol 111.5487 ± 0.0049 3474-42-8*0 Bromobenzene cation [C6H5Br]+ (g) 995.1 973.6 ± 1.3 kJ/mol 157.0074 ± 0.0049 55450-33-4*0 Iodobenzene C6H5I (cr,l) 113.6 113.7 ± 1.1 kJ/mol 204.0084 ± 0.0048 591-50-4*500 Nitrobenzene C6H5N(O)O (g) 82.2 62.2 ± 1.4 kJ/mol 123.1094 ± 0.0049 98-95-3*0 3-Methylenecyclopropene cation [CH2C(CHCH)]+ (g) 1181.7 1174.6 ± 1.2 kJ/mol 52.0740 ± 0.0032 79105-72-9*0 1-Hydroxy-1-methylethyl cation [CH3C(OH)CH3]+ (g) 521.3 501.0 ± 1.2 kJ/mol 59.0865 ± 0.0025 *5131-95-3*0 1-Hydroxypropyl CH3CH2CHOH (g) -55.4 -73.1 ± 1.1 kJ/mol 59.0871 ± 0.0025 5723-77-3*0 1,3-Butadien-2-ol CH2C(OH)CHCH2 (g, s-trans, syn) -53.4 -70.4 ± 1.5 kJ/mol 70.0898 ± 0.0032 59120-04-6*11 Ethenedione OCCO (g) 14.5 17.0 ± 1.2 kJ/mol 56.0202 ± 0.0017 4363-38-6*0 Chlorine fluoride cation [ClF]+ (g) 1165.52 1165.70 ± 0.49 kJ/mol 54.45055 ± 0.00090 12432-44-9*0 Formaldonitrone CH2NHO (g) 78.4 67.1 ± 1.4 kJ/mol 45.04066 ± 0.00088 67353-84-8*0 Bifluoride [FFH]- (g, triplet) -68.0 -67.6 ± 1.6 kJ/mol 39.005295 ± 0.000070 *18130-74-0*1 (E)-Diazene cation [HNNH]+ (g, trans) 1132.49 1125.55 ± 0.64 kJ/mol 30.02881 ± 0.00020 59952-06-6*0 (Z)-Diazene HNNH (g, cis) 228.83 221.69 ± 0.63 kJ/mol 30.02936 ± 0.00020 15626-42-3*0 2-Cyclopropen-1-imine (CHCH)CNH (g) 401.9 394.1 ± 1.4 kJ/mol 53.0627 ± 0.0024 31589-17-0*0 1-Isocyanovinyl CH2CNC (g) 519.1 517.3 ± 1.4 kJ/mol 52.0547 ± 0.0024 321850-14-0*0 Perchloric acid HOCl(O)(O)O (g) 11.7 0.2 ± 1.3 kJ/mol 100.4582 ± 0.0015 7601-90-3*0 Vinylvinylidene CH2CHCHC (g, singlet) 494.2 488.8 ± 1.7 kJ/mol 52.0746 ± 0.0032 148759-16-4*2 Dioxiranylidene C(OO) (g) 190.3 191.1 ± 1.4 kJ/mol 44.00950 ± 0.00100 138832-57-2*0 But-1-en-3-yn-1-ide [HCCCHCH]- (g, trans) 422.3 421.0 ± 1.3 kJ/mol 51.0672 ± 0.0032 119611-65-3*1 Tetrahedryl anion [C(CH(CHCH))]- (g) 634.6 630.8 ± 1.6 kJ/mol 51.0672 ± 0.0032 138805-00-2*0 Silicon carbide SiC (g) 739.8 744.7 ± 2.4 kJ/mol 40.09620 ± 0.00085 409-21-2*0 Silicon carbide SiC (cr, alpha-hex) -71.6 -72.6 ± 1.4 kJ/mol 40.09620 ± 0.00085 409-21-2*501 Silanide [SiH3]- (g) 68.7 63.1 ± 1.4 kJ/mol 31.10987 ± 0.00037 15807-96-2*0 Oxofluoronium [FO]+ (g) 1342.66 1342.61 ± 0.80 kJ/mol 34.99725 ± 0.00030 12763-67-6*0 Fluorohydrochlorine cation [FClH]+ (g) 975.3 972.3 ± 2.0 kJ/mol 55.45849 ± 0.00090 70110-64-4*0 Dimethylsilanone CH3Si(O)CH3 (g) -237.8 -253.2 ± 2.3 kJ/mol 74.1539 ± 0.0017 47956-45-6*0 Dimethylsilane CH3SiH2CH3 (g) -66.7 -88.2 ± 1.2 kJ/mol 60.1704 ± 0.0017 1111-74-6*0 Deuterium atom D (g) 219.804 221.717 ± 0.000 kJ/mol 2.01410177800 ± 0.00000000040 16873-17-9*0 Hydroxysilyl anion [SiH2OH]- (g, syn) -220.0 -227.9 ± 2.1 kJ/mol 47.10927 ± 0.00047 78450-47-2*1 Triprismane ((CHCH)((CHCH)(CHCH) (g) 576.0 556.7 ± 1.3 kJ/mol 78.1118 ± 0.0048 650-42-0*0 Propargylallene CH2CCHCH2CCH (g, gauche) 431.4 419.8 ± 1.4 kJ/mol 78.1118 ± 0.0048 33142-15-3*3 Hydrogen fluoride HF (aq, 40 H2O) -321.15 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*821 Diacetylide [CCCCH]- (g) 460.9 466.0 ± 1.0 kJ/mol 49.0513 ± 0.0032 59012-21-4*0 Sulfur trioxide anion [OS(O)O]- (g) -604.4 -610.0 ± 2.8 kJ/mol 80.0647 ± 0.0061 12210-38-7*0 Hydrogen atom H (ad, 1 Pt(111) atop) -18.9 -21.4 ± 4.3 kJ/mol 1.007940 ± 0.000070 12385-13-6*1002001 Hydrogen atom H (ad, 4 Pt(111) atop) -30.3 -32.7 ± 5.3 kJ/mol 1.007940 ± 0.000070 12385-13-6*1002004 Isoformyl anion [COH]- (g, triplet) 267.4 268.0 ± 1.6 kJ/mol 29.01859 ± 0.00086 81747-63-9*2 Carbonic acid C(O)(OH)2 (g) -602.53 -611.84 ± 0.75 kJ/mol 62.0248 ± 0.0012 463-79-6*0 Dihydrogen cation [H2]+ (g) 1488.364 1488.480 ± 0.000 kJ/mol 2.01533 ± 0.00014 12184-90-6*0 Allene cation [CH2CCH2]+ (g) 1132.20 1125.04 ± 0.23 kJ/mol 40.0633 ± 0.0024 65812-77-3*0 2-Propenylidene CHCHCH2 (g, triplet anti) 417.4 409.9 ± 1.5 kJ/mol 40.0639 ± 0.0024 19527-08-3*11 2-Propenylidene CHCHCH2 (g, singlet) 452.62 445.49 ± 0.90 kJ/mol 40.0639 ± 0.0024 19527-08-3*2 Cycloprop-1-enylide [CH2(CHC)]- (g) 373.6 369.2 ± 1.7 kJ/mol 39.0565 ± 0.0024 80251-77-0*0 2-Cyclopropen-1-ylium-1-yl [C(CHCH)]+ (g) 1382.0 1381.0 ± 1.1 kJ/mol 38.0474 ± 0.0024 85398-75-0*0 Propynylidene HCCCH (g, cis singlet) 597.7 599.4 ± 1.3 kJ/mol 38.0480 ± 0.0024 67152-18-5*3 Propenediylidene CHCHC (g) 796.2 797.4 ± 1.4 kJ/mol 38.0480 ± 0.0024 60731-11-5*0 n-Butylium [CH3CH2CH2CH2]+ (g) 827.4 803.1 ± 1.2 kJ/mol 57.1137 ± 0.0033 25453-90-1*0 Hydrogen fluoride HF (aq, 22 H2O) -321.07 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*902 2-Butynylium [CH3CCCH2]+ (g, singlet) 1085.8 1077.6 ± 1.3 kJ/mol 53.0820 ± 0.0032 64235-83-2*2 1-Methylene-2-propenyl anion [CH2CHCCH2]- (g) 256.4 246.5 ± 1.4 kJ/mol 53.0830 ± 0.0032 64480-63-3*0 1,3-Butadienyl anion [CH2CHCHCH]- (g) 265.3 255.0 ± 1.5 kJ/mol 53.0830 ± 0.0032 65114-68-3*0 Iminomethide [HCNH]- (g, trans) 237.4 233.5 ± 1.8 kJ/mol 28.03387 ± 0.00082 90623-30-6*1 n-Decane CH3(CH2)8CH3 (g) -192.08 -248.83 ± 0.80 kJ/mol 142.2817 ± 0.0081 124-18-5*0 Ethyloxoniumyl [CH3CH2OH]+ (g) 783.3 766.3 ± 1.7 kJ/mol 46.0679 ± 0.0017 34480-55-2*0 1-Hydroxyethyl CH3CHOH (g, gauche-syn) -41.50 -54.97 ± 0.92 kJ/mol 45.0605 ± 0.0017 2348-46-1*2 1-Hydroxyethylium [CH3CHOH]+ (g) 608.73 594.31 ± 0.38 kJ/mol 45.0600 ± 0.0017 18682-96-7*0 2-Cyclopropyn-1-ylidene C(CC) (g, triplet) 898.8 905.7 ± 1.6 kJ/mol 36.0321 ± 0.0024 102508-15-6*1 2-Hydroxyethylium [CH2CH2OH]+ (g, staggered-anti) 1019.1 1006.3 ± 1.5 kJ/mol 45.0600 ± 0.0017 38607-31-7*3 Ethyloxoniumylidene [CH3CH2O]+ (g) 988.7 975.0 ± 1.5 kJ/mol 45.0600 ± 0.0017 54387-07-4*0 Trifluoromethide [CF3]- (g) -637.5 -639.3 ± 1.8 kJ/mol 69.00646 ± 0.00080 54128-17-5*0 Acetaldehyde cation [CH3CHO]+ (g) 831.96 821.99 ± 0.23 kJ/mol 44.0520 ± 0.0017 36505-03-0*0 2-Cyclopropyn-1-ylium-1-yl [C(CC)]+ (g) 1944.7 1952.6 ± 1.9 kJ/mol 36.0316 ± 0.0024 154702-35-9*0 1-Hydroxyethylidene CH3COH (g, gauche triplet) 184.9 175.5 ± 1.4 kJ/mol 44.0526 ± 0.0017 30967-49-8*1 Methoxymethylene CH3OCH (g, gauche triplet) 245.3 235.8 ± 1.4 kJ/mol 44.0526 ± 0.0017 19527-10-7*1 1-Hydroxyethenyl CH2COH (g) 121.35 114.96 ± 0.88 kJ/mol 43.0446 ± 0.0016 81847-74-7*0 Oxiranylium [CH2(CHO)]+ (g, triplet) 1233.6 1226.6 ± 1.6 kJ/mol 43.0441 ± 0.0016 57789-76-1*1 Oxiranyl anion [CH2(CHO)]- (g, triplet) 141.1 135.1 ± 1.6 kJ/mol 43.0452 ± 0.0016 72722-59-9*1 Ketenyl anion [HCCO]- (g) -48.45 -47.53 ± 0.82 kJ/mol 41.0293 ± 0.0016 64066-01-9*0 Dicarbon monoxide anion [CCO]- (g) 154.19 157.83 ± 0.83 kJ/mol 40.0213 ± 0.0016 87191-88-6*0 Oxochloronium [ClO]+ (g) 1150.86 1150.70 ± 0.66 kJ/mol 51.45155 ± 0.00095 12301-79-0*0 Dicarbon monoxide CCO (g, singlet) 440.23 444.56 ± 0.83 kJ/mol 40.0208 ± 0.0016 12071-23-7*2 COC vdW (CO)(C) (g, singlet) 726.3 734.6 ± 1.7 kJ/mol 40.0208 ± 0.0016 *12071-24-8*2 C=O-C cation [COC]+ (g, doublet) 1585.8 1592.9 ± 2.7 kJ/mol 40.0203 ± 0.0016 83483-98-1*1 C=O=C anion [COC]- (g) 550.3 554.1 ± 1.7 kJ/mol 40.0213 ± 0.0016 *87191-88-6*0 Oxirene cation [O(CHCH)]+ (g) 1106.3 1102.6 ± 1.9 kJ/mol 42.0361 ± 0.0016 94664-69-4*0 Ethynol HCCOH (g, gauche triplet) 400.0 397.6 ± 1.9 kJ/mol 42.0367 ± 0.0016 32038-79-2*11 Oxoethylidene HCC(O)H (g, anti-triplet) 265.9 262.6 ± 1.6 kJ/mol 42.0367 ± 0.0016 39920-84-8*11 Dioxygen O2 (g, singlet) 94.410 94.383 ± 0.000 kJ/mol 31.99880 ± 0.00060 7782-44-7*2 1,3-Butadiyne-1,4-diyl CCCC (g) 1052.37 1062.34 ± 0.65 kJ/mol 48.0428 ± 0.0032 78015-07-3*0 Formic acid cation [HC(O)OH]+ (g, anti) 723.8 716.7 ± 1.2 kJ/mol 46.0248 ± 0.0010 50614-05-6*2 Formic acid anion [HC(O)OH]- (g, syn) -256.2 -262.3 ± 1.8 kJ/mol 46.0259 ± 0.0010 19066-82-1*1 Nitrous acid HONO (g, cis) -71.35 -77.71 ± 0.26 kJ/mol 47.01348 ± 0.00061 7782-77-6*2 Isocyanic acid cation [HNCO]+ (g) 1002.99 1000.32 ± 0.49 kJ/mol 43.02423 ± 0.00086 444010-28-0*0 Fulminic acid cation [HCNO]+ (g) 1215.7 1212.9 ± 1.3 kJ/mol 43.02423 ± 0.00086 114766-65-3*0 Hydrogen difluoride (F)(HF) (g, perp) -187.4 -187.1 ± 1.6 kJ/mol 39.004746 ± 0.000070 12528-21-1*2 Acetic acid CH3C(O)OH (aq, 1500 H2O) -484.83 ± 0.23 kJ/mol 60.0520 ± 0.0017 64-19-7*840 1,2-Ethenediol HOCHCHOH (g, trans) -254.0 -266.4 ± 1.3 kJ/mol 60.0520 ± 0.0017 1571-60-4*2 Hydrogen fluoride HF (aq, 50 H2O) -321.17 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*822 Acetyl chloride CH3C(O)Cl (l) -272.11 ± 0.33 kJ/mol 78.4973 ± 0.0019 75-36-5*500 Methyl formate HC(O)OCH3 (l) -388.56 ± 0.68 kJ/mol 60.0520 ± 0.0017 107-31-3*500 Ethyl formate HC(O)OCH2CH3 (g, anti) -355.4 -374.6 ± 1.4 kJ/mol 74.0785 ± 0.0025 109-94-4*2 Acetoxy CH3C(O)O (g, 2A") -182.20 -191.02 ± 0.85 kJ/mol 59.0440 ± 0.0017 13799-69-4*1 2-Methoxy-2-oxoethyl CH2C(O)OCH3 (g, anti) -172.9 -188.1 ± 1.7 kJ/mol 73.0706 ± 0.0025 54668-31-4*2 (Acetyloxy)methyl CH3C(O)OCH2 (g, anti) -173.9 -186.9 ± 1.7 kJ/mol 73.0706 ± 0.0025 2887-49-2*2 Hydroxyoxoethenyl HOCCO (g) 24.6 22.8 ± 1.7 kJ/mol 57.0281 ± 0.0017 702699-39-6*0 Azanylium [NH2]+ (g) 1266.55 1264.48 ± 0.11 kJ/mol 16.02207 ± 0.00016 15194-15-7*0 Isocyanomethylidyne CNC (g) 672.2 676.6 ± 1.7 kJ/mol 38.0281 ± 0.0016 53590-27-5*0 Cyanomethylidyne CCN (g) 684.7 689.1 ± 2.1 kJ/mol 38.0281 ± 0.0016 4120-02-9*0 Tetrachloromethane CCl4 (l) -104.60 -124.02 ± 0.41 kJ/mol 153.8215 ± 0.0037 56-23-5*500 Dihydrogen fluoride anion [(F)(HH)]- (g, singlet) -257.0 -260.1 ± 1.9 kJ/mol 21.01483 ± 0.00014 *117339-92-1*2 Dichloromethylene anion [CCl2]- (g) 75.99 78.27 ± 0.77 kJ/mol 82.9166 ± 0.0020 118364-73-1*0 Dichloromethylium [CHCl2]+ (g) 895.4 892.2 ± 1.2 kJ/mol 83.9235 ± 0.0020 56932-33-3*0 Dichloromethide [CHCl2]- (g) -40.7 -42.5 ± 2.0 kJ/mol 83.9246 ± 0.0020 32180-91-9*0 Chloromethylium [CH2Cl]+ (g) 962.4 958.5 ± 1.2 kJ/mol 49.4787 ± 0.0012 59000-00-9*0 Chloromethylene CHCl (g, triplet) 346.25 346.55 ± 0.89 kJ/mol 48.4713 ± 0.0012 2108-20-5*1 Dibromide [Br2]- (g) -196.9 -211.0 ± 2.3 kJ/mol 159.8085 ± 0.0020 12595-70-9*0 Hydroxydioxonitrate [HON(O)O]- (g) -193.2 -197.5 ± 2.4 kJ/mol 63.01343 ± 0.00091 58875-09-5*0 1,2-Dichloroethane CH2ClCH2Cl (cr,l) -165.66 ± 0.56 kJ/mol 98.9586 ± 0.0024 107-06-2*500 1,1-Dichloroethane CH3CHCl2 (cr,l) -163.75 ± 0.48 kJ/mol 98.9586 ± 0.0024 75-34-3*500 1,1,2-Trichloroethane CH2ClCHCl2 (l) -187.6 ± 1.1 kJ/mol 133.4033 ± 0.0031 79-00-5*500 Pentachloroethane CHCl2CCl3 (g) -150.5 -156.4 ± 1.9 kJ/mol 202.2928 ± 0.0048 76-01-7*0 Dioxymethylidyne COO (g) 299.8 301.1 ± 1.7 kJ/mol 44.00950 ± 0.00100 791121-04-5*0 Chlorosyl chloride ClClO (g) 134.5 133.2 ± 1.4 kJ/mol 86.9048 ± 0.0018 86825-56-1*0 Vinylidene CCH2 (g, triplet) 610.45 610.15 ± 0.50 kJ/mol 26.0373 ± 0.0016 2143-69-3*1 Ammonia NH3 (aq, undissoc) -80.880 ± 0.053 kJ/mol 17.03056 ± 0.00022 7664-41-7*1000 Chloroform CHCl3 (l) -130.93 ± 0.42 kJ/mol 119.3767 ± 0.0028 67-66-3*590 Chlorodibromomethane CHClBr2 (g) 21.4 2.6 ± 3.5 kJ/mol 208.2793 ± 0.0023 124-48-1*0 Bromochloromethane CH2ClBr (g) -28.3 -42.4 ± 1.3 kJ/mol 129.3833 ± 0.0016 74-97-5*0 Fluoromethylene CHF (g) 148.40 148.69 ± 0.43 kJ/mol 32.01704 ± 0.00080 13453-52-6*0 Chloride Cl- (aq) -166.990 ± 0.023 kJ/mol 35.45325 ± 0.00090 16887-00-6*800 Ethyl iodide CH3CH2I (g) 8.73 -7.14 ± 0.49 kJ/mol 155.9656 ± 0.0016 75-03-6*0 1,2-Dibromoacetylene BrCCBr (g) 332.4 321.5 ± 2.3 kJ/mol 183.8294 ± 0.0026 624-61-3*0 Fluoro(fluorooxy)methylene FCOF (g, vdW triplet) -97.4 -95.6 ± 1.6 kJ/mol 66.00691 ± 0.00085 479587-30-9*101 Fluorooxomethylium [FCO]+ (g) 724.9 724.6 ± 1.2 kJ/mol 47.00795 ± 0.00085 38264-00-5*0 Fluoroisoformyl COF (g) -37.8 -32.4 ± 1.6 kJ/mol 47.00850 ± 0.00085 *1871-24-5*0 Ammonium nitrate (NH4)NO3 (cr,l) -350.23 -365.19 ± 0.18 kJ/mol 80.04344 ± 0.00095 6484-52-2*500 Azidonitrene NNNN (g, Cs) 692.1 687.5 ± 1.4 kJ/mol 56.02696 ± 0.00028 147363-92-6*2 Benzene cation [C6H6]+ (g) 992.65 976.18 ± 0.22 kJ/mol 78.1113 ± 0.0048 34504-50-2*0 Benzoic acid C6H5C(O)OH (cr,l) -367.30 -384.72 ± 0.17 kJ/mol 122.1213 ± 0.0056 65-85-0*500 2,3-Dimethylbenzaldehyde CH3C6H3(CH3)C(O)H (g, ortho-meta) -66.3 -94.3 ± 2.4 kJ/mol 134.1751 ± 0.0072 5779-93-1*0 (2,3-dimethylphenyl)oxomethyl CH3C6H3(CH3)CO (g, ortho-meta) 82.6 59.9 ± 2.6 kJ/mol 133.1672 ± 0.0072 *104680-89-9*0 m-Chlorophenide [C6H4Cl]- (g) 172.5 162.3 ± 1.5 kJ/mol 111.5492 ± 0.0049 77748-34-6*0 p-Chlorophenide [C6H4Cl]- (g) 179.4 169.0 ± 1.5 kJ/mol 111.5492 ± 0.0049 77748-42-6*0 o-Chlorophenide [C6H4Cl]- (g) 158.6 148.7 ± 1.5 kJ/mol 111.5492 ± 0.0049 72863-53-7*0 Nitronium [ONO]+ (g) 961.81 958.25 ± 0.20 kJ/mol 46.00499 ± 0.00060 14522-82-8*0 Cyanogen iodide anion [ICN]- (g) 86.5 88.9 ± 8.1 kJ/mol 152.92246 ± 0.00080 1356929-44-6*0 2-Oxopropylium [CH3C(O)CH2]+ (g) 784.7 770.9 ± 1.7 kJ/mol 57.0707 ± 0.0024 54088-52-7*0 Diiodide [I2]- (g) -178.13 -180.72 ± 0.48 kJ/mol 253.809489 ± 0.000060 12190-71-5*0 2,3-Butanedione CH3C(O)C(O)CH3 (g) -310.56 -327.12 ± 0.63 kJ/mol 86.0892 ± 0.0033 431-03-8*0 1,2-Dibromoethane CH2BrCH2Br (g) -11.7 -38.5 ± 1.2 kJ/mol 187.8612 ± 0.0026 106-93-4*0 Methanol CH3OH (l) -235.27 -238.61 ± 0.16 kJ/mol 32.04186 ± 0.00090 67-56-1*500 Ethylene cation [CH2CH2]+ (g) 1075.21 1067.99 ± 0.12 kJ/mol 28.0526 ± 0.0016 34470-02-5*0 (Hydroxyimino)methyl HCNOH (g, trans-trans) 250.1 244.0 ± 1.8 kJ/mol 44.03272 ± 0.00087 206442-92-4*1 Trihydrogen dioxide anion [HOHOH]- (g) -487.4 -495.7 ± 1.1 kJ/mol 35.02317 ± 0.00064 12501-19-8*0 Fluorochlorate [ClF]- (g) -256.03 -255.43 ± 0.81 kJ/mol 54.45165 ± 0.00090 12272-56-9*0 Fluoronium [(HF)(H)]+ (g, triplet) 1490.1 1491.4 ± 1.9 kJ/mol 21.01373 ± 0.00014 12206-67-6*1 Fluorosyl fluoride FFO (g, triplet) 192.8 193.3 ± 2.3 kJ/mol 53.99621 ± 0.00030 86825-57-2*1 1-Isocyanoethylidene CH3CNC (g, triplet) 545.6 540.7 ± 1.6 kJ/mol 53.0627 ± 0.0024 *498544-34-6*1 3-Imino-2-propen-1-ylidene CHCHCNH (g, anti-triplet) 571.9 566.9 ± 1.6 kJ/mol 53.0627 ± 0.0024 916765-05-4*21 2-(Methylidyneamino)ethenyl CHCHNCH (g, anti-triplet) 634.5 629.8 ± 1.6 kJ/mol 53.0627 ± 0.0024 123416-74-0*21 Azete (CHCHCH)N (g) 469.5 461.4 ± 1.5 kJ/mol 53.0627 ± 0.0024 287-24-1*0 Peroxychlorite [OClOO]- (g) -34.4 -34.4 ± 2.0 kJ/mol 83.4514 ± 0.0013 852472-63-0*0 Peroxyimidogen NOO (g) 405.4 403.4 ± 1.9 kJ/mol 46.00554 ± 0.00060 *60488-31-5*0 2-Cyanovinylium [CHCHCN]+ (g, anti triplet) 1517.3 1515.1 ± 1.8 kJ/mol 52.0542 ± 0.0024 85398-67-0*21 2-Cyanovinyl anion [CHCHCN]- (g, syn) 263.8 260.8 ± 1.8 kJ/mol 52.0553 ± 0.0024 *85398-67-0*2 2-Isocyanovinyl CHCHNC (g, anti) 543.2 541.3 ± 1.7 kJ/mol 52.0547 ± 0.0024 225798-14-1*1 3-Oxo-1,2-propadienylidene CCCO (g) 330.4 336.3 ± 1.9 kJ/mol 52.0315 ± 0.0024 11127-17-6*0 Vinylacetylene cation [CH2CHCCH]+ (g) 1221.7 1215.2 ± 1.1 kJ/mol 52.0740 ± 0.0032 59699-48-8*0 Dioxygenyl ion monohydrate [(H2O)(O2)]+ (g) 828.5 821.5 ± 2.1 kJ/mol 50.01353 ± 0.00091 11083-61-7*0 Bicyclo[1.1.0]but-2-ylium-1-yl [CH2(CCH)CH]+ (g) 1287.0 1278.0 ± 1.5 kJ/mol 52.0740 ± 0.0032 *78525-41-4*0 Formaldehyde cation [CH2O]+ (g) 944.856 941.235 ± 0.097 kJ/mol 30.02543 ± 0.00087 54288-05-0*0 3-Methylene-1-cyclopropen-1-yl anion [CH2C(CHC)]- (g) 417.3 413.5 ± 1.6 kJ/mol 51.0672 ± 0.0032 *117469-28-0*0 2-Cyclopropen-1-ylidenemethyl CHC(CHCH) (g) 635.7 632.6 ± 1.3 kJ/mol 51.0666 ± 0.0032 127611-25-0*0 5-Methyl-1,3-cyclopentadiene CH3CH(CHCHCHCH) (g) 133.8 110.9 ± 1.4 kJ/mol 80.1277 ± 0.0048 96-38-8*0 Disilicon Si2 (g) 586.3 590.1 ± 1.6 kJ/mol 56.17100 ± 0.00060 12597-35-2*0 1-Chloro ozone ClOOO (g, cis vdW) 226.3 223.0 ± 2.3 kJ/mol 83.4509 ± 0.0013 141801-66-3*101 Disiloxane SiH3OSiH3 (g) -331.6 -348.6 ± 2.3 kJ/mol 78.21804 ± 0.00079 13597-73-4*0 Tetramethylsilane Si(CH3)4 (g) -184.9 -215.3 ± 2.1 kJ/mol 88.2236 ± 0.0033 75-76-3*0 Trimethylsilyl Si(CH3)3 (g) 47.2 25.2 ± 2.1 kJ/mol 73.1891 ± 0.0025 16571-41-8*0 1,2,3,5-Hexatetraene CH2CCCHCHCH2 (g, trans) 391.7 380.0 ± 1.6 kJ/mol 78.1118 ± 0.0048 60239-33-0*1 1,2,3-Pentatriene CH2CCCHCH3 (g) 302.5 290.2 ± 1.4 kJ/mol 66.1011 ± 0.0040 62018-46-6*0 (Z)-1-Methylallyl CH3CHCHCH2 (g, cis) 154.7 137.3 ± 1.0 kJ/mol 55.0984 ± 0.0032 98705-00-1*0 Oxadiazirene O(NN) (g) 351.7 349.9 ± 1.7 kJ/mol 44.01288 ± 0.00033 227934-45-4*0 Chlorohydrofluorine cation [ClFH]+ (g) 1000.8 998.1 ± 2.1 kJ/mol 55.45849 ± 0.00090 70110-63-3*0 Triiodide [I3]- (g) -254.3 -257.5 ± 3.4 kJ/mol 380.713959 ± 0.000090 14900-04-0*0 Diazenide [NNH]- (g, vdW) 175.6 176.7 ± 1.6 kJ/mol 29.02197 ± 0.00016 71004-29-0*100 NON NON (g) 545.5 542.6 ± 1.7 kJ/mol 44.01288 ± 0.00033 227934-46-5*0 Hydrogen atom H (ad, 1 Pt(111) fcc) -22.3 -25.6 ± 1.5 kJ/mol 1.007940 ± 0.000070 12385-13-6*1001001 Hydrogen atom H (ad, 4 Pt(111) fcc) -33.4 -36.7 ± 1.5 kJ/mol 1.007940 ± 0.000070 12385-13-6*1001004 Hydroxyamidogen anion [HNOH]- (g) 90.6 84.8 ± 2.8 kJ/mol 32.02257 ± 0.00034 *66097-71-0*0 Hydrogen fluoride HF (aq, 18 H2O) -321.04 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*901 Hydrogen bromide HBr (aq, 600 H2O) -120.39 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*834 Trioxidaniumyl [HOOOH]+ (g, c, t) 935.2 926.1 ± 1.5 kJ/mol 50.01353 ± 0.00091 161321-37-5*3 Nitrosyl nitrate ON(O2)NO (g, perp) 70.7 62.4 ± 1.8 kJ/mol 92.0111 ± 0.0012 *15969-55-8*0 Hydrogen bromide HBr (aq, 1000 H2O) -120.49 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*839 Nitrogen hydride oxide NH3O (g) 71.2 60.0 ± 1.5 kJ/mol 33.02996 ± 0.00037 38544-48-8*0 n-Pentane CH3CH2CH2CH2CH3 (cr,l) -155.81 -172.78 ± 0.30 kJ/mol 72.1488 ± 0.0041 109-66-0*500 iso-Pentane CH3CH2CH(CH3)2 (l) -178.17 ± 0.39 kJ/mol 72.1488 ± 0.0041 78-78-4*500 neo-Pentane C(CH3)4 (l) -189.49 ± 0.38 kJ/mol 72.1488 ± 0.0041 463-82-1*500 Cyclopentane CH2(CH2CH2CH2CH2) (l) -104.93 ± 0.41 kJ/mol 70.1329 ± 0.0041 287-92-3*590 2-Methylpentane CH3CH2CH2CH(CH3)2 (g) -134.43 -173.69 ± 0.73 kJ/mol 86.1754 ± 0.0049 107-83-5*0 3-Methylpentane CH3CH2CH(CH3)CH2CH3 (g) -131.89 -171.39 ± 0.76 kJ/mol 86.1754 ± 0.0049 96-14-0*0 2,3-Dimethylbutane CH3CH(CH3)CH(CH3)CH3 (g) -136.47 -177.57 ± 0.81 kJ/mol 86.1754 ± 0.0049 79-29-8*0 Iminomethide [HCNH]- (g, cis) 252.7 248.9 ± 1.8 kJ/mol 28.03387 ± 0.00082 90623-30-6*2 Cyclohexane CH2(CH2CH2CH2CH2CH2) (l) -131.78 -155.90 ± 0.29 kJ/mol 84.1595 ± 0.0049 110-82-7*500 1,5-Hexadiene CH2CHCH2CH2CHCH2 (g) 108.54 83.95 ± 0.39 kJ/mol 82.1436 ± 0.0049 592-42-7*0 Peroxyformic acid HC(O)OOH (g, gauche) -265.2 -273.0 ± 1.5 kJ/mol 62.0248 ± 0.0012 107-32-4*3 2-Hydroxyethyl CH2CH2OH (g, staggered-anti) -6.0 -18.4 ± 1.5 kJ/mol 45.0605 ± 0.0017 4422-54-2*3 Hydrogen bromide HBr (aq, 1250 H2O) -120.53 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*954 Ethoxy CH3CH2O (g) 1.26 -12.17 ± 0.43 kJ/mol 45.0605 ± 0.0017 2154-50-9*0 Fluorine atom cation F+ (g) 1758.301 1760.599 ± 0.017 kJ/mol 18.99785462 ± 0.00000050 14701-13-4*0 Hydrogen bromide HBr (aq, 5000 H2O) -120.69 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*844 Dihydrooxooxygen cation [(H2O)O]+ (g) 994.8 988.1 ± 1.6 kJ/mol 34.01413 ± 0.00062 177329-59-8*0 Hydrogen cyanide cation [HCN]+ (g) 1442.52 1442.05 ± 0.20 kJ/mol 27.02483 ± 0.00081 12601-62-6*0 Hydrogen chloride HCl (aq, 2000 H2O) -166.681 ± 0.024 kJ/mol 36.46064 ± 0.00090 7647-01-0*841 Dicarbon monoxide cation [CCO]+ (g) 1434.0 1439.0 ± 2.1 kJ/mol 40.0203 ± 0.0016 12287-08-0*0 Ethynylene cation [C2]+ (g) 1964.96 1971.54 ± 0.40 kJ/mol 24.0209 ± 0.0016 12595-79-8*0 C=O-C cation [COC]+ (g, quartet) 1816.9 1820.9 ± 2.0 kJ/mol 40.0203 ± 0.0016 83483-98-1*2 Oxirene anion [O(CHCH)]- (g) 288.3 285.3 ± 2.2 kJ/mol 42.0372 ± 0.0016 *157-18-6*0 Oxoethylidene HCC(O)H (g, triplet) 261.1 258.3 ± 1.1 kJ/mol 42.0367 ± 0.0016 39920-84-8*1 Formic acid anion [HC(O)OH]- (g, anti) -241.2 -246.9 ± 1.9 kJ/mol 46.0259 ± 0.0010 19066-82-1*2 Dioxirane cation [CH2(OO)]+ (g) 1050.8 1043.2 ± 2.0 kJ/mol 46.0248 ± 0.0010 232262-10-1*0 Dioxymethyl cation [CH2OO]+ (g) 1075.0 1068.6 ± 1.8 kJ/mol 46.0248 ± 0.0010 232262-11-2*0 Nitrilomethylium [CN]+ (g) 1783.17 1786.65 ± 0.48 kJ/mol 26.01689 ± 0.00080 12539-57-0*0 Dioxymethylene HCOO (g, cis) 341.8 339.8 ± 3.0 kJ/mol 45.0174 ± 0.0010 438586-67-5*2 OH-CO vdW complex (OH)(CO) (g, vdW) -80.23 -76.51 ± 0.88 kJ/mol 45.0174 ± 0.0010 *2564-85-4*100 CO-HO vdW complex (CO)(HO) (g, vdW) -77.3 -73.2 ± 1.3 kJ/mol 45.0174 ± 0.0010 *2564-84-3*100 Cyanato cation [NCO]+ (g) 1261.50 1262.00 ± 0.58 kJ/mol 42.01629 ± 0.00086 17247-99-3*0 Fluoroniumyl ion [HF]+ (g) 1275.556 1275.788 ± 0.022 kJ/mol 20.005795 ± 0.000070 12381-92-9*0 Nitrosomethyliumylidene [CNO]+ (g) 1509.8 1510.9 ± 1.7 kJ/mol 42.01629 ± 0.00086 67197-19-7*0 Fulminate [CNO]- (g) 59.5 59.8 ± 1.7 kJ/mol 42.01739 ± 0.00086 28269-67-2*0 Acetic acid CH3C(O)OH (l) -484.02 -483.59 ± 0.18 kJ/mol 60.0520 ± 0.0017 64-19-7*500 Acetic acid CH3C(O)OH (aq, 75 H2O) -484.63 ± 0.23 kJ/mol 60.0520 ± 0.0017 64-19-7*825 Acetic acid CH3C(O)OH (aq, 700 H2O) -484.82 ± 0.23 kJ/mol 60.0520 ± 0.0017 64-19-7*835 Fluorodioxidenium [FOO]+ (g) 1221.9 1219.5 ± 2.0 kJ/mol 50.99665 ± 0.00060 139584-95-5*0 Deuterium atom cation D+ (g) 1532.210 1534.123 ± 0.000 kJ/mol 2.01355319809 ± 0.00000000040 14464-47-2*0 Fluorodioxidanide [FOO]- (g) -256.8 -256.1 ± 1.9 kJ/mol 50.99775 ± 0.00060 23553-17-5*0 Nitrous acid HONO (g) -72.966 -78.623 ± 0.080 kJ/mol 47.01348 ± 0.00061 7782-77-6*0 Trioxidanylium [HOOO]+ (g, cis) 1085.2 1078.9 ± 1.4 kJ/mol 49.00559 ± 0.00090 74241-49-9*2 Hydrogen chloride HCl (aq, 75 H2O) -165.555 ± 0.026 kJ/mol 36.46064 ± 0.00090 7647-01-0*825 Glyoxal OCHCHO (g, cis) -189.33 -194.77 ± 0.72 kJ/mol 58.0361 ± 0.0017 107-22-2*2 Glyoxal OCHCHO (g) -207.77 -213.33 ± 0.57 kJ/mol 58.0361 ± 0.0017 107-22-2*0 Ethynediol HOCCOH (g) -18.3 -22.0 ± 1.7 kJ/mol 58.0361 ± 0.0017 16005-17-7*0 Chlorine difluoride anion [FClF]- (g) -504.9 -505.8 ± 1.9 kJ/mol 73.45005 ± 0.00090 16892-05-0*0 Dimethylaminylium [(CH3)2N]+ (g) 1040.4 1025.0 ± 1.8 kJ/mol 44.0752 ± 0.0017 49784-85-2*0 Hydroxylamine NH2OH (g, cis) -15.4 -25.9 ± 1.4 kJ/mol 33.02996 ± 0.00037 7803-49-8*2 Ethylimidogen CH3CH2N (g) 306.1 291.6 ± 2.1 kJ/mol 43.0678 ± 0.0016 27770-44-1*0 Diisocyanogen CNNC (g) 610.9 613.2 ± 1.7 kJ/mol 52.0349 ± 0.0016 78800-21-2*0 Bifluoride [FHF]- (g) -705.22 -709.07 ± 0.35 kJ/mol 39.005295 ± 0.000070 18130-74-0*0 Trioxidanyl HOOO (g, cis) 26.36 23.09 ± 0.19 kJ/mol 49.00614 ± 0.00090 12500-78-6*2 Aminyliumyl [NH]+ (g) 1659.03 1659.96 ± 0.24 kJ/mol 15.014131 ± 0.000099 19067-62-0*0 Aminooxy cation [NH2O]+ (g) 945.99 938.86 ± 0.77 kJ/mol 32.02147 ± 0.00034 *51375-41-8*0 Dichloromethylene CCl2 (g, triplet) 314.00 315.21 ± 0.90 kJ/mol 82.9161 ± 0.0020 1605-72-7*1 Chlorite [OClO]- (g) -105.51 -107.69 ± 0.37 kJ/mol 67.4520 ± 0.0011 14998-27-7*0 Chloromethyliumyl [CHCl]+ (g) 1207.4 1207.7 ± 2.0 kJ/mol 48.4708 ± 0.0012 89877-51-0*0 Chloromethylene anion [CHCl]- (g) 203.54 204.36 ± 0.94 kJ/mol 48.4719 ± 0.0012 75466-08-9*0 Chlorohydroxymethyl CH(Cl)OH (g, anti-gauche) -46.2 -51.8 ± 2.0 kJ/mol 65.4787 ± 0.0012 147139-06-8*2 Hydroxylamine cation [NH2OH]+ (g) 857.7 847.9 ± 1.6 kJ/mol 33.02941 ± 0.00037 62675-55-2*0 1,1,1,2-Tetrachloroethane CH2ClCCl3 (cr,l) -193.5 ± 1.1 kJ/mol 167.8481 ± 0.0039 630-20-6*500 Tetraoxidanyl (HO2)(O2) (g, vdW) 2.1 0.4 ± 2.9 kJ/mol 65.0055 ± 0.0012 69696-93-1*100 Hexachloroethane CCl3CCl3 (cr,l) -214.1 ± 2.8 kJ/mol 236.7376 ± 0.0056 67-72-1*500 Aquacarbon H2OC (g, singlet vdW) 467.6 465.5 ± 1.9 kJ/mol 30.02598 ± 0.00087 81434-73-3*102 3-Chloro-3-methyl-3H-diazirine (NN)CClCH3 (g) 251.5 239.6 ± 2.7 kJ/mol 90.5114 ± 0.0019 4222-21-3*0 trans-1,2-Dichloroethene CHClCHCl (g, trans) 5.65 0.23 ± 0.56 kJ/mol 96.9427 ± 0.0024 156-60-5*0 Bromine dioxide OBrO (g) 165.6 156.0 ± 2.1 kJ/mol 111.9028 ± 0.0012 21255-83-4*0 Dioxofluorine OFO (g) 523.9 523.2 ± 1.0 kJ/mol 50.99720 ± 0.00060 175861-93-5*0 Propyne cation [CH3CCH]+ (g) 1192.62 1186.89 ± 0.38 kJ/mol 40.0633 ± 0.0024 34526-53-9*0 Aquacarbon cation [H2OC]+ (g) 1196.1 1193.0 ± 1.7 kJ/mol 30.02543 ± 0.00087 *81434-73-3*0 Dihydrogen fluoride anion [(HF)(H)]- (g, singlet) -61.9 -60.5 ± 3.2 kJ/mol 21.01483 ± 0.00014 117339-92-1*2 Nitric acid HON(O)O (aq, 1000 H2O) -206.27 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*839 Fluorochlorobromomethane CHFClBr (g) -218.3 -230.9 ± 4.9 kJ/mol 147.3737 ± 0.0016 593-98-6*0 Fluoromethyliumyl [CHF]+ (g) 1116.6 1116.9 ± 1.7 kJ/mol 32.01649 ± 0.00080 89877-52-1*0 Fluoromethylene anion [CHF]- (g) 95.95 96.48 ± 0.61 kJ/mol 32.01759 ± 0.00080 71267-42-0*0 Hydrogen bromide HBr (aq, 2000 H2O) -120.59 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*841 Polytetrafluoroethylene CF2CF2 (s) -829.90 ± 0.54 kJ/mol 100.0150 ± 0.0016 9002-84-0*591 Hydrogen fluoride HF (l) -302.42 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*590 trans-1,2-Difluoroethene CHFCHF (g, trans) -299.58 -306.02 ± 0.89 kJ/mol 64.0341 ± 0.0016 1630-78-0*0 Nitric acid HON(O)O (cr,l) -178.96 -173.24 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*500 Ethane cation [CH3CH3]+ (g) 1043.15 1029.14 ± 0.59 kJ/mol 30.0685 ± 0.0017 34488-65-8*0 Fluoroethynide [CCF]- (g) 133.3 137.5 ± 1.5 kJ/mol 43.0204 ± 0.0016 85905-56-2*0 Formyl fluoride cation [CHFO]+ (g) 816.6 813.3 ± 1.3 kJ/mol 48.01589 ± 0.00086 99766-68-4*0 Cyclopropylidene C(CH2CH2) (g, triplet) 544.7 535.9 ± 1.5 kJ/mol 40.0639 ± 0.0024 2143-70-6*2 Formyl fluoride [FCO]- (g) -405.1 -403.6 ± 1.6 kJ/mol 47.00905 ± 0.00085 62227-71-8*0 Fluoroisoformyl cation [COF]+ (g) 1347.4 1349.5 ± 1.9 kJ/mol 47.00795 ± 0.00085 *1871-25-6*0 Azidonitrene NNNN (g, C2h) 660.8 657.6 ± 1.6 kJ/mol 56.02696 ± 0.00028 147363-92-6*1 Dihydrogen fluoride (H)(HF) (g) -55.9 -54.9 ± 1.6 kJ/mol 21.01428 ± 0.00014 12592-22-2*1 o-Benzyne cation [C6H4]+ (g) 1392.8 1384.8 ± 1.7 kJ/mol 76.0954 ± 0.0048 70220-84-7*0 m-Benzyne cation [C6H4]+ (g) 1364.8 1356.3 ± 1.8 kJ/mol 76.0954 ± 0.0048 121058-08-0*0 p-Benzyne C6H4 (g, triplet) 603.6 594.2 ± 1.2 kJ/mol 76.0960 ± 0.0048 3355-34-8*1 Hydrofluorate ion [HF]- (g) -75.6 -75.1 ± 1.8 kJ/mol 20.006892 ± 0.000070 37249-79-9*0 1,3-Cycloheptadiene CH2(CHCHCHCHCH2CH2) (g, c-c) 123.58 94.47 ± 0.78 kJ/mol 94.1543 ± 0.0056 4054-38-0*1 Tropylium [CH(CHCHCHCHCHCH)]+ (g) 898.9 879.2 ± 1.1 kJ/mol 91.1299 ± 0.0056 26811-28-9*0 Chlorine difluoride ClFF (g) 22.5 23.8 ± 1.9 kJ/mol 73.44951 ± 0.00090 91483-78-2*0 Hydrogen fluoride HF (aq, 10 H2O) -320.89 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*815 Fluorosyl fluoride anion [FFO]- (g, doublet) -147.1 -146.8 ± 3.0 kJ/mol 53.99675 ± 0.00030 *86825-57-2*2 cis-1,2-Dibromoethene CHBrCHBr (g, cis) 121.2 100.6 ± 2.0 kJ/mol 185.8453 ± 0.0026 590-11-4*0 1,1-Dibromoethane CH3CHBr2 (g) -5.3 -32.3 ± 1.8 kJ/mol 187.8612 ± 0.0026 557-91-5*0 Trioxodinitrate anion [ONN(O)O]- (g, vdW) -104.2 -107.5 ± 1.9 kJ/mol 76.01223 ± 0.00091 194856-62-7*100 Ethylene anion [CH2CH2]- (g, anti ?) 232.1 224.4 ± 2.0 kJ/mol 28.0537 ± 0.0016 34527-91-8*1 Perchloryloxy OCl(O)(O)O (g) 248.4 240.8 ± 1.8 kJ/mol 99.4503 ± 0.0015 12133-63-0*0 Hydrogen fluoride HF (aq, 60 H2O) -321.19 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*823 Carbamoyl HNCOH (g, trans-trans) 74.1 67.7 ± 2.7 kJ/mol 44.03272 ± 0.00087 *2858-51-7*1 Formaldiminoxy CH2NO (g) 160.9 153.9 ± 1.5 kJ/mol 44.03272 ± 0.00087 2683-96-7*0 Chlorine oxide peroxide OClOO (g, vdW) 226.5 227.4 ± 2.5 kJ/mol 83.4509 ± 0.0013 141801-67-4*100 Formaldoxime CH2NOH (g, cis) 50.6 39.8 ± 1.8 kJ/mol 45.04066 ± 0.00088 75-17-2*2 Oxaziridine CH2(NHO) (g) 115.5 103.7 ± 2.1 kJ/mol 45.04066 ± 0.00088 6827-26-5*0 Hydroxyaminylium [HNOH]+ (g, cis) 1048.5 1041.3 ± 2.6 kJ/mol 32.02147 ± 0.00034 66097-71-0*2 Cyanoethynyl CCCN (g) 715.7 722.1 ± 1.2 kJ/mol 50.0388 ± 0.0024 62435-43-2*0 Dioxaziridinyl cation [N(OO)]+ (g) 1365.8 1363.3 ± 1.7 kJ/mol 46.00499 ± 0.00060 *66252-29-7*0 Dioxaziridinyl anion [N(OO)]- (g) 295.9 293.4 ± 1.7 kJ/mol 46.00609 ± 0.00060 66252-31-1*0 (E)-Diazene anion [HNNH]- (g, trans) 265.5 258.7 ± 2.0 kJ/mol 30.02991 ± 0.00020 *59952-06-6*0 Methyleneoxonium cation [CH2OH2]+ (g) 827.7 818.3 ± 1.7 kJ/mol 32.04131 ± 0.00090 *177788-17-9*0 2-Methylene-2H-azirine (CHN)CCH2 (g) 404.2 396.9 ± 1.7 kJ/mol 53.0627 ± 0.0024 110027-86-6*0 (Z)-Diazene cation [HNNH]+ (g, cis) 1157.0 1150.1 ± 1.3 kJ/mol 30.02881 ± 0.00020 86631-37-0*0 2-Cyanovinylium [CHCHCN]+ (g, syn triplet) 1517.4 1515.3 ± 1.8 kJ/mol 52.0542 ± 0.0024 85398-67-0*22 2-Cyanovinyl anion [CHCHCN]- (g, anti) 266.2 263.3 ± 1.8 kJ/mol 52.0553 ± 0.0024 *85398-67-0*1 Propynylidene cation [HCCCH]+ (g) 1410.9 1413.5 ± 1.3 kJ/mol 38.0474 ± 0.0024 75123-91-0*0 2-Isocyanovinyl CHCHNC (g, syn) 544.6 542.7 ± 1.7 kJ/mol 52.0547 ± 0.0024 225798-14-1*2 Cyanomethylene HCCN (g, singlet) 529.5 530.5 ± 1.3 kJ/mol 39.0361 ± 0.0016 2612-62-6*2 Isocyanomethylene HCNC (g, triplet) 586.3 587.3 ± 1.7 kJ/mol 39.0361 ± 0.0016 78694-65-2*2 Hydroxymethanide [CH2OH]- (g) 9.5 2.9 ± 1.7 kJ/mol 31.03447 ± 0.00088 55830-71-2*0 Propynylidene HCCCH (g, trans singlet) 597.4 599.3 ± 1.1 kJ/mol 38.0480 ± 0.0024 67152-18-5*4 3-Methylcycloprop-3-en-2-ylium-1-yl [CH3C(CHC)]+ (g) 1283.9 1277.4 ± 1.5 kJ/mol 52.0740 ± 0.0032 *185841-59-2*0 Vinylvinylidene cation [CH2CHCHC]+ (g, trans) 1429.9 1424.2 ± 2.0 kJ/mol 52.0740 ± 0.0032 161054-20-2*1 1,2-Butadien-1-ylidene CH3CHCC (g, singlet) 511.8 506.3 ± 2.1 kJ/mol 52.0746 ± 0.0032 119908-55-3*2 Trifluoride ion [F3]- (g) -348.9 -349.7 ± 2.6 kJ/mol 56.9957582 ± 0.0000015 25730-99-8*0 1-Buten-3-ynylium [HCCCHCH]+ (g, trans) 1482.3 1479.8 ± 1.4 kJ/mol 51.0661 ± 0.0032 84654-85-3*1 Formaldehyde CH2O (g, singlet) -105.386 -109.226 ± 0.096 kJ/mol 30.02598 ± 0.00087 50-00-0*2 Iodine I (g, 2P1/2) 198.109 197.709 ± 0.0021 kJ/mol 126.904470 ± 0.000030 14362-44-8*2 3-Buten-1-ynylium [CH2CHCC]+ (g, triplet) 1572.6 1570.2 ± 1.7 kJ/mol 51.0661 ± 0.0032 103928-84-3*1 Peroxyimidogen cation [NOO]+ (g) 1409.7 1406.8 ± 1.9 kJ/mol 46.00499 ± 0.00060 *60488-32-6*0 3-Methylene-1-cyclopropen-1-ylium [CH2C(CHC)]+ (g, singlet) 1398.7 1395.4 ± 1.7 kJ/mol 51.0661 ± 0.0032 117469-28-0*2 Nitrosyl fluoride FNO (g) -85.47 -87.84 ± 0.79 kJ/mol 49.00454 ± 0.00031 7789-25-5*0 Butyraldehyde CH3CH2CH2CHO (g) -185.31 -205.67 ± 0.85 kJ/mol 72.1057 ± 0.0033 123-72-8*0 Chloroallene CH2CCHCl (g) 181.8 175.1 ± 1.6 kJ/mol 74.5086 ± 0.0026 3223-70-9*0 1-Chloropropyne CH3CCCl (g) 192.0 187.9 ± 1.6 kJ/mol 74.5086 ± 0.0026 7747-84-4*0 Peroxyimidogen anion [NOO]- (g) 165.1 162.7 ± 1.7 kJ/mol 46.00609 ± 0.00060 60488-31-5*0 Methylcyclopentane CH3CH(CH2CH2CH2CH2) (g) -68.59 -106.12 ± 0.37 kJ/mol 84.1595 ± 0.0049 96-37-7*0 Propadienylidenide [CH2CC]- (g) 381.18 382.08 ± 0.41 kJ/mol 38.0485 ± 0.0024 109292-49-1*0 Dioxosilane SiO2 (cr,l) -906.27 -911.25 ± 0.83 kJ/mol 60.08430 ± 0.00067 7631-86-9*500 Dioxosilane SiO2 (vitr) -825.82 -901.75 ± 0.84 kJ/mol 60.08430 ± 0.00067 7631-86-9*520 Silicon carbide cation [SiC]+ (g) 1601.4 1606.0 ± 2.6 kJ/mol 40.09565 ± 0.00085 78393-58-5*0 Silyliumyl [SiH2]+ (g) 1154.86 1153.24 ± 0.96 kJ/mol 30.10083 ± 0.00033 28149-31-7*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 Disilanyl anion [SiH3SiH2]- (g) 62.2 49.8 ± 2.2 kJ/mol 61.21125 ± 0.00069 53199-49-8*0 1-Chloro ozone anion [ClOOO]- (g, perp) -109.0 -111.5 ± 2.2 kJ/mol 83.4514 ± 0.0013 224299-15-4*3 Disilene SiH2SiH2 (g, triplet) 392.0 383.5 ± 2.3 kJ/mol 60.20276 ± 0.00066 15435-77-5*1 Di-mu-hydrodihydrodisilicon HSi(HSiHH) (g, cis-singlet) 384.2 373.8 ± 2.7 kJ/mol 60.20276 ± 0.00066 129970-82-7*22 1-Hydrazinylium-1-yl [NNH2]+ (g) 1143.4 1136.4 ± 1.4 kJ/mol 30.02881 ± 0.00020 63986-30-1*0 Nirous oxide cation [NNO]+ (g) 1329.70 1326.80 ± 0.12 kJ/mol 44.01233 ± 0.00033 12269-46-4*0 Hydroxymethylene cation [HCOH]+ (g, cis) 986.4 982.8 ± 1.6 kJ/mol 30.02543 ± 0.00087 135395-06-1*2 1-Chloro ozone anion [ClOOO]- (g, cis) -66.9 -68.8 ± 2.1 kJ/mol 83.4514 ± 0.0013 224299-15-4*1 (3E)-1,3-Hexadien-5-yne CH2CHCHCHCCH (g, trans) 358.8 346.5 ± 1.9 kJ/mol 78.1118 ± 0.0048 5222-77-5*0 Divinylacetylene CH2CHCCCHCH2 (g, cis) 361.8 350.4 ± 2.0 kJ/mol 78.1118 ± 0.0048 821-08-9*2 Hydroxymethylene cation [HCOH]+ (g, gauche quartet) 1482.1 1479.4 ± 1.9 kJ/mol 30.02543 ± 0.00087 135395-06-1*3 1,2,4-Cyclohexatriene CH2(CHCHCHCCH) (g) 419.5 403.6 ± 2.0 kJ/mol 78.1118 ± 0.0048 124869-33-6*0 Pentatetraene CH2CCCCH2 (g) 452.7 448.7 ± 1.6 kJ/mol 64.0853 ± 0.0040 21986-03-8*0 Perchlorate [OCl(O)(O)O]- (g) -263.9 -272.8 ± 2.1 kJ/mol 99.4508 ± 0.0015 14797-73-0*0 2-Methyl-2-propanamine (CH3)3CNH2 (g) -86.98 -120.63 ± 0.55 kJ/mol 73.1369 ± 0.0033 75-64-9*0 Acetylene anion [HCCH]- (g, trans ?) 356.9 356.7 ± 1.9 kJ/mol 26.0378 ± 0.0016 50443-89-5*1 Biphenyl C6H5C6H5 (g) 207.1 178.9 ± 1.1 kJ/mol 154.2078 ± 0.0096 92-52-4*0 Hydroxymethylene anion [HCOH]- (g, cis) 160.2 157.5 ± 1.7 kJ/mol 30.02653 ± 0.00087 207914-87-2*2 Helium He (g, triplet) 1912.302 1912.302 ± 0.000 kJ/mol 4.0026020 ± 0.0000020 7440-59-7*1 Helium cation He+ (g) 2372.322 2372.322 ± 0.000 kJ/mol 4.0020534 ± 0.0000020 14234-48-1*0 Helium hydride cation [HeH]+ (g) 1350.148 1348.258 ± 0.000 kJ/mol 5.009993 ± 0.000070 17009-49-3*0 Krypton hydride cation [KrH]+ (g) 1106.33 1104.55 ± 0.69 kJ/mol 84.8074 ± 0.1000 37276-90-7*0 Monosulfur cation S+ (g) 1276.48 1278.27 ± 0.14 kJ/mol 32.0655 ± 0.0060 14701-12-3*0 Hydrogen peroxide cation [H2O2]+ (g, cis) 931.04 924.18 ± 0.98 kJ/mol 34.01413 ± 0.00062 12325-10-9*2 Oxosulfur [SO]+ (g) 999.33 999.93 ± 0.13 kJ/mol 48.0649 ± 0.0060 767269-11-4*0 Hydroxymethylene anion [HCOH]- (g, gauche quartet) 334.0 334.8 ± 2.1 kJ/mol 30.02653 ± 0.00087 207914-87-2*3 Hydrosulfide [SH]- (g) -80.51 -80.51 ± 0.19 kJ/mol 33.0745 ± 0.0060 15035-72-0*0 Oxadiazirine anion [O(NN)]- (g) 95.1 95.5 ± 2.9 kJ/mol 44.01343 ± 0.00033 350586-31-1*0 Sulfuric acid OS(O)(OH)2 (aq, 2500 H2O) -895.08 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*898 Diazenide [NNH]- (g, triplet) 347.5 344.6 ± 1.6 kJ/mol 29.02197 ± 0.00016 71004-29-0*1 Hydrogen sulfate [OHS(O)(O)O]- (g) -942.4 -952.8 ± 1.9 kJ/mol 97.0721 ± 0.0061 14996-02-2*0 Sulfurous acid S(O)(OH)2 (aq, 2500 H2O) -619.42 ± 0.15 kJ/mol 82.0801 ± 0.0061 7782-99-2*898 Hydrogen sulfite [OS(OH)O]- (g) -684.0 -691.3 ± 1.9 kJ/mol 81.0727 ± 0.0061 15181-46-1*0 Platinum Pt (g) 563.4 564.3 ± 1.7 kJ/mol 195.0780 ± 0.0020 7440-06-4*0 Oxiranylidene CH2(CO) (g, triplet) 456.2 452.1 ± 2.2 kJ/mol 42.0367 ± 0.0016 50983-85-2*1 Oxiranylidene cation [CH2(CO)]+ (g) 1165.4 1161.9 ± 2.5 kJ/mol 42.0361 ± 0.0016 *50983-85-2*0 Oxiranylidene anion [CH2(CO)]- (g) 236.4 232.4 ± 2.3 kJ/mol 42.0372 ± 0.0016 *50983-86-3*0 1-Methylene-2-propenylium [CH2CHCCH2]+ (g, triplet) 1256.3 1246.6 ± 1.7 kJ/mol 53.0820 ± 0.0032 62698-26-4*1 Methyl hydroperoxide cation [CH3OOH]+ (g) 833.7 819.7 ± 2.0 kJ/mol 48.0407 ± 0.0010 112465-88-0*0 Tribromine Br3 (g) 156.0 134.3 ± 3.2 kJ/mol 239.7120 ± 0.0030 11094-39-6*0 Methoxyoxoniumylidene [CH3OO]+ (g) 1012.61 1003.78 ± 0.68 kJ/mol 47.0328 ± 0.0010 86475-50-5*0 Dioxygen O2 (g, triplet) -0.000 -0.000 ± 0.000 kJ/mol 31.99880 ± 0.00060 7782-44-7*1 Dibromine Br2 (aq) -2.25 ± 0.18 kJ/mol 159.8080 ± 0.0020 7726-95-6*800 Hydrogen chloride HCl (aq, 150 H2O) -165.977 ± 0.024 kJ/mol 36.46064 ± 0.00090 7647-01-0*829 Dioxirane anion [CH2(OO)]- (g) -173.0 -179.8 ± 3.4 kJ/mol 46.0259 ± 0.0010 *157-26-6*0 Dioxymethyl anion [CH2OO]- (g) 55.0 49.8 ± 1.4 kJ/mol 46.0259 ± 0.0010 93207-29-5*0 1,2-Propadien-1-yl-3-ylidene anion [CCC]- (g) 621.9 629.3 ± 1.3 kJ/mol 36.0326 ± 0.0024 109292-47-9*0 H-CO2 vdW complex (H)(OCO) (g, vdW) -178.3 -177.5 ± 2.1 kJ/mol 45.0174 ± 0.0010 *2564-83-2*100 Tetroxidane HOOOOH (g) -34.0 -44.5 ± 1.8 kJ/mol 66.0135 ± 0.0012 29683-94-1*0 2-Propanol CH3CH(OH)CH3 (cr,l) -305.39 -318.20 ± 0.27 kJ/mol 60.0950 ± 0.0025 67-63-0*500 1-Propanol CH3CH2CH2OH (cr,l) -290.38 -302.56 ± 0.23 kJ/mol 60.0950 ± 0.0025 71-23-8*500 Tribromide [Br3]- (g) -287.5 -308.5 ± 1.9 kJ/mol 239.7125 ± 0.0030 14522-80-6*0 iso-Proplylide [CH3CHCH3]- (g) 128.8 110.4 ± 1.5 kJ/mol 43.0882 ± 0.0024 25012-80-0*0 Methyleneaminylium [CH2N]+ (g, triplet) 1456.6 1453.0 ± 2.1 kJ/mol 28.03277 ± 0.00082 53518-13-1*1 1,3-Butadienylium [CH2CHCHCH]+ (g, singlet) 1133.6 1123.6 ± 2.5 kJ/mol 53.0820 ± 0.0032 86181-69-3*2 Oxazirinyl cation [C(NO)]+ (g) 1565.5 1566.2 ± 2.3 kJ/mol 42.01629 ± 0.00086 *228850-18-8*0 Oxazirinyl anion [C(NO)]- (g) 448.2 449.0 ± 2.4 kJ/mol 42.01739 ± 0.00086 28269-68-3*0 3-Methanetetrayl-1,2-cyclopropanediylidene CC(CC) (g) 1154.8 1164.3 ± 1.9 kJ/mol 48.0428 ± 0.0032 78015-08-4*0 Hydrogen bromide HBr (aq, 2570 H2O) -120.62 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*952 Ammonium radical NH4 (g) 190.01 179.42 ± 0.43 kJ/mol 18.03850 ± 0.00029 92075-50-8*0 Ethyl formate HC(O)OCH2CH3 (cr,l) -426.0 ± 1.1 kJ/mol 74.0785 ± 0.0025 109-94-4*500 2-Cyclopropyn-1-ylidenemethyl anion [CC(CC)]- (g) 800.9 809.9 ± 1.7 kJ/mol 48.0433 ± 0.0032 289679-90-9*0 Carbon C (g, singlet) 833.342 838.488 ± 0.044 kJ/mol 12.01070 ± 0.00080 7440-44-0*2 Aminomethyl anion [CH2NH2]- (g) 209.5 199.2 ± 2.1 kJ/mol 30.04975 ± 0.00085 74215-21-7*0 Propionic acid CH3CH2C(O)OH (g, anti) -415.5 -433.1 ± 1.3 kJ/mol 74.0785 ± 0.0025 79-09-4*2 Hydroxyoxoammoniumyl [HONO]+ (g) 984.1 977.7 ± 1.8 kJ/mol 47.01293 ± 0.00061 80371-48-8*0 Methylamine anion [CH3NH2]- (g) 84.2 69.4 ± 2.8 kJ/mol 31.05769 ± 0.00088 81096-79-9*0 Fluorosyl fluoride anion [FFO]- (g, quartet) -56.6 -55.7 ± 2.4 kJ/mol 53.99675 ± 0.00030 *86825-57-2*1 Cyclopentene CH2(CH2CHCHCH2) (l) 7.06 ± 0.51 kJ/mol 68.1170 ± 0.0040 142-29-0*590 Chlorine difluoride cation [ClFF]+ (g) 1346.3 1344.9 ± 2.1 kJ/mol 73.44896 ± 0.00090 86825-59-4*0 (1Z)-Ethanimine CH3CHNH (g, cis) 58.9 44.3 ± 1.4 kJ/mol 43.0678 ± 0.0016 56003-82-8*0 Hydroperoxyimidogen HOON (g, trans) 103.4 99.8 ± 2.4 kJ/mol 47.01348 ± 0.00061 877456-58-1*1 Cyanogen cation [NCCN]+ (g) 1598.24 1600.46 ± 0.42 kJ/mol 52.0343 ± 0.0016 37354-81-7*0 Isocyanogen CNCN (g) 412.1 414.4 ± 1.3 kJ/mol 52.0349 ± 0.0016 83951-85-3*0 Diazoethenylidene NNCC (g) 658.6 661.2 ± 1.8 kJ/mol 52.0349 ± 0.0016 130760-10-0*0 Isocyanomethyliumylidene [CNC]+ (g) 1615.7 1621.3 ± 1.9 kJ/mol 38.0276 ± 0.0016 78271-45-1*0 Isocyanomethylidyne anion [CNC]- (g) 479.3 483.0 ± 2.0 kJ/mol 38.0287 ± 0.0016 *53590-27-5*0 Cyanomethyliumylidene [CCN]+ (g) 1719.8 1725.3 ± 2.1 kJ/mol 38.0276 ± 0.0016 76619-90-4*0 Cyanomethylidyne anion [CCN]- (g) 410.1 413.7 ± 2.2 kJ/mol 38.0287 ± 0.0016 12373-35-2*0 2,3-didehydro-1H-azirin-1-yl N(CC) (g) 720.4 724.4 ± 2.1 kJ/mol 38.0281 ± 0.0016 439586-06-8*0 Cyanoaminylium [HNCN]+ (g) 1362.8 1359.7 ± 2.4 kJ/mol 41.03157 ± 0.00082 205443-18-1*0 Cyanoamidogen anion [HNCN]- (g) 69.91 66.90 ± 0.94 kJ/mol 41.03267 ± 0.00082 67131-47-9*0 Hydrogen fluoride HF (aq, 23 H2O) -321.08 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*903 Cyanamide NH2CN (g) 140.8 134.5 ± 1.5 kJ/mol 42.04006 ± 0.00082 420-04-2*0 Diazomethylene CNN (g) 579.3 580.0 ± 3.8 kJ/mol 40.02418 ± 0.00081 2468-81-7*0 Deuterium hydride cation [HD]+ (g) 1490.498 1490.587 ± 0.000 kJ/mol 3.021493 ± 0.000070 12181-16-7*0 Hydrogen chloride HCl (aq, 140 H2O) -165.944 ± 0.026 kJ/mol 36.46064 ± 0.00090 7647-01-0*907 Trichloromethylium [CCl3]+ (g) 856.14 854.62 ± 0.93 kJ/mol 118.3683 ± 0.0028 27130-34-3*0 Hypofluorous acid anion [HOF]- (g, quartet) 155.3 154.7 ± 2.6 kJ/mol 36.00629 ± 0.00031 36505-07-4*2 Dichloromethyliumyl [CCl2]+ (g) 1122.0 1122.9 ± 1.8 kJ/mol 82.9156 ± 0.0020 55945-51-2*0 Hydrogen chloride HCl (aq, 2439 H2O) -166.711 ± 0.024 kJ/mol 36.46064 ± 0.00090 7647-01-0*951 Nitric acid cation [HON(O)O]+ (g) 1029.19 1020.13 ± 0.69 kJ/mol 63.01233 ± 0.00091 272109-63-4*0 Imidogen anion [NH]- (g) 322.62 322.67 ± 0.16 kJ/mol 15.015229 ± 0.000099 23841-33-0*0 Hypochlorous acid anion [HOCl]- (g) 198.7 198.4 ± 2.5 kJ/mol 52.46059 ± 0.00095 34524-94-2*0 Triazirinylium ion [N(NN)]+ (g) 1608.8 1605.9 ± 1.6 kJ/mol 42.01967 ± 0.00021 92220-05-8*0 Hydrogen chloride HCl (aq, 1500 H2O) -166.635 ± 0.025 kJ/mol 36.46064 ± 0.00090 7647-01-0*840 Aminooxy anion [NH2O]- (g) 47.3 40.4 ± 1.7 kJ/mol 32.02257 ± 0.00034 51375-41-8*0 1,1,1-Trichloroethane CH3CCl3 (l) -183.83 -177.19 ± 0.52 kJ/mol 133.4033 ± 0.0031 71-55-6*500 Cyclopropylide [CH(CH2CH2)]- (g) 264.8 252.0 ± 1.7 kJ/mol 41.0723 ± 0.0024 1724-45-4*0 Isocyanomethylium [CH2NC]+ (g) 1272.9 1270.7 ± 2.2 kJ/mol 40.0435 ± 0.0016 78269-43-9*0 Vinyl chloride CH2CHCl (cr,l) -3.61 0.96 ± 0.91 kJ/mol 62.4979 ± 0.0018 75-01-4*500 Cyclohexene CH2(CHCHCH2CH2CH2) (g) 27.21 -4.26 ± 0.32 kJ/mol 82.1436 ± 0.0049 110-83-8*0 Cyclohexene CH2(CHCHCH2CH2CH2) (cr,l) -21.94 -37.81 ± 0.30 kJ/mol 82.1436 ± 0.0049 110-83-8*500 Aminomethylene anion [CHNH2]- (g) 353.0 346.1 ± 2.3 kJ/mol 29.04181 ± 0.00083 207914-86-1*0 Chlorine difluoride anion [ClFF]- (g) -319.0 -319.1 ± 2.2 kJ/mol 73.45005 ± 0.00090 91419-41-9*0 Chloromethane cation [CH3Cl]+ (g) 1014.56 1007.79 ± 0.16 kJ/mol 50.4867 ± 0.0012 12538-71-5*0 Dinitrogen pentoxide O2NONO2 (cr,l) -41.11 ± 0.38 kJ/mol 108.0105 ± 0.0015 10102-03-1*500 Triazirine HN(NN) (g) 464.1 457.6 ± 2.6 kJ/mol 43.02816 ± 0.00022 157-29-9*0 Bromofluoromethane CH2FBr (g) -197.4 -211.9 ± 4.9 kJ/mol 112.9290 ± 0.0013 373-52-4*0 Hydrogen bromide HBr (aq, 3000 H2O) -120.64 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*842 Fluorodibromomethane CHFBr2 (g) -159.7 -179.3 ± 4.9 kJ/mol 191.8250 ± 0.0022 1868-53-7*0 Fluorosyl fluoride cation [FFO]+ (g, quartet) 1413.1 1413.4 ± 3.5 kJ/mol 53.99566 ± 0.00030 *86825-50-5*1 Difluorochlorobromomethane CF2ClBr (g) -428.9 -439.9 ± 4.9 kJ/mol 165.3642 ± 0.0016 353-59-3*0 Dichlorofluorobromomethane CCl2FBr (g) -228.3 -238.3 ± 4.9 kJ/mol 181.8185 ± 0.0022 353-58-2*0 Dibromofluorochloromethane CBr2FCl (g) -169.9 -186.8 ± 4.9 kJ/mol 226.2698 ± 0.0023 353-55-9*0 Krypton cation Kr+ (g) 1350.756 1350.756 ± 0.000 kJ/mol 83.7995 ± 0.1000 16915-28-9*0 Methylammoniumyl [CH3NH2]+ (g) 865.96 852.02 ± 0.26 kJ/mol 31.05659 ± 0.00088 34516-31-9*0 Ammonium chloride (NH4)Cl (cr) -311.549 -314.710 ± 0.063 kJ/mol 53.49120 ± 0.00095 12125-02-9*510 1-Propenylidene CH3CHC (g, triplet) 630.3 622.8 ± 1.7 kJ/mol 40.0639 ± 0.0024 70277-78-0*2 Chlorosyl chloride cation [ClClO]+ (g) 1132.6 1130.8 ± 2.0 kJ/mol 86.9043 ± 0.0018 *86825-56-1*0 Hydrogen fluoride HF (aq, 55 H2O) -321.18 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*905 1,2-Difluoroacetylene cation [FCCF]+ (g) 1081.7 1084.5 ± 1.3 kJ/mol 62.0177 ± 0.0016 268566-70-7*0 Methyliumylamino [CH2NH]+ (g) 1056.1 1049.3 ± 1.7 kJ/mol 29.04071 ± 0.00083 65130-65-6*0 Difluorophosgene cation [CF2O]+ (g) 653.46 650.70 ± 0.51 kJ/mol 66.00636 ± 0.00085 73256-56-1*0 Ammonium bromide (NH4)Br (cr) -253.63 -270.21 ± 0.15 kJ/mol 97.9425 ± 0.0010 12124-97-9*510 1-Hydroxyethanide [CH3CHOH]- (g) -20.3 -33.7 ± 2.2 kJ/mol 45.0610 ± 0.0017 88032-18-2*0 Chloro(chlorooxy)methylene ClCOCl (g, cis) 73.5 73.7 ± 3.6 kJ/mol 98.9155 ± 0.0020 479587-31-0*2 Chlorohydroxymethylene ClCOH (g, trans) 14.0 11.1 ± 2.5 kJ/mol 64.4707 ± 0.0012 147723-60-2*1 (Chlorooxy)methylene HCOCl (g, cis) 119.3 117.9 ± 2.7 kJ/mol 64.4707 ± 0.0012 331419-80-8*2 Chlorosyl chloride anion [ClClO]- (g) -185.4 -184.7 ± 2.3 kJ/mol 86.9053 ± 0.0018 *86825-55-0*0 Dibromophosgene CBr2O (l) -144.38 ± 0.95 kJ/mol 187.8181 ± 0.0022 593-95-3*590 2-Chloroethanol ClCH2CH2OH (l) -314.91 ± 0.53 kJ/mol 80.5132 ± 0.0019 107-07-3*590 2-Bromoethanol BrCH2CH2OH (l) -274.72 ± 0.46 kJ/mol 124.9645 ± 0.0019 540-51-2*590 Ethanium [C2H7]+ (g, classical Cs I) 888.7 870.3 ± 1.8 kJ/mol 31.0764 ± 0.0017 24669-33-8*2 2-Cyclopropyn-1-ylidene C(CC) (g, singlet) 993.2 1000.0 ± 2.5 kJ/mol 36.0321 ± 0.0024 102508-15-6*2 Phenylium [C6H5]+ (g, singlet) 1149.17 1136.39 ± 0.85 kJ/mol 77.1034 ± 0.0048 17333-73-2*2 Ethanium [C2H7]+ (g, classical Cs II) 895.1 877.3 ± 1.9 kJ/mol 31.0764 ± 0.0017 24669-33-8*3 Hydrogen chloride HCl (aq, 74 H2O) -165.544 ± 0.027 kJ/mol 36.46064 ± 0.00090 7647-01-0*953 Azanidylmethyl [CH2NH]- (g) 224.4 217.2 ± 2.2 kJ/mol 29.04181 ± 0.00083 127593-73-1*0 m-Benzyne anion [C6H4]- (g) 444.2 435.3 ± 1.3 kJ/mol 76.0965 ± 0.0048 249589-31-9*0 p-Benzyne anion [C6H4]- (g) 465.1 455.5 ± 1.3 kJ/mol 76.0965 ± 0.0048 219298-17-6*0 Cycloheptane CH2(CH2CH2CH2CH2CH2C (cr,l) -126.63 -156.52 ± 0.51 kJ/mol 98.1861 ± 0.0057 291-64-5*500 Nitrate [ON(O)O]- (aq) -206.58 ± 0.18 kJ/mol 62.00549 ± 0.00090 14797-55-8*800 Ethylbenzene C6H5CH2CH3 (cr,l) -12.35 ± 0.54 kJ/mol 106.1650 ± 0.0064 100-41-4*500 Phenylacetylene C6H5CCH (cr,l) 273.95 ± 0.73 kJ/mol 102.1332 ± 0.0064 536-74-3*500 Phenyloxoniumylidene [C6H5O]+ (g) 901.6 887.2 ± 2.2 kJ/mol 93.1028 ± 0.0048 41071-17-4*0 Anisole C6H5OCH3 (g) -47.70 -72.54 ± 0.79 kJ/mol 108.1378 ± 0.0056 100-66-3*0 Cyanogen bromide anion [BrCN]- (g) 57.7 54.1 ± 3.8 kJ/mol 105.9220 ± 0.0013 54092-05-6*0 Ozone cation [OOO]+ (g) 1352.880 1350.541 ± 0.041 kJ/mol 47.99765 ± 0.00090 12596-82-6*0 Hydrogen chloride HCl (aq, 1250 H2O) -166.604 ± 0.024 kJ/mol 36.46064 ± 0.00090 7647-01-0*954 Tetranitrogen cation [NNNN]+ (g) 1392.8 1392.5 ± 1.5 kJ/mol 56.02641 ± 0.00028 12185-04-5*0 Hydrogen difluoride cation [FFH]+ (g, singlet) 1174.3 1171.3 ± 1.5 kJ/mol 39.004198 ± 0.000070 *126950-54-7*2 Fluorobenzene C6H5F (cr,l) -151.72 -149.30 ± 0.89 kJ/mol 96.1023 ± 0.0048 462-06-6*500 Water H2O (l, eq.press.) -285.797 ± 0.025 kJ/mol 18.01528 ± 0.00033 7732-18-5*589 Bromobenzene C6H5Br (cr,l) 60.3 ± 1.3 kJ/mol 157.0079 ± 0.0049 108-86-1*500 Chloroniumyl ion [HCl]+ (g) 1137.798 1137.732 ± 0.0051 kJ/mol 36.46009 ± 0.00090 12258-94-5*0 Trifluorine cation [F3]+ (g) 1529.5 1527.4 ± 2.3 kJ/mol 56.9946610 ± 0.0000015 64710-22-1*0 Pyridinium [NH(CHCHCHCHCH)]+ (g) 761.7 740.8 ± 1.3 kJ/mol 80.1073 ± 0.0040 16969-45-2*0 Acetone CH3C(O)CH3 (cr,l) -244.59 -247.71 ± 0.27 kJ/mol 58.0791 ± 0.0025 67-64-1*500 2-Hydroxy-2-propenyl CH2C(OH)CH2 (g) 4.0 -9.5 ± 1.2 kJ/mol 57.0712 ± 0.0024 742072-56-6*0 Hydrogen fluoride HF (aq, 22.2 H2O) -321.07 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*888 Methanol anion [CH3OH]- (g) -89.1 -99.8 ± 2.8 kJ/mol 32.04241 ± 0.00090 68474-04-4*0 Propionaldehyde CH3CH2CHO (cr,l) -218.02 -216.57 ± 0.28 kJ/mol 58.0791 ± 0.0025 123-38-6*500 Triiodine cation [I3]+ (g) 946.1 941.0 ± 4.1 kJ/mol 380.712861 ± 0.000090 12596-32-6*0 Diazenium [NH2NH]+ (g) 968.64 957.38 ± 0.73 kJ/mol 31.03675 ± 0.00025 37369-93-0*0 Ethyl nitrite CH3CH2ONO (g) -81.30 -98.70 ± 0.87 kJ/mol 75.0666 ± 0.0017 109-95-5*0 trans-1,2-Dibromoethene CHBrCHBr (g, trans) 121.4 101.6 ± 2.0 kJ/mol 185.8453 ± 0.0026 590-12-5*0 1,1-Dibromoethene CH2CBr2 (g) 125.3 105.0 ± 2.1 kJ/mol 185.8453 ± 0.0026 593-92-0*0 Norbornadiene (CHCH)(CHCH2CH)(CHCH (g) 267.65 242.21 ± 0.98 kJ/mol 92.1384 ± 0.0056 121-46-0*0 Methylimidogen anion [CH3N]- (g) 321.1 313.5 ± 1.4 kJ/mol 29.04181 ± 0.00083 82539-34-2*0 Monoammonium succinate (CH2C(O)OH)2(NH3) (cr) -1067.82 ± 0.72 kJ/mol 135.1186 ± 0.0035 38457-08-8*510 Diammonium succinate (CH2COOH)2(NH3)2 (cr) -1182.32 ± 0.48 kJ/mol 152.1492 ± 0.0035 2226-88-2*510 (Methylmethylene)oxonium [CH3OCH2]+ (g) 685.8 671.6 ± 2.2 kJ/mol 45.0600 ± 0.0017 23653-97-6*0 Acrolein CH2CHCHO (g, cis) -46.4 -56.7 ± 1.4 kJ/mol 56.0633 ± 0.0024 107-02-8*2 Methoxymethyl anion [CH3OCH2]- (g) 23.3 10.3 ± 2.3 kJ/mol 45.0610 ± 0.0017 61192-30-1*0 Ethenedione cation [OCCO]+ (g) 909.5 912.7 ± 2.0 kJ/mol 56.0197 ± 0.0017 12541-99-0*0 Acetaldehyde anion [CH3CHO]- (g) -62.2 -72.4 ± 2.2 kJ/mol 44.0531 ± 0.0017 60427-04-5*0 2-Propenylidyne anion [CH2CHC]- (g) 464.6 460.9 ± 1.7 kJ/mol 39.0565 ± 0.0024 120126-89-8*0 2-Propen-3-yliumylidene [CHCHCH]+ (g) 1494.5 1491.5 ± 1.7 kJ/mol 39.0554 ± 0.0024 84654-86-4*0 Ethylene anion [CH2CH2]- (g, syn ?) 231.6 225.5 ± 2.0 kJ/mol 28.0537 ± 0.0016 34527-91-8*2 2-Propenylidene anion [CHCHCH]- (g) 536.0 532.6 ± 1.7 kJ/mol 39.0565 ± 0.0024 98705-30-7*0 1-Ethylium-1-yl [CH3CH]+ (g) 1182.0 1174.7 ± 3.2 kJ/mol 28.0526 ± 0.0016 85944-79-2*0 3-Imino-2-propen-1-ylidene CHCHCNH (g, anti-singlet) 533.0 527.9 ± 1.8 kJ/mol 53.0627 ± 0.0024 916765-05-4*12 3-Imino-2-propen-1-ylidene CHCHCNH (g, syn-triplet) 572.6 567.3 ± 2.0 kJ/mol 53.0627 ± 0.0024 916765-05-4*22 2-(Methylidyneamino)ethenyl CHCHNCH (g, syn-singlet) 604.5 599.7 ± 1.9 kJ/mol 53.0627 ± 0.0024 123416-74-0*12 2-(Methylidyneamino)ethenyl CHCHNCH (g, syn-triplet) 637.1 632.3 ± 2.0 kJ/mol 53.0627 ± 0.0024 123416-74-0*22 2-Cyclopropyn-1-yl anion [C(CC)]- (g) 664.7 672.0 ± 1.6 kJ/mol 36.0326 ± 0.0024 500574-36-7*0 1-Cyanovinylium [CH2CCN]+ (g) 1318.3 1317.1 ± 2.2 kJ/mol 52.0542 ± 0.0024 85399-09-3*0 Ethylidene anion [CH3CH]- (g) 325.7 318.4 ± 1.8 kJ/mol 28.0537 ± 0.0016 35829-99-3*0 Aminomethyliumylidene [CNH2]+ (g) 1168.3 1165.1 ± 2.2 kJ/mol 28.03277 ± 0.00082 86784-42-1*0 Tetraoxygen O4 (g, C2h singlet) 145.8 142.2 ± 3.8 kJ/mol 63.9976 ± 0.0012 12596-83-7*22 Nitrosyl nitrate ONONO2 (g, trans) 48.3 40.4 ± 1.8 kJ/mol 92.0111 ± 0.0012 15969-55-8*1 Butatriene cation [CH2CCCH2]+ (g) 1210.5 1204.6 ± 1.3 kJ/mol 52.0740 ± 0.0032 65513-85-1*0 Hydrooxonitrate [HNO]- (g) 78.62 75.71 ± 0.99 kJ/mol 31.01463 ± 0.00032 66057-02-1*0 Bicyclo[1.1.0]but-3-ene CH2(CCH)CH (g) 483.2 474.2 ± 1.6 kJ/mol 52.0746 ± 0.0032 78525-41-4*0 Propynylidene HCCCH (g) 543.51 546.51 ± 0.65 kJ/mol 38.0480 ± 0.0024 67152-18-5*0 Hypochlorous acid cation [HOCl]+ (g) 998.94 995.90 ± 0.90 kJ/mol 52.45949 ± 0.00095 71606-47-8*0 Vinylvinylidene anion [CH2CHCHC]- (g, trans) 405.7 399.0 ± 2.0 kJ/mol 52.0751 ± 0.0032 167386-49-4*1 Tetrahedrane cation [CH(CH(CHCH))]+ (g) 1326.7 1318.6 ± 1.7 kJ/mol 52.0740 ± 0.0032 80826-01-3*0 Bicyclo[1.1.0]but-1(3)-ene CH2(CC)CH2 (g) 578.8 570.4 ± 1.9 kJ/mol 52.0746 ± 0.0032 58208-49-4*0 Bicyclo[1.1.0]but-1(3)-ene cation [CH2(CC)CH2]+ (g) 1461.6 1453.5 ± 2.1 kJ/mol 52.0740 ± 0.0032 *58208-49-4*0 Chloryl chloride ClCl(O)O (g) 126.1 122.1 ± 1.7 kJ/mol 102.9042 ± 0.0019 117489-73-3*0 1-Buten-3-yn-1-yl HCCCHCH (g, cis) 547.8 545.0 ± 1.2 kJ/mol 51.0666 ± 0.0032 2810-61-9*2 Formaldehyde anion [CH2O]- (g) -26.7 -28.3 ± 2.0 kJ/mol 30.02653 ± 0.00087 27837-46-3*0 3-Buten-1-ynylium [CH2CHCC]+ (g, singlet) 1603.8 1602.9 ± 1.7 kJ/mol 51.0661 ± 0.0032 103928-84-3*2 2-Butynylium [CH3CCCH2]+ (g, triplet) 1258.7 1251.4 ± 1.6 kJ/mol 53.0820 ± 0.0032 64235-83-2*1 3-Methylene-1-cyclopropen-1-ylium [CH2C(CHC)]+ (g, triplet) 1467.6 1464.0 ± 1.6 kJ/mol 51.0661 ± 0.0032 117469-28-0*1 2-Cyclopropen-1-ylidenemethylium [CHC(CHCH)]+ (g, singlet) 1346.4 1343.8 ± 1.8 kJ/mol 51.0661 ± 0.0032 112936-36-4*2 1,3-Cyclobutadien-1-ylium [C(CHCHCH)]+ (g, singlet) 1388.3 1383.3 ± 1.9 kJ/mol 51.0661 ± 0.0032 81913-77-1*2 Cyanic azide NCNNN (g) 502.6 498.2 ± 1.9 kJ/mol 68.03766 ± 0.00085 764-05-6*0 Peroxychloric acid HOOCl(O)O (g) 76.6 68.4 ± 2.5 kJ/mol 100.4582 ± 0.0015 177778-91-5*0 Phenyl hydroperoxide C6H5OOH (g) 13.4 -5.7 ± 2.1 kJ/mol 110.1106 ± 0.0049 36112-26-2*0 Methylcyclopentane CH3CH(CH2CH2CH2CH2) (cr,l) -116.54 -137.90 ± 0.36 kJ/mol 84.1595 ± 0.0049 96-37-7*500 Ketene cation [CH2CO]+ (g) 882.22 879.05 ± 0.11 kJ/mol 42.0361 ± 0.0016 64999-16-2*0 Ketene anion [CH2CO]- (g) -16.0 -19.1 ± 2.2 kJ/mol 42.0372 ± 0.0016 56391-79-8*0 Dioxosilane SiO2 (cr, quartz) -906.27 -911.25 ± 0.83 kJ/mol 60.08430 ± 0.00067 7631-86-9*505 Dioxosilane SiO2 (cr, cristobalite) -903.57 -908.43 ± 0.87 kJ/mol 60.08430 ± 0.00067 7631-86-9*510 Formaldehyde CH2O (g, triplet) 196.005 192.702 ± 0.096 kJ/mol 30.02598 ± 0.00087 50-00-0*1 Dioxodiazoxane ONONO (g, t, c) 109.4 105.3 ± 1.8 kJ/mol 76.01168 ± 0.00091 122413-35-8*2 Silylene anion [SiH2]- (g) 166.5 164.8 ± 1.4 kJ/mol 30.10193 ± 0.00033 54991-62-7*0 Silyliumylidene [SiH]+ (g) 1134.1 1135.3 ± 1.1 kJ/mol 29.09289 ± 0.00031 31241-66-4*0 Oxoethenylium [HCCO]+ (g) 1139.7 1142.5 ± 2.1 kJ/mol 41.0282 ± 0.0016 92056-63-8*0 Disilene cation [SiH2SiH2]+ (g) 1068.2 1059.1 ± 2.0 kJ/mol 60.20221 ± 0.00066 108492-63-3*0 Aminomethyliumyl [CHNH2]+ (g) 1039.5 1031.9 ± 2.3 kJ/mol 29.04071 ± 0.00083 89302-94-3*0 Di-mu-hydrodihydrodisilicon cation [HSi(HSiHH)]+ (g, trans) 1178.8 1171.2 ± 3.3 kJ/mol 60.20221 ± 0.00066 *129970-82-7*1 Di-mu-hydrodihydrodisilicon anion [HSi(HSiHH)]- (g, trans) 287.0 278.5 ± 3.4 kJ/mol 60.20331 ± 0.00066 *129970-83-8*1 mu-Hydrotrihydrodisilicon Si(HSiH3) (g, triplet) 457.9 449.7 ± 2.5 kJ/mol 60.20276 ± 0.00066 497967-55-2*1 1-Cyclopropene-1,2-diyl CH2(CC) (g) 791.1 790.6 ± 1.5 kJ/mol 38.0480 ± 0.0024 202744-75-0*0 Methylaminilium [CH3NH]+ (g) 1135.1 1125.2 ± 2.1 kJ/mol 30.04865 ± 0.00085 49784-84-1*0 Fluoronium [HFH]+ (g) 774.04 771.10 ± 0.91 kJ/mol 21.01373 ± 0.00014 12206-67-6*0 Dewar benzene (CHCH)(CHCHCHCH) (g) 422.1 405.1 ± 1.8 kJ/mol 78.1118 ± 0.0048 5649-95-6*0 2-Chloro ozone anion [ClO(O)O]- (g) -103.6 -105.9 ± 3.2 kJ/mol 83.4514 ± 0.0013 *141801-67-4*0 Hypofluorous acid cation [HOF]+ (g) 1142.02 1139.01 ± 0.87 kJ/mol 36.00519 ± 0.00031 90243-22-4*0 1,2-Hexadien-4-yne CH2CCHCCCH3 (g) 407.5 397.5 ± 1.7 kJ/mol 78.1118 ± 0.0048 34783-10-3*0 3-Methylene-1-penten-4-yne CH2CHC(CH2)CCH (g, trans) 362.6 350.0 ± 2.2 kJ/mol 78.1118 ± 0.0048 6929-96-0*1 Carbon C (g, triplet) 711.411 716.896 ± 0.044 kJ/mol 12.01070 ± 0.00080 7440-44-0*1 3-Methyl-1,4-pentadiyne HCCCH(CH3)CCH (g) 439.0 427.6 ± 1.6 kJ/mol 78.1118 ± 0.0048 57242-04-3*0 Nirous oxide anion [NNO]- (g) 99.3 96.7 ± 1.9 kJ/mol 44.01343 ± 0.00033 12274-12-3*0 2-Methyl-2-propanamine (CH3)3CNH2 (cr,l) -133.08 -150.56 ± 0.54 kJ/mol 73.1369 ± 0.0033 75-64-9*500 1,2-Diphenylethane C6H5CH2CH2C6H5 (cr,l) 84.88 51.14 ± 0.76 kJ/mol 182.2610 ± 0.0112 103-29-7*500 Bromine atom Br (g, 2P3/2) 117.910 111.848 ± 0.056 kJ/mol 79.90400 ± 0.00100 10097-32-2*1 Carbon tetracation [C]+4 (g) 14993.627 14998.773 ± 0.053 kJ/mol 12.00851 ± 0.00080 16092-62-9*0 Anthracene C6H4(CH(CC(C4H4)CH)) (g) 255.95 226.94 ± 0.98 kJ/mol 178.2292 ± 0.0112 120-12-7*0 Anthracene C6H4(CH(CC(C4H4)CH)) (cr,l) 150.58 124.77 ± 0.92 kJ/mol 178.2292 ± 0.0112 120-12-7*500 Acetylene anion [HCCH]- (g, cis ?) 380.1 380.3 ± 1.9 kJ/mol 26.0378 ± 0.0016 50443-89-5*2 Phenanthrene C6H4(C2H2(CC(C4H4))) (cr,l) 136.24 110.96 ± 0.66 kJ/mol 178.2292 ± 0.0112 85-01-8*500 Diphenylacetylene C6H5CCC6H5 (g) 432.4 407.4 ± 1.2 kJ/mol 178.2292 ± 0.0112 501-65-5*0 Diphenylacetylene C6H5CCC6H5 (cr,l) 334.72 312.77 ± 0.94 kJ/mol 178.2292 ± 0.0112 501-65-5*500 Bicyclo[1.1.0]buta-1,1-diene-2,4-diyl C(CCH)C (g) 990.4 993.6 ± 2.0 kJ/mol 49.0507 ± 0.0032 *99417-53-5*0 Benzoic acid C6H5C(O)OH (g) -274.30 -294.10 ± 0.19 kJ/mol 122.1213 ± 0.0056 65-85-0*0 Dihelium He2 (g, triplet) 1733.310 1729.576 ± 0.018 kJ/mol 8.0052040 ± 0.0000040 12184-98-4*1 Neon hydride cation [NeH]+ (g) 1324.81 1322.99 ± 0.94 kJ/mol 21.18709 ± 0.00060 12200-65-6*0 1-Methylene-2-propenylium [CH2CHCCH2]+ (g, singlet) 1059.4 1049.3 ± 1.7 kJ/mol 53.0820 ± 0.0032 62698-26-4*2 Cyclopropenyliumdiyl [CH(CC)]+ (g) 1692.1 1695.1 ± 1.9 kJ/mol 37.0395 ± 0.0024 127476-05-5*0 Monosulfur anion S- (g) 76.48 78.54 ± 0.14 kJ/mol 32.0665 ± 0.0060 14337-03-2*0 Cyclopropynyl anion [CH(CC)]- (g) 518.13 521.12 ± 0.88 kJ/mol 37.0406 ± 0.0024 136861-42-2*0 Thiodioxy SOO (g) 206.8 204.6 ± 2.1 kJ/mol 64.0648 ± 0.0060 164034-62-2*0 Trioxidanylium [HOOO]+ (g) 1070.4 1064.2 ± 1.4 kJ/mol 49.00559 ± 0.00090 74241-49-9*0 Sulfur oxide peroxide OSOO (g, cis) -25.9 -30.2 ± 2.3 kJ/mol 80.0642 ± 0.0061 175799-68-5*2 Hydrogen carbonate [HOC(O)O]- (aq) -689.861 ± 0.040 kJ/mol 61.0174 ± 0.0012 71-52-3*800 Hydrogen fluoride HF (aq, 37 H2O) -321.14 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*890 Hydroxyimidogen anion [NOH]- (g) 229.8 227.4 ± 2.2 kJ/mol 31.01463 ± 0.00032 *35337-59-8*0 Hydrogen atom H (ad, 1 Pt(111)) -22.3 -24.0 ± 1.5 kJ/mol 1.007940 ± 0.000070 12385-13-6*1000001 Hydrogen fluoride HF (aq, 55.51 H2O) -321.19 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*891 Hydrogen atom H (ad, 1 Pt(111) hcp) -17.0 -20.2 ± 5.2 kJ/mol 1.007940 ± 0.000070 12385-13-6*1003001 Hydrogen atom H (ad, 1 Pt(111) bridge) -14.1 -17.0 ± 8.5 kJ/mol 1.007940 ± 0.000070 12385-13-6*1004001 Hydrogen atom H (ad, 4 Pt(111) hcp) -30.3 -33.4 ± 7.2 kJ/mol 1.007940 ± 0.000070 12385-13-6*1003004 Hydrogen atom H (ad, 4 Pt(111) bridge) -28.3 -31.1 ± 7.6 kJ/mol 1.007940 ± 0.000070 12385-13-6*1004004 Hydronium radical (H2O)(H) (g, vdW) -18.5 -21.5 ± 2.1 kJ/mol 19.02322 ± 0.00037 12168-76-2*100 1,3-Butadiynyl anion [CCCC]- (g) 677.3 686.4 ± 1.1 kJ/mol 48.0433 ± 0.0032 59158-53-1*0 Formyloxidanyl HC(O)O (g) -125.82 -127.18 ± 0.55 kJ/mol 45.0174 ± 0.0010 16499-21-1*0 Cyanamide NH2CN (cr) 58.92 ± 0.54 kJ/mol 42.04006 ± 0.00082 420-04-2*500 Dioxiranyl HC(OO) (g) 217.3 213.8 ± 2.0 kJ/mol 45.0174 ± 0.0010 120595-16-6*0 Diazomethyliumyl [CNN]+ (g) 1641.2 1642.4 ± 4.1 kJ/mol 40.02363 ± 0.00081 307495-90-5*0 Diazomethylene anion [CNN]- (g) 408.3 408.5 ± 3.8 kJ/mol 40.02473 ± 0.00081 205498-92-6*0 3H-Diazirin-3-ylidene C(NN) (g) 579.1 579.4 ± 2.7 kJ/mol 40.02418 ± 0.00081 253308-70-2*0 Oxobromonium [BrO]+ (g) 1139.9 1132.1 ± 1.6 kJ/mol 95.9029 ± 0.0010 142315-39-7*0 1,2-Butadienylium [CH3CHCCH]+ (g, triplet) 1315.5 1307.4 ± 1.7 kJ/mol 53.0820 ± 0.0032 *65114-67-2*1 Chloromethyliumylidene [CCl]+ (g) 1282.8 1285.9 ± 2.4 kJ/mol 47.4629 ± 0.0012 69773-94-0*0 Chloromethylidyne anion [CCl]- (g) 319.9 323.6 ± 2.5 kJ/mol 47.4639 ± 0.0012 117129-77-8*0 Trioxidane HOOOH (g) -81.95 -90.55 ± 0.62 kJ/mol 50.01408 ± 0.00091 14699-99-1*0 1-Propenylium [CH3CHCH]+ (g, cis) 1231.9 1221.6 ± 1.7 kJ/mol 41.0713 ± 0.0024 50457-58-4*2 Ammonia anion [NH3]- (g) 94.3 87.3 ± 2.4 kJ/mol 17.03111 ± 0.00022 37353-00-7*0 1-Propenylide [CH3CHCH]- (g, cis) 204.0 192.7 ± 1.8 kJ/mol 41.0723 ± 0.0024 65887-20-9*2 Ethoxyethane CH3CH2OCH2CH3 (cr,l) -266.17 -278.49 ± 0.61 kJ/mol 74.1216 ± 0.0033 60-29-7*500 Ethynylene C2 (g, triplet) 827.241 833.946 ± 0.092 kJ/mol 24.0214 ± 0.0016 12070-15-4*1 Hydrogen difluoride cation [FHF]+ (g, triplet ?) 1241. 1238. ± 17. kJ/mol 39.004198 ± 0.000070 126950-54-7*1 Cyclopropylium [CH(CH2CH2)]+ (g) 1104.9 1093.4 ± 2.4 kJ/mol 41.0713 ± 0.0024 1724-43-2*0 Cyclobutane CH2(CH2CH2CH2) (l) 3.92 ± 0.39 kJ/mol 56.1063 ± 0.0032 287-23-0*590 Nitrosyl nitrite anion [ONONO]- (g, t, t) -103.0 -106.2 ± 2.8 kJ/mol 76.01223 ± 0.00091 *122413-35-8*1 Hydroxyoxoammoniumyl [HONO]+ (g, trans) 984.1 977.7 ± 1.8 kJ/mol 47.01293 ± 0.00061 80371-48-8*1 2,4,5-Trioxa-1,3-diazabicyclo[1.1.1]pentane N(O3)N (g) 602.6 593.3 ± 2.1 kJ/mol 76.01168 ± 0.00091 224950-18-9*0 Hydrogen bromide HBr (aq, 1500 H2O) -120.55 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*840 Poly(vinylchloride) CH2CHCl (s, poly) -84.5 -94.0 ± 1.3 kJ/mol 62.4979 ± 0.0018 9002-86-2*500 1,1-Dichloroethene CH2CCl2 (l) -23.44 ± 0.51 kJ/mol 96.9427 ± 0.0024 75-35-4*500 Ethynylaminylium [HCCNH]+ (g, triplet) 1277.9 1277.5 ± 2.6 kJ/mol 40.0435 ± 0.0016 103835-08-1*1 n-Heptane CH3(CH2)5CH3 (cr,l) -201.43 -223.88 ± 0.46 kJ/mol 100.2019 ± 0.0057 142-82-5*500 n-Octane CH3(CH2)6CH3 (cr,l) -226.23 -249.35 ± 0.54 kJ/mol 114.2285 ± 0.0065 111-65-9*500 Dichloromethane CH2Cl2 (l) -122.76 ± 0.36 kJ/mol 84.9320 ± 0.0020 75-09-2*590 n-Nonane CH3(CH2)7CH3 (cr,l) -247.52 -274.38 ± 0.49 kJ/mol 128.2551 ± 0.0073 111-84-2*500 Tribromofluoromethane CBr3F (g) -99.1 -123.1 ± 1.5 kJ/mol 270.7211 ± 0.0031 353-54-8*0 Tribromochloromethane CBr3Cl (g) 85.4 62.6 ± 1.5 kJ/mol 287.1754 ± 0.0032 594-15-0*0 Nitric acid HON(O)O (aq, 1 H2O) -186.80 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*801 Difluoromethylene anion [CF2]- (g) -211.13 -209.95 ± 0.58 kJ/mol 50.00805 ± 0.00080 66212-40-6*0 Nitric acid HON(O)O (aq, 3 H2O) -197.71 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*805 Fluoromethylidyne anion [CF]- (g) 200.8 204.3 ± 1.9 kJ/mol 31.00965 ± 0.00080 33412-12-3*0 n-Decane CH3(CH2)8CH3 (cr,l) -272.67 -300.21 ± 0.80 kJ/mol 142.2817 ± 0.0081 124-18-5*500 Methylcyclopropane CH3CH(CH2CH2) (l) 1.96 ± 0.59 kJ/mol 56.1063 ± 0.0032 594-11-6*590 1,5-Hexadiene CH2CHCH2CH2CHCH2 (cr,l) 54.59 ± 0.31 kJ/mol 82.1436 ± 0.0049 592-42-7*500 Bromosyl bromide BrBrO (g) 180.3 164.5 ± 2.1 kJ/mol 175.8074 ± 0.0020 68322-97-4*0 Trihydrogen H(HH) (g, 2p 2A2" Ry) 756.931 754.146 ± 0.015 kJ/mol 3.02382 ± 0.00021 12184-91-7*2 Hydrogen fluoride HF (aq, 400 H2O) -321.48 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*832 Bicyclo[1.1.0]buta-1,3-dien-2-yl anion [C(CC)C]- (g) 803.2 810.8 ± 1.8 kJ/mol 48.0433 ± 0.0032 289679-89-6*0 Oxygen atom hexacation [O]+6 (g) 42035.28 42037.14 ± 0.12 kJ/mol 15.99611 ± 0.00030 14158-22-6*0 Isocyanic fluoride FNC (g) 301.1 302.9 ± 1.8 kJ/mol 45.01584 ± 0.00080 16992-26-0*0 Peroxyhypochlorous acid cation [HOOCl]+ (g, trans) 1030.4 1024.6 ± 2.5 kJ/mol 68.4589 ± 0.0011 *67952-07-2*1 Bromoniumyl [HBr]+ (g) 1097.79 1089.94 ± 0.13 kJ/mol 80.9114 ± 0.0010 12258-64-9*0 Difluorovinylidene CCF2 (g) 129.4 130.7 ± 2.2 kJ/mol 62.0182 ± 0.0016 41895-33-4*0 1,3-Butadienylium [CH2CHCHCH]+ (g, triplet) 1255.9 1246.5 ± 2.3 kJ/mol 53.0820 ± 0.0032 86181-69-3*1 Fluoroethynylium [CCF]+ (g) 1536.3 1541.0 ± 2.3 kJ/mol 43.0193 ± 0.0016 268566-69-4*0 Bromoacetylene HCCBr (g) 281.6 275.1 ± 1.6 kJ/mol 104.9333 ± 0.0019 593-61-3*0 Tetraoxidanyl HOOOO (g, cis) 53.1 46.1 ± 5.1 kJ/mol 65.0055 ± 0.0012 69696-93-1*2 Hydroxymethyleneoxonium [CH2OOH]+ (g) 792.90 782.76 ± 0.66 kJ/mol 47.0328 ± 0.0010 77144-12-8*0 Chloro(chlorooxy)methylene ClCOCl (g, trans singlet) 98. 101. ± 15. kJ/mol 98.9155 ± 0.0020 479587-31-0*11 Trioxidanyl HOOO (g) 25.36 23.27 ± 0.13 kJ/mol 49.00614 ± 0.00090 12500-78-6*0 Hydrogen chloride HCl (aq, 200 H2O) -166.103 ± 0.024 kJ/mol 36.46064 ± 0.00090 7647-01-0*830 Nitric acid trihydrate (HON(O)O)(H2O)3 (cr,l) -1061.95 -1055.10 ± 0.21 kJ/mol 117.0587 ± 0.0019 13444-83-2*500 Chlorooxomethylium [ClCO]+ (g) 783.7 783.8 ± 2.2 kJ/mol 63.4623 ± 0.0012 38264-03-8*0 Nitric acid monohydrate (HON(O)O)(H2O) (cr,l) -479.09 -472.59 ± 0.19 kJ/mol 81.0282 ± 0.0012 13444-82-1*500 2-Iodoethanol ICH2CH2OH (l) -207.2 ± 2.4 kJ/mol 171.9650 ± 0.0017 624-76-0*590 1,3-Butadiyne cation [HCCCCH]+ (g) 1440.19 1442.05 ± 0.63 kJ/mol 50.0581 ± 0.0032 55468-55-8*0 Carbon suboxide cation [OCCCO]+ (g) 928.7 932.2 ± 1.1 kJ/mol 68.0304 ± 0.0025 151528-67-5*0 Carbon suboxide anion [OCCCO]- (g) -131.2 -127.7 ± 2.5 kJ/mol 68.0314 ± 0.0025 109362-94-9*0 Benzene anion [C6H6]- (g) 209.2 197.3 ± 1.2 kJ/mol 78.1124 ± 0.0048 34562-85-1*0 Acetic acid CH3C(O)OH (aq, 1000 H2O) -484.83 ± 0.23 kJ/mol 60.0520 ± 0.0017 64-19-7*839 Tetrazete N(NNN) (g, D2h) 764.9 759.0 ± 1.8 kJ/mol 56.02696 ± 0.00028 42851-09-2*0 o-Benzyne C6H4 (g, triplet) 625.7 616.4 ± 1.1 kJ/mol 76.0960 ± 0.0048 462-80-6*1 Isocyanogen chloride ClNC (g) 314.7 316.4 ± 2.4 kJ/mol 61.4701 ± 0.0012 75754-69-7*0 Carbon dioxide anion [CO2]- (g) -340.6 -340.1 ± 2.2 kJ/mol 44.01005 ± 0.00100 14485-07-5*0 m-Benzyne C6H4 (g) 527.0 518.6 ± 1.2 kJ/mol 76.0960 ± 0.0048 1828-89-3*0 Dihydrogen H2 (g, ortho) 1.417 0.019 ± 0.000 kJ/mol 2.01588 ± 0.00014 1333-74-0*1 p-Benzyne cation [C6H4]+ (g) 1425.0 1417.7 ± 2.1 kJ/mol 76.0954 ± 0.0048 121058-09-1*0 p-Benzyne C6H4 (g) 587.1 577.7 ± 1.2 kJ/mol 76.0960 ± 0.0048 3355-34-8*0 Deuterium hydride HD (g) 0.328 0.319 ± 0.000 kJ/mol 3.022042 ± 0.000070 13983-20-5*0 Toluene C6H5CH3 (l) 19.80 12.05 ± 0.31 kJ/mol 92.1384 ± 0.0056 108-88-3*500 Cyclopentadienylium [CH(CHCHCHCH)]+ (g) 1088.35 1075.49 ± 0.92 kJ/mol 65.0927 ± 0.0040 29661-18-5*0 Cycloheptene CH2(CHCHCH2CH2CH2CH2 (cr,l) -25.2 -46.3 ± 1.7 kJ/mol 96.1702 ± 0.0057 628-92-2*500 Cycloheptatriene CH2(CHCHCHCHCHCH) (cr,l) 154.11 145.33 ± 0.96 kJ/mol 92.1384 ± 0.0056 544-25-2*500 Tetraazatetrahedrane N(N(N)N) (g, Td) 763.7 757.2 ± 1.7 kJ/mol 56.02696 ± 0.00028 12596-63-3*0 1,2-Propadien-1-ylium-1-yl-3-ylidene [CCC]+ (g, lin) 1981.4 1989.3 ± 2.2 kJ/mol 36.0316 ± 0.0024 118090-85-0*1 Dihydrogen cation [H2]+ (g, ortho) 1489.060 1488.480 ± 0.000 kJ/mol 2.01533 ± 0.00014 12184-90-6*1 Hydraziniumyl [NH2NH2]+ (g) 886.6 873.3 ± 2.0 kJ/mol 32.04469 ± 0.00031 20771-51-1*0 Phenylethene C6H5CHCH2 (cr,l) 104.45 ± 0.48 kJ/mol 104.1491 ± 0.0064 100-42-5*500 Peroxyhypochlorite [ClOO]- (g) -252.78 -251.75 ± 0.34 kJ/mol 67.4520 ± 0.0011 224299-14-3*0 Glycolaldehyde HC(O)CH2OH (g, anti-anti) -292.3 -304.9 ± 1.7 kJ/mol 60.0520 ± 0.0017 141-46-8*21 Benzonitrile C6H5CN (cr,l) 161.22 163.58 ± 0.91 kJ/mol 103.1213 ± 0.0056 100-47-0*500 Isocyanobenzene C6H5NC (g) 321.1 307.2 ± 1.8 kJ/mol 103.1213 ± 0.0056 931-54-4*0 Phenol C6H5OH (cr,l) -146.42 -162.26 ± 0.65 kJ/mol 94.1112 ± 0.0048 108-95-2*500 Glycolaldehyde HC(O)CH2OH (g, gauche-anti) -290.6 -303.0 ± 1.7 kJ/mol 60.0520 ± 0.0017 141-46-8*31 Glycolaldehyde HC(O)CH2OH (g, anti-syn) -283.9 -296.8 ± 1.7 kJ/mol 60.0520 ± 0.0017 141-46-8*22 Anisole C6H5OCH3 (l) -119.46 ± 0.77 kJ/mol 108.1378 ± 0.0056 100-66-3*500 Benzaldehyde C6H5C(O)H (cr,l) -86.13 -87.20 ± 0.95 kJ/mol 106.1219 ± 0.0056 100-52-7*500 Peroxynitrous acid HOONO (g) -5.76 -11.59 ± 0.36 kJ/mol 63.01288 ± 0.00091 14691-52-2*0 Acetophenone C6H5C(O)CH3 (cr,l) -140.1 ± 1.1 kJ/mol 120.1485 ± 0.0064 98-86-2*500 1-Phenylethenol C6H5C(OH)CH2 (g) -9.5 -33.3 ± 2.1 kJ/mol 120.1485 ± 0.0064 4383-15-7*0 p-Tolualdehyde CH3C6H4C(O)H (cr, l, para) -126.4 ± 1.3 kJ/mol 120.1485 ± 0.0064 104-87-0*500 Hydrazine NH2NH2 (cr,l) 57.31 50.75 ± 0.18 kJ/mol 32.04524 ± 0.00031 302-01-2*500 Chlorodioxidanyl ClOO (g) 100.36 99.27 ± 0.34 kJ/mol 67.4515 ± 0.0011 17376-09-9*0 o-Tolualdehyde CH3C6H4C(O)H (cr, l, ortho) -119.4 ± 1.1 kJ/mol 120.1485 ± 0.0064 529-20-4*500 Tetraoxodinitrogen cation [O2NNO2]+ (g) 1030.7 1025.2 ± 2.6 kJ/mol 92.0105 ± 0.0012 64476-91-1*0 Fluorobenzene anion [C6H5F]- (g) -18.2 -30.1 ± 1.8 kJ/mol 96.1029 ± 0.0048 34561-55-2*0 Isocyanogen bromide BrNC (g) 341.0 335.3 ± 3.5 kJ/mol 105.9214 ± 0.0013 65997-98-0*0 m-Chlorophenylium [C6H4Cl]+ (g) 1161.3 1151.2 ± 2.6 kJ/mol 111.5481 ± 0.0049 127983-85-1*0 p-Chlorophenylium [C6H4Cl]+ (g) 1148.6 1139.1 ± 2.5 kJ/mol 111.5481 ± 0.0049 42766-43-8*0 Acetonitrile CH3CN (cr,l) 40.62 ± 0.22 kJ/mol 41.0520 ± 0.0016 75-05-8*500 o-Chlorophenylium [C6H4Cl]+ (g) 1167.9 1158.6 ± 2.5 kJ/mol 111.5481 ± 0.0049 137963-70-3*0 Carbon monoxide anion [CO]- (g) 30.0 33.7 ± 2.3 kJ/mol 28.01065 ± 0.00085 12539-63-8*0 1-Propynylium [CH3CC]+ (g) 1547.1 1545.2 ± 3.1 kJ/mol 39.0554 ± 0.0024 24858-94-4*0 Methyl acetate CH3C(O)OCH3 (l) -445.61 ± 0.57 kJ/mol 74.0785 ± 0.0025 79-20-9*500 Iodobenzene cation [C6H5I]+ (g) 1023.48 1008.04 ± 0.99 kJ/mol 204.0078 ± 0.0048 38406-85-8*0 Isocyanogen iodide INC (g) 341.7 342.0 ± 4.9 kJ/mol 152.92191 ± 0.00080 66004-32-8*0 Hydrogen difluoride cation [(HF)(F)]+ (g, triplet) 1267.6 1265.4 ± 4.1 kJ/mol 39.004198 ± 0.000070 *126950-54-7*1 Nitrobenzene C6H5N(O)O (cr,l) 7.1 ± 1.4 kJ/mol 123.1094 ± 0.0049 98-95-3*500 Isocyanogen iodide anion [INC]- (g) 123.1 125.2 ± 9.3 kJ/mol 152.92246 ± 0.00080 *66004-32-8*0 Pyridine N(CHCHCHCHCH) (cr,l) 102.26 100.23 ± 0.39 kJ/mol 79.0999 ± 0.0040 110-86-1*500 Hydrogen fluoride HF (aq, 35 H2O) -321.13 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*904 Cycloprop-1-enylium [CH2(CHC)]+ (g) 1502.3 1498.0 ± 2.2 kJ/mol 39.0554 ± 0.0024 117067-78-4*0 Ethyl hydroperoxide CH3CH2OOH (cr,l) -210. ± 20. kJ/mol 62.0678 ± 0.0018 3031-74-1*500 Hydrazoic acid cation [HNNN]+ (g) 1333.63 1327.95 ± 0.83 kJ/mol 43.02761 ± 0.00022 58852-14-5*0 Nitromethane CH3N(O)O (cr,l) -114.09 -112.90 ± 0.43 kJ/mol 61.0401 ± 0.0010 75-52-5*500 Hydrazoic acid anion [HNNN]- (g, trans) 309.0 302.7 ± 2.3 kJ/mol 43.02871 ± 0.00022 203264-98-6*1 1-Methyl-1-ethylium-1-yl [CH3CCH3]+ (g) 1058.2 1045.7 ± 1.9 kJ/mol 42.0792 ± 0.0024 121408-19-3*0 2-Cyclopropyn-1-ylidenemethyliumyl [CC(CC)]+ (g) 2239.8 2247.6 ± 2.3 kJ/mol 48.0423 ± 0.0032 289679-92-1*0 Dioxohydrazine ONNO (g, cis) 172.94 171.17 ± 0.14 kJ/mol 60.01228 ± 0.00062 16824-89-8*2 Isopropylidene anion [CH3CCH3]- (g) 282.5 268.4 ± 2.0 kJ/mol 42.0803 ± 0.0024 *121408-19-3*0 Propane cation [CH3CH2CH3]+ (g) 974.7 954.6 ± 1.7 kJ/mol 44.0951 ± 0.0025 34479-70-4*0 2,2,4-Trimethylpentane (CH3)2CHCH2C(CH3)3 (cr,l) -224.2 -258.6 ± 1.5 kJ/mol 114.2285 ± 0.0065 540-84-1*500 cis-1,2-Diiodoethene CHICHI (g, cis) 217.42 209.14 ± 0.35 kJ/mol 279.8462 ± 0.0016 590-26-1*0 trans-1,2-Diiodoethene CHICHI (g, trans) 215.08 207.68 ± 0.35 kJ/mol 279.8462 ± 0.0016 590-27-2*0 2-Oxo-1-ethylium-1-yl [HCC(O)H]+ (g, anti-quartet) 1289.4 1286.0 ± 2.5 kJ/mol 42.0361 ± 0.0016 214464-96-7*11 Norbornadiene (CHCH)(CHCH2CH)(CHCH (l) 208.9 ± 1.2 kJ/mol 92.1384 ± 0.0056 121-46-0*500 2,3-Butanedione CH3C(O)C(O)CH3 (cr,l) -365.53 ± 0.53 kJ/mol 86.0892 ± 0.0033 431-03-8*500 Succinic acid (CH2C(O)OH)2 (g) -801.5 -823.7 ± 2.7 kJ/mol 118.0880 ± 0.0034 110-15-6*0 1-Hydroxy-2-propanone CH3C(O)CH2OH (g, anti-anti) -340.7 -360.4 ± 1.7 kJ/mol 74.0785 ± 0.0025 116-09-6*21 Cycloprop-2-enylide [CH(CHCH)]- (g) 514.9 511.9 ± 2.2 kJ/mol 39.0565 ± 0.0024 20829-57-6*0 1-Hydroxy-2-propanone CH3C(O)CH2OH (g, gauche-anti) -338.1 -356.3 ± 1.7 kJ/mol 74.0785 ± 0.0025 116-09-6*31 1,2-Diiodoethane CH2ICH2I (g) 87.86 73.19 ± 0.90 kJ/mol 281.8621 ± 0.0016 624-73-7*0 1,2-Diiodoethane CH2ICH2I (cr,l) 9.32 ± 0.60 kJ/mol 281.8621 ± 0.0016 624-73-7*500 2-Butanone CH3CH2C(O)CH3 (cr,l) -267.75 -273.24 ± 0.79 kJ/mol 72.1057 ± 0.0033 78-93-3*500 1-Hydroxy-2-propanone CH3C(O)CH2OH (g, anti-syn) -329.8 -349.7 ± 1.7 kJ/mol 74.0785 ± 0.0025 116-09-6*22 Acrolein CH2CHCHO (cr,l) -95.6 ± 1.4 kJ/mol 56.0633 ± 0.0024 107-02-8*500 Peroxychlorous acid HOOClO (g, anti) 102.7 96.9 ± 2.4 kJ/mol 84.4588 ± 0.0013 177778-92-6*2 Ethenedione anion [OCCO]- (g) -149.7 -147.1 ± 1.7 kJ/mol 56.0207 ± 0.0017 77783-15-4*0 Carbon monoxide CO (g, triplet) 465.578 469.285 ± 0.026 kJ/mol 28.01010 ± 0.00085 630-08-0*1 Hydroxylamine NH2OH (aq, undissoc) -97.0 ± 2.2 kJ/mol 33.02996 ± 0.00037 7803-49-8*1000 Perchloryl cation [OCl(O)O]+ (g) 1252.1 1246.4 ± 2.5 kJ/mol 83.4504 ± 0.0013 23594-88-9*0 Urea NH2C(O)NH2 (cr,l) -317.72 -333.32 ± 0.12 kJ/mol 60.05534 ± 0.00091 57-13-6*500 Formamide CH(O)NH2 (cr,l) -251.02 ± 0.28 kJ/mol 45.04066 ± 0.00088 75-12-7*500 Nitrogen atom dianion [N]-2 (g) 1062.8 1064.9 ± 2.8 kJ/mol 14.007837 ± 0.000070 16727-21-2*0 Acetamide CH3C(O)NH2 (cr,l) -315.86 ± 0.53 kJ/mol 59.0672 ± 0.0017 60-35-5*500 Nitrous acid anion [HONO]- (g, cis) -105.82 -110.44 ± 0.78 kJ/mol 47.01403 ± 0.00061 256393-36-9*2 Methoxyoxomethyl CH3OCO (g, syn-staggered) -151.6 -160.6 ± 1.5 kJ/mol 59.0440 ± 0.0017 16481-04-2*2 Methanol dimer (CH3OH)2 (g) -398.5 -419.1 ± 1.4 kJ/mol 64.0837 ± 0.0018 42845-44-3*0 Acrylonitrile CH2CHCN (g, triplet) 446.4 441.0 ± 1.8 kJ/mol 53.0627 ± 0.0024 107-13-1*2 Acrylonitrile CH2CHCN (cr,l) 146.34 154.00 ± 0.77 kJ/mol 53.0627 ± 0.0024 107-13-1*500 Isocyanoethene CH2CHNC (g, triplet) 544.1 539.2 ± 1.8 kJ/mol 53.0627 ± 0.0024 14668-82-7*2 1-Isocyanoethylidene CH3CNC (g) 527.9 523.2 ± 1.1 kJ/mol 53.0627 ± 0.0024 *498544-34-6*0 Dioxymethylidyne cation [COO]+ (g, doublet) 1436.6 1439.1 ± 2.7 kJ/mol 44.00895 ± 0.00100 *791121-04-5*2 Carbon dioxide cation [CO2]+ (g, quartet) 1335.0 1335.5 ± 2.4 kJ/mol 44.00895 ± 0.00100 12181-61-2*1 Cyclopropenylidene anion [C(CHCH)]- (g) 544.3 543.9 ± 2.2 kJ/mol 38.0485 ± 0.0024 *16165-40-5*0 Methoxymethylene CH3OCH (g, syn singlet) 144.7 134.3 ± 1.4 kJ/mol 44.0526 ± 0.0017 19527-10-7*22 Chlorine hydride oxide HCl(O)(O)O (g) 163.9 154.0 ± 2.4 kJ/mol 84.4588 ± 0.0013 1027055-52-2*0 Peroxyhypochlorous acid anion [HOOCl]- (g, cis quartet) -32.1 -33.9 ± 2.6 kJ/mol 68.4600 ± 0.0011 *67952-08-3*2 Oxoethylidene anion [HCC(O)H]- (g, anti-gauche) 86.9 83.6 ± 2.1 kJ/mol 42.0372 ± 0.0016 106543-38-8*1 Tetraoxygen O4 (g, C2h triplet) 104.4 102.4 ± 3.5 kJ/mol 63.9976 ± 0.0012 12596-83-7*11 Vinylacetylene CH2CHCCH (cr,l) 266.3 ± 2.1 kJ/mol 52.0746 ± 0.0032 689-97-4*500 Difluorodioxidanium [FOOF]+ (g, trans) 1283.7 1279.1 ± 2.3 kJ/mol 69.99506 ± 0.00060 *7783-44-0*1 Vinylvinylidene CH2CHCHC (g, triplet, trans) 690.5 684.4 ± 2.7 kJ/mol 52.0746 ± 0.0032 148759-16-4*11 1,3-Propanediyl CH2CH2CH2 (g, triplet) 320.1 308.2 ± 1.6 kJ/mol 42.0797 ± 0.0024 32458-33-6*1 Dihydrogen fluoride (HF)(H) (g) -56.5 -54.2 ± 1.7 kJ/mol 21.01428 ± 0.00014 12592-22-2*2 2-Hydroxyethenyl CHCHOH (g, cis-cis) 143.8 137.3 ± 1.0 kJ/mol 43.0446 ± 0.0016 108665-16-3*11 (Z)-Diazene anion [HNNH]- (g, cis) 280.0 273.3 ± 2.0 kJ/mol 30.02991 ± 0.00020 *86631-37-0*0 Azide [NNN]- (aq) 272.58 ± 0.48 kJ/mol 42.02077 ± 0.00021 14343-69-2*800 2-Hydroxyethenyl CHCHOH (g, trans-trans) 147.2 140.9 ± 1.2 kJ/mol 43.0446 ± 0.0016 108665-16-3*22 1-Buten-3-ynylium [HCCCHCH]+ (g, cis) 1483.1 1480.5 ± 1.7 kJ/mol 51.0661 ± 0.0032 84654-85-3*2 Propionic acid CH3CH2C(O)OH (cr,l) -505.35 -509.50 ± 0.18 kJ/mol 74.0785 ± 0.0025 79-09-4*500 2-Hydroxyethenyl CHCHOH (g, cis-trans) 150.6 144.5 ± 1.6 kJ/mol 43.0446 ± 0.0016 108665-16-3*12 Hydrochlorate ion [HCl]- (g) -25.2 -24.2 ± 2.5 kJ/mol 36.46119 ± 0.00090 63099-75-2*0 Dioxodiazoxane ONONO (g, c, p) 125.7 120.4 ± 2.1 kJ/mol 76.01168 ± 0.00091 122413-35-8*3 Ethylene glycol (CH2OH)2 (cr,l) -448.63 -455.15 ± 0.37 kJ/mol 62.0678 ± 0.0018 107-21-1*500 Formic acid HC(O)OH (cr,l) -431.50 -424.67 ± 0.20 kJ/mol 46.0254 ± 0.0010 64-18-6*500 2-Cyclopropen-1-ylidenemethylium [CHC(CHCH)]+ (g, triplet) 1433.1 1429.3 ± 1.9 kJ/mol 51.0661 ± 0.0032 112936-36-4*1 1,3-Cyclobutadien-1-ylium [C(CHCHCH)]+ (g, triplet) 1473.0 1468.4 ± 1.9 kJ/mol 51.0661 ± 0.0032 81913-77-1*1 1,3-Cyclobutadien-1-yl anion [C(CHCHCH)]- (g) 616.3 611.8 ± 2.1 kJ/mol 51.0672 ± 0.0032 154675-37-3*0 Cyclobutenylium [CH2(CHCHCH)]+ (g) 1038.6 1025.5 ± 2.8 kJ/mol 53.0820 ± 0.0032 12316-90-4*0 Butyraldehyde CH3CH2CH2CHO (cr,l) -235.83 -239.36 ± 0.84 kJ/mol 72.1057 ± 0.0033 123-72-8*500 Trioxirane O(OO) (g) 272.7 270.1 ± 1.3 kJ/mol 47.99820 ± 0.00090 153851-84-4*0 Disilicon cation [Si2]+ (g) 1348.7 1352.3 ± 2.7 kJ/mol 56.17045 ± 0.00060 12597-36-3*0 Dioxosilane cation [SiO2]+ (g) 945.6 945.6 ± 2.8 kJ/mol 60.08375 ± 0.00067 59458-81-0*0 Silicate [SiO2]- (g) -478.1 -478.9 ± 2.6 kJ/mol 60.08485 ± 0.00067 53095-83-3*0 Oxosilicate [SiO]- (g) -106.6 -105.4 ± 2.6 kJ/mol 44.08545 ± 0.00042 12503-59-2*0 Oxalic acid (C(O)OH)2 (cr) -819.54 -829.63 ± 0.42 kJ/mol 90.0349 ± 0.0020 144-62-7*500 Silicon carbide SiC (cr, beta-cubic) -73.0 -74.0 ± 1.4 kJ/mol 40.09620 ± 0.00085 409-21-2*502 Dioxygen difluoride OOF2 (g) 75.1 71.6 ± 3.6 kJ/mol 69.99561 ± 0.00060 183051-89-0*0 Silane cation [SiH4]+ (g) 1104.1 1096.9 ± 1.6 kJ/mol 32.11671 ± 0.00041 34826-51-2*0 Silylium [SiH3]+ (g) 989.05 983.47 ± 0.98 kJ/mol 31.10877 ± 0.00037 41753-67-7*0 Dimethylamine (CH3)2NH (l) -43.32 ± 0.37 kJ/mol 45.0837 ± 0.0017 124-40-3*500 Dioxiranylidene cation [C(OO)]+ (g) 1409.1 1410.3 ± 2.6 kJ/mol 44.00895 ± 0.00100 *138832-57-2*0 Silylidyne anion [SiH]- (g) 247.8 249.0 ± 1.1 kJ/mol 29.09399 ± 0.00031 68865-96-3*0 Paraformaldehyde CH2O (cr, paraformaldehyde) -179.2 ± 1.6 kJ/mol 30.02598 ± 0.00087 30525-89-4*500 Disilanylium [SiH3SiH2]+ (g) 980.5 969.1 ± 2.6 kJ/mol 61.21015 ± 0.00069 86860-82-4*0 Dioxiranylidene anion [C(OO)]- (g, ?) -110.2 -109.7 ± 3.0 kJ/mol 44.01005 ± 0.00100 *138832-58-3*0 1-Disilanylium-1-yl [SiH3SiH]+ (g) 1122.8 1115.2 ± 2.3 kJ/mol 60.20221 ± 0.00066 108492-64-4*0 Oxygen difluoride anion [FOF]- (g) -202.0 -201.9 ± 2.7 kJ/mol 53.99675 ± 0.00030 *7783-41-7*0 Di-mu-hydrodihydrodisilicon cation [HSi(HSiHH)]+ (g, cis) 1192.9 1183.3 ± 3.5 kJ/mol 60.20221 ± 0.00066 *129970-82-7*2 Hydrogen peroxide H2O2 (cr,l) -193.098 -187.281 ± 0.079 kJ/mol 34.01468 ± 0.00062 7722-84-1*500 Di-mu-hydrodihydrodisilicon anion [HSi(HSiHH)]- (g, cis) 295.2 287.7 ± 3.5 kJ/mol 60.20331 ± 0.00066 *129970-83-8*2 Chloryl ion [OClO]+ (g) 1100.26 1097.60 ± 0.53 kJ/mol 67.4510 ± 0.0011 25052-55-5*0 Dioxymethylidyne cation [(C)(OO)]+ (g, vdW quartet) 1388.2 1391.7 ± 3.2 kJ/mol 44.00895 ± 0.00100 *791121-04-5*101 2-Propen-3-ylium-1-ylidyne [CHCHC]+ (g) 1791.2 1792.8 ± 2.6 kJ/mol 38.0474 ± 0.0024 161054-36-0*0 Hydrogen fluoride HF (aq, 18.5 H2O) -321.05 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*887 Isodiazene anion [NNH2]- (g) 380.9 374.1 ± 2.1 kJ/mol 30.02991 ± 0.00020 *63986-30-1*0 Oxygen difluoride cation [FOF]+ (g) 1292.12 1289.60 ± 0.66 kJ/mol 53.99566 ± 0.00030 39432-25-2*0 2,4-Hexadiyne CH3CCCCCH3 (cr,l) 319.06 312.71 ± 0.99 kJ/mol 78.1118 ± 0.0048 2809-69-0*500 Trimethylenecyclopropane (C3)(CH2)3 (g) 454.2 441.4 ± 1.8 kJ/mol 78.1118 ± 0.0048 3227-90-5*0 3,4-Bis(methylene)cyclobutene CH2(CCHCHC)CH2 (g) 355.5 340.9 ± 1.8 kJ/mol 78.1118 ± 0.0048 5291-90-7*0 Aziridine NH(CH2CH2) (cr,l) 92.11 ± 0.88 kJ/mol 43.0678 ± 0.0016 151-56-4*500 Carbonate [OC(O)O]-2 (g) -223.4 -226.6 ± 2.5 kJ/mol 60.0100 ± 0.0012 3812-32-6*0 Propenediylidene anion [CHCHC]- (g) 588.8 590.0 ± 2.3 kJ/mol 38.0485 ± 0.0024 *161054-36-0*0 1-Ethynylcyclobutene HCCC(CHCH2CH2) (g) 402.2 387.9 ± 1.8 kJ/mol 78.1118 ± 0.0048 813466-25-0*0 3-Methyl-1,2-pentadien-4-yne CH2CC(CH3)CCH (g) 414.6 403.4 ± 2.3 kJ/mol 78.1118 ± 0.0048 813466-14-7*0 Carbon dication [C]+2 (g) 4150.480 4155.627 ± 0.044 kJ/mol 12.00960 ± 0.00080 16092-61-8*0 Trimethylamine (CH3)3N (l) -48.70 ± 0.86 kJ/mol 59.1103 ± 0.0025 75-50-3*500 1,3-Pentadiyne HCCCCCH3 (cr,l) 385.0 ± 5.0 kJ/mol 64.0853 ± 0.0040 4911-55-1*500 Ethylamine CH3CH2NH2 (cr,l) -73.97 ± 0.51 kJ/mol 45.0837 ± 0.0017 75-04-7*500 Trifluorine F3 (g) 80.6 81.9 ± 2.6 kJ/mol 56.9952096 ± 0.0000015 73455-86-4*0 1-Propanamine CH3CH2CH2NH2 (cr,l) -93.78 -101.39 ± 0.40 kJ/mol 59.1103 ± 0.0025 107-10-8*500 Triiodine I3 (g) 153.4 149.4 ± 3.6 kJ/mol 380.713410 ± 0.000090 12596-31-5*0 2-Propanamine CH3CH(CH3)NH2 (cr,l) -101.55 -112.16 ± 0.52 kJ/mol 59.1103 ± 0.0025 75-31-0*500 Methylamine CH3NH2 (l) -45.21 ± 0.44 kJ/mol 31.05714 ± 0.00088 74-89-5*500 Naphthalene C6H4(C4H4) (cr,l) 94.62 75.03 ± 0.59 kJ/mol 128.1705 ± 0.0080 91-20-3*500 Carbon dioxide CO2 (aq, undissoc) -413.196 ± 0.019 kJ/mol 44.00950 ± 0.00100 124-38-9*1000 Cyanogen anion [NCCN]- (g) 281.5 284.7 ± 2.2 kJ/mol 52.0354 ± 0.0016 11118-88-0*0 Biphenyl C6H5C6H5 (cr,l) 121.7 97.3 ± 1.1 kJ/mol 154.2078 ± 0.0096 92-52-4*500 Biphenyl C6H5C6H5 (cr) 121.7 97.3 ± 1.1 kJ/mol 154.2078 ± 0.0096 92-52-4*520 Dioxohydrazine ONNO (g) 172.94 171.17 ± 0.14 kJ/mol 60.01228 ± 0.00062 16824-89-8*0 Diisocyanogen cation [CNNC]+ (g, trans) 1825.3 1828.1 ± 3.2 kJ/mol 52.0343 ± 0.0016 *78800-21-2*1 Aniline C6H5NH2 (cr,l) 37.29 31.03 ± 0.64 kJ/mol 93.1265 ± 0.0048 62-53-3*500 Bicyclo[1.1.0]buta-1,3-dien-4-ylium-2-yl [C(CC)C]+ (g) 2087.8 2097.6 ± 2.3 kJ/mol 48.0423 ± 0.0032 289679-91-0*0 Chlorine chlorite ClOClO (g, cis) 177.4 175.1 ± 2.2 kJ/mol 102.9042 ± 0.0019 105206-44-8*2 Dihydrohelium cation [HeHH]+ (g) 1467.27 1461.99 ± 0.44 kJ/mol 6.01793 ± 0.00014 12500-88-8*0 Neon cation Ne+ (g) 2080.662 2080.769 ± 0.000 kJ/mol 20.17915 ± 0.00060 14782-23-1*0 Xenon hydride cation [XeH]+ (g) 1038.13 1036.35 ± 0.89 kJ/mol 132.2974 ± 0.0200 37276-91-8*0 1-Ethenylium-1-yl [CCH2]+ (g) 1507.1 1507.1 ± 2.1 kJ/mol 26.0367 ± 0.0016 80541-07-7*0 Pyruvic acid CH3C(O)C(O)OH (cr,l) -588.52 ± 0.74 kJ/mol 88.0621 ± 0.0026 127-17-3*500 Oxadiazirine cation [O(NN)]+ (g) 1509.9 1507.2 ± 2.4 kJ/mol 44.01233 ± 0.00033 *227934-45-4*0 Sulfur dioxide OSO (aq, undissoc) -322.82 ± 0.14 kJ/mol 64.0648 ± 0.0060 7446-09-5*1000 Iodine monochloride ICl (cr) -36.511 -35.537 ± 0.063 kJ/mol 162.35717 ± 0.00090 7790-99-0*510 Sulfur trioxide OS(O)O (l) -440.84 ± 0.30 kJ/mol 80.0642 ± 0.0061 7446-11-9*590 Sulfanylium [SH]+ (g) 1148.48 1148.48 ± 0.20 kJ/mol 33.0734 ± 0.0060 12273-42-6*0 Sulfuric acid OS(O)(OH)2 (cr,l) -811.80 -813.80 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*500 Hydrogen chloride HCl (aq, 3000 H2O) -166.739 ± 0.024 kJ/mol 36.46064 ± 0.00090 7647-01-0*842 Sulfuric acid OS(O)(OH)2 (aq, 70 H2O) -887.03 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*824 Sulfur hydroxide oxide cation [OHS(O)(O)O]+ (g, eclipsed) 659.1 648.3 ± 3.5 kJ/mol 97.0710 ± 0.0061 *12337-07-4*2 Sulfurous acid S(O)(OH)2 (g) -511.14 -520.65 ± 0.89 kJ/mol 82.0801 ± 0.0061 7782-99-2*0 NON cation [NON]+ (g) 1444.0 1444.2 ± 2.8 kJ/mol 44.01233 ± 0.00033 *227934-46-5*0 Sulfurous acid S(O)(OH)2 (aq, undissoc) -608.62 ± 0.14 kJ/mol 82.0801 ± 0.0061 7782-99-2*1000 NON anion [NON]- (g) 495.3 492.8 ± 2.5 kJ/mol 44.01343 ± 0.00033 *227934-47-6*0 Sulfur dioxide - hydroxyl complex (OH)(OSO) (g, vdW) -265.8 -267.9 ± 2.2 kJ/mol 81.0721 ± 0.0061 *32750-86-0*100 Platinum dimer Pt2 (g) 823.5 822.5 ± 3.9 kJ/mol 390.1560 ± 0.0040 12596-95-1*0 Platinum hydride PtH (g) 457.1 456.2 ± 9.2 kJ/mol 196.0859 ± 0.0020 13966-55-7*0 Hydrogen atom H (ad, Pt(111)) -37.0 -38.7 ± 1.1 kJ/mol 1.007940 ± 0.000070 12385-13-6*1000000 Isoprene CH2C(CH3)CHCH2 (cr,l) 48.95 ± 0.69 kJ/mol 68.1170 ± 0.0040 78-79-5*500 Hydrogen atom H (ad, 4 Pt(111)) -33.4 -35.1 ± 1.5 kJ/mol 1.007940 ± 0.000070 12385-13-6*1000004 Cyanoaminyliumyl [NCN]+ (g) 1672.2 1673.6 ± 2.6 kJ/mol 40.02363 ± 0.00081 316122-03-9*0 Cyanoamidogen anion [NCN]- (g) 211.73 211.66 ± 0.62 kJ/mol 40.02473 ± 0.00081 189879-95-6*0 Bromomethane CH3Br (l) -56.62 -59.64 ± 0.17 kJ/mol 94.9385 ± 0.0013 74-83-9*590 Nitrous acid anion [HONO]- (g, trans) -105.4 -109.3 ± 1.8 kJ/mol 47.01403 ± 0.00061 256393-36-9*1 Cyclopropane cation [CH2(CH2CH2)]+ (g) 1022.3 1006.9 ± 1.6 kJ/mol 42.0792 ± 0.0024 34496-93-0*0 Ethynylaminylium [HCCNH]+ (g, singlet) 1350.7 1348.9 ± 2.5 kJ/mol 40.0435 ± 0.0016 103835-08-1*2 Chlorine atom dication [Cl]+2 (g) 3668.474 3670.081 ± 0.013 kJ/mol 35.45160 ± 0.00090 15723-23-6*0 Deuterium molecule cation [D2]+ (g) 1492.286 1492.361 ± 0.000 kJ/mol 4.02765497609 ± 0.00000000080 12184-84-8*0 Trihydrogen (H)(HH) (g, vdW) 215.9 218.3 ± 1.1 kJ/mol 3.02382 ± 0.00021 12184-91-7*100 Methyl acetate CH3C(O)OCH3 (g) -394.15 -413.02 ± 0.57 kJ/mol 74.0785 ± 0.0025 79-20-9*0 Dioxofluorine cation [OFO]+ (g) 1667.0 1664.8 ± 2.8 kJ/mol 50.99665 ± 0.00060 223566-05-0*0 Dihydrogen anion [H2]- (g) 253.8 254.7 ± 1.2 kJ/mol 2.01643 ± 0.00014 12184-89-3*0 Fluorine atom F (g, 2P3/2) 77.253 79.038 ± 0.017 kJ/mol 18.99840320 ± 0.00000050 14762-94-8*1 Isocyanogen bromide anion [BrNC]- (g) 104.8 101.6 ± 4.6 kJ/mol 105.9220 ± 0.0013 *238754-53-5*0 Chlorine trifluoride cation [FCl(F)F]+ (g) 1053.5 1049.2 ± 2.3 kJ/mol 92.44736 ± 0.00090 478167-77-0*0 Bromodioxy BrOO (g) 116.7 107.7 ± 3.8 kJ/mol 111.9028 ± 0.0012 67177-47-3*0 Methylaminyliumyl [CH3N]+ (g, doublet ?) 1388.3 1381.9 ± 2.3 kJ/mol 29.04071 ± 0.00083 56924-51-7*1 Tetraoxodinitrate anion [O2NNO2]- (g) -184.6 -187.8 ± 2.4 kJ/mol 92.0116 ± 0.0012 63552-02-3*0 Tribromine cation [Br3]+ (g) 1036.2 1013.5 ± 2.5 kJ/mol 239.7115 ± 0.0030 33105-86-1*0 Trihydrogen H(HH) (g, 2s 2A1' Ry) 745.878 743.094 ± 0.062 kJ/mol 3.02382 ± 0.00021 12184-91-7*1 Chlorodioxidenium [ClOO]+ (g) 1215.1 1212.9 ± 6.3 kJ/mol 67.4510 ± 0.0011 64710-10-7*0 Hydrazine monohydrate (NH2NH2)(H2O) (l) -242.56 ± 0.19 kJ/mol 50.06052 ± 0.00053 7803-57-8*500 Chlorine atom hexacation [Cl]+6 (g) 28501. 28503. ± 11. kJ/mol 35.44941 ± 0.00090 22541-73-7*0 Fluorine atom dication [F]+2 (g) 5132.471 5134.256 ± 0.021 kJ/mol 18.99730604 ± 0.00000050 14701-07-6*0 Hydroxylamine NH2OH (g) -33.07 -43.44 ± 0.42 kJ/mol 33.02996 ± 0.00037 7803-49-8*0 Methyl formate HC(O)OCH3 (g) -346.94 -359.98 ± 0.65 kJ/mol 60.0520 ± 0.0017 107-31-3*0 Tribromide [Br3]- (aq) -129.54 ± 0.23 kJ/mol 239.7125 ± 0.0030 14522-80-6*800 Nitrogen atom tetracation [N]+4 (g) 16781.74 16783.60 ± 0.23 kJ/mol 14.004546 ± 0.000070 14452-70-1*0 Ethyl formate HC(O)OCH2CH3 (g) -375.1 -393.9 ± 1.0 kJ/mol 74.0785 ± 0.0025 109-94-4*0 Chlorine atom tetracation [Cl]+4 (g) 12615.5 12617.1 ± 4.6 kJ/mol 35.45051 ± 0.00090 22541-74-8*0 Water H2O (cr) -286.267 -292.708 ± 0.025 kJ/mol 18.01528 ± 0.00033 7732-18-5*510 Ammonium hydroxide NH4OH (aq, undissoc) -366.676 ± 0.061 kJ/mol 35.04584 ± 0.00047 1336-21-6*1000 3-Methylpentane CH3CH2CH(CH3)CH2CH3 (cr,l) -177.59 -201.86 ± 0.76 kJ/mol 86.1754 ± 0.0049 96-14-0*500 Fluorine atom tetracation [F]+4 (g) 19594.3 19596.5 ± 1.7 kJ/mol 18.99620888 ± 0.00000050 14700-79-9*0 Hydrazoic acid anion [HNNN]- (g, cis) 316.2 310.0 ± 2.3 kJ/mol 43.02871 ± 0.00022 203264-98-6*2 Fluorine atom hexacation [F]+6 (g) 45781.5 45783.3 ± 1.8 kJ/mol 18.99511172 ± 0.00000050 14701-04-3*0 Oxonium [H3O]+ (g, para) 605.88 599.13 ± 0.17 kJ/mol 19.02267 ± 0.00037 13968-08-6*2 Succinic acid (CH2C(O)OH)2 (cr,l) -918.47 -940.19 ± 0.12 kJ/mol 118.0880 ± 0.0034 110-15-6*500 Fluorine atom trication [F]+3 (g) 11182.872 11186.696 ± 0.032 kJ/mol 18.99675746 ± 0.00000050 14700-88-0*0 1-Propenylium [CH3CHCH]+ (g, trans) 1233.8 1223.4 ± 2.0 kJ/mol 41.0713 ± 0.0024 50457-58-4*1 Chlorine atom pentacation [Cl]+5 (g) 19147. 19149. ± 11. kJ/mol 35.44996 ± 0.00090 20337-89-7*0 1,2-Dibromoethane CH2BrCH2Br (cr,l) -80.3 ± 1.2 kJ/mol 187.8612 ± 0.0026 106-93-4*500 2,3-Dimethylbutane CH3CH(CH3)CH(CH3)CH3 (cr,l) -182.39 -206.90 ± 0.81 kJ/mol 86.1754 ± 0.0049 79-29-8*500 Dinitrogen dimer (N2)2 (g) -0.88 0.84 ± 0.67 kJ/mol 56.02696 ± 0.00028 154680-01-0*0 1,3-Butadien-2-ol CH2C(OH)CHCH2 (g, s-cis, syn) -42.7 -59.2 ± 2.3 kJ/mol 70.0898 ± 0.0032 59120-04-6*21 1,3-Butadien-2-ol CH2C(OH)CHCH2 (g, s-trans) -53.4 -68.7 ± 1.5 kJ/mol 70.0898 ± 0.0032 59120-04-6*1 Hydrazoic acid HNNN (aq, undissoc) 257.59 ± 0.48 kJ/mol 43.02816 ± 0.00022 7782-79-8*1000 Formylimidogen HC(O)N (g, singlet) 245.3 242.1 ± 3.3 kJ/mol 43.02478 ± 0.00086 42288-92-6*2 Acrolein CH2CHCHO (g) -55.2 -65.3 ± 1.2 kJ/mol 56.0633 ± 0.0024 107-02-8*0 1,2-Propadien-1-one cation [CH2CCO]+ (g) 1012.7 1011.2 ± 1.9 kJ/mol 54.0468 ± 0.0024 87612-93-9*0 2-Propynal cation [CHCCHO]+ (g) 1168.2 1167.1 ± 1.3 kJ/mol 54.0468 ± 0.0024 100815-70-1*0 2-Oxo-1-ethylium-1-yl [HCC(O)H]+ (g, syn-quartet) 1292.1 1288.7 ± 2.4 kJ/mol 42.0361 ± 0.0016 214464-96-7*12 2-Propen-1-ylium-1-ylidene [CH2CHC]+ (g) 1373.2 1369.6 ± 2.0 kJ/mol 39.0554 ± 0.0024 88000-25-3*0 Formylethynyl cation [CC(CHO)]+ (g, singlet) 1539.9 1541.8 ± 2.7 kJ/mol 53.0389 ± 0.0024 *85905-64-2*2 Formylethynyl cation [CCCHO]+ (g, triplet) 1540.6 1542.7 ± 2.8 kJ/mol 53.0389 ± 0.0024 *85905-64-2*1 Carbon monoxide CO (g, singlet) -113.804 -110.524 ± 0.026 kJ/mol 28.01010 ± 0.00085 630-08-0*2 Ethyl bromide CH3CH2Br (l) -55.73 -91.26 ± 0.26 kJ/mol 108.9651 ± 0.0019 74-96-4*500 Propylene cation [CH3CHCH2]+ (g) 975.14 961.61 ± 0.19 kJ/mol 42.0792 ± 0.0024 34504-10-4*0 2-Methylpentane CH3CH2CH2CH(CH3)2 (cr,l) -180.14 -203.79 ± 0.73 kJ/mol 86.1754 ± 0.0049 107-83-5*500 Acetaldehyde CH3CHO (cr,l) -187.05 -191.77 ± 0.29 kJ/mol 44.0526 ± 0.0017 75-07-0*500 Dihydrogen cation [H2]+ (g, para) 1488.364 1488.480 ± 0.000 kJ/mol 2.01533 ± 0.00014 12184-90-6*2 (Hydroxyimino)methyl HCNOH (g, trans-cis) 258.9 252.7 ± 2.0 kJ/mol 44.03272 ± 0.00087 206442-92-4*2 Vinyl iodide CH2CHI (g) 139.6 130.8 ± 1.2 kJ/mol 153.9497 ± 0.0016 593-66-8*0 Hydrazoic acid HNNN (aq) 272.58 ± 0.48 kJ/mol 43.02816 ± 0.00022 7782-79-8*800 Peroxyformate [HC(O)OO]- (g, anti) -320.9 -326.7 ± 1.8 kJ/mol 61.0174 ± 0.0012 104960-05-6*2 Trihydrogen cation [H3]+ (g, para) 1110.304 1106.697 ± 0.013 kJ/mol 3.02327 ± 0.00021 28132-48-1*2 Cyanoacetylene cation [HCCCN]+ (g) 1495.46 1497.76 ± 0.62 kJ/mol 51.0462 ± 0.0024 85398-68-1*0 1-Hydroxyethyl CH3CHOH (g) -42.86 -56.29 ± 0.47 kJ/mol 45.0605 ± 0.0017 2348-46-1*0 Isocyanoacetylene cation [HCCNC]+ (g) 1567.7 1570.3 ± 1.3 kJ/mol 51.0462 ± 0.0024 145076-03-5*0 Cyanoethynylium [CCCN]+ (g) 1867.6 1874.3 ± 3.2 kJ/mol 50.0383 ± 0.0024 104233-69-4*0 1-Propenylide [CH3CHCH]- (g, trans) 210.4 199.3 ± 2.0 kJ/mol 41.0723 ± 0.0024 65887-20-9*1 Fluorine atom octacation [F]+8 (g) 155686.5 155688.3 ± 1.8 kJ/mol 18.99401456 ± 0.00000050 15721-58-1*0 1,3-Butadiyne-1,4-diyl CCCC (g, triplet) 1052.37 1062.34 ± 0.65 kJ/mol 48.0428 ± 0.0032 78015-07-3*1 Oxygen atom trication [O]+3 (g) 10249.929 10252.880 ± 0.018 kJ/mol 15.99775 ± 0.00030 14127-64-1*0 Difluorovinylidene cation [CCF2]+ (g) 1181.6 1183.1 ± 2.3 kJ/mol 62.0177 ± 0.0016 268566-71-8*0 Peroxyformyl HC(O)OO (g, anti) -90.6 -96.1 ± 1.8 kJ/mol 61.0168 ± 0.0012 56240-83-6*2 1-Propen-1-yl-3-ylidene CHCHCH (g, quartet) 656.7 653.3 ± 1.1 kJ/mol 39.0559 ± 0.0024 84654-90-0*1 3-Imino-2-propen-1-ylidene CHCHCNH (g, singlet) 530.7 526.3 ± 1.2 kJ/mol 53.0627 ± 0.0024 916765-05-4*1 Hydrogen peroxide cation [H2O2]+ (g, trans, ortho) 897.29 890.31 ± 0.51 kJ/mol 34.01413 ± 0.00062 12325-10-9*11 2-(Methylidyneamino)ethenyl CHCHNCH (g, singlet) 600.7 596.4 ± 1.2 kJ/mol 53.0627 ± 0.0024 123416-74-0*1 Acetoxy CH3C(O)O (g) -182.20 -190.92 ± 0.85 kJ/mol 59.0440 ± 0.0017 13799-69-4*0 Water trimer (H2O)3 (g) -762.63 -776.73 ± 0.20 kJ/mol 54.04584 ± 0.00099 31014-12-7*0 Oxoniumyl ion [H2O]+ (g, ortho) 978.501 975.597 ± 0.026 kJ/mol 18.01473 ± 0.00033 56583-62-1*1 Nitrogen atom anion N- (g) 488.2 490.5 ± 2.3 kJ/mol 14.007289 ± 0.000070 17778-87-9*0 Tetraoxygen O4 (g, D2h singlet) 69.8 65.1 ± 4.4 kJ/mol 63.9976 ± 0.0012 12596-83-7*21 Tetraoxygen O4 (g, D2d singlet) 399.0 393.4 ± 3.9 kJ/mol 63.9976 ± 0.0012 12596-83-7*23 Tetraoxygen O4 (g, D3h singlet) 465.6 459.6 ± 4.2 kJ/mol 63.9976 ± 0.0012 12596-83-7*24 Nitrosyl nitrite anion [ONONO]- (g, t, c) -100.2 -103.4 ± 2.9 kJ/mol 76.01223 ± 0.00091 *122413-35-8*2 mu-Oxodichlorine cation [ClOCl]+ (g) 1130.45 1126.84 ± 0.63 kJ/mol 86.9043 ± 0.0018 51174-96-0*0 1,2-Butadien-1-ylium-1-yl [CH3CHCC]+ (g) 1466.9 1461.7 ± 3.1 kJ/mol 52.0740 ± 0.0032 161054-21-3*0 Bicyclo[1.1.0]butan-3-id-1-yl [CH2(CC)CH2]- (g) 524.6 516.0 ± 2.6 kJ/mol 52.0751 ± 0.0032 131273-95-5*0 1,2-Cyclobutadiene C(CHCH2CH) (g) 586.0 579.4 ± 2.2 kJ/mol 52.0746 ± 0.0032 50682-90-1*0 Water H2O (g, para) -238.898 -241.801 ± 0.025 kJ/mol 18.01528 ± 0.00033 7732-18-5*2 Propionic acid CH3CH2C(O)OH (g) -435.93 -453.82 ± 0.59 kJ/mol 74.0785 ± 0.0025 79-09-4*0 Peroxyhypochlorous acid cation [HOOCl]+ (g, cis) 1050.8 1045.2 ± 2.5 kJ/mol 68.4589 ± 0.0011 *67952-07-2*2 Hydroxylamine NH2OH (cr,l) -107.46 ± 0.60 kJ/mol 33.02996 ± 0.00037 7803-49-8*500 Nitride [N]-3 (g) 1879.1 1881.0 ± 4.4 kJ/mol 14.008386 ± 0.000070 18851-77-9*0 But-3-en-1-yn-1-ide [CH2CHCC]- (g, triplet) 559.1 558.4 ± 2.2 kJ/mol 51.0672 ± 0.0032 58870-47-6*1 Nitrogen atom dication [N]+2 (g) 4728.994 4731.823 ± 0.025 kJ/mol 14.005643 ± 0.000070 17439-59-7*0 Difluorine cation [F2]+ (g) 1514.301 1514.475 ± 0.013 kJ/mol 37.9962578 ± 0.0000010 12184-86-0*0 Bicyclo[1.1.0]buta-1,3-diene-2,4-diyl C(CC)C (g, singlet) 1047.22 1054.81 ± 0.68 kJ/mol 48.0428 ± 0.0032 12184-80-4*2 Formaldehyde CH2O (g, para singlet) -105.386 -109.226 ± 0.096 kJ/mol 30.02598 ± 0.00087 50-00-0*21 Oxygen atom octacation [O]+8 (g) 197447.75 197449.60 ± 0.12 kJ/mol 15.99501 ± 0.00030 21450-98-6*0 1-Methylethenylium [CH3CCH2]+ (g) 995.2 986.1 ± 1.9 kJ/mol 41.0713 ± 0.0024 50457-57-3*0 Chloro(chlorooxy)methylene ClCOCl (g, trans triplet) 101.1 104.7 ± 4.8 kJ/mol 98.9155 ± 0.0020 479587-31-0*12 Nitrogen atom N (g, quartet) 470.580 472.442 ± 0.024 kJ/mol 14.006740 ± 0.000070 17778-88-0*1 Silicon cation Si+ (g) 1236.25 1240.38 ± 0.57 kJ/mol 28.08495 ± 0.00030 14067-07-3*0 Silicon atom dication [Si]+2 (g) 2813.39 2816.37 ± 0.57 kJ/mol 28.08440 ± 0.00030 14175-55-4*0 Silicon atom trication [Si]+3 (g) 6044.97 6047.95 ± 0.57 kJ/mol 28.08385 ± 0.00030 14175-56-5*0 Hydrogen peroxide cation [H2O2]+ (g, cis, para) 931.04 924.18 ± 0.98 kJ/mol 34.01413 ± 0.00062 12325-10-9*22 Trioxirane cation [O(OO)]+ (g) 1444.5 1442.3 ± 2.2 kJ/mol 47.99765 ± 0.00090 *153851-84-4*0 Dioxosilane SiO2 (cr, tridymite) -901.0 -905.8 ± 1.5 kJ/mol 60.08430 ± 0.00067 7631-86-9*515 Oxosilyliumyl [SiO]+ (g) 1021.6 1022.8 ± 3.0 kJ/mol 44.08435 ± 0.00042 12359-18-1*0 Fluorosyl fluoride FFO (g, singlet) 227. 225. ± 21. kJ/mol 53.99621 ± 0.00030 86825-57-2*2 Oxygen atom heptacation [O]+7 (g) 113369.48 113371.34 ± 0.12 kJ/mol 15.99556 ± 0.00030 14274-89-6*0 2,2-Dimethylbutane CH3CH2C(CH3)3 (cr,l) -187.90 -213.62 ± 0.75 kJ/mol 86.1754 ± 0.0049 75-83-2*500 Hydrogen peroxide H2O2 (g, para) -129.411 -135.396 ± 0.061 kJ/mol 34.01468 ± 0.00062 7722-84-1*2 Polyoxymethylene CH2O (cr, polyoxymethylene) -170.85 ± 0.21 kJ/mol 30.02598 ± 0.00087 9002-81-7*500 Difluorodioxidanium [FOOF]+ (g, cis) 1287.2 1283.0 ± 2.3 kJ/mol 69.99506 ± 0.00060 *7783-44-0*2 Ketene CH2CO (g, para singlet) -45.35 -48.41 ± 0.11 kJ/mol 42.0367 ± 0.0016 463-51-4*21 mu-Hydrotetrahydrodisilicon cation [SiH2(HSiH2)]+ (g) 980.5 967.8 ± 2.8 kJ/mol 61.21015 ± 0.00069 160896-65-1*0 Di-mu-hydrotrihydrodisilicon cation [SiH2(HSiHH)]+ (g) 1032.6 1019.3 ± 2.8 kJ/mol 61.21015 ± 0.00069 *160896-65-1*0 Nitrogen atom pentacation [N]+5 (g) 26226.70 26228.56 ± 0.23 kJ/mol 14.003997 ± 0.000070 20508-99-0*0 Disilene anion [SiH2SiH2]- (g) 177.1 168.7 ± 3.1 kJ/mol 60.20331 ± 0.00066 157379-08-3*0 Acetic acid CH3C(O)OH (aq, 500 H2O) -484.81 ± 0.23 kJ/mol 60.0520 ± 0.0017 64-19-7*833 Silylsilylene anion [SiH3SiH]- (g) 158.8 150.1 ± 3.1 kJ/mol 60.20331 ± 0.00066 286949-98-2*0 Silylsilylene SiH3SiH (g, triplet) 380.0 371.1 ± 2.7 kJ/mol 60.20276 ± 0.00066 50420-90-1*1 mu-Hydrotrihydrodisilicon SiH2(HSiH) (g) 316.4 306.4 ± 2.2 kJ/mol 60.20276 ± 0.00066 497967-56-3*0 Chlorine atom trication [Cl]+3 (g) 7487.2 7490.2 ± 3.3 kJ/mol 35.45105 ± 0.00090 16547-50-5*0 1,2-Propadien-1-ylium-1-yl-3-ylidene [CCC]+ (g) 1944.7 1952.6 ± 1.9 kJ/mol 36.0316 ± 0.0024 118090-85-0*0 mu-Hydrotrihydrodisilicon cation [Si(HSiH3)]+ (g) 1158.8 1150.8 ± 2.6 kJ/mol 60.20221 ± 0.00066 *497967-55-2*0 Formaldehyde CH2O (aq) -171.20 ± 0.59 kJ/mol 30.02598 ± 0.00087 50-00-0*800 Oxoethylidene anion [HCC(O)H]- (g, syn-gauche) 92.3 89.0 ± 2.3 kJ/mol 42.0372 ± 0.0016 106543-38-8*2 Dihydrogen H2 (g, para) -0.000 -0.058 ± 0.000 kJ/mol 2.01588 ± 0.00014 1333-74-0*2 Oxygen atom dication [O]+2 (g) 4949.458 4953.000 ± 0.013 kJ/mol 15.99830 ± 0.00030 14127-63-0*0 Carbon suboxide OCCCO (cr,l) -131.3 -116.2 ± 1.1 kJ/mol 68.0309 ± 0.0025 504-64-3*500 Silyloxoniumylidene [SiH3O]+ (g, triplet) 1095.5 1089.2 ± 2.9 kJ/mol 47.10817 ± 0.00047 152720-17-7*1 Trioxodinitrate anion [ONN(O)O]- (g, non-vdW) -87.3 -93.0 ± 2.2 kJ/mol 76.01223 ± 0.00091 194856-62-7*1 Hydroxysilylium [SiH2OH]+ (g) 599.5 590.8 ± 2.9 kJ/mol 47.10817 ± 0.00047 66639-72-3*0 Carbide [C]-4 (g) 2709.5 2714.7 ± 2.7 kJ/mol 12.01289 ± 0.00080 12385-15-8*0 Hydrogen iodide HI (aq) -56.828 ± 0.089 kJ/mol 127.912410 ± 0.000076 10034-85-2*800 1,5-Hexadiyne HCCCH2CH2CCH (cr,l) 385.9 ± 1.9 kJ/mol 78.1118 ± 0.0048 628-16-0*500 Oxygen atom pentacation [O]+5 (g) 28708.788 28710.645 ± 0.053 kJ/mol 15.99666 ± 0.00030 14127-66-3*0 Acetic acid CH3C(O)OH (aq, 10000 H2O) -484.86 ± 0.23 kJ/mol 60.0520 ± 0.0017 64-19-7*850 Fluorine atom heptacation [F]+7 (g) 63649.3 63651.1 ± 1.8 kJ/mol 18.99456314 ± 0.00000050 14700-77-7*0 Cyclopentadiene CH2(CHCHCHCH) (l) 110.09 ± 0.59 kJ/mol 66.1011 ± 0.0040 542-92-7*590 Bicyclo[3.1.0]hexa-1,3-diene CH2((CCH)(CHCHCH)) (g) 406.4 390.8 ± 2.3 kJ/mol 78.1118 ± 0.0048 28425-23-2*0 3-Ethenylidenecyclobutene CH2CC(CHCHCH2) (g) 406.5 392.4 ± 2.3 kJ/mol 78.1118 ± 0.0048 813466-23-8*0 Methylene CH2 (g) 391.060 391.618 ± 0.096 kJ/mol 14.02658 ± 0.00081 2465-56-7*0 3,4-Hexadien-1-yne HCCCHCCHCH3 (g) 418.6 407.5 ± 2.6 kJ/mol 78.1118 ± 0.0048 194024-51-6*0 3-Ethynylcyclobutene HCCCH(CHCHCH2) (g) 421.7 407.4 ± 2.4 kJ/mol 78.1118 ± 0.0048 175090-90-1*0 sec-Butylium [CH3CH2CHCH3]+ (g) 792.7 769.1 ± 1.6 kJ/mol 57.1137 ± 0.0033 16548-59-7*0 Nitrosyl nitrate ONONO2 (g, cis-perp) 60.4 52.5 ± 1.9 kJ/mol 92.0111 ± 0.0012 15969-55-8*2 2-Chloro ozone ClO(O)O (g) 265.7 265.1 ± 3.7 kJ/mol 83.4509 ± 0.0013 *141801-66-3*0 Trioxygen difluoride FOOOF (g) 112.3 107.1 ± 1.1 kJ/mol 85.99501 ± 0.00090 16829-28-0*0 Hydroxyoxoammoniumyl [HONO]+ (g, cis) 1014.8 1008.5 ± 2.0 kJ/mol 47.01293 ± 0.00061 80371-48-8*2 Dioxaziridine HN(OO) (g) 277.6 270.9 ± 1.9 kJ/mol 47.01348 ± 0.00061 67394-35-8*0 Oxygen atom tetracation [O]+4 (g) 17719.207 17721.064 ± 0.025 kJ/mol 15.99721 ± 0.00030 14127-65-2*0 Nitrogen atom trication [N]+3 (g) 9306.68 9308.55 ± 0.23 kJ/mol 14.005094 ± 0.000070 18396-22-0*0 1,2-Diphenylethane C6H5CH2CH2C6H5 (g) 180.78 142.29 ± 0.76 kJ/mol 182.2610 ± 0.0112 103-29-7*0 m-Benzyne C6H4 (g, triplet) 614.7 605.3 ± 1.4 kJ/mol 76.0960 ± 0.0048 1828-89-3*1 Acetylene anion [HCCH]- (g) 356.9 356.7 ± 1.9 kJ/mol 26.0378 ± 0.0016 50443-89-5*0 2-Naphthalenylium [C6H4(CHCCHCH)]+ (g) 1195.5 1177.6 ± 3.5 kJ/mol 127.1620 ± 0.0080 79319-69-0*0 1-Naphthalenylium [C6H4(CCHCHCH)]+ (g) 1192.5 1174.6 ± 3.4 kJ/mol 127.1620 ± 0.0080 79319-68-9*0 Carbon trication [C]+3 (g) 8770.948 8776.095 ± 0.050 kJ/mol 12.00905 ± 0.00080 14067-06-2*0 Isocyanogen cation [CNCN]+ (g) 1654.1 1656.5 ± 1.4 kJ/mol 52.0343 ± 0.0016 133415-63-1*0 Nitrogen atom hexacation [N]+6 (g) 79493.10 79494.96 ± 0.23 kJ/mol 14.003449 ± 0.000070 15721-56-9*0 Carbon pentacation [C]+5 (g) 52824.610 52829.757 ± 0.053 kJ/mol 12.00796 ± 0.00080 14280-11-6*0 2-Hydroxyethylium [CH2CH2OH]+ (g, gauche) 1024.6 1012.0 ± 2.0 kJ/mol 45.0600 ± 0.0017 38607-31-7*1 Biphenyl C6H5C6H5 (l) 113.9 ± 1.1 kJ/mol 154.2078 ± 0.0096 92-52-4*590 Iodine monochloride ICl (l) -24.048 ± 0.063 kJ/mol 162.35717 ± 0.00090 7790-99-0*590 Buckminsterfullerene C60 (g) 2525.0 2520.4 ± 6.5 kJ/mol 720.6420 ± 0.0480 99685-96-8*0 Buckminsterfullerene C60 (cr,l) 2329.9 2339.4 ± 6.5 kJ/mol 720.6420 ± 0.0480 99685-96-8*500 Carbon hexacation [C]+6 (g) 100101.765 100106.911 ± 0.053 kJ/mol 12.00741 ± 0.00080 16249-02-8*0 Cyclobutatrienyl CH(CCC) (g) 962.0 965.5 ± 2.4 kJ/mol 49.0507 ± 0.0032 *99417-52-4*0 Diisocyanogen cation [CNNC]+ (g, cis) 1838.6 1842.6 ± 3.1 kJ/mol 52.0343 ± 0.0016 *78800-21-2*2 Acetylene HCCH (g, cis-triplet) 599.1 598.9 ± 1.5 kJ/mol 26.0373 ± 0.0016 74-86-2*11 1-Methylethenyl anion [CH3CCH2]- (g) 199.4 188.2 ± 2.0 kJ/mol 41.0723 ± 0.0024 65887-19-6*0 Hypochloroperoxoous acid, hydroxy ester HOOOCl (g, anti) 48.8 41.8 ± 2.5 kJ/mol 84.4588 ± 0.0013 928652-99-7*2 Helium anion He- (g, 1s.2s.2p 4P) 1904.822 1904.822 ± 0.000 kJ/mol 4.0031506 ± 0.0000020 14452-58-5*3 Helium anion He- (g, 2p3 4S3/2) 5724.96 5724.96 ± 0.32 kJ/mol 4.0031506 ± 0.0000020 14452-58-5*4 Dihelium cation [He2]+ (g) 2143.643 2139.915 ± 0.018 kJ/mol 8.0046554 ± 0.0000040 12184-99-5*0 Dihelium anion [He2]- (g, quartet 4Pig) 1714.9 1711.2 ± 1.9 kJ/mol 8.0057526 ± 0.0000040 90188-47-9*1 Carbonic acid C(O)(OH)2 (aq, undissoc) -698.991 ± 0.030 kJ/mol 62.0248 ± 0.0012 463-79-6*1000 Helium dihydride HeHH (g) -0.05 0.87 ± 0.42 kJ/mol 6.01848 ± 0.00014 33309-42-1*0 Helium dihydride HHeH (g) 614.5 608.9 ± 2.6 kJ/mol 6.01848 ± 0.00014 *33309-42-1*0 Dihydrohelium cation [HHeH]+ (g) 1572.2 1568.9 ± 2.4 kJ/mol 6.01793 ± 0.00014 *12500-88-8*0 Neon dication [Ne]+2 (g) 6032.988 6033.214 ± 0.0041 kJ/mol 20.17860 ± 0.00060 14041-55-5*0 Neon trication [Ne]+3 (g) 12152.403 12152.403 ± 0.032 kJ/mol 20.17805 ± 0.00060 14158-25-9*0 Neon tetracation [Ne]+4 (g) 21529.82 21531.45 ± 0.25 kJ/mol 20.17751 ± 0.00060 14041-56-6*0 Neon pentacation [Ne]+5 (g) 33711.1 33711.1 ± 1.2 kJ/mol 20.17696 ± 0.00060 14175-48-5*0 Neon hexacation [Ne]+6 (g) 48949.3 48949.3 ± 1.3 kJ/mol 20.17641 ± 0.00060 14041-57-7*0 Neon heptacation [Ne]+7 (g) 68948.7 68948.7 ± 1.4 kJ/mol 20.17586 ± 0.00060 14175-50-9*0 Neon octacation [Ne]+8 (g) 92018.2 92018.2 ± 1.4 kJ/mol 20.17531 ± 0.00060 14782-26-4*0 Neon nonacation [Ne]+9 (g) 207396.1 207396.1 ± 1.4 kJ/mol 20.17476 ± 0.00060 15721-59-2*0 Chlorine atom Cl (g, 2P3/2) 119.621 121.228 ± 0.0011 kJ/mol 35.45270 ± 0.00090 22537-15-1*1 Dioxofluorine anion [OFO]- (g) 155.9 154.4 ± 2.5 kJ/mol 50.99775 ± 0.00060 *175861-93-5*0 Sulfur atom dication [S]+2 (g) 3528.24 3531.94 ± 0.14 kJ/mol 32.0649 ± 0.0060 14127-58-3*0 Sulfur atom trication [S]+3 (g) 6890.9 6892.9 ± 3.2 kJ/mol 32.0644 ± 0.0060 22541-72-6*0 Sulfur atom tetracation [S]+4 (g) 11447.1 11448.9 ± 3.4 kJ/mol 32.0638 ± 0.0060 20681-10-1*0 Sulfur atom pentacation [S]+5 (g) 18451.4 18453.2 ± 3.4 kJ/mol 32.0633 ± 0.0060 14127-59-4*0 Dioxathiirane S(OO) (g) 167.3 164.9 ± 2.3 kJ/mol 64.0648 ± 0.0060 191663-73-7*0 Peroxyhypochlorous acid anion [HOOCl]- (g, trans quartet) -2.8 -3.3 ± 2.6 kJ/mol 68.4600 ± 0.0011 *67952-08-3*1 Fluorine atom pentacation [F]+5 (g) 30617.6 30619.4 ± 1.8 kJ/mol 18.99566030 ± 0.00000050 14701-05-4*0 Sulfur trioxide OS(O)O (cr,l) -454.30 ± 0.37 kJ/mol 80.0642 ± 0.0061 7446-11-9*500 3-Oxidedioxathiirane OS(OO) (g) -127.8 -132.8 ± 2.2 kJ/mol 80.0642 ± 0.0061 2243010-16-2*0 Trioxathietane S(OOO) (g) 263.7 258.6 ± 2.3 kJ/mol 80.0642 ± 0.0061 *2243010-16-2*0 Deuteride D- (g) 146.991 148.904 ± 0.0021 kJ/mol 2.01465035791 ± 0.00000000040 14452-69-8*0 Oxadithiirane O(SS) (g) 136.5 134.4 ± 2.5 kJ/mol 80.1314 ± 0.0120 488092-02-0*0 Sulfanylideneoxidaniumthiolate SOS (g) 220.9 219.1 ± 2.0 kJ/mol 80.1314 ± 0.0120 401811-43-6*0 Sulfuric acid OS(O)(OH)2 (aq) -878.85 -909.09 ± 0.14 kJ/mol 98.0795 ± 0.0061 7664-93-9*800 Sulfuric acid OS(O)(OH)2 (aq, 75 H2O) -887.11 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*825 Sulfuric acid OS(O)(OH)2 (aq, 115 H2O) -887.63 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*893 Ethynylene C2 (g, singlet) 820.017 826.590 ± 0.092 kJ/mol 24.0214 ± 0.0016 12070-15-4*2 Tropylide [CH(CHCHCHCHCHCH)]- (g) 261.5 245.2 ± 2.0 kJ/mol 91.1310 ± 0.0056 34464-18-1*0 Sulfurous acid S(O)(OH)2 (aq) -635.3 ± 4.0 kJ/mol 82.0801 ± 0.0061 7782-99-2*800 Hydrogen fluoride HF (aq, 45 H2O) -321.16 ± 0.16 kJ/mol 20.006343 ± 0.000070 7664-39-3*906 Tetrabromomethane CBr4 (cr, monoclinic) 58.7 ± 1.2 kJ/mol 331.6267 ± 0.0041 558-13-4*500 Tetraiodomethane CI4 (cr, monoclinic) 392.5 ± 8.0 kJ/mol 519.62858 ± 0.00081 507-25-5*500 Hydroxymethylene HCOH (g) 112.69 108.93 ± 0.27 kJ/mol 30.02598 ± 0.00087 19710-56-6*0 mu-Oxodichlorate anion [ClOCl]- (g) -147.8 -147.7 ± 2.5 kJ/mol 86.9053 ± 0.0018 365546-30-1*0 1,3-Butadiyn-4-ylium-1-yl [CCCC]+ (g) 2110.0 2120.6 ± 2.8 kJ/mol 48.0423 ± 0.0032 124708-46-9*0 Methoxymethylene CH3OCH (g, singlet) 129.13 118.62 ± 0.78 kJ/mol 44.0526 ± 0.0017 19527-10-7*2 Cyclopropylidene C(CH2CH2) (g) 474.94 466.91 ± 0.85 kJ/mol 40.0639 ± 0.0024 2143-70-6*0 Dibromovinylidene CCBr2 (g) 509.9 498.8 ± 4.1 kJ/mol 183.8294 ± 0.0026 261771-36-2*0 Hydrogen peroxide H2O2 (aq) -190.69 ± 0.30 kJ/mol 34.01468 ± 0.00062 7722-84-1*800 Fluorovinylidene CCHF (g) 298.9 300.1 ± 3.1 kJ/mol 44.0277 ± 0.0016 70302-00-0*0 Benzaldehyde cation [C6H5C(O)H]+ (g) 896.4 879.7 ± 1.8 kJ/mol 106.1214 ± 0.0056 80226-59-1*0 Methoxymethylene CH3OCH (g) 129.13 118.62 ± 0.78 kJ/mol 44.0526 ± 0.0017 19527-10-7*0 Tetraoxidanyl HOOOO (g) 2.1 0.4 ± 2.9 kJ/mol 65.0055 ± 0.0012 69696-93-1*0 2-Cyanovinyl CHCHCN (g) 447.80 445.40 ± 0.99 kJ/mol 52.0547 ± 0.0024 189141-20-6*0 2-Cyanovinylium [CHCHCN]+ (g, triplet) 1517.3 1515.2 ± 1.8 kJ/mol 52.0542 ± 0.0024 85398-67-0*2 2-Cyanovinyl anion [CHCHCN]- (g) 263.8 261.5 ± 1.8 kJ/mol 52.0553 ± 0.0024 *85398-67-0*0 Diazenide [NNH]- (g) 175.6 176.7 ± 1.6 kJ/mol 29.02197 ± 0.00016 71004-29-0*0 Peroxyformyl HC(O)OO (g) -100.65 -105.75 ± 0.93 kJ/mol 61.0168 ± 0.0012 56240-83-6*0 2-Isocyanovinyl CHCHNC (g) 543.2 541.8 ± 1.7 kJ/mol 52.0547 ± 0.0024 225798-14-1*0 Imidogen NH (g, triplet) 358.74 358.79 ± 0.16 kJ/mol 15.014680 ± 0.000099 13774-92-0*1 Dioxyamidogen HNOO (g, trans) 251.2 244.6 ± 2.5 kJ/mol 47.01348 ± 0.00061 71843-95-3*1 Cyanomethyliumyl [HCCN]+ (g) 1506.7 1508.2 ± 2.3 kJ/mol 39.0355 ± 0.0016 34447-38-6*0 Cyanomethylene anion [HCCN]- (g) 286.5 287.1 ± 1.5 kJ/mol 39.0366 ± 0.0016 12373-24-9*0 Cyanomethylene HCCN (g) 479.9 483.2 ± 1.1 kJ/mol 39.0361 ± 0.0016 2612-62-6*0 Ethoxyethene CH2CHOCH2CH3 (g) -118.0 -136.5 ± 1.5 kJ/mol 72.1057 ± 0.0033 109-92-2*0 Dichlorine cation [Cl2]+ (g) 1108.307 1108.286 ± 0.0062 kJ/mol 70.9049 ± 0.0018 12595-90-3*0 Isocyanomethyliumyl [HCNC]+ (g) 1505.9 1507.8 ± 3.3 kJ/mol 39.0355 ± 0.0016 99045-54-2*0 Isocyanomethylene anion [HCNC]- (g) 400.6 401.3 ± 2.1 kJ/mol 39.0366 ± 0.0016 144141-01-5*0 Isocyanomethylene HCNC (g) 582.3 584.6 ± 1.7 kJ/mol 39.0361 ± 0.0016 78694-65-2*0 Hydroperoxonium [H2OOH]+ (g) 738.2 727.9 ± 1.2 kJ/mol 35.02207 ± 0.00064 70850-26-9*0 3-Oxo-1,2-propadien-1-ylium-1-yl [CCCO]+ (g) 1380.3 1385.6 ± 3.8 kJ/mol 52.0310 ± 0.0024 151455-13-9*0 3-Oxo-1,2-propadienylidene anion [CCCO]- (g) 224.4 230.2 ± 3.5 kJ/mol 52.0320 ± 0.0024 109292-50-4*0 Methyl nitrite CH3ONO (g, trans) -52.43 -64.39 ± 0.89 kJ/mol 61.0401 ± 0.0010 624-91-9*1 Bromovinylidene CCHBr (g) 466.1 460.1 ± 3.8 kJ/mol 104.9333 ± 0.0019 161957-27-3*0 Methane anion [CH4]- (g) 27.3 19.4 ± 5.1 kJ/mol 16.04301 ± 0.00085 27680-53-1*0 Methyl nitrite CH3ONO (cr,l) -88.78 ± 0.56 kJ/mol 61.0401 ± 0.0010 624-91-9*500 Benzaldehyde anion [C6H5C(O)H]- (g) -55.6 -73.3 ± 2.7 kJ/mol 106.1225 ± 0.0056 34473-57-9*0 Ethylidene CH3CH (g) 361.27 354.29 ± 0.46 kJ/mol 28.0532 ± 0.0016 4218-50-2*0 (Formyloxy)methyl HC(O)OCH2 (g) -151.5 -159.6 ± 1.1 kJ/mol 59.0440 ± 0.0017 3122-12-1*0 Hydroxyamidogen HNOH (g) 101.26 94.43 ± 0.80 kJ/mol 32.02202 ± 0.00034 13940-32-4*0 Carboxymethyl CH2C(O)OH (g) -226.7 -236.6 ± 1.1 kJ/mol 59.0440 ± 0.0017 2887-46-9*0 Aminomethylidyne anion [CNH2]- (g, triplet) 481.6 478.1 ± 3.2 kJ/mol 28.03387 ± 0.00082 96808-04-7*1 Peroxyformate [HC(O)OO]- (g) -341.15 -346.60 ± 0.98 kJ/mol 61.0174 ± 0.0012 104960-05-6*0 1,3-Cyclobutadiene cation [CH(CHCHCH)]+ (g) 1215.7 1207.4 ± 3.0 kJ/mol 52.0740 ± 0.0032 34531-09-4*0 Isofulminic acid cation [HONC]+ (g) 1376.9 1374.8 ± 2.9 kJ/mol 43.02423 ± 0.00086 117800-60-9*0 Ethyl nitrite CH3CH2ONO (g, gauche-trans) -80.2 -98.5 ± 1.9 kJ/mol 75.0666 ± 0.0017 109-95-5*2 2-Methyl-2-cyclopropen-1-ylidene CH3C(CHC) (g) 448.0 441.8 ± 1.2 kJ/mol 52.0746 ± 0.0032 185841-59-2*0 2-Methyl-2-cyclopropen-1-ylidene CH3C(CHC) (g, triplet) 670.6 664.6 ± 2.8 kJ/mol 52.0746 ± 0.0032 185841-59-2*1 Oxonium [H3O]+ (aq) -285.795 ± 0.025 kJ/mol 19.02267 ± 0.00037 13968-08-6*800 Trioxidaniumyl [HOOOH]+ (g) 925.5 916.6 ± 1.5 kJ/mol 50.01353 ± 0.00091 161321-37-5*0 Difluorophosgene anion [CF2O]- (g) -602.3 -604.2 ± 3.3 kJ/mol 66.00745 ± 0.00085 474815-26-4*0 2-Methoxy-2-oxoethyl CH2C(O)OCH3 (g) -203.0 -218.2 ± 1.5 kJ/mol 73.0706 ± 0.0025 54668-31-4*0 Chlorine pentafluoride cation [FCl(F)(F)(F)F]+ (g) 1005.9 996.9 ± 3.2 kJ/mol 130.44417 ± 0.00090 478167-78-1*0 1-Methylethylidene CH3CCH3 (g) 316.03 303.13 ± 0.98 kJ/mol 42.0797 ± 0.0024 40852-89-9*0 Vinylvinylidene CH2CHCHC (g) 494.2 488.8 ± 1.7 kJ/mol 52.0746 ± 0.0032 148759-16-4*0 Vinylvinylidene CH2CHCHC (g, triplet) 690.5 684.7 ± 2.7 kJ/mol 52.0746 ± 0.0032 148759-16-4*1 Ethane anion [CH3CH3]- (g) 41.8 26.5 ± 4.4 kJ/mol 30.0696 ± 0.0017 54064-82-3*0 Vinylvinylidene CH2CHCHC (g, triplet, cis) 695.4 689.0 ± 3.3 kJ/mol 52.0746 ± 0.0032 148759-16-4*12 Vinylvinylidene cation [CH2CHCHC]+ (g) 1429.9 1424.5 ± 2.0 kJ/mol 52.0740 ± 0.0032 161054-20-2*0 Vinylvinylidene cation [CH2CHCHC]+ (g, cis) 1437.9 1432.2 ± 2.7 kJ/mol 52.0740 ± 0.0032 161054-20-2*2 Vinylvinylidene anion [CH2CHCHC]- (g) 405.7 399.0 ± 2.0 kJ/mol 52.0751 ± 0.0032 167386-49-4*0 Vinylvinylidene anion [CH2CHCHC]- (g, cis) 423.2 416.7 ± 2.7 kJ/mol 52.0751 ± 0.0032 167386-49-4*2 2-Hydroxyethenyl CHCHOH (g) 138.01 132.19 ± 0.72 kJ/mol 43.0446 ± 0.0016 108665-16-3*0 Ethyl nitrite CH3CH2ONO (g, gauche-cis) -78.2 -97.1 ± 1.9 kJ/mol 75.0666 ± 0.0017 109-95-5*3 1,2-Butadien-1-ylidene CH3CHCC (g) 511.8 506.3 ± 2.1 kJ/mol 52.0746 ± 0.0032 119908-55-3*0 1,2-Butadien-1-ylidene CH3CHCC (g, triplet) 651.7 646.2 ± 3.7 kJ/mol 52.0746 ± 0.0032 119908-55-3*1 (Acetyloxy)methyl CH3C(O)OCH2 (g) -200.2 -213.9 ± 1.5 kJ/mol 73.0706 ± 0.0025 2887-49-2*0 Bromine atom Br (g, 2P1/2) 161.994 155.932 ± 0.056 kJ/mol 79.90400 ± 0.00100 10097-32-2*2 Isocyanic fluoride anion [FNC]- (g) 74.1 75.8 ± 5.7 kJ/mol 45.01639 ± 0.00080 357426-78-9*0 Oxonium [H3O]+ (g, ortho) 605.95 599.13 ± 0.17 kJ/mol 19.02267 ± 0.00037 13968-08-6*1 Propyl nitrite CH3CH2CH2ONO (g) -95.9 -119.7 ± 1.8 kJ/mol 89.0932 ± 0.0025 543-67-9*0 Propyl nitrite CH3CH2CH2ONO (g, trans-trans-cis) -95.6 -120.2 ± 2.5 kJ/mol 89.0932 ± 0.0025 543-67-9*2 Propyl nitrite CH3CH2CH2ONO (g, gauche-gauche-trans) -95.7 -120.3 ± 2.5 kJ/mol 89.0932 ± 0.0025 543-67-9*3 Fluoro(fluorooxy)methylene FCOF (g) -134.8 -136.0 ± 1.3 kJ/mol 66.00691 ± 0.00085 479587-30-9*0 Hypobromous acid cation [HOBr]+ (g) 975.16 964.54 ± 0.54 kJ/mol 96.9108 ± 0.0010 154804-02-1*0 1,2,3-Butatrien-1-ylium [CH2CCCH]+ (g) 1271.8 1270.0 ± 1.1 kJ/mol 51.0661 ± 0.0032 81932-79-8*0 Propyl nitrite CH3CH2CH2ONO (g, gauche-gauche-trans II) -95.0 -119.5 ± 2.5 kJ/mol 89.0932 ± 0.0025 543-67-9*4 Nitrosodioxaziridine ONN(OO) (g, gauche) 415.4 409.5 ± 2.8 kJ/mol 76.01168 ± 0.00091 132871-99-9*3 Formic acid cation [HC(O)OH]+ (g) 721.93 715.40 ± 0.25 kJ/mol 46.0248 ± 0.0010 50614-05-6*0 Peroxyformic acid HC(O)OOH (g) -279.23 -288.36 ± 0.88 kJ/mol 62.0248 ± 0.0012 107-32-4*0 1,2-Butadienylium [CH3CHCCH]+ (g) 1099.2 1089.9 ± 1.2 kJ/mol 53.0820 ± 0.0032 *65114-67-2*0 Propyl nitrite CH3CH2CH2ONO (g, trans-gauche-trans) -94.9 -119.2 ± 2.5 kJ/mol 89.0932 ± 0.0025 543-67-9*5 1-Buten-3-yn-1-yl HCCCHCH (g) 547.27 544.75 ± 0.87 kJ/mol 51.0666 ± 0.0032 2810-61-9*0 1-Buten-3-ynylium [HCCCHCH]+ (g) 1482.3 1480.2 ± 1.4 kJ/mol 51.0661 ± 0.0032 84654-85-3*0 But-1-en-3-yn-1-ide [HCCCHCH]- (g) 419.7 419.1 ± 1.2 kJ/mol 51.0672 ± 0.0032 119611-65-3*0 Propyl nitrite CH3CH2CH2ONO (g, trans-gauche-cis) -93.0 -118.0 ± 2.5 kJ/mol 89.0932 ± 0.0025 543-67-9*6 2-Cyclopropyn-1-ylidene C(CC) (g) 898.8 905.7 ± 1.6 kJ/mol 36.0321 ± 0.0024 102508-15-6*0 Formic acid anion [HC(O)OH]- (g) -256.2 -262.3 ± 1.8 kJ/mol 46.0259 ± 0.0010 19066-82-1*0 2-Hydroxyethyl CH2CH2OH (g) -13.07 -26.33 ± 0.49 kJ/mol 45.0605 ± 0.0017 4422-54-2*0 Propyl nitrite CH3CH2CH2ONO (g, gauche-gauche-cis) -92.7 -117.8 ± 2.5 kJ/mol 89.0932 ± 0.0025 543-67-9*7 3-Buten-1-ynylium [CH2CHCC]+ (g) 1572.6 1570.2 ± 1.7 kJ/mol 51.0661 ± 0.0032 103928-84-3*0 But-3-en-1-yn-1-ide [CH2CHCC]- (g) 326.7 323.6 ± 1.4 kJ/mol 51.0672 ± 0.0032 58870-47-6*0 Phosgene cation [CCl2O]+ (g) 897.0 896.0 ± 1.7 kJ/mol 98.9150 ± 0.0020 73249-38-4*0 Phosgene CCl2O (cr, l, I+liquid) -242.78 ± 0.24 kJ/mol 98.9155 ± 0.0020 75-44-5*501 Phosgene CCl2O (cr, l, II+liquid) -255.49 -242.78 ± 0.24 kJ/mol 98.9155 ± 0.0020 75-44-5*502 Propyl nitrite CH3CH2CH2ONO (g, gauche-gauche-cis II) -91.3 -116.2 ± 2.8 kJ/mol 89.0932 ± 0.0025 543-67-9*8 3-Methylene-1-cyclopropen-1-ylium [CH2C(CHC)]+ (g) 1398.7 1395.4 ± 1.7 kJ/mol 51.0661 ± 0.0032 117469-28-0*0 Propynylidene HCCCH (g, singlet) 597.7 599.5 ± 1.3 kJ/mol 38.0480 ± 0.0024 67152-18-5*2 1,2-Dibromoethene CHBrCHBr (g) 121.2 101.0 ± 2.0 kJ/mol 185.8453 ± 0.0026 540-49-8*0 Ethynylamidogen anion [HCCNH]- (g) 233.8 230.6 ± 3.2 kJ/mol 40.0446 ± 0.0016 64066-03-1*0 2-Cyclopropen-1-ylidenemethylium [CHC(CHCH)]+ (g) 1346.4 1343.8 ± 1.8 kJ/mol 51.0661 ± 0.0032 112936-36-4*0 Nitrosodioxaziridine ONN(OO) (g) 413.7 408.2 ± 1.8 kJ/mol 76.01168 ± 0.00091 132871-99-9*0 Fluorosyl fluoride anion [FFO]- (g) -147.1 -146.8 ± 3.0 kJ/mol 53.99675 ± 0.00030 *86825-57-2*0 Chloro(chlorooxy)methylene ClCOCl (g) 73.5 73.9 ± 3.6 kJ/mol 98.9155 ± 0.0020 479587-31-0*0 Chloro(chlorooxy)methylene ClCOCl (g, trans) 98. 105. ± 15. kJ/mol 98.9155 ± 0.0020 479587-31-0*1 1,3-Cyclobutadien-1-ylium [C(CHCHCH)]+ (g) 1388.3 1383.3 ± 1.9 kJ/mol 51.0661 ± 0.0032 81913-77-1*0 Chlorine atom Cl (g, 2P1/2) 130.176 131.783 ± 0.0011 kJ/mol 35.45270 ± 0.00090 22537-15-1*2 Fluorosyl fluoride cation [FFO]+ (g) 1413.1 1413.4 ± 3.5 kJ/mol 53.99566 ± 0.00030 *86825-50-5*0 Cyclopropane CH2(CH2CH2) (l) 41.45 35.76 ± 0.52 kJ/mol 42.0797 ± 0.0024 75-19-4*500 Cyclobutenide [CH2(CHCHCH)]- (g) 320.3 307.9 ± 3.2 kJ/mol 53.0830 ± 0.0032 60211-42-9*0 Iodine monochloride ICl (cr,l) -36.511 -35.537 ± 0.063 kJ/mol 162.35717 ± 0.00090 7790-99-0*500 Oxiranylium [CH2(CHO)]+ (g) 901.3 893.3 ± 1.4 kJ/mol 43.0441 ± 0.0016 57789-76-1*0 2,2,4-Trimethylpentane (CH3)2CHCH2C(CH3)3 (g) -171.0 -223.4 ± 1.5 kJ/mol 114.2285 ± 0.0065 540-84-1*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 Phenylperoxy cation [C6H5OO]+ (g) 1018.6 1001.6 ± 3.1 kJ/mol 109.1022 ± 0.0049 956036-17-2*0 Phenylperoxy anion [C6H5OO]- (g) -39.2 -56.2 ± 3.3 kJ/mol 109.1032 ± 0.0049 *956036-17-2*0 Dioxoethylium [OCHCO]+ (g) 688.7 690.0 ± 3.0 kJ/mol 57.0276 ± 0.0017 *1994332-01-2*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 Oxiranyl anion [CH2(CHO)]- (g) 121.4 113.5 ± 1.5 kJ/mol 43.0452 ± 0.0016 72722-59-9*0 Dioxohydrazine ONNO (g, trans) 192.3 188.7 ± 1.8 kJ/mol 60.01228 ± 0.00062 16824-89-8*1 Oxoniumyl ion [H2O]+ (g, para) 978.750 975.599 ± 0.026 kJ/mol 18.01473 ± 0.00033 56583-62-1*2 Fulvene cation [CH2C(CHCHCHCH)]+ (g) 1043.6 1027.8 ± 2.7 kJ/mol 78.1113 ± 0.0048 34504-75-1*0 Fulvene anion [CH2C(CHCHCHCH)]- (g) 191.3 176.3 ± 4.0 kJ/mol 78.1124 ± 0.0048 34504-63-7*0 Propargylenide [HCCCH]- (g) 434.5 437.7 ± 1.1 kJ/mol 38.0485 ± 0.0024 82906-05-6*0 Trihydrogen H(HH) (g, TS) 477.4 474.7 ± 2.3 kJ/mol 3.02382 ± 0.00021 12184-91-7*201 Ethanedial anion [OCHCO]- (g) -188.6 -190.2 ± 3.1 kJ/mol 57.0287 ± 0.0017 1994332-01-2*0 Water H2O (g, ortho) -238.613 -241.801 ± 0.025 kJ/mol 18.01528 ± 0.00033 7732-18-5*1 Hydrogen peroxide cation [H2O2]+ (g) 897.29 890.31 ± 0.51 kJ/mol 34.01413 ± 0.00062 12325-10-9*0 Peroxyhypochlorous acid anion [HOOCl]- (g, quartet) -32.1 -33.9 ± 2.6 kJ/mol 68.4600 ± 0.0011 *67952-08-3*0 Chloromethylene CHCl (g) 320.37 320.65 ± 0.89 kJ/mol 48.4713 ± 0.0012 2108-20-5*0 Silicon atom tetracation [Si]+4 (g) 10400.49 10403.47 ± 0.57 kJ/mol 28.08331 ± 0.00030 22537-24-2*0 Silicon anion Si- (g) 315.67 318.65 ± 0.57 kJ/mol 28.08605 ± 0.00030 14337-02-1*0 Propylidene anion [CH3CH2CH]- (g) 300.9 286.7 ± 3.2 kJ/mol 42.0803 ± 0.0024 *121408-55-7*0 Water dimer cation [(H2O)2]+ (g) 556.9 546.4 ± 3.0 kJ/mol 36.03001 ± 0.00066 158061-35-9*0 Disilicon anion [Si2]- (g) 373.9 377.8 ± 1.8 kJ/mol 56.17155 ± 0.00060 64236-73-3*0 Chlorous acid anion [HOClO]- (g) -154.3 -156.1 ± 3.3 kJ/mol 68.4600 ± 0.0011 99559-66-7*0 Chlorohydroxymethylene ClCOH (g, cis) 14.4 11.5 ± 3.2 kJ/mol 64.4707 ± 0.0012 147723-60-2*2 Chlorohydroxymethylene ClCOH (g) 14.0 11.3 ± 2.5 kJ/mol 64.4707 ± 0.0012 147723-60-2*0 Hydroxyoxoethenylium [HOCCO]+ (g) 866.5 865.3 ± 3.5 kJ/mol 57.0276 ± 0.0017 *1994332-00-1*0 Ethynediolide [HOCCO]- (g) -132.8 -134.0 ± 3.5 kJ/mol 57.0287 ± 0.0017 1994332-00-1*0 Nitrous acid anion [HONO]- (g) -105.82 -109.29 ± 0.78 kJ/mol 47.01403 ± 0.00061 256393-36-9*0 1-Hydroxy-2-propanone CH3C(O)CH2OH (g) -354.56 -373.89 ± 0.84 kJ/mol 74.0785 ± 0.0025 116-09-6*0 Hydrogen cyanide anion [HCN]- (g) 129.515 129.037 ± 0.088 kJ/mol 27.02593 ± 0.00081 12334-27-9*0 Chlorine atom heptacation [Cl]+7 (g) 39520. 39522. ± 11. kJ/mol 35.44886 ± 0.00090 22537-27-5*0 Nitrogen atom heptacation [N]+7 (g) 143853.26 143855.13 ± 0.23 kJ/mol 14.002900 ± 0.000070 40549-08-4*0 Dichloromethylene CCl2 (g) 229.89 231.07 ± 0.64 kJ/mol 82.9161 ± 0.0020 1605-72-7*0 Formaldehyde CH2O (g, ortho singlet) -105.260 -109.226 ± 0.096 kJ/mol 30.02598 ± 0.00087 50-00-0*22 Bromoform CHBr3 (l) 7.5 ± 1.1 kJ/mol 252.7306 ± 0.0031 75-25-2*590 Silicon carbide anion [SiC]- (g) 509.2 513.8 ± 4.4 kJ/mol 40.09675 ± 0.00085 86017-99-4*0 (Chlorooxy)methylene HCOCl (g, trans) 155.5 155.3 ± 3.7 kJ/mol 64.4707 ± 0.0012 331419-80-8*1 Isocyanogen bromide cation [BrNC]+ (g) 1469.7 1464.0 ± 5.9 kJ/mol 105.9209 ± 0.0013 238754-53-5*0 (Chlorooxy)methylene HCOCl (g) 119.3 117.9 ± 2.7 kJ/mol 64.4707 ± 0.0012 331419-80-8*0 Silicon carbide SiC (cr,l) -71.6 -72.6 ± 1.4 kJ/mol 40.09620 ± 0.00085 409-21-2*500 Tetrafluorosilane cation [SiF4]+ (g) -138.3 -142.7 ± 5.9 kJ/mol 104.07856 ± 0.00030 62859-94-3*0 Water H2O (cr, l, eq.press.) -286.269 -285.797 ± 0.025 kJ/mol 18.01528 ± 0.00033 7732-18-5*499 Cyanomethylium [CH2CN]+ (g) 1256.70 1254.06 ± 0.66 kJ/mol 40.0435 ± 0.0016 34430-18-7*0 Ethynylaminylium [HCCNH]+ (g) 1277.9 1277.5 ± 2.6 kJ/mol 40.0435 ± 0.0016 103835-08-1*0 Chloroformyl anion [ClCO]- (g) -356.5 -352.9 ± 3.3 kJ/mol 63.4633 ± 0.0012 41976-93-6*0 Benzoyl anion [C6H5CO]- (g) 69.7 57.1 ± 4.0 kJ/mol 105.1145 ± 0.0056 78944-74-8*0 Difluoromethane CH2F2 (l) -468.79 ± 0.35 kJ/mol 52.02339 ± 0.00081 75-10-5*590 Diazene HNNH (g, trans-cis-iso equilib) 207.12 199.98 ± 0.41 kJ/mol 30.02936 ± 0.00020 3618-05-1*0 1,1-Dibromoethane CH3CHBr2 (cr,l) -67.2 ± 1.3 kJ/mol 187.8612 ± 0.0026 557-91-5*500 Hydrobromate ion [HBr]- (g) -5.9 -12.4 ± 4.3 kJ/mol 80.9125 ± 0.0010 85532-97-4*0 Silylene SiH2 (g) 270.79 269.12 ± 0.86 kJ/mol 30.10138 ± 0.00033 13825-90-6*0 1,3-Butadienyl CH2CHCHCH (g) 372.23 363.01 ± 0.87 kJ/mol 53.0825 ± 0.0032 86181-68-2*0 Hydrogen peroxide H2O2 (g, ortho) -129.390 -135.396 ± 0.061 kJ/mol 34.01468 ± 0.00062 7722-84-1*1 2-Propenylidene CHCHCH2 (g, triplet) 417.4 410.5 ± 1.5 kJ/mol 40.0639 ± 0.0024 19527-08-3*1 2-Propenylidene CHCHCH2 (g) 417.4 410.5 ± 1.5 kJ/mol 40.0639 ± 0.0024 19527-08-3*0 Disilane cation [SiH3SiH3]+ (g) 1029.1 1016.4 ± 2.2 kJ/mol 62.21809 ± 0.00073 96301-43-8*0 Ketene CH2CO (g, ortho singlet) -45.24 -48.41 ± 0.11 kJ/mol 42.0367 ± 0.0016 463-51-4*22 1,3-Butadienyl CH2CHCHCH (g, trans-cis) 374.9 364.4 ± 2.0 kJ/mol 53.0825 ± 0.0032 86181-68-2*12 Nitrosodioxaziridine ONN(OO) (g, cis) 413.9 408.1 ± 3.2 kJ/mol 76.01168 ± 0.00091 132871-99-9*2 Chlorohydroxymethyl CH(Cl)OH (g) -54.9 -60.6 ± 1.1 kJ/mol 65.4787 ± 0.0012 147139-06-8*0 Hydrazoic acid anion [HNNN]- (g) 309.0 303.1 ± 2.3 kJ/mol 43.02871 ± 0.00022 203264-98-6*0 Trioxodinitrate anion [ONN(O)O]- (g) -104.2 -107.5 ± 1.9 kJ/mol 76.01223 ± 0.00091 194856-62-7*0 (Methylamino)methyl anion [CH3NHCH2]- (g) 201.6 184.7 ± 3.1 kJ/mol 44.0763 ± 0.0017 *31277-25-5*0 Nitrosyl nitrite anion [ONONO]- (g) -103.0 -106.1 ± 2.8 kJ/mol 76.01223 ± 0.00091 *122413-35-8*0 Disilene SiH2SiH2 (g) 287.4 278.7 ± 1.9 kJ/mol 60.20276 ± 0.00066 15435-77-5*0 Hydroxyaminylium [HNOH]+ (g) 1019.5 1012.3 ± 2.5 kJ/mol 32.02147 ± 0.00034 66097-71-0*0 Hydroperoxyimidogen HOON (g, cis) 111.9 109.0 ± 2.8 kJ/mol 47.01348 ± 0.00061 877456-58-1*2 3-Buten-2-one CH3C(O)CHCH2 (g) -95.40 -110.94 ± 0.85 kJ/mol 70.0898 ± 0.0032 78-94-4*0 Diazanide [NH2NH]- (g) 249.3 239.3 ± 3.1 kJ/mol 31.03785 ± 0.00025 25415-88-7*0 Silylsilylene SiH3SiH (g) 315.9 308.0 ± 2.0 kJ/mol 60.20276 ± 0.00066 50420-90-1*0 3-Buten-2-one CH3C(O)CHCH2 (g, cis) -93.8 -109.9 ± 1.6 kJ/mol 70.0898 ± 0.0032 78-94-4*2 Methylaminyliumyl [CH3N]+ (g ?) 1388.3 1381.9 ± 2.3 kJ/mol 29.04071 ± 0.00083 56924-51-7*0 Diazene HNNH (g, trans-cis equilib) 207.12 199.98 ± 0.41 kJ/mol 30.02936 ± 0.00020 3618-05-1*1 1-Methylene-2-propenylium [CH2CHCCH2]+ (g) 1059.4 1049.3 ± 1.7 kJ/mol 53.0820 ± 0.0032 62698-26-4*0 Ethoxyethene CH2CHOCH2CH3 (g, cis-perp) -111.5 -135.4 ± 2.3 kJ/mol 72.1057 ± 0.0033 109-92-2*21 2-Iodoethanol ICH2CH2OH (g) -131.9 -150.1 ± 2.5 kJ/mol 171.9650 ± 0.0017 624-76-0*0 1,3-Butadien-2-ol CH2C(OH)CHCH2 (g, s-trans, anti) -48.1 -64.4 ± 2.3 kJ/mol 70.0898 ± 0.0032 59120-04-6*12 Oxide [O]-2 (g) 651. 653. ± 15. kJ/mol 16.00050 ± 0.00030 16833-27-5*0 Di-mu-hydrodihydrodisilicon HSi(HSiHH) (g) 373.3 363.0 ± 2.4 kJ/mol 60.20276 ± 0.00066 129970-82-7*0 Di-mu-hydrodihydrodisilicon HSi(HSiHH) (g, trans) 373.3 362.9 ± 2.4 kJ/mol 60.20276 ± 0.00066 129970-82-7*1 Di-mu-hydrodihydrodisilicon HSi(HSiHH) (g, trans-triplet) 542.8 534.8 ± 3.7 kJ/mol 60.20276 ± 0.00066 129970-82-7*11 Di-mu-hydrodihydrodisilicon cation [HSi(HSiHH)]+ (g) 1178.8 1171.2 ± 3.3 kJ/mol 60.20221 ± 0.00066 *129970-82-7*0 Di-mu-hydrodihydrodisilicon anion [HSi(HSiHH)]- (g) 287.0 278.9 ± 3.4 kJ/mol 60.20331 ± 0.00066 *129970-83-8*0 Hypochloroperoxoous acid, hydroxy ester HOOOCl (g) 48.5 41.7 ± 1.8 kJ/mol 84.4588 ± 0.0013 928652-99-7*0 1,3-Butadien-2-ol CH2C(OH)CHCH2 (g, s-cis, anti) -37.9 -54.3 ± 2.3 kJ/mol 70.0898 ± 0.0032 59120-04-6*22 Oxooxoniumylmethoxy [OC(O)O]+ (g) 1178.3 1177.6 ± 5.8 kJ/mol 60.0084 ± 0.0012 952586-28-6*0 Fluoroform CHF3 (l) -704.59 ± 0.41 kJ/mol 70.01385 ± 0.00080 75-46-7*590 Fluorosyl fluoride FFO (g) 192.8 193.3 ± 2.3 kJ/mol 53.99621 ± 0.00030 86825-57-2*0 Fluorine atom nonacation [F]+9 (g) 262121.1 262122.9 ± 1.8 kJ/mol 18.99346598 ± 0.00000050 35424-07-8*0 1,3-Butadien-2-ol CH2C(OH)CHCH2 (g, s-cis) -42.7 -58.8 ± 2.3 kJ/mol 70.0898 ± 0.0032 59120-04-6*2 1,3-Butadien-2-ol CH2C(OH)CHCH2 (g) -53.4 -68.4 ± 1.5 kJ/mol 70.0898 ± 0.0032 59120-04-6*0 Perchloric acid cation [HOCl(O)(O)O]+ (g) 1190.2 1180.6 ± 3.3 kJ/mol 100.4577 ± 0.0015 91712-47-9*0 Ethanimine CH3CHNH (g) 55.82 41.19 ± 0.79 kJ/mol 43.0678 ± 0.0016 20729-41-3*0 Hydrazoic acid HNNN (cr,l) 261.46 ± 0.65 kJ/mol 43.02816 ± 0.00022 7782-79-8*500 1,3-Butadienyl CH2CHCHCH (g, gauche-cis) 385.5 375.3 ± 2.0 kJ/mol 53.0825 ± 0.0032 86181-68-2*22 Iminomethyl HCNH (g) 275.80 272.20 ± 0.61 kJ/mol 28.03332 ± 0.00082 15691-95-9*0 Nitrosyl nitrate ONONO2 (g) 48.3 40.4 ± 1.8 kJ/mol 92.0111 ± 0.0012 15969-55-8*0 Cyanogen iodide cation [ICN]+ (g) 1271.4 1271.2 ± 1.7 kJ/mol 152.92136 ± 0.00080 34749-78-5*0 Formylimidogen HC(O)N (g, triplet) 245.2 242.1 ± 4.6 kJ/mol 43.02478 ± 0.00086 42288-92-6*1 Methoxyethene CH2CHOCH3 (g) -89.5 -106.8 ± 1.1 kJ/mol 58.0791 ± 0.0025 107-25-5*0 Hydroxysilyl anion [SiH2OH]- (g) -220.0 -227.7 ± 2.1 kJ/mol 47.10927 ± 0.00047 78450-47-2*0 Hydroxysilyl anion [SiH2OH]- (g, anti) -219.6 -227.5 ± 2.7 kJ/mol 47.10927 ± 0.00047 78450-47-2*2 Cyanic fluoride cation [FCN]+ (g) 1294.3 1294.8 ± 1.1 kJ/mol 45.01529 ± 0.00080 62532-69-8*0 2-Propenylidene CHCHCH2 (g, triplet syn) 419.0 411.5 ± 2.3 kJ/mol 40.0639 ± 0.0024 19527-08-3*12 Pentachloroethylium [CCl3CCl2]+ (g) 838.1 836.5 ± 3.3 kJ/mol 201.2844 ± 0.0048 *7094-17-9*0 Hydroperoxonium [H2OOH]+ (g, cis) 762.5 752.7 ± 2.0 kJ/mol 35.02207 ± 0.00064 70850-26-9*2 Benzvalene cation [((CHCH)(CH(CHCH)CH) (g) 1200.2 1184.8 ± 2.7 kJ/mol 78.1113 ± 0.0048 81050-63-7*0 2-Butynylium [CH3CCCH2]+ (g) 1085.8 1077.6 ± 1.3 kJ/mol 53.0820 ± 0.0032 64235-83-2*0 Dicarbon monoxide CCO (g) 377.13 381.17 ± 0.83 kJ/mol 40.0208 ± 0.0016 12071-23-7*0 Pentachloroethanide [CCl3CCl2]- (g) -281.8 -280.3 ± 3.9 kJ/mol 201.2854 ± 0.0048 263019-83-6*0 Diazene cation [HNNH]+ (g, trans-iso-cis equilib) 1132.49 1125.83 ± 0.64 kJ/mol 30.02881 ± 0.00020 76986-17-9*0 1,2-Propadien-1-one anion [CH2CCO]- (g) 49.7 48.5 ± 3.1 kJ/mol 54.0479 ± 0.0024 159171-62-7*0 Hydrodioxonitrogen cation [HN(O)O]+ (g) 1130.3 1123.6 ± 3.0 kJ/mol 47.01293 ± 0.00061 252986-76-8*0 Peroxychlorous acid HOOClO (g, perp ?) 101.5 95.4 ± 3.6 kJ/mol 84.4588 ± 0.0013 177778-92-6*3 Carbon C (diamond) 2.390 1.862 ± 0.044 kJ/mol 12.01070 ± 0.00080 7440-44-0*501 mu-Oxodioxodinitrogen [ONONO]+ (g, t, t) 984.0 981.1 ± 3.2 kJ/mol 76.01113 ± 0.00091 87950-63-8*1 Cyanogen chloride cation [ClCN]+ (g) 1326.26 1327.59 ± 0.97 kJ/mol 61.4696 ± 0.0012 37612-72-9*0 Water anion [H2O]- (g) -50.1 -53.0 ± 4.3 kJ/mol 18.01583 ± 0.00033 12259-30-2*0 Butadienylacetylene CH2CHCHCHCCH (g) 358.8 346.3 ± 1.9 kJ/mol 78.1118 ± 0.0048 10420-90-3*0 Methylaminyliumyl [CH3N]+ (g, quartet) 1423.0 1416.1 ± 2.3 kJ/mol 29.04071 ± 0.00083 56924-51-7*2 (3Z)-1,3-Hexadien-5-yne CH2CHCHCHCCH (g, cis) 358.8 346.2 ± 2.5 kJ/mol 78.1118 ± 0.0048 5222-76-4*0 Divinylacetylene CH2CHCCCHCH2 (g) 361.8 350.6 ± 2.0 kJ/mol 78.1118 ± 0.0048 821-08-9*0 Oxoethylidene HCC(O)H (g) 261.1 258.3 ± 1.1 kJ/mol 42.0367 ± 0.0016 39920-84-8*0 Divinylacetylene CH2CHCCCHCH2 (g, trans) 362.4 351.3 ± 2.6 kJ/mol 78.1118 ± 0.0048 821-08-9*1 Biallenyl CH2CCHCHCCH2 (g) 410.6 399.5 ± 1.5 kJ/mol 78.1118 ± 0.0048 29776-96-3*0 Oxoiodonium [IO]+ (g) 1066.1 1064.1 ± 1.9 kJ/mol 142.90332 ± 0.00030 81182-81-2*0 Biallenyl CH2CCHCHCCH2 (g, cis) 419.5 408.2 ± 2.3 kJ/mol 78.1118 ± 0.0048 29776-96-3*2 Propargylallene CH2CCHCH2CCH (g) 431.4 420.0 ± 1.4 kJ/mol 78.1118 ± 0.0048 33142-15-3*0 COC vdW (CO)(C) (g) 589.8 598.5 ± 1.5 kJ/mol 40.0208 ± 0.0016 *12071-24-8*0 Propargylallene CH2CCHCH2CCH (g, cis) 432.3 420.7 ± 2.2 kJ/mol 78.1118 ± 0.0048 33142-15-3*2 Ethylimidogen anion [CH3CH2N]- (g) 277.4 263.5 ± 3.6 kJ/mol 43.0684 ± 0.0016 82539-33-1*0 1-Oxo-2-propyn-1-ylium [HCCCO]+ (g) 1001.7 1003.1 ± 3.0 kJ/mol 53.0389 ± 0.0024 53474-99-0*0 3-Methylene-1-penten-4-yne CH2CHC(CH2)CCH (g) 362.6 350.2 ± 2.2 kJ/mol 78.1118 ± 0.0048 6929-96-0*0 3-Methylene-1-penten-4-yne CH2CHC(CH2)CCH (g, gauche) 374.7 362.4 ± 2.8 kJ/mol 78.1118 ± 0.0048 6929-96-0*3 1,2,3,5-Hexatetraene CH2CCCHCHCH2 (g) 391.7 380.3 ± 1.6 kJ/mol 78.1118 ± 0.0048 60239-33-0*0 1,3-Butadienyl CH2CHCHCH (g, cis-trans) 384.0 374.5 ± 2.0 kJ/mol 53.0825 ± 0.0032 86181-68-2*21 1,2,3,5-Hexatetraene CH2CCCHCHCH2 (g, cis) 400.5 388.9 ± 2.3 kJ/mol 78.1118 ± 0.0048 60239-33-0*2 Cyanogen chloride anion [ClCN]- (g) 46.9 51.3 ± 3.1 kJ/mol 61.4707 ± 0.0012 12281-43-5*0 3-Oxo-1,2-propadien-1-yl anion [HCCCO]- (g) 179.4 182.0 ± 3.2 kJ/mol 53.0400 ± 0.0024 557113-97-0*0 1,2-Propadien-1-yl-3-ylidene anion [CCC]- (g, lin) 621.9 629.3 ± 1.3 kJ/mol 36.0326 ± 0.0024 109292-47-9*1 Chlorine trifluoride anion [FCl(F)F]- (g) -480.4 -481.9 ± 3.5 kJ/mol 92.44846 ± 0.00090 184289-50-7*0 1,3-Butadiyne-1,4-diyl CCCC (g, singlet) 1084.11 1093.91 ± 0.84 kJ/mol 48.0428 ± 0.0032 78015-07-3*2 Isocyanic acid anion [HNCO]- (g) -54.3 -57.4 ± 3.0 kJ/mol 43.02533 ± 0.00086 *444010-28-0*0 Formylethynyl anion [CCCHO]- (g) 100.4 101.7 ± 3.4 kJ/mol 53.0400 ± 0.0024 85905-64-2*0 Chloromethane CH3Cl (l) -106.51 -102.55 ± 0.16 kJ/mol 50.4872 ± 0.0012 74-87-3*590 Ethylimidogen cation [CH3CH2N]+ (g, quartet) 1394.6 1381.4 ± 3.7 kJ/mol 43.0673 ± 0.0016 *82539-33-1*1 2-Cyclopropen-1-one cation [OC(CHCH)]+ (g) 1078.6 1075.5 ± 2.0 kJ/mol 54.0468 ± 0.0024 100815-68-7*0 Hydrodioxonitrate [HN(O)O]- (g) -61.8 -68.2 ± 3.2 kJ/mol 47.01403 ± 0.00061 61508-71-2*0 Chlorous acid cation [HOClO]+ (g) 996.6 991.6 ± 3.1 kJ/mol 68.4589 ± 0.0011 *99559-66-7*0 Carbonylbis(oxy) OC(O)O (g) -143.5 -144.6 ± 3.0 kJ/mol 60.0089 ± 0.0012 16518-45-9*0 1-Methylallyl CH3CHCHCH2 (g) 152.61 136.14 ± 0.80 kJ/mol 55.0984 ± 0.0032 15819-46-2*0 Diazene cation [HNNH]+ (g, trans-cis equilib) 1132.49 1125.55 ± 0.64 kJ/mol 30.02881 ± 0.00020 76986-17-9*1 Diazene anion [HNNH]- (g, trans-cis-iso equilib) 265.5 258.7 ± 2.0 kJ/mol 30.02991 ± 0.00020 100429-75-2*0 1-Methyl-1-propenyl CH3CCHCH3 (g) 240.00 224.62 ± 0.67 kJ/mol 55.0984 ± 0.0032 71790-71-1*0 Trihydrogen H(HH) (g, Ry) 745.878 743.199 ± 0.062 kJ/mol 3.02382 ± 0.00021 12184-91-7*0 1-Methyl-1-propenyl CH3CCHCH3 (g, cis) 243.3 227.0 ± 1.9 kJ/mol 55.0984 ± 0.0032 71790-71-1*2 Cyanogen bromide cation [BrCN]+ (g) 1331.1 1324.8 ± 1.4 kJ/mol 105.9209 ± 0.0013 34749-77-4*0 Diazene anion [HNNH]- (g, trans-cis equilib) 265.5 258.7 ± 2.0 kJ/mol 30.02991 ± 0.00020 100429-75-2*1 1-Butenyl CH3CH2CHCH (g) 263.41 246.35 ± 0.69 kJ/mol 55.0984 ± 0.0032 2669-61-6*0 Diatomic bromine cation [Br2]+ (g) 1060.31 1045.36 ± 0.23 kJ/mol 159.8075 ± 0.0020 12595-71-0*0 1-Butenyl CH3CH2CHCH (g, gauche) 263.8 246.6 ± 1.9 kJ/mol 55.0984 ± 0.0032 2669-61-6*3 Propylidyne CH3CH2C (g) 492.6 483.0 ± 1.2 kJ/mol 41.0718 ± 0.0024 85056-54-8*0 Difluorodioxidane anion [FOOF]- (g) -251. -251. ± 28. kJ/mol 69.99615 ± 0.00060 *7783-45-1*0 Tetraoxidanyl HOOOO (g, trans) 76.7 69.5 ± 6.1 kJ/mol 65.0055 ± 0.0012 69696-93-1*1 Ethoxyethene CH2CHOCH2CH3 (g, trans-trans) -111.0 -133.2 ± 2.6 kJ/mol 72.1057 ± 0.0033 109-92-2*1 Pyridiniumyl [N(CHCHCHCHCH)]+ (g) 1051.35 1035.40 ± 0.61 kJ/mol 79.0994 ± 0.0040 16399-94-3*0 Chloroethane CH3CH2Cl (cr,l) -134.34 -135.96 ± 0.25 kJ/mol 64.5138 ± 0.0019 75-00-3*500 Iminomethide [HCNH]- (g) 237.4 233.6 ± 1.8 kJ/mol 28.03387 ± 0.00082 90623-30-6*0 N-Methylethanamine CH3CH2NHCH3 (cr,l) -75.1 ± 2.3 kJ/mol 59.1103 ± 0.0025 624-78-2*500 Dioxodiazoxane ONONO (g) 93.0 88.2 ± 1.3 kJ/mol 76.01168 ± 0.00091 122413-35-8*0 Isourea NHC(OH)NH2 (g) -156.1 -172.7 ± 2.6 kJ/mol 60.05534 ± 0.00091 4744-36-9*0 1,1-Ethenediol CH2C(OH)2 (g) -307.66 -320.19 ± 0.83 kJ/mol 60.0520 ± 0.0017 10375-04-9*0 2-Methyl-2-propanamine (CH3)3CNH2 (l) -150.56 ± 0.54 kJ/mol 73.1369 ± 0.0033 75-64-9*590 2-Propene-1,2-diol CH2C(OH)CH2OH (g) -295.5 -314.5 ± 1.2 kJ/mol 74.0785 ± 0.0025 44169-27-9*0 Isocyanomethane CH3NC (cr,l) 146.4 ± 2.2 kJ/mol 41.0520 ± 0.0016 593-75-9*500 (Dimethylamino)methyl anion [(CH3)2NCH2]- (g) 190.5 166.3 ± 3.3 kJ/mol 58.1029 ± 0.0025 125231-49-4*0 Naphthalene cation [C6H4(C4H4)]+ (g) 956.84 933.76 ± 0.60 kJ/mol 128.1700 ± 0.0080 34512-27-1*0 Naphthalene anion [C6H4(C4H4)]- (g) 187.5 164.6 ± 3.0 kJ/mol 128.1711 ± 0.0080 34509-91-6*0 Trioxygen difluoride FOOOF (g, cis) 113.5 107.7 ± 2.0 kJ/mol 85.99501 ± 0.00090 16829-28-0*2 Carbamoyl anion [NH2CO]- (g) -81.9 -87.8 ± 3.1 kJ/mol 44.03327 ± 0.00087 78944-69-1*0 Pyridine anion [N(CHCHCHCHCH)]- (g) 214.4 200.9 ± 3.2 kJ/mol 79.1005 ± 0.0040 12169-63-0*0 Ethoxyethene CH2CHOCH2CH3 (g, trans-perp) -109.0 -132.2 ± 2.3 kJ/mol 72.1057 ± 0.0033 109-92-2*11 Carbamoyl HNCOH (g) 74.1 68.3 ± 2.7 kJ/mol 44.03272 ± 0.00087 *2858-51-7*0 Carbamoyl HNCOH (g, trans-cis) 76.4 69.9 ± 3.2 kJ/mol 44.03272 ± 0.00087 *2858-51-7*2 Oxiranylidene CH2(CO) (g) 213.5 209.3 ± 1.4 kJ/mol 42.0367 ± 0.0016 50983-85-2*0 Imidogen NH (g, singlet) 509.34 509.39 ± 0.17 kJ/mol 15.014680 ± 0.000099 13774-92-0*2 Cyanogen NCCN (cr,l) 273.94 289.19 ± 0.42 kJ/mol 52.0349 ± 0.0016 460-19-5*500 Hydrogen isocyanide anion [HNC]- (g) 191.60 191.78 ± 0.33 kJ/mol 27.02593 ± 0.00081 96913-22-3*0 Carbamoyl HNCOH (g, cis-trans) 96.3 90.1 ± 3.2 kJ/mol 44.03272 ± 0.00087 *2858-51-7*3 Isocyanogen anion [CNCN]- (g) 386.6 388.7 ± 3.3 kJ/mol 52.0354 ± 0.0016 *83951-85-3*0 Carbamoyl HNCOH (g, cis-cis) 110.9 104.8 ± 3.2 kJ/mol 44.03272 ± 0.00087 *2858-51-7*4 Hydrogen peroxide cation [H2O2]+ (g, trans, para) 897.32 890.31 ± 0.51 kJ/mol 34.01413 ± 0.00062 12325-10-9*12 C=O-C cation [COC]+ (g) 1585.8 1592.9 ± 2.7 kJ/mol 40.0203 ± 0.0016 83483-98-1*0 Cyanic fluoride anion [FCN]- (g) -20.6 -18.6 ± 2.9 kJ/mol 45.01639 ± 0.00080 34507-50-1*0 (Hydroxyimino)methyl HCNOH (g) 250.1 244.3 ± 1.8 kJ/mol 44.03272 ± 0.00087 206442-92-4*0 Trihydrogen HHH (g, TS) 254.5 250.7 ± 1.2 kJ/mol 3.02382 ± 0.00021 12184-91-7*200 Carbon C (g, quintuplet) 1114.974 1120.120 ± 0.044 kJ/mol 12.01070 ± 0.00080 7440-44-0*3 (Hydroxyimino)methyl HCNOH (g, cis-trans) 262.5 257.1 ± 2.5 kJ/mol 44.03272 ± 0.00087 206442-92-4*3 (Hydroxyimino)methyl HCNOH (g, cis-cis) 281.4 275.9 ± 2.5 kJ/mol 44.03272 ± 0.00087 206442-92-4*4 Butadiynylium [CCCCH]+ (g) 1781.3 1787.8 ± 3.2 kJ/mol 49.0502 ± 0.0032 76108-67-3*0 1,1-Ethenediol CH2C(OH)2 (g, syn-syn C2v) -302.4 -315.8 ± 1.9 kJ/mol 60.0520 ± 0.0017 10375-04-9*2 Trihydrogen cation [H3]+ (g, ortho) 1110.577 1106.695 ± 0.013 kJ/mol 3.02327 ± 0.00021 28132-48-1*1 1,2-Dichloroethene CHClCHCl (g) 3.82 -1.50 ± 0.55 kJ/mol 96.9427 ± 0.0024 540-59-0*0 Cyanic acid cation [HOCN]+ (g) 1135.7 1133.2 ± 2.9 kJ/mol 43.02423 ± 0.00086 59780-31-3*0 Nitrato [ON(O)O]+ (g) 1290.61 1285.90 ± 0.86 kJ/mol 62.00439 ± 0.00090 133057-96-2*0 Chlorine atom dianion [Cl]-2 (g) 406.6 408.2 ± 4.8 kJ/mol 35.45380 ± 0.00090 33944-49-9*0 Helium He (g, singlet) -0.000 -0.000 ± 0.000 kJ/mol 4.0026020 ± 0.0000020 7440-59-7*2 Isocyanic fluoride cation [FNC]+ (g) 1618.2 1618.8 ± 4.0 kJ/mol 45.01529 ± 0.00080 *16992-26-0*0 1-Methoxyethenol CH2C(OH)OCH3 (g) -284.3 -302.8 ± 1.2 kJ/mol 74.0785 ± 0.0025 4453-91-2*0 Helium dication [He]+2 (g) 7622.839 7622.839 ± 0.000 kJ/mol 4.0015048 ± 0.0000020 12587-46-1*0 Acetone enol CH3C(OH)CH2 (g) -151.35 -168.16 ± 0.69 kJ/mol 58.0791 ± 0.0025 29456-04-0*0 Formaldoxime CH2NOH (g) 30.5 19.9 ± 1.3 kJ/mol 45.04066 ± 0.00088 75-17-2*0 Diisocyanogen anion [CNNC]- (g) 456.8 462.5 ± 3.6 kJ/mol 52.0354 ± 0.0016 *78800-22-3*0 Chlorine chlorite ClOClO (g) 168.6 166.4 ± 1.3 kJ/mol 102.9042 ± 0.0019 105206-44-8*0 Acetone enol CH3C(OH)CH2 (g, anti) -145.3 -162.6 ± 1.9 kJ/mol 58.0791 ± 0.0025 29456-04-0*2 Dihelium He2 (g) 1733.310 1729.576 ± 0.018 kJ/mol 8.0052040 ± 0.0000040 12184-98-4*0 Dihelium He2 (g, singlet) 1761.349 1757.613 ± 0.018 kJ/mol 8.0052040 ± 0.0000040 12184-98-4*2 Ethenol CH2CHOH (g) -113.37 -123.71 ± 0.38 kJ/mol 44.0526 ± 0.0017 557-75-5*0 Hydrohelate [HeH]- (g) 143.256 139.027 ± 0.0021 kJ/mol 5.011091 ± 0.000070 12325-01-8*0 Bromomethane cation [CH3Br]+ (g) 996.21 981.30 ± 0.17 kJ/mol 94.9380 ± 0.0013 12538-70-4*0 Isocyanogen chloride cation [ClNC]+ (g) 1481.0 1482.3 ± 3.9 kJ/mol 61.4696 ± 0.0012 956475-91-5*0 Cyanic acid anion [HOCN]- (g) -9.2 -9.6 ± 3.1 kJ/mol 43.02533 ± 0.00086 58199-47-6*0 Phenol anion [C6H5OH]- (g) 22.8 7.9 ± 4.9 kJ/mol 94.1118 ± 0.0048 38752-11-3*0 Nitrogen sesquioxide cation [ONN(O)O]+ (g, vdW) 1027.7 1023.7 ± 4.8 kJ/mol 76.01113 ± 0.00091 *10544-73-7*0 Carbonylmethyloxonium [CH3OCO]+ (g) 561.3 553.1 ± 3.1 kJ/mol 59.0435 ± 0.0017 24434-00-2*0 Ethylene anion [CH2CH2]- (g) 232.1 225.6 ± 2.0 kJ/mol 28.0537 ± 0.0016 34527-91-8*0 1,2-Difluoroethene CHFCHF (g) -302.82 -308.91 ± 0.89 kJ/mol 64.0341 ± 0.0016 1691-13-0*0 Vinyl alcohol cation [CH2CHOH]+ (g) 778.6 767.6 ± 1.3 kJ/mol 44.0520 ± 0.0017 57239-63-1*0 Diiodine cation [I2]+ (g) 963.523 960.408 ± 0.018 kJ/mol 253.808391 ± 0.000060 28712-14-3*0 1-Propen-2-ol-1-yl CH3C(OH)CH (g) 101.57 90.22 ± 0.87 kJ/mol 57.0712 ± 0.0024 1976041-84-5*0 1-Propen-2-ol-1-yl CH3C(OH)CH (g, cis-cis) 106.5 94.5 ± 1.9 kJ/mol 57.0712 ± 0.0024 1976041-84-5*12 1-Propen-2-ol-1-yl CH3C(OH)CH (g, trans-trans) 114.0 102.8 ± 1.9 kJ/mol 57.0712 ± 0.0024 1976041-84-5*21 Neon decacation [Ne]+10 (g) 338828.3 338828.3 ± 1.4 kJ/mol 20.17421 ± 0.00060 32218-07-8*0 Neon hydride NeH (g) 215.989 211.755 ± 0.024 kJ/mol 21.18764 ± 0.00060 17438-52-7*0 Diisocyanogen cation [CNNC]+ (g) 1825.3 1828.5 ± 3.2 kJ/mol 52.0343 ± 0.0016 *78800-21-2*0 Hydroneonate [NeH]- (g) 143.096 142.084 ± 0.035 kJ/mol 21.18819 ± 0.00060 75514-98-6*0 Methoxyethene CH2CHOCH3 (g, trans) -82.1 -99.2 ± 2.4 kJ/mol 58.0791 ± 0.0025 107-25-5*1 Chlorine pentafluoride anion [FCl(F)(F)(F)F]- (g) -619.1 -622.6 ± 4.3 kJ/mol 130.44526 ± 0.00090 184851-42-1*0 Krypton dication [Kr]+2 (g) 3701.124 3701.124 ± 0.013 kJ/mol 83.7989 ± 0.1000 18469-91-5*0 1-Propen-2-ol-1-yl CH3C(OH)CH (g, cis-trans) 115.1 104.3 ± 1.9 kJ/mol 57.0712 ± 0.0024 1976041-84-5*22 Xenon dication [Xe]+2 (g) 3194.14 3194.14 ± 0.36 kJ/mol 131.2889 ± 0.0200 14066-95-6*0 Iodomethane cation [CH3I]+ (g) 944.69 935.29 ± 0.18 kJ/mol 141.93844 ± 0.00083 12538-72-6*0 2-Oxo-1-ethylium-1-yl [HCC(O)H]+ (g, quartet) 1289.4 1286.8 ± 2.5 kJ/mol 42.0361 ± 0.0016 214464-96-7*1 Cyclopentadienide [CH(CHCHCHCH)]- (g) 100.8 87.8 ± 1.1 kJ/mol 65.0937 ± 0.0040 12127-83-2*0 Diazoethenylidene cation [NNCC]+ (g) 1771.1 1773.1 ± 3.5 kJ/mol 52.0343 ± 0.0016 *130760-10-0*0 Oxirene O(CHCH) (g) 273.20 271.04 ± 0.92 kJ/mol 42.0367 ± 0.0016 157-18-6*0 Methoxyoxomethyl CH3OCO (g) -152.6 -160.3 ± 1.2 kJ/mol 59.0440 ± 0.0017 16481-04-2*0 1-Propen-1-yl-3-ylidene CHCHCH (g) 656.7 653.3 ± 1.1 kJ/mol 39.0559 ± 0.0024 84654-90-0*0 1-Cyanoethylidene CH3CCN (g) 437.6 433.8 ± 1.5 kJ/mol 53.0627 ± 0.0024 498544-34-6*0 Dioxymethylene HCOO (g) 341.8 339.8 ± 3.0 kJ/mol 45.0174 ± 0.0010 438586-67-5*0 Sulfur atom hexacation [S]+6 (g) 26947.2 26949.0 ± 3.4 kJ/mol 32.0627 ± 0.0060 22537-26-4*0 Diazoethenylidene anion [NNCC]- (g) 529.6 532.2 ± 3.5 kJ/mol 52.0354 ± 0.0016 *130760-11-1*0 Sulfur atom dianion [S]-2 (g) 454.1 455.9 ± 3.2 kJ/mol 32.0671 ± 0.0060 18496-25-8*0 Isocyanogen chloride anion [ClNC]- (g) 103.0 107.4 ± 3.9 kJ/mol 61.4707 ± 0.0012 923019-39-0*0 Disulfur cation [S2]+ (g) 1030.23 1030.82 ± 0.33 kJ/mol 64.1315 ± 0.0120 12597-02-3*0 Disulfur anion [S2]- (g) -34.0 -33.1 ± 1.2 kJ/mol 64.1325 ± 0.0120 12185-15-8*0 Difluorodioxidanium [FOOF]+ (g) 1283.7 1280.1 ± 2.3 kJ/mol 69.99506 ± 0.00060 *7783-44-0*0 Oxirene O(CHCH) (g, triplet) 387.9 384.5 ± 1.4 kJ/mol 42.0367 ± 0.0016 157-18-6*1 3H-diazirin-3-ylidene-methylene CC(NN) (g) 837.3 839.9 ± 2.3 kJ/mol 52.0349 ± 0.0016 204253-88-3*0 Sulfonyl cation [OSO]+ (g) 897.07 894.81 ± 0.13 kJ/mol 64.0643 ± 0.0060 12439-77-9*0 Carbon dianion [C]-2 (g) 1027.5 1033.0 ± 4.9 kJ/mol 12.01180 ± 0.00080 50802-47-6*0 Sulfur dioxide OSO (cr,l) -331.4 -320.1 ± 1.9 kJ/mol 64.0648 ± 0.0060 7446-09-5*500 1,1-Ethenediol CH2C(OH)2 (g, gauche-gauche C2) -296.1 -309.3 ± 1.9 kJ/mol 60.0520 ± 0.0017 10375-04-9*3 Hydrogen peroxide cation [H2O2]+ (g, cis, ortho) 931.07 924.18 ± 0.98 kJ/mol 34.01413 ± 0.00062 12325-10-9*21 2-Hydroxyethylium [CH2CH2OH]+ (g) 1019.1 1007.0 ± 1.5 kJ/mol 45.0600 ± 0.0017 38607-31-7*0 Difluorovinylidene anion [CCF2]- (g) -88.2 -87.1 ± 2.3 kJ/mol 62.0188 ± 0.0016 107693-92-5*0 Oxosulfate [SO]- (g) -102.59 -101.83 ± 0.50 kJ/mol 48.0659 ± 0.0060 12269-52-2*0 Fluorine atom F (g, 2P1/2) 82.088 83.873 ± 0.017 kJ/mol 18.99840320 ± 0.00000050 14762-94-8*2 Sulfur trioxide cation [OS(O)O]+ (g) 847.65 844.75 ± 0.68 kJ/mol 80.0637 ± 0.0061 12710-95-1*0 Ethynol cation [HCCOH]+ (g) 1063.8 1061.2 ± 2.9 kJ/mol 42.0361 ± 0.0016 84005-02-7*0 Sulfite [OS(O)O]-2 (g) -275.1 -280.7 ± 4.4 kJ/mol 80.0653 ± 0.0061 14265-45-3*0 1-Hydroxyethylidene CH3COH (g, singlet) 57.35 47.04 ± 0.77 kJ/mol 44.0526 ± 0.0017 30967-49-8*2 Methoxyoxomethyl CH3OCO (g, anti-eclipsed) -151.7 -159.8 ± 2.1 kJ/mol 59.0440 ± 0.0017 16481-04-2*3 Sulfur oxide peroxide OSOO (g) -25.9 -30.2 ± 2.3 kJ/mol 80.0642 ± 0.0061 175799-68-5*0 Dinitrogen anion [N2]- (g) 192.5 192.5 ± 1.7 kJ/mol 28.01403 ± 0.00014 12185-02-3*0 Sulfur oxide peroxide OSOO (g, trans) -3.4 -7.0 ± 3.0 kJ/mol 80.0642 ± 0.0061 175799-68-5*1 1-Propen-1-yl-3-ylidene CHCHCH (g, c-t quartet) 656.7 653.2 ± 2.0 kJ/mol 39.0559 ± 0.0024 84654-90-0*12 Acetylide [C2]-2 (g) 843.0 849.6 ± 3.2 kJ/mol 24.0225 ± 0.0016 34846-56-5*0 3-Imino-2-propen-1-ylidene CHCHCNH (g) 530.7 526.3 ± 1.2 kJ/mol 53.0627 ± 0.0024 916765-05-4*0 Disulfur oxide cation [SSO]+ (g) 970.66 969.38 ± 0.61 kJ/mol 80.1309 ± 0.0120 135758-60-0*0 Oxothioxosulfate [SSO]- (g) -231.82 -233.42 ± 0.87 kJ/mol 80.1319 ± 0.0120 12143-07-6*0 Methanediol CH2(OH)2 (g) -379.16 -392.55 ± 0.74 kJ/mol 48.0413 ± 0.0010 463-57-0*0 3-Imino-2-propen-1-ylidene CHCHCNH (g, triplet) 571.9 567.1 ± 1.6 kJ/mol 53.0627 ± 0.0024 916765-05-4*2 Sulfoniumyl [H2S]+ (g) 992.68 989.77 ± 0.19 kJ/mol 34.0813 ± 0.0060 26453-60-1*0 Dihydrogen sulfide ion [H2S]- (g) 108.3 106.9 ± 3.2 kJ/mol 34.0824 ± 0.0060 12311-21-6*0 Carbon trianion [C]-3 (g) 1813.2 1818.6 ± 5.9 kJ/mol 12.01235 ± 0.00080 50802-48-7*0 trans-Cycloheptene CH2(CHCHCH2CH2CH2CH2 (g) 141.9 103.8 ± 1.9 kJ/mol 96.1702 ± 0.0057 45509-99-7*0 Ethynol anion [HCCOH]- (g) 163.5 165.0 ± 3.3 kJ/mol 42.0372 ± 0.0016 864971-50-6*0 Ethynol HCCOH (g) 95.29 92.81 ± 0.78 kJ/mol 42.0367 ± 0.0016 32038-79-2*0 Sulfuric acid cation [OS(O)(OH)2]+ (g) 401.3 388.4 ± 3.3 kJ/mol 98.0789 ± 0.0061 247933-66-0*0 1-Hydroxyethylidene CH3COH (g) 57.35 47.04 ± 0.77 kJ/mol 44.0526 ± 0.0017 30967-49-8*0 Sulfate [SO4]-2 (aq) -909.09 ± 0.14 kJ/mol 96.0647 ± 0.0061 14808-79-8*800 Isoformyl anion [COH]- (g) 55.7 58.4 ± 1.8 kJ/mol 29.01859 ± 0.00086 81747-63-9*0 Glycolaldehyde HC(O)CH2OH (g) -304.46 -317.50 ± 0.90 kJ/mol 60.0520 ± 0.0017 141-46-8*0 Acetyloxoniumylidene [CH3C(O)O]+ (g, triplet) 892.3 883.8 ± 2.9 kJ/mol 59.0435 ± 0.0017 67057-47-0*1 1-Propen-1-yl-3-ylidene CHCHCH (g, t-t quartet) 665.8 662.3 ± 2.0 kJ/mol 39.0559 ± 0.0024 84654-90-0*13 Sulfuric acid OS(O)(OH)2 (aq, 1000 H2O) -892.16 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*839 Sulfuric acid OS(O)(OH)2 (aq, 1500 H2O) -893.34 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*840 Sulfuric acid OS(O)(OH)2 (aq, 2000 H2O) -894.29 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*841 Sulfuric acid OS(O)(OH)2 (aq, 3000 H2O) -895.76 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*842 Oxoethylidene anion [HCC(O)H]- (g) 86.9 84.2 ± 2.1 kJ/mol 42.0372 ± 0.0016 106543-38-8*0 Sulfuric acid OS(O)(OH)2 (aq, 1250 H2O) -892.80 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*954 Bicyclo[1.1.0]buta-1,3-diene-2,4-diyl C(CC)C (g, triplet) 1133.2 1141.0 ± 2.7 kJ/mol 48.0428 ± 0.0032 12184-80-4*1 Ethynol HCCOH (g, t-c triplet) 406.4 403.2 ± 3.2 kJ/mol 42.0367 ± 0.0016 32038-79-2*12 Dichlorovinylidene CCCl2 (g) 424.3 427.5 ± 3.0 kJ/mol 94.9268 ± 0.0024 20394-25-6*0 Ethynol HCCOH (g, t-t triplet) 409.4 406.3 ± 3.2 kJ/mol 42.0367 ± 0.0016 32038-79-2*13 Sulfur hydroxide oxide OHS(O)(O)O (g) -473.9 -482.9 ± 1.7 kJ/mol 97.0715 ± 0.0061 12337-07-4*0 Sulfur hydroxide oxide OHS(O)(O)O (g, eclipsed) -473.2 -482.4 ± 2.5 kJ/mol 97.0715 ± 0.0061 12337-07-4*2 Sulfur hydroxide oxide cation [OHS(O)(O)O]+ (g) 659.1 648.9 ± 3.5 kJ/mol 97.0710 ± 0.0061 *12337-07-4*0 Sulfur hydroxide oxide cation [OHS(O)(O)O]+ (g, staggered) 663.6 652.7 ± 4.0 kJ/mol 97.0710 ± 0.0061 *12337-07-4*1 Chlorovinylidene CCHCl (g) 429.2 430.9 ± 2.9 kJ/mol 60.4820 ± 0.0018 70277-82-6*0 2-(Methylidyneamino)ethenyl CHCHNCH (g) 600.7 596.4 ± 1.2 kJ/mol 53.0627 ± 0.0024 123416-74-0*0 Sulfurous acid S(O)(OH)2 (g, trans) -506.9 -517.5 ± 1.3 kJ/mol 82.0801 ± 0.0061 7782-99-2*1 Sulfurous acid S(O)(OH)2 (g, gauche) -497.3 -507.4 ± 1.4 kJ/mol 82.0801 ± 0.0061 7782-99-2*3 Ethynol HCCOH (g, c-t triplet) 455.5 452.2 ± 3.2 kJ/mol 42.0367 ± 0.0016 32038-79-2*14 1,2-Butadiene CH3CHCCH2 (cr,l) 137.79 138.85 ± 0.64 kJ/mol 54.0904 ± 0.0032 590-19-2*500 Peroxychlorous acid HOOClO (g) 95.4 89.8 ± 2.0 kJ/mol 84.4588 ± 0.0013 177778-92-6*0 Sulfite [OS(O)O]-2 (aq) -635.3 ± 4.0 kJ/mol 80.0653 ± 0.0061 14265-45-3*800 Hydroxyformyl HOCO (g) -181.18 -183.73 ± 0.42 kJ/mol 45.0174 ± 0.0010 2564-86-5*0 Sulfurous acid S(O)(OH)2 (aq, 500 H2O) -615.38 ± 0.15 kJ/mol 82.0801 ± 0.0061 7782-99-2*833 Sulfurous acid S(O)(OH)2 (aq, 1000 H2O) -616.99 ± 0.15 kJ/mol 82.0801 ± 0.0061 7782-99-2*839 Sulfurous acid S(O)(OH)2 (aq, 1500 H2O) -618.10 ± 0.15 kJ/mol 82.0801 ± 0.0061 7782-99-2*840 Sulfurous acid S(O)(OH)2 (aq, 2000 H2O) -618.86 ± 0.15 kJ/mol 82.0801 ± 0.0061 7782-99-2*841 Sulfurous acid S(O)(OH)2 (aq, 3000 H2O) -619.90 ± 0.15 kJ/mol 82.0801 ± 0.0061 7782-99-2*842 Sulfonic acid SH(O)(O)OH (g) -482.1 -494.6 ± 1.4 kJ/mol 82.0801 ± 0.0061 *7782-99-2*0 2-(Methylidyneamino)ethenyl CHCHNCH (g, triplet) 634.5 630.5 ± 1.6 kJ/mol 53.0627 ± 0.0024 123416-74-0*2 Bisulfite cation [OS(OH)O]+ (g) 556.0 547.3 ± 3.2 kJ/mol 81.0716 ± 0.0061 43637-78-1*0 Ethynol HCCOH (g, c-c triplet) 464.2 460.9 ± 3.2 kJ/mol 42.0367 ± 0.0016 32038-79-2*15 Water H2O (cr, eq.press.) -286.269 -292.710 ± 0.025 kJ/mol 18.01528 ± 0.00033 7732-18-5*509 Hydroxyformyl anion [HOCO]- (g) -319.54 -321.40 ± 0.57 kJ/mol 45.0180 ± 0.0010 78944-70-4*0 Platinum atom cation Pt+ (g) 1427.8 1428.3 ± 1.7 kJ/mol 195.0775 ± 0.0020 20561-56-2*0 Platinum atom anion Pt- (g) 358.4 358.9 ± 1.7 kJ/mol 195.0785 ± 0.0020 40817-31-0*0 Nitrogen atom N (g, doublet) 700.555 702.458 ± 0.024 kJ/mol 14.006740 ± 0.000070 17778-88-0*2 Platinum dimer cation [Pt2]+ (g) 1661.0 1659.6 ± 4.3 kJ/mol 390.1555 ± 0.0040 73146-08-4*0 Platinum dimer anion [Pt2]- (g) 640.3 639.8 ± 3.9 kJ/mol 390.1565 ± 0.0040 153298-77-2*0 m-Tolualdehyde CH3C6H4C(O)H (cr, l, meta) -125.6 ± 1.3 kJ/mol 120.1485 ± 0.0064 620-23-5*500 Platinum hydride cation [PtH]+ (g) 1336. 1355. ± 22. kJ/mol 196.0854 ± 0.0020 87882-39-1*0 Fluoromethane cation [CH3F]+ (g) 981.83 974.33 ± 0.62 kJ/mol 34.03237 ± 0.00083 59122-96-2*0 Hydrogen atom H (ad, Pt(111) fcc) -37.0 -40.2 ± 1.1 kJ/mol 1.007940 ± 0.000070 12385-13-6*1001000 Peroxyhypochlorous acid cation [HOOCl]+ (g) 1030.4 1024.6 ± 2.5 kJ/mol 68.4589 ± 0.0011 *67952-07-2*0 Hydrazine anion [NH2NH2]- (g) 232.3 217.9 ± 4.1 kJ/mol 32.04579 ± 0.00031 65391-88-0*0 Fluoromethane CH3F (l) -245.73 ± 0.45 kJ/mol 34.03292 ± 0.00083 593-53-3*590 Hydroxymethylene anion [HCOH]- (g) 147.2 144.2 ± 1.6 kJ/mol 30.02653 ± 0.00087 207914-87-2*0 Hydrogen atom H (ad, Pt(111) atop) -32. -34. ± 20. kJ/mol 1.007940 ± 0.000070 12385-13-6*1002000 1-Propen-1-yl-3-ylidene CHCHCH (g, doublet) 699.3 696.4 ± 3.4 kJ/mol 39.0559 ± 0.0024 84654-90-0*2 Carbonate [OC(O)O]-2 (aq) -675.159 ± 0.055 kJ/mol 60.0100 ± 0.0012 3812-32-6*800 Phenol cation [C6H5OH]+ (g) 746.18 727.39 ± 0.64 kJ/mol 94.1107 ± 0.0048 40932-22-7*0 Hydroxymethylene cation [HCOH]+ (g) 971.9 968.3 ± 1.4 kJ/mol 30.02543 ± 0.00087 135395-06-1*0 Dinitrogen tetraoxide O2NNO2 (cr,l) -37.82 -26.97 ± 0.19 kJ/mol 92.0111 ± 0.0012 10544-72-6*500 1,3-Butadienylium [CH2CHCHCH]+ (g) 1133.6 1123.6 ± 2.5 kJ/mol 53.0820 ± 0.0032 86181-69-3*0 Argon cation Ar+ (g) 1520.571 1520.580 ± 0.000 kJ/mol 39.94745 ± 0.00100 14791-69-6*0 Argon dimer cation [Ar2]+ (g) 1393.760 1391.173 ± 0.018 kJ/mol 79.8955 ± 0.0020 17596-58-6*0 Argon atom dication [Ar]+2 (g) 4186.429 4186.468 ± 0.013 kJ/mol 39.94690 ± 0.00100 15056-24-3*0 Argon dimer Ar2 (g) -1.013 -6.347 ± 0.0051 kJ/mol 79.8960 ± 0.0020 12595-59-4*0 Helium anion He- (g, 1s2.2s 2S1/2) 51. 51. ± 130. kJ/mol 4.0031506 ± 0.0000020 14452-58-5*1 Helium anion He- (g) 51. 51. ± 130. kJ/mol 4.0031506 ± 0.0000020 14452-58-5*0 Argon anion Ar- (g, 2S1/2) 23. 23. ± 75. kJ/mol 39.94855 ± 0.00100 16544-90-4*1 Argon anion Ar- (g) 23. 23. ± 75. kJ/mol 39.94855 ± 0.00100 16544-90-4*0 Helium anion He- (g, 1s.2s2 2S1/2) 1868.42 1868.42 ± 0.19 kJ/mol 4.0031506 ± 0.0000020 14452-58-5*2 Argon anion Ar- (g, 4S3/2) 1111.116 1111.116 ± 0.098 kJ/mol 39.94855 ± 0.00100 16544-90-4*2 Radon cation Rn+ (g) 1037.07 1037.07 ± 0.61 kJ/mol 221.9995 ± 0.1000 22541-65-7*0 Hydron H+ (aq) 0 0 exact 1.007391 ± 0.000070 12408-02-5*800
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Thermochemistry
Computer Aided Chem. Eng. 45 , 3-114 (2019)
[DOI: 10.1016/B978-0-444-64087-1.00001-2]
Formula
The aggregate state is given in parentheses following the formula, such as: g - gas-phase, cr - crystal, l - liquid, etc.
Uncertainties
The listed uncertainties correspond to estimated 95% confidence limits, as customary in thermochemistry (see, for example, Ruscic [6,7 ]).
Note that an uncertainty of ± 0.000 kJ/mol indicates that the estimated uncertainty is < ± 0.0005 kJ/mol.
Website Functionality Credits
The reorganization of the website was developed and implemented by David H. Bross (ANL).
The find function is based on the complete Species Dictionary entries for the appropriate version of the ATcT TN.
The molecule images are rendered by Indigo-depict .
The XYZ renderings are based on Jmol: an open-source Java viewer for chemical structures in 3D. http://www.jmol.org/ .
Acknowledgement
This work was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences under Contract No. DE-AC02-06CH11357.
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