ATcT [1 , 2 ] enthalpies of formation based on version 1.124 of the Thermochemical Network [3 ]
Below is a list of 0 K and 298.15 K enthalpies of formation
for all 2791 species included in version 1.124 (as of 09/01/2022). This version of ATcT results was generated by additional expansion of version 1.122x [4 ] to include additional information relevant to the study of thermophysical and thermochemical properties of CH2 and CH3 using nonrigid rotor anharmonic oscillator (NRRAO) partition functions [5 ], the development and benchmarking of a state-of-the-art computational approach that aims to reproduce total atomization energies of small molecules within 10–15 cm-1 [6 ], as well as the study of the reversible reaction C2 H3 + H2 ⇌ C2 H4 + H ⇌ C2 H5 [7 ]
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) 711.404 716.889 ± 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) -66.551 -74.520 ± 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 Water H2O (cr,l) -286.268 -285.796 ± 0.025 kJ/mol 18.01528 ± 0.00033 7732-18-5*500 Carbon dioxide CO2 (g) -393.110 -393.476 ± 0.015 kJ/mol 44.00950 ± 0.00100 124-38-9*0 Ethane CH3CH3 (g) -68.39 -84.02 ± 0.12 kJ/mol 30.0690 ± 0.0017 74-84-0*0 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) 77.252 79.358 ± 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 Methyl CH3 (g) 149.872 146.471 ± 0.053 kJ/mol 15.03452 ± 0.00083 2229-07-4*0 Propane CH3CH2CH3 (g) -82.72 -105.00 ± 0.16 kJ/mol 44.0956 ± 0.0025 74-98-6*0 Methanol CH3OH (g) -190.04 -200.92 ± 0.15 kJ/mol 32.04186 ± 0.00090 67-56-1*0 Ammonia NH3 (g) -38.563 -45.556 ± 0.029 kJ/mol 17.03056 ± 0.00022 7664-41-7*0 Hydroxyl OH (g) 37.283 37.522 ± 0.025 kJ/mol 17.00734 ± 0.00031 3352-57-6*0 Bromine atom Br (g) 117.910 111.847 ± 0.056 kJ/mol 79.90400 ± 0.00100 10097-32-2*0 Formaldehyde CH2O (g) -105.389 -109.229 ± 0.096 kJ/mol 30.02598 ± 0.00087 50-00-0*0 Acetylene HCCH (g) 228.88 228.32 ± 0.13 kJ/mol 26.0373 ± 0.0016 74-86-2*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 Hydrogen chloride HCl (g) -91.988 -92.172 ± 0.0062 kJ/mol 36.46064 ± 0.00090 7647-01-0*0 Hydrogen fluoride HF (g) -272.680 -272.727 ± 0.019 kJ/mol 20.006343 ± 0.000070 7664-39-3*0 Benzene C6H6 (g) 100.75 83.23 ± 0.22 kJ/mol 78.1118 ± 0.0048 71-43-2*0 Ethyl CH3CH2 (g) 131.38 120.63 ± 0.22 kJ/mol 29.0611 ± 0.0016 2025-56-1*0 Propene CH3CHCH2 (g) 34.85 20.02 ± 0.19 kJ/mol 42.0797 ± 0.0024 115-07-1*0 Hydrogen cyanide HCN (g) 129.678 129.294 ± 0.089 kJ/mol 27.02538 ± 0.00081 74-90-8*0 Iodine I (g) 107.157 106.757 ± 0.0021 kJ/mol 126.904470 ± 0.000030 14362-44-8*0 Hydrogen bromide HBr (g) -27.88 -35.73 ± 0.13 kJ/mol 80.9119 ± 0.0010 10035-10-6*0 Nitric oxide NO (g) 90.638 91.142 ± 0.066 kJ/mol 30.00614 ± 0.00031 10102-43-9*0 Chloromethane CH3Cl (g) -74.73 -82.66 ± 0.16 kJ/mol 50.4872 ± 0.0012 74-87-3*0 Propyne CH3CCH (g) 192.67 185.51 ± 0.22 kJ/mol 40.0639 ± 0.0024 74-99-7*0 Acetaldehyde CH3CHO (g) -155.03 -165.55 ± 0.23 kJ/mol 44.0526 ± 0.0017 75-07-0*0 Hydroxyde [OH]- (g) -139.059 -139.025 ± 0.025 kJ/mol 17.00789 ± 0.00031 14280-30-9*0 Nitrogen dioxide ONO (g) 36.878 34.071 ± 0.066 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 Methylamine CH3NH2 (g) -6.54 -21.25 ± 0.23 kJ/mol 31.05714 ± 0.00088 74-89-5*0 Dioxidanyl HO2 (g) 15.14 12.23 ± 0.15 kJ/mol 33.00674 ± 0.00060 3170-83-0*0 Fluoromethane CH3F (g) -227.48 -235.51 ± 0.23 kJ/mol 34.03292 ± 0.00083 593-53-3*0 Hydrogen iodide HI (g) 28.643 26.467 ± 0.036 kJ/mol 127.912410 ± 0.000076 10034-85-2*0 Hydrogen peroxide H2O2 (g) -129.411 -135.397 ± 0.061 kJ/mol 34.01468 ± 0.00062 7722-84-1*0 Vinyl CH2CH (g) 301.26 297.22 ± 0.30 kJ/mol 27.0452 ± 0.0016 2669-89-8*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) 197.40 189.95 ± 0.23 kJ/mol 40.0639 ± 0.0024 463-49-0*0 Methylene CH2 (g, triplet) 391.054 391.600 ± 0.096 kJ/mol 14.02658 ± 0.00081 2465-56-7*1 Ammonium hydroxide NH4OH (aq, 1000 H2O) -366.37 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*839 Methylene CH2 (g, singlet) 428.71 429.13 ± 0.11 kJ/mol 14.02658 ± 0.00081 2465-56-7*2 Nitrilomethyl CN (g) 436.73 440.02 ± 0.14 kJ/mol 26.01744 ± 0.00080 2074-87-5*0 Silicon Si (g) 450.37 454.70 ± 0.59 kJ/mol 28.08550 ± 0.00030 7440-21-3*0 Hydrogen chloride HCl (aq, 100 H2O) -165.755 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*828 Bromomethane CH3Br (g) -20.91 -36.31 ± 0.16 kJ/mol 94.9385 ± 0.0013 74-83-9*0 1,3-Butadiene CH2CHCHCH2 (g) 125.54 111.07 ± 0.32 kJ/mol 54.0904 ± 0.0032 106-99-0*0 Hydrogen iodide HI (aq, 5000 H2O) -56.646 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*844 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) 28.92 21.55 ± 0.27 kJ/mol 31.03392 ± 0.00088 2143-68-2*0 Formic acid HC(O)OH (g, syn) -371.05 -378.37 ± 0.22 kJ/mol 46.0254 ± 0.0010 64-18-6*1 Acetic acid CH3C(O)OH (aq, 100 H2O) -484.66 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*828 Fluoride F- (g) -250.912 -249.128 ± 0.017 kJ/mol 18.99895178 ± 0.00000050 16984-48-8*0 Hydrogen bromide HBr (aq, 3000 H2O) -120.64 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*842 iso-Butane CH(CH3)3 (g) -105.88 -134.48 ± 0.28 kJ/mol 58.1222 ± 0.0033 75-28-5*0 Formic acid HC(O)OH (aq, 100 H2O) -425.30 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*828 Silane SiH4 (g) 42.75 33.13 ± 0.66 kJ/mol 32.11726 ± 0.00041 7803-62-5*0 Hydrogen fluoride HF (l) -303.21 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*590 Hypochlorous acid HOCl (g) -73.835 -76.775 ± 0.026 kJ/mol 52.46004 ± 0.00095 7790-92-3*0 Ketene CH2CO (g) -45.36 -48.42 ± 0.11 kJ/mol 42.0367 ± 0.0016 463-51-4*0 Phenyl C6H5 (g) 352.15 338.79 ± 0.63 kJ/mol 77.1039 ± 0.0048 2396-01-2*0 Methoxide [CH3O]- (g) -122.47 -130.20 ± 0.27 kJ/mol 31.03447 ± 0.00088 3315-60-4*0 Dibromine Br2 (g) 45.67 30.87 ± 0.11 kJ/mol 159.8080 ± 0.0020 7726-95-6*0 Amidogen NH2 (g) 188.92 186.03 ± 0.11 kJ/mol 16.02262 ± 0.00016 13770-40-6*0 Acetic acid CH3C(O)OH (g, syn) -418.53 -432.70 ± 0.36 kJ/mol 60.0520 ± 0.0017 64-19-7*1 Tetrafluoromethane CF4 (g) -927.77 -933.74 ± 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 Propargyl CH2CCH (g) 354.05 351.46 ± 0.32 kJ/mol 39.0559 ± 0.0024 2932-78-7*0 Formyl HCO (g) 41.381 41.755 ± 0.096 kJ/mol 29.01804 ± 0.00086 2597-44-6*0 Allyl CH2CHCH2 (g) 179.95 168.23 ± 0.39 kJ/mol 41.0718 ± 0.0024 1981-80-2*0 Hydroxymethyl CH2OH (g) -10.37 -16.67 ± 0.28 kJ/mol 31.03392 ± 0.00088 2597-43-5*0 Chloroethane CH3CH2Cl (g) -96.95 -111.54 ± 0.25 kJ/mol 64.5138 ± 0.0019 75-00-3*0 Methylidyne CH (g) 592.837 596.171 ± 0.097 kJ/mol 13.01864 ± 0.00080 3315-37-5*0 Ethynyl CCH (g) 563.76 567.88 ± 0.15 kJ/mol 25.0293 ± 0.0016 2122-48-7*0 Fluoroform CHF3 (g) -689.34 -696.29 ± 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) -464.92 -467.72 ± 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 Methanimine CH2NH (g) 96.42 88.51 ± 0.36 kJ/mol 29.04126 ± 0.00083 2053-29-4*0 Phenol C6H5OH (g) -74.67 -93.26 ± 0.63 kJ/mol 94.1112 ± 0.0048 108-95-2*0 Tetrachloromethane CCl4 (g) -89.36 -91.53 ± 0.41 kJ/mol 153.8215 ± 0.0037 56-23-5*0 Sulfur dioxide OSO (g) -294.13 -296.67 ± 0.13 kJ/mol 64.0648 ± 0.0060 7446-09-5*0 Bromide Br- (g) -206.627 -212.690 ± 0.056 kJ/mol 79.90455 ± 0.00100 24959-67-9*0 Oxomethylium [HCO]+ (g) 827.757 827.172 ± 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 Ethenol CH2CHOH (g, syn) -113.38 -124.50 ± 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) -19.77 -37.56 ± 0.77 kJ/mol 106.1219 ± 0.0056 100-52-7*0 Ethylamine CH3CH2NH2 (g) -28.11 -49.88 ± 0.46 kJ/mol 45.0837 ± 0.0017 75-04-7*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) -114.87 -127.69 ± 0.46 kJ/mol 48.0413 ± 0.0010 3031-73-0*0 iso-Propyl CH3CHCH3 (g) 105.57 88.70 ± 0.44 kJ/mol 43.0877 ± 0.0024 2025-55-0*0 Acetyl CH3CO (g) -3.46 -10.03 ± 0.30 kJ/mol 43.0446 ± 0.0016 3170-69-2*0 Formamide CH(O)NH2 (g) -178.59 -188.95 ± 0.35 kJ/mol 45.04066 ± 0.00088 75-12-7*0 n-Propyl CH3CH2CH2 (g) 118.38 100.98 ± 0.47 kJ/mol 43.0877 ± 0.0024 2143-61-5*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 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) -124.47 -134.18 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*0 Ethoxide [CH3CH2O]- (g) -163.87 -178.81 ± 0.44 kJ/mol 45.0610 ± 0.0017 16331-64-9*0 Methoxymethane CH3OCH3 (g) -166.51 -184.01 ± 0.37 kJ/mol 46.0684 ± 0.0017 115-10-6*0 Methylperoxy CH3OO (g) 22.52 13.07 ± 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 Methylium [CH3]+ (g) 1099.345 1095.402 ± 0.049 kJ/mol 15.03397 ± 0.00083 14531-53-4*0 Isocyanic acid HNCO (g) -115.96 -118.95 ± 0.28 kJ/mol 43.02478 ± 0.00086 75-13-8*0 Difluorophosgene CF2O (g) -603.36 -606.46 ± 0.40 kJ/mol 66.00691 ± 0.00085 353-50-4*0 Hypofluorous acid HOF (g) -84.37 -87.27 ± 0.19 kJ/mol 36.00574 ± 0.00031 14034-79-8*0 Oxygen atom anion O- (g) 105.868 108.097 ± 0.0021 kJ/mol 15.99995 ± 0.00030 14337-01-0*0 Nitric acid HON(O)O (aq, 1000 H2O) -206.24 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*839 Iodomethane CH3I (g) 24.39 14.86 ± 0.18 kJ/mol 141.93899 ± 0.00083 74-88-4*0 N-Methylenemethanamine CH3NCH2 (g) 94.50 79.58 ± 0.68 kJ/mol 43.0678 ± 0.0016 1761-67-7*0 Dichloromethane CH2Cl2 (g) -86.92 -93.77 ± 0.33 kJ/mol 84.9320 ± 0.0020 75-09-2*0 1,3-Butadiyne HCCCCH (g) 458.36 460.08 ± 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 Hydrogen chloride HCl (aq, 600 H2O) -166.449 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*834 Ethynide [CCH]- (g) 277.32 280.73 ± 0.19 kJ/mol 25.0299 ± 0.0016 29075-95-4*0 1,2-Butadiene CH3CHCCH2 (g) 176.02 162.52 ± 0.43 kJ/mol 54.0904 ± 0.0032 590-19-2*0 Dimethylamine (CH3)2NH (g) 4.21 -17.43 ± 0.40 kJ/mol 45.0837 ± 0.0017 124-40-3*0 Trihydrogen cation [H3]+ (g) 1110.304 1106.696 ± 0.013 kJ/mol 3.02327 ± 0.00021 28132-48-1*0 Hydride H- (g) 143.264 145.228 ± 0.000 kJ/mol 1.008489 ± 0.000070 12184-88-2*0 Cyanogen chloride ClCN (g) 135.17 135.86 ± 0.46 kJ/mol 61.4701 ± 0.0012 506-77-4*0 Isocyanomethane CH3NC (g) 183.84 177.30 ± 0.48 kJ/mol 41.0520 ± 0.0016 593-75-9*0 Cyclopropane CH2(CH2CH2) (g) 71.00 53.88 ± 0.38 kJ/mol 42.0797 ± 0.0024 75-19-4*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 -359.99 ± 0.65 kJ/mol 60.0520 ± 0.0017 107-31-3*1 Sulfur trioxide OS(O)O (g) -389.74 -395.49 ± 0.24 kJ/mol 80.0642 ± 0.0061 7446-11-9*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 (aq, 2500 H2O) -619.41 ± 0.14 kJ/mol 82.0801 ± 0.0061 7782-99-2*898 Ammonium [NH4]+ (g) 643.01 631.69 ± 0.20 kJ/mol 18.03795 ± 0.00029 14798-03-9*0 2-Butyne CH3CCCH3 (g) 159.42 146.45 ± 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) 151.45 134.33 ± 0.61 kJ/mol 66.1011 ± 0.0040 542-92-7*0 Difluoromethane CH2F2 (g) -443.38 -450.99 ± 0.33 kJ/mol 52.02339 ± 0.00081 75-10-5*0 Silyl SiH3 (g) 204.79 199.32 ± 0.86 kJ/mol 31.10932 ± 0.00037 13765-44-1*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 Nitrosyl hydride HNO (g) 109.94 106.97 ± 0.11 kJ/mol 31.01408 ± 0.00032 14332-28-6*0 Propynylidene HCCCH (g, triplet) 543.50 546.49 ± 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 -12.64 ± 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 -373.95 ± 0.84 kJ/mol 74.0785 ± 0.0025 116-09-6*11 Chloroform CHCl3 (g) -94.65 -99.55 ± 0.39 kJ/mol 119.3767 ± 0.0028 67-66-3*0 Tetrafluoroethylene CF2CF2 (g) -670.77 -674.17 ± 0.49 kJ/mol 100.0150 ± 0.0016 116-14-3*0 Fluoromethylidyne CF (g) 243.12 246.72 ± 0.12 kJ/mol 31.00910 ± 0.00080 3889-75-6*0 Phenide [C6H5]- (g) 244.40 230.98 ± 0.39 kJ/mol 77.1044 ± 0.0048 30922-78-2*0 Acrylonitrile CH2CHCN (g, singlet) 193.81 187.05 ± 0.66 kJ/mol 53.0627 ± 0.0024 107-13-1*1 Silanol SiH3OH (g) -271.1 -282.8 ± 1.3 kJ/mol 48.11666 ± 0.00051 14475-38-8*0 Nitrous acid HONO (g, trans) -72.970 -79.113 ± 0.079 kJ/mol 47.01348 ± 0.00061 7782-77-6*1 1,2-Propadiene-1,3-diylidene CCC (g) 814.55 823.50 ± 0.53 kJ/mol 36.0321 ± 0.0024 12075-35-3*0 Oxirane O(CH2CH2) (g) -39.97 -52.51 ± 0.35 kJ/mol 44.0526 ± 0.0017 75-21-8*0 Vinyl anion [CH2CH]- (g) 237.03 232.61 ± 0.68 kJ/mol 27.0458 ± 0.0016 25012-81-1*0 Methylamidogen CH3NH (g) 187.89 177.24 ± 0.40 kJ/mol 30.04920 ± 0.00085 15622-51-2*0 Cyanide [CN]- (g) 63.974 67.260 ± 0.093 kJ/mol 26.01799 ± 0.00080 57-12-5*0 Cyanogen bromide BrCN (g) 186.5 180.0 ± 1.4 kJ/mol 105.9214 ± 0.0013 506-68-3*0 Oxygen atom cation O+ (g) 1560.786 1562.643 ± 0.0021 kJ/mol 15.99885 ± 0.00030 14581-93-2*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) -463.17 -466.82 ± 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 -63.27 ± 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) -55.54 -67.32 ± 0.45 kJ/mol 61.0401 ± 0.0010 624-91-9*2 Naphthalene C6H4(C4H4) (g) 171.07 147.60 ± 0.59 kJ/mol 128.1705 ± 0.0080 91-20-3*0 Chlorine fluoride ClF (g) -55.623 -55.718 ± 0.030 kJ/mol 54.45110 ± 0.00090 7790-89-8*0 Diazynium [NNH]+ (g) 1042.52 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 Aminomethyl CH2NH2 (g) 159.35 149.51 ± 0.36 kJ/mol 30.04920 ± 0.00085 10507-29-6*0 n-Butyl CH3CH2CH2CH2 (g) 102.99 80.48 ± 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) 142.8 113.2 ± 1.1 kJ/mol 331.6267 ± 0.0041 558-13-4*0 Vinyl fluoride CH2CHF (g) -134.54 -142.34 ± 0.45 kJ/mol 46.0436 ± 0.0016 75-02-5*0 Phenylium [C6H5]+ (g) 1149.15 1136.37 ± 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 Azanide [NH2]- (g) 114.71 111.84 ± 0.29 kJ/mol 16.02317 ± 0.00016 17655-31-1*0 Methanium [CH5]+ (g) 921.98 911.73 ± 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) 8.59 8.92 ± 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) 126.94 127.41 ± 0.33 kJ/mol 42.01684 ± 0.00086 22400-26-6*0 Aziridine NH(CH2CH2) (g) 143.25 126.72 ± 0.89 kJ/mol 43.0678 ± 0.0016 151-56-4*0 Methanetetraylbisamidogen NCN (g) 451.24 451.65 ± 0.44 kJ/mol 40.02418 ± 0.00081 2669-76-3*0 Fluoroethane CH3CH2F (g) -257.24 -272.10 ± 0.36 kJ/mol 48.0595 ± 0.0016 353-36-6*0 Chlorotrifluoromethane CF3Cl (g) -704.36 -709.47 ± 0.56 kJ/mol 104.4586 ± 0.0012 75-72-9*0 Fluorobenzene C6H5F (g) -99.41 -115.09 ± 0.88 kJ/mol 96.1023 ± 0.0048 462-06-6*0 Nitromethane CH3N(O)O (g) -60.75 -74.64 ± 0.46 kJ/mol 61.0401 ± 0.0010 75-52-5*0 Pyridine N(CHCHCHCHCH) (g) 157.36 140.55 ± 0.40 kJ/mol 79.0999 ± 0.0040 110-86-1*0 Acrylonitrile CH2CHCN (g) 193.81 187.05 ± 0.66 kJ/mol 53.0627 ± 0.0024 107-13-1*0 1,2,3-Butatrien-1-yl CH2CCCH (g) 497.43 497.44 ± 0.69 kJ/mol 51.0666 ± 0.0032 22112-56-7*0 Disilane SiH3SiH3 (g) 92.2 76.1 ± 1.4 kJ/mol 62.21864 ± 0.00073 1590-87-0*0 2,4-Hexadiyne CH3CCCCCH3 (g) 380.23 370.20 ± 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) 820.005 828.470 ± 0.092 kJ/mol 24.0214 ± 0.0016 12070-15-4*0 Methylidyne CH (g, quartet) 664.59 667.93 ± 0.54 kJ/mol 13.01864 ± 0.00080 3315-37-5*2 Ethanide [CH3CH2]- (g) 155.44 144.36 ± 0.87 kJ/mol 29.0616 ± 0.0016 25013-41-6*0 Vinylium [CH2CH]+ (g) 1119.08 1115.63 ± 0.55 kJ/mol 27.0447 ± 0.0016 14604-48-9*0 Hydroxymethylium [CH2OH]+ (g) 717.67 709.73 ± 0.19 kJ/mol 31.03337 ± 0.00088 18682-95-6*0 Hydroxymethylene HCOH (g, trans) 112.68 108.91 ± 0.27 kJ/mol 30.02598 ± 0.00087 19710-56-6*1 Peroxyformic acid HC(O)OOH (g, cis) -279.22 -288.57 ± 0.88 kJ/mol 62.0248 ± 0.0012 107-32-4*1 1,2-Propadienyl anion [CH2CCH]- (g) 266.06 263.00 ± 0.64 kJ/mol 39.0565 ± 0.0024 64066-06-4*0 Propadienylidene CH2CC (g) 554.43 555.58 ± 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) -43.68 -76.25 ± 0.41 kJ/mol 70.1329 ± 0.0041 287-92-3*0 Vinoxy CH2CHO (g) 23.04 16.24 ± 0.57 kJ/mol 43.0446 ± 0.0016 6912-06-7*0 Propionaldehyde CH3CH2CHO (g) -171.22 -186.62 ± 0.24 kJ/mol 58.0791 ± 0.0025 123-38-6*0 Phenolate [C6H5O]- (g) -146.43 -161.90 ± 0.84 kJ/mol 93.1038 ± 0.0048 3229-70-7*0 (1E)-Ethanimine CH3CHNH (g, trans) 55.71 39.50 ± 0.73 kJ/mol 43.0678 ± 0.0016 56003-81-7*0 Bromotrifluoromethane CF3Br (g) -638.73 -650.84 ± 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) 275.23 262.12 ± 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) 547.70 539.30 ± 0.91 kJ/mol 52.0746 ± 0.0032 157-39-1*0 Silylene SiH2 (g, singlet) 271.44 269.77 ± 0.86 kJ/mol 30.10138 ± 0.00033 13825-90-6*2 Hydrogen sulfide H2S (g) -17.34 -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 (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 (E)-Iminomethyl HCNH (g, trans) 275.81 272.20 ± 0.56 kJ/mol 28.03332 ± 0.00082 54980-10-8*0 Cyanogen NCCN (g) 308.17 310.12 ± 0.41 kJ/mol 52.0349 ± 0.0016 460-19-5*0 Water H2O (l) -285.796 ± 0.025 kJ/mol 18.01528 ± 0.00033 7732-18-5*590 1-Methylethenyl CH3CCH2 (g) 263.01 252.61 ± 0.62 kJ/mol 41.0718 ± 0.0024 15552-77-9*0 neo-Pentane C(CH3)4 (g) -134.23 -167.10 ± 0.38 kJ/mol 72.1488 ± 0.0041 463-82-1*0 Trioxidane HOOOH (g, trans) -81.95 -90.79 ± 0.62 kJ/mol 50.01408 ± 0.00091 14699-99-1*1 Ethenamine CH2CHNH2 (g) 69.27 54.71 ± 0.69 kJ/mol 43.0678 ± 0.0016 593-67-9*0 Trimethylamine (CH3)3N (g) 2.23 -26.62 ± 0.75 kJ/mol 59.1103 ± 0.0025 75-50-3*0 Dichloromethylene CCl2 (g, singlet) 229.88 231.07 ± 0.64 kJ/mol 82.9161 ± 0.0020 1605-72-7*2 Trifluoromethylium [CF3]+ (g) 409.72 406.51 ± 0.42 kJ/mol 69.00536 ± 0.00080 18851-76-8*0 Ethyl nitrite CH3CH2ONO (g, trans-cis) -81.29 -100.02 ± 0.87 kJ/mol 75.0666 ± 0.0017 109-95-5*1 Ozonide [OOO]- (g) -58.47 -60.82 ± 0.21 kJ/mol 47.99875 ± 0.00090 12596-80-4*0 Hypobromite [BrO]- (g) -96.04 -103.53 ± 0.54 kJ/mol 95.9039 ± 0.0010 14380-62-2*0 Azido radical NNN (g) 452.24 449.65 ± 0.60 kJ/mol 42.02022 ± 0.00021 12596-60-0*0 Nitrous oxide NNO (g) 86.023 82.594 ± 0.096 kJ/mol 44.01288 ± 0.00033 10024-97-2*0 Hydroxyoxomethylium [HOCO]+ (g) 600.67 597.59 ± 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 Aminomethylium [CH2NH2]+ (g) 763.55 751.58 ± 0.53 kJ/mol 30.04865 ± 0.00085 488821-23-4*0 Chloroacetylene HCCCl (g) 229.32 230.18 ± 0.45 kJ/mol 60.4820 ± 0.0018 593-63-5*0 Fluoroacetylene HCCF (g) 104.97 105.68 ± 0.40 kJ/mol 44.0277 ± 0.0016 2713-09-9*0 Dioxidanide [HO2]- (g) -88.86 -91.52 ± 0.35 kJ/mol 33.00729 ± 0.00060 14691-59-9*0 Peroxyformyl HC(O)OO (g, syn) -100.64 -105.95 ± 0.93 kJ/mol 61.0168 ± 0.0012 56240-83-6*1 1-Propenyl CH3CHCH (g, cis) 278.19 267.35 ± 0.63 kJ/mol 41.0718 ± 0.0024 6067-68-1*2 Difluorodioxidane FOOF (g) 35.33 31.60 ± 0.40 kJ/mol 69.99561 ± 0.00060 7783-44-0*0 Ketenyl HCCO (g) 177.06 178.15 ± 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) -304.47 -317.74 ± 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) -207.80 -213.43 ± 0.55 kJ/mol 58.0361 ± 0.0017 107-22-2*1 (Methylamino)methyl CH3NHCH2 (g) 168.53 152.08 ± 0.69 kJ/mol 44.0758 ± 0.0017 31277-24-4*0 Trichloromethyl CCl3 (g) 73.77 73.30 ± 0.84 kJ/mol 118.3688 ± 0.0028 3170-80-7*0 1,1-Dichloroethane CH3CHCl2 (g) -120.17 -132.95 ± 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 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) 436.66 428.21 ± 0.69 kJ/mol 52.0746 ± 0.0032 1120-53-2*0 Silanone SiH2O (g) -93.8 -99.1 ± 1.0 kJ/mol 46.10078 ± 0.00045 22755-01-7*0 Silyloxy SiH3O (g) 8.4 0.5 ± 1.5 kJ/mol 47.10872 ± 0.00047 81429-20-1*0 Sulfur S (g) 276.90 279.14 ± 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 Methyleneamidogen CH2N (g) 242.09 238.44 ± 0.55 kJ/mol 28.03332 ± 0.00082 15845-29-1*0 Cyanogen iodide ICN (g) 222.5 222.0 ± 1.7 kJ/mol 152.92191 ± 0.00080 506-78-5*0 Formyl anion [HCO]- (g) 11.59 11.98 ± 0.44 kJ/mol 29.01859 ± 0.00086 57340-31-5*0 2-Propynylidyne CCCH (g) 718.06 722.41 ± 0.80 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 46.97 ± 0.77 kJ/mol 44.0526 ± 0.0017 30967-49-8*21 Hypofluorite [FO]- (g) -108.84 -108.67 ± 0.48 kJ/mol 34.99835 ± 0.00030 12763-66-5*0 Dicarbon monoxide CCO (g, triplet) 377.12 381.16 ± 0.83 kJ/mol 40.0208 ± 0.0016 12071-23-7*1 1-Propanol CH3CH2CH2OH (g) -231.26 -255.10 ± 0.24 kJ/mol 60.0950 ± 0.0025 71-23-8*0 Dimethylamidogen (CH3)2N (g) 174.79 157.45 ± 0.91 kJ/mol 44.0758 ± 0.0017 15337-44-7*0 2-Iminoethyl CH2CHNH (g, anti) 219.27 207.91 ± 0.87 kJ/mol 42.0599 ± 0.0016 73843-90-0*2 Chloromethylene CHCl (g, singlet) 320.36 320.64 ± 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) -343.49 -350.55 ± 0.76 kJ/mol 64.0341 ± 0.0016 75-38-7*0 Fluorodioxidanyl FOO (g) 26.89 25.18 ± 0.26 kJ/mol 50.99720 ± 0.00060 15499-23-7*0 Phenylacetylene C6H5CCH (g) 332.91 317.75 ± 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) -18.49 -32.09 ± 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) -218.18 -234.58 ± 0.42 kJ/mol 60.05534 ± 0.00091 57-13-6*0 Oxomethaniminium [NH2CO]+ (g) 695.31 688.75 ± 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) 242.7 230.6 ± 1.6 kJ/mol 61.21070 ± 0.00069 73151-72-1*0 Disilene SiH2SiH2 (g, singlet) 288.7 280.0 ± 1.9 kJ/mol 60.20276 ± 0.00066 15435-77-5*2 1,3-Hexadiyne HCCCCCH2CH3 (g) 405.15 393.45 ± 0.98 kJ/mol 78.1118 ± 0.0048 4447-21-6*0 (E)-1-Methylallyl CH3CHCHCH2 (g, trans) 152.57 135.26 ± 0.80 kJ/mol 55.0984 ± 0.0032 17787-86-9*0 Sulfuric acid OS(O)(OH)2 (aq, 1000 H2O) -892.16 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*839 Chlorine trifluoride FCl(F)F (g) -158.63 -162.73 ± 0.86 kJ/mol 92.44791 ± 0.00090 7790-91-2*0 Iodine monochloride ICl (g) 19.024 17.391 ± 0.013 kJ/mol 162.35717 ± 0.00090 7790-99-0*0 Iodotrifluoromethane CF3I (g) -583.30 -589.18 ± 0.45 kJ/mol 195.91038 ± 0.00080 2314-97-8*0 Trinitrogen cation [NNN]+ (g) 1519.41 1516.77 ± 0.89 kJ/mol 42.01967 ± 0.00021 12185-03-4*0 Oxonitrate anion [NO]- (g) 88.11 88.15 ± 0.25 kJ/mol 30.00669 ± 0.00031 14967-78-3*0 Nitrosyl ion [NO]+ (g) 984.506 984.501 ± 0.066 kJ/mol 30.00559 ± 0.00031 14452-93-8*0 Nitrogen sesquioxide ONN(O)O (g) 90.76 86.19 ± 0.15 kJ/mol 76.01168 ± 0.00091 10544-73-7*0 Methylene anion [CH2]- (g) 328.16 328.59 ± 0.18 kJ/mol 14.02713 ± 0.00081 50928-07-9*0 Methylidyne anion [CH]- (g) 475.75 479.07 ± 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 Dioxygen anion [O2]- (g) -43.36 -42.72 ± 0.17 kJ/mol 31.99935 ± 0.00060 11062-77-4*0 Hydrogen isocyanide HNC (g) 192.06 192.44 ± 0.32 kJ/mol 27.02538 ± 0.00081 6914-07-4*0 iso-Propylium [CH3CHCH3]+ (g) 822.95 805.86 ± 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) 318.08 310.72 ± 0.67 kJ/mol 53.0825 ± 0.0032 82252-88-8*0 1,2-Butadienyl CH3CHCCH (g) 328.92 320.20 ± 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 1-Hydroxyethylium [CH3CHOH]+ (g, anti) 608.73 594.31 ± 0.38 kJ/mol 45.0600 ± 0.0017 18682-96-7*1 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) -125.84 -127.50 ± 0.55 kJ/mol 45.0174 ± 0.0010 16499-21-1*1 Methoxyethane CH3CH2OCH3 (g) -194.78 -217.67 ± 0.57 kJ/mol 60.0950 ± 0.0025 540-67-0*0 Chloronium [HClH]+ (g) 881.5 878.4 ± 1.1 kJ/mol 37.46803 ± 0.00091 36658-55-6*0 1,1,1-Trichloroethane CH3CCl3 (g) -133.99 -144.56 ± 0.51 kJ/mol 133.4033 ± 0.0031 71-55-6*0 Tetrachloroethene CCl2CCl2 (g) -20.56 -21.42 ± 0.99 kJ/mol 165.8322 ± 0.0039 127-18-4*0 Chlorodifluoromethane CHClF2 (g) -475.65 -481.84 ± 0.99 kJ/mol 86.4681 ± 0.0012 75-45-6*0 Fluoromethylene CHF (g, singlet) 148.39 148.67 ± 0.43 kJ/mol 32.01704 ± 0.00080 13453-52-6*2 Fluoroformyl FCO (g) -176.63 -176.04 ± 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) 71.03 55.74 ± 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) 132.13 130.50 ± 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) 395.97 388.03 ± 0.83 kJ/mol 52.0746 ± 0.0032 4095-06-1*0 Phenylperoxy C6H5OO (g) 153.5 136.5 ± 1.4 kJ/mol 109.1027 ± 0.0049 91422-02-5*0 Trimethylsilane SiH(CH3)3 (g) -124.7 -150.8 ± 1.6 kJ/mol 74.1970 ± 0.0025 993-07-7*0 1-Methyl-1-propenyl CH3CCHCH3 (g, trans) 239.98 223.81 ± 0.67 kJ/mol 55.0984 ± 0.0032 71790-71-1*1 1-Butenyl CH3CH2CHCH (g, cis) 263.39 246.05 ± 0.69 kJ/mol 55.0984 ± 0.0032 2669-61-6*2 Ammonium [NH4]+ (aq) -133.074 ± 0.056 kJ/mol 18.03795 ± 0.00029 14798-03-9*800 Methanide [CH3]- (g) 141.11 137.66 ± 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 Chlorine atom cation Cl+ (g) 1370.807 1372.603 ± 0.0021 kJ/mol 35.45215 ± 0.00090 24203-47-2*0 Isocyanomethanide [CH2NC]- (g) 254.18 251.14 ± 0.90 kJ/mol 40.0446 ± 0.0016 81704-80-5*0 Hydroxyde [OH]- (aq) -229.752 ± 0.025 kJ/mol 17.00789 ± 0.00031 14280-30-9*800 Peroxyformate [HC(O)OO]- (g, syn) -341.14 -346.60 ± 0.98 kJ/mol 61.0174 ± 0.0012 104960-05-6*1 n-Propylium [CH3CH2CH2]+ (g) 856.77 838.49 ± 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 Hydrogen peroxide cation [H2O2]+ (g, trans) 897.29 890.31 ± 0.51 kJ/mol 34.01413 ± 0.00062 12325-10-9*1 Cyclobutene CH2(CH2CHCH) (g) 178.01 160.96 ± 0.61 kJ/mol 54.0904 ± 0.0032 822-35-5*0 Trioxidanide [HOOO]- (g, gauche) -120.0 -123.1 ± 1.6 kJ/mol 49.00669 ± 0.00090 89965-38-8*2 1,3-Butadienyl CH2CHCHCH (g, trans-trans) 372.22 361.74 ± 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) 129.12 118.59 ± 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) 170.71 169.26 ± 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) -232.54 -241.53 ± 0.39 kJ/mol 78.4973 ± 0.0019 75-36-5*0 Dioxoethyl OCHCO (g) -63.15 -64.57 ± 0.86 kJ/mol 57.0281 ± 0.0017 702699-38-5*0 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) 9.29 3.30 ± 0.50 kJ/mol 96.9427 ± 0.0024 75-35-4*0 Dichlorodifluoromethane CF2Cl2 (g) -488.97 -493.15 ± 0.44 kJ/mol 120.9129 ± 0.0020 75-71-8*0 Fluorodichloromethane CHFCl2 (g) -277.69 -283.15 ± 0.90 kJ/mol 102.9224 ± 0.0020 75-43-4*0 Difluoromethylene CF2 (g, singlet) -193.88 -193.41 ± 0.35 kJ/mol 50.00751 ± 0.00080 2154-59-8*2 Fluoromethylene CHF (g, triplet) 210.37 210.71 ± 0.66 kJ/mol 32.01704 ± 0.00080 13453-52-6*1 Formyl fluoride CHFO (g) -378.64 -382.23 ± 0.31 kJ/mol 48.01644 ± 0.00086 1493-02-3*0 p-Tolualdehyde CH3C6H4C(O)H (g, para) -49.9 -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 89.34 ± 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) 447.79 445.30 ± 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) 547.26 544.59 ± 0.87 kJ/mol 51.0666 ± 0.0032 2810-61-9*1 3-Buten-1-ynyl CH2CHCC (g) 628.5 626.3 ± 1.0 kJ/mol 51.0666 ± 0.0032 108179-98-2*0 Hydroxysilyl SiH2OH (g) -104.3 -112.2 ± 1.5 kJ/mol 47.10872 ± 0.00047 113648-09-2*0 Trimethylsilanol (CH3)3SiOH (g) -464.6 -490.9 ± 1.9 kJ/mol 90.1964 ± 0.0025 1066-40-6*0 2-Aminoethyl CH2CH2NH2 (g) 174.30 157.83 ± 0.82 kJ/mol 44.0758 ± 0.0017 4422-53-1*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 Carbon dioxide cation [CO2]+ (g) 936.091 936.926 ± 0.017 kJ/mol 44.00895 ± 0.00100 12181-61-2*0 Hydrazino NH2NH (g) 234.77 224.25 ± 0.69 kJ/mol 31.03730 ± 0.00025 13598-46-4*0 Carbon anion C- (g) 589.628 594.774 ± 0.044 kJ/mol 12.01125 ± 0.00080 14337-00-9*0 Dichloride [Cl2]- (g) -229.8 -228.7 ± 1.4 kJ/mol 70.9059 ± 0.0018 12595-89-0*0 Hydrogen isocyanide cation [HNC]+ (g) 1351.53 1351.49 ± 0.83 kJ/mol 27.02483 ± 0.00081 74158-11-5*0 Chlorooxy hypochlorite ClOOCl (g) 134.58 131.34 ± 0.56 kJ/mol 102.9042 ± 0.0019 12292-23-8*0 Methyloxonium [CH3OH2]+ (g) 589.1 574.9 ± 1.1 kJ/mol 33.04925 ± 0.00092 17836-08-7*0 Chlorine pentafluoride FCl(F)(F)(F)F (g) -226.0 -234.1 ± 1.3 kJ/mol 130.44472 ± 0.00090 13637-63-3*0 n-Propylide [CH3CH2CH2]- (g) 123.1 105.5 ± 1.2 kJ/mol 43.0882 ± 0.0024 59513-13-2*0 Allyl anion [CH2CHCH2]- (g) 133.96 122.95 ± 0.22 kJ/mol 41.0723 ± 0.0024 1724-46-5*0 Cyclopropyl CH(CH2CH2) (g) 303.88 291.25 ± 0.90 kJ/mol 41.0718 ± 0.0024 2417-82-5*0 Propargylenide [HCCCH]- (g, transoid 2B) 434.4 437.0 ± 1.1 kJ/mol 38.0485 ± 0.0024 82906-05-6*1 t-Butyl (CH3)3C (g) 75.32 50.02 ± 0.76 kJ/mol 57.1143 ± 0.0033 1605-73-8*0 Peroxyhypochlorous acid HOOCl (g) 3.98 -1.29 ± 0.95 kJ/mol 68.4594 ± 0.0011 67952-07-2*0 2-Butyn-1-yl anion [CH3CCCH2]- (g) 253.7 244.8 ± 1.1 kJ/mol 53.0830 ± 0.0032 65114-66-1*0 Ethoxy CH3CH2O (g, A 2A') 5.53 -8.90 ± 0.43 kJ/mol 45.0605 ± 0.0017 2154-50-9*52 Ethenol CH2CHOH (g, anti) -108.96 -119.67 ± 0.50 kJ/mol 44.0526 ± 0.0017 557-75-5*2 Oxiranyl CH2(CHO) (g) 172.84 164.56 ± 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 1-Iminoethyl CH3CNH (g, anti) 233.0 222.9 ± 1.1 kJ/mol 42.0599 ± 0.0016 128365-64-0*2 Cyanoamidogen HNCN (g) 322.95 320.46 ± 0.84 kJ/mol 41.03212 ± 0.00082 12347-01-2*0 Chloromethylidyne CCl (g) 430.64 434.39 ± 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 -18.9 ± 1.1 kJ/mol 65.4787 ± 0.0012 114282-89-2*0 Tetrafluorosilane SiF4 (g) -1608.81 -1614.32 ± 0.53 kJ/mol 104.07911 ± 0.00030 7783-61-1*0 Fluorotrichloromethane CCl3F (g) -283.31 -286.46 ± 0.76 kJ/mol 137.3672 ± 0.0028 75-69-4*0 Hexafluoroethane CF3CF3 (g) -1334.11 -1342.40 ± 0.82 kJ/mol 138.0118 ± 0.0016 76-16-4*0 Formyl chloride CHClO (g) -179.87 -183.08 ± 0.67 kJ/mol 64.4707 ± 0.0012 2565-30-2*0 2-Chloroethanol ClCH2CH2OH (g) -249.81 -266.53 ± 0.59 kJ/mol 80.5132 ± 0.0019 107-07-3*0 Hydroperoxonium [H2OOH]+ (g, trans) 738.2 727.9 ± 1.2 kJ/mol 35.02207 ± 0.00064 70850-26-9*1 o-Benzyne C6H4 (g, singlet) 468.20 459.29 ± 0.86 kJ/mol 76.0960 ± 0.0048 462-80-6*2 Tropyl CH(CHCHCHCHCHCH) (g) 296.5 279.1 ± 1.1 kJ/mol 91.1305 ± 0.0056 3551-27-7*0 m-Toluoyl CH3C6H4CO (g, meta) 108.7 90.1 ± 1.5 kJ/mol 119.1406 ± 0.0064 67958-04-7*0 Iodobenzene C6H5I (g) 178.46 162.47 ± 0.99 kJ/mol 204.0084 ± 0.0048 591-50-4*0 1-Hydroxy-1-methylethyl CH3C(OH)CH3 (g) -78.29 -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) 285.19 278.69 ± 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) 448.20 445.74 ± 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) -98.36 -97.20 ± 0.54 kJ/mol 44.08490 ± 0.00042 10097-28-6*0 Chloro hypochlorite ClOCl (g) 79.79 77.98 ± 0.36 kJ/mol 86.9048 ± 0.0018 7791-21-1*0 Silyloxy anion [SiH3O]- (g) -311.9 -321.2 ± 1.6 kJ/mol 47.10927 ± 0.00047 43336-62-5*0 Cyclobutyl CH(CH2CH2CH2) (g) 246.50 227.60 ± 0.73 kJ/mol 55.0984 ± 0.0032 4548-06-5*0 1-Propanamine CH3CH2CH2NH2 (g) -42.21 -69.95 ± 0.42 kJ/mol 59.1103 ± 0.0025 107-10-8*0 Disulfur S2 (g) 127.50 127.81 ± 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 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) -206.56 ± 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) 1092.47 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) 7.82 0.74 ± 0.41 kJ/mol 63.01288 ± 0.00091 14691-52-2*1 Carbon cation C+ (g) 1797.857 1803.455 ± 0.044 kJ/mol 12.01015 ± 0.00080 14067-05-1*0 Oxygen atom O (g, triplet) 246.844 249.229 ± 0.0021 kJ/mol 15.99940 ± 0.00030 17778-80-2*1 Oxoniumyl ion [H2O]+ (g) 978.501 975.597 ± 0.026 kJ/mol 18.01473 ± 0.00033 56583-62-1*0 Ethylidyne CH3C (g) 508.60 504.90 ± 0.80 kJ/mol 27.0452 ± 0.0016 67624-57-1*0 Ethynylium [CCH]+ (g) 1687.63 1690.97 ± 0.16 kJ/mol 25.0288 ± 0.0016 16456-59-0*0 Methylamidogen anion [CH3NH]- (g) 145.35 134.52 ± 0.64 kJ/mol 30.04975 ± 0.00085 54448-39-4*0 Methylimidogen CH3N (g) 323.0 315.3 ± 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 Methylperoxy anion [CH3OO]- (g) -89.77 -99.91 ± 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) 474.93 466.91 ± 0.85 kJ/mol 40.0639 ± 0.0024 2143-70-6*1 Propargylium [CH2CCH]+ (g) 1193.53 1190.71 ± 0.32 kJ/mol 39.0554 ± 0.0024 21540-27-2*0 Cycloprop-1-enyl CH2(CHC) (g) 527.45 523.06 ± 0.58 kJ/mol 39.0559 ± 0.0024 19528-44-0*0 Cyclopropenylidene C(CHCH) (g) 497.08 496.11 ± 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) 1598.1 1602.5 ± 1.3 kJ/mol 37.0395 ± 0.0024 75104-46-0*0 1-Methylene-2-propenyl CH2CHCCH2 (g) 327.11 317.11 ± 0.75 kJ/mol 53.0825 ± 0.0032 1204515-52-5*0 Cyclopentene CH2(CH2CHCHCH2) (g) 59.60 35.34 ± 0.46 kJ/mol 68.1170 ± 0.0040 142-29-0*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) -160.98 -207.82 ± 0.54 kJ/mol 114.2285 ± 0.0065 111-65-9*0 Methoxymethyl CH3OCH2 (g) 13.19 0.63 ± 0.91 kJ/mol 45.0605 ± 0.0017 16520-04-0*0 Trioxidane HOOOH (g, cis) -72.68 -81.17 ± 0.82 kJ/mol 50.01408 ± 0.00091 14699-99-1*2 Oxoethanide [CH3CO]- (g) -43.9 -49.4 ± 1.3 kJ/mol 43.0452 ± 0.0016 78944-68-0*0 Oxirene O(CHCH) (g, singlet) 273.19 271.03 ± 0.92 kJ/mol 42.0367 ± 0.0016 157-18-6*2 Hydroxyformyl HOCO (g, cis) -174.34 -177.36 ± 0.50 kJ/mol 45.0174 ± 0.0010 2564-86-5*2 Hydroxyformyl anion [HOCO]- (g, cis) -319.55 -322.13 ± 0.57 kJ/mol 45.0180 ± 0.0010 78944-70-4*2 Ethoxyethane CH3CH2OCH2CH3 (g) -223.72 -251.14 ± 0.60 kJ/mol 74.1216 ± 0.0033 60-29-7*0 Water dimer (H2O)2 (g) -491.016 -499.056 ± 0.048 kJ/mol 36.03056 ± 0.00066 25655-83-8*0 Chloric acid HOCl(O)O (g) 0.6 -6.5 ± 1.1 kJ/mol 84.4588 ± 0.0013 7790-93-4*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) -496.06 -505.19 ± 0.85 kJ/mol 59.0446 ± 0.0017 71-50-1*0 2-Hydrotrioxy OO(H)O (g) 299.6 293.9 ± 1.2 kJ/mol 49.00614 ± 0.00090 *12500-78-6*0 (Methylimino)methyl CH3NCH (g, trans) 277.9 267.8 ± 1.1 kJ/mol 42.0599 ± 0.0016 117928-23-1*1 1-Aziridinyl N(CH2CH2) (g) 313.7 301.5 ± 1.4 kJ/mol 42.0599 ± 0.0016 23838-09-7*0 (Dimethylamino)methyl (CH3)2NCH2 (g) 166.1 143.1 ± 1.3 kJ/mol 58.1024 ± 0.0025 30208-47-0*0 Chloromethide [CH2Cl]- (g) 56.3 53.0 ± 2.0 kJ/mol 49.4798 ± 0.0012 60291-29-4*0 Hexachloroethane CCl3CCl3 (g) -144.2 -146.6 ± 1.3 kJ/mol 236.7376 ± 0.0056 67-72-1*0 cis-1,2-Dichloroethene CHClCHCl (g, cis) 3.81 -2.19 ± 0.55 kJ/mol 96.9427 ± 0.0024 156-59-2*0 Dichloroacetylene ClCCCl (g) 232.75 236.06 ± 0.73 kJ/mol 94.9268 ± 0.0024 7572-29-4*0 Difluoromethylene CF2 (g) -193.88 -193.41 ± 0.35 kJ/mol 50.00751 ± 0.00080 2154-59-8*0 Perchloryl OCl(O)O (g) 191.76 186.09 ± 0.62 kJ/mol 83.4509 ± 0.0013 13932-10-0*0 1,1-Difluoroethane CH3CHF2 (g) -489.00 -502.72 ± 0.53 kJ/mol 66.0500 ± 0.0016 75-37-6*0 2-Fluoroethanol FCH2CH2OH (g) -405.73 -422.97 ± 0.99 kJ/mol 64.0589 ± 0.0017 371-62-0*0 Chlorate [OCl(O)O]- (g) -208.2 -213.7 ± 1.5 kJ/mol 83.4514 ± 0.0013 14866-68-3*0 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) 58.38 29.91 ± 0.54 kJ/mol 106.1650 ± 0.0064 100-41-4*0 Phenylethene C6H5CHCH2 (g) 169.84 148.50 ± 0.54 kJ/mol 104.1491 ± 0.0064 100-42-5*0 Benzonitrile C6H5CN (g) 230.06 215.87 ± 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 -201.13 ± 0.92 kJ/mol 57.0717 ± 0.0024 24262-31-5*0 Methyl nitrite CH3ONO (g) -55.54 -66.21 ± 0.45 kJ/mol 61.0401 ± 0.0010 624-91-9*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 Fluoronium [HFH]+ (g, singlet) 774.04 771.10 ± 0.91 kJ/mol 21.01373 ± 0.00014 12206-67-6*2 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) 224.3 221.5 ± 1.2 kJ/mol 52.0553 ± 0.0024 36259-97-9*0 1,2,3-Butatrien-1-yl anion [CH2CCCH]- (g) 388.4 386.5 ± 1.1 kJ/mol 51.0672 ± 0.0032 102275-54-7*0 Bromanylium Br+ (g) 1257.770 1251.708 ± 0.056 kJ/mol 79.90345 ± 0.00100 22541-56-6*0 Silylene SiH2 (g, triplet) 362.0 360.4 ± 1.1 kJ/mol 30.10138 ± 0.00033 13825-90-6*1 Di-mu-hydrodihydrodisilicon HSi(HSiHH) (g, trans-singlet) 374.6 364.2 ± 2.4 kJ/mol 60.20276 ± 0.00066 129970-82-7*12 Methylsilane CH3SiH3 (g) -9.57 -25.75 ± 0.93 kJ/mol 46.14384 ± 0.00095 992-94-9*0 Trimethylsiloxy (CH3)3SiO (g) -187.5 -210.5 ± 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) 155.86 138.74 ± 0.78 kJ/mol 55.0984 ± 0.0032 15157-95-6*0 3-Butenyl CH2CHCH2CH2 (g) 223.14 206.64 ± 0.91 kJ/mol 55.0984 ± 0.0032 2154-62-3*0 2-Methyl-1-propenyl CH3C(CH3)CH (g) 251.15 234.13 ± 0.73 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 -52.49 ± 0.43 kJ/mol 80.1314 ± 0.0120 20901-21-7*0 Difluoride [F2]- (g) -291.0 -290.2 ± 1.5 kJ/mol 37.9973550 ± 0.0000010 12184-85-9*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 Dioxaziridinyl N(OO) (g) 355.1 352.6 ± 1.4 kJ/mol 46.00554 ± 0.00060 66252-29-7*0 Dinitrogen tetraoxide O2NNO2 (g) 20.19 10.90 ± 0.14 kJ/mol 92.0111 ± 0.0012 10544-72-6*0 Nitroxyl ON(O)O (g) 79.40 74.14 ± 0.19 kJ/mol 62.00494 ± 0.00090 12033-49-7*0 Azanylium [NH3]+ (g) 944.274 937.319 ± 0.029 kJ/mol 17.03001 ± 0.00022 19496-55-0*0 Trioxidanyl HOOO (g, trans) 25.36 23.38 ± 0.13 kJ/mol 49.00614 ± 0.00090 12500-78-6*1 Iodine I (g, 2P3/2) 107.157 106.757 ± 0.0021 kJ/mol 126.904470 ± 0.000030 14362-44-8*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) 1619.762 1623.105 ± 0.051 kJ/mol 13.01809 ± 0.00080 24361-82-8*0 Ethylidyne CH3C (g, doublet) 508.60 504.90 ± 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 Cyanomethanide [CH2CN]- (g) 114.16 111.33 ± 0.59 kJ/mol 40.0446 ± 0.0016 21438-99-3*0 Hydrogen fluoride HF (aq, 5500 H2O) -324.57 ± 0.13 kJ/mol 20.006343 ± 0.000070 7664-39-3*955 Methanol cation [CH3OH]+ (g) 856.81 846.49 ± 0.32 kJ/mol 32.04131 ± 0.00090 12538-91-9*0 Hydroxymethylene HCOH (g, gauche triplet) 219.3 216.4 ± 1.1 kJ/mol 30.02598 ± 0.00087 19710-56-6*3 Aquacarbon H2OC (g, triplet) 442.7 441.1 ± 1.3 kJ/mol 30.02598 ± 0.00087 81434-73-3*1 Carbonic acid C(O)(OH)2 (g, cis-trans) -596.69 -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 Propylidyne CH3CH2C (g, quartet) 624.8 613.2 ± 1.3 kJ/mol 41.0718 ± 0.0024 85056-54-8*2 1-Propynyl CH3CC (g) 528.53 526.36 ± 0.65 kJ/mol 39.0559 ± 0.0024 89342-91-6*0 1-Propynylide [CH3CC]- (g) 264.59 261.01 ± 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) 91.28 66.51 ± 0.85 kJ/mol 57.1143 ± 0.0033 2348-55-2*0 t-Butyl anion [(CH3)3C]- (g) 76.8 52.1 ± 1.3 kJ/mol 57.1148 ± 0.0033 65114-21-8*0 Oxidanylium [OH]+ (g) 1293.361 1293.390 ± 0.026 kJ/mol 17.00679 ± 0.00031 12259-29-9*0 Hydroperoxymethyl CH2OOH (g) 73.1 65.8 ± 1.1 kJ/mol 47.0333 ± 0.0010 74087-87-9*0 2-Hydroxyethenyl CHCHOH (g, trans-cis) 138.00 131.26 ± 0.72 kJ/mol 43.0446 ± 0.0016 108665-16-3*21 Oxirene O(CHCH) (g, t-triplet) 387.8 383.6 ± 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 Hydroxyformyl anion [HOCO]- (g, trans) -313.66 -315.47 ± 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 -285.14 ± 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) -369.66 -389.28 ± 0.40 kJ/mol 62.0678 ± 0.0018 107-21-1*0 Hypochloroperoxoous acid, hydroxy ester HOOOCl (g, syn) 48.5 41.5 ± 1.8 kJ/mol 84.4588 ± 0.0013 928652-99-7*1 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) 729.25 710.63 ± 0.95 kJ/mol 44.0752 ± 0.0017 *31277-24-4*0 (Methyleneamino)methyl anion [CH2NCH2]- (g) 186.9 176.5 ± 1.6 kJ/mol 42.0604 ± 0.0016 73859-26-4*0 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) -29.70 -38.85 ± 0.54 kJ/mol 198.2728 ± 0.0030 75-62-7*0 Dichloromethyl CHCl2 (g) 92.89 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 -63.1 ± 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) -256.47 -263.67 ± 0.85 kJ/mol 68.4777 ± 0.0012 593-70-4*0 Difluoromethyliumyl [CF2]+ (g) 908.26 908.69 ± 0.77 kJ/mol 50.00696 ± 0.00080 54250-40-7*0 Fluoromethyliumylidene [CF]+ (g) 1123.08 1126.29 ± 0.45 kJ/mol 31.00855 ± 0.00080 33412-11-2*0 1,2-Difluoroacetylene FCCF (g) 2.85 5.68 ± 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 o-Benzyne anion [C6H4]- (g) 413.81 404.70 ± 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) -288.5 -304.9 ± 1.3 kJ/mol 124.1124 ± 0.0056 455-32-3*0 Fluorobenzene cation [C6H5F]+ (g) 788.56 773.54 ± 0.88 kJ/mol 96.1018 ± 0.0048 34468-25-2*0 Nitrosobenzene C6H5NO (g) 216.7 199.7 ± 1.2 kJ/mol 107.1100 ± 0.0048 586-96-9*0 1-Methylethoxy CH3CH(O)CH3 (g) -25.12 -43.88 ± 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 2-Butanone CH3CH2C(O)CH3 (g) -216.87 -238.32 ± 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 Iodine monobromide IBr (g) 49.712 40.764 ± 0.067 kJ/mol 206.8085 ± 0.0010 7789-33-5*0 Formaldoxime CH2NOH (g, trans) 30.5 19.9 ± 1.3 kJ/mol 45.04066 ± 0.00088 75-17-2*1 1,3-Cyclobutadien-1-yl C(CHCHCH) (g) 653.8 649.3 ± 1.1 kJ/mol 51.0666 ± 0.0032 127611-22-7*0 Bromochlorane BrCl (g) 21.875 14.432 ± 0.060 kJ/mol 115.3567 ± 0.0013 13863-41-7*0 Trioxygen difluoride FOOOF (g, trans) 112.3 106.6 ± 1.1 kJ/mol 85.99501 ± 0.00090 16829-28-0*1 Silylsilylene SiH3SiH (g, singlet) 317.2 309.4 ± 2.0 kJ/mol 60.20276 ± 0.00066 50420-90-1*2 Trimethylsiloxide [(CH3)3SiO]- (g) -486.1 -509.9 ± 2.1 kJ/mol 89.1890 ± 0.0025 41866-81-3*0 1,3-Pentadiyne HCCCCCH3 (g) 418.03 413.81 ± 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) 429.8 420.1 ± 1.6 kJ/mol 78.1118 ± 0.0048 177856-38-1*0 1-Aminoethyl CH3CHNH2 (g) 133.17 116.39 ± 0.94 kJ/mol 44.0758 ± 0.0017 30208-36-7*0 Ethylamidogen CH3CH2NH (g) 166.57 150.44 ± 0.95 kJ/mol 44.0758 ± 0.0017 41084-92-8*0 2-Naphthyl anion [C6H4(CHCCHCH)]- (g) 288.7 269.3 ± 1.3 kJ/mol 127.1631 ± 0.0080 88760-89-8*0 1-Naphthyl anion [C6H4(CCHCHCH)]- (g) 283.5 264.1 ± 1.2 kJ/mol 127.1631 ± 0.0080 125254-29-7*0 Nitrosamine NH2NO (g) 84.99 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) -401.05 -403.31 ± 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 Diazenyl NNH (g) 252.14 249.23 ± 0.45 kJ/mol 29.02142 ± 0.00016 36882-13-0*0 Dioxidenium [HO2]+ (g) 1110.88 1107.99 ± 0.11 kJ/mol 33.00619 ± 0.00060 12207-52-2*0 Hydroxyimidogen NOH (g) 217.86 214.98 ± 0.77 kJ/mol 31.01408 ± 0.00032 35337-59-8*0 Iodine cation I+ (g) 1115.549 1115.149 ± 0.0062 kJ/mol 126.903921 ± 0.000030 22541-93-1*0 Azide [NNN]- (g) 193.52 190.02 ± 0.91 kJ/mol 42.02077 ± 0.00021 14343-69-2*0 Peroxynitric acid HOON(O)O (g) -42.6 -52.9 ± 1.3 kJ/mol 79.0123 ± 0.0012 26404-66-0*0 Nitrosyl chloride ClNO (g) 54.473 52.571 ± 0.069 kJ/mol 65.45884 ± 0.00095 2696-92-6*0 Carbide [C2]- (g) 504.42 510.99 ± 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 Hydrogen difluoride (F)(HF) (g, lin) -198.5 -198.4 ± 1.2 kJ/mol 39.004746 ± 0.000070 12528-21-1*1 Bicyclo[1.1.0]buta-1,3-diene-2,4-diyl C(CC)C (g) 1047.19 1054.79 ± 0.68 kJ/mol 48.0428 ± 0.0032 12184-80-4*0 Methane cation [CH4]+ (g) 1150.679 1144.296 ± 0.061 kJ/mol 16.04191 ± 0.00085 20741-88-2*0 Chlorine difluoride FClF (g) -47.0 -48.2 ± 1.4 kJ/mol 73.44951 ± 0.00090 24801-48-7*0 Ethanium [C2H7]+ (g) 874.33 858.09 ± 0.62 kJ/mol 31.0764 ± 0.0017 24669-33-8*0 Acetylene cation [HCCH]+ (g) 1328.89 1328.22 ± 0.13 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) 363.6 361.1 ± 1.1 kJ/mol 40.0440 ± 0.0016 70971-59-4*0 1H-Triazirin-1-yl N(NN) (g) 585.9 584.1 ± 2.0 kJ/mol 42.02022 ± 0.00021 912535-95-6*0 Methyloxoniumylidene [CH3O]+ (g) 1062.68 1054.86 ± 0.57 kJ/mol 31.03337 ± 0.00088 58157-09-8*0 Hydroxymethylene HCOH (g, cis) 131.10 127.36 ± 0.29 kJ/mol 30.02598 ± 0.00087 19710-56-6*2 Hydroxymethylene cation [HCOH]+ (g, trans) 971.9 968.2 ± 1.4 kJ/mol 30.02543 ± 0.00087 135395-06-1*1 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 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) 964.51 952.95 ± 0.39 kJ/mol 41.0713 ± 0.0024 1724-44-3*0 1-Propenyl CH3CHCH (g, trans) 280.27 269.44 ± 0.77 kJ/mol 41.0718 ± 0.0024 6067-68-1*1 Bifluoride [(HF)(F)]- (g, singlet) -481.8 -480.6 ± 1.9 kJ/mol 39.005295 ± 0.000070 *18130-74-0*2 Cyclopropynyl CH(CC) (g) 711.00 715.12 ± 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) 255.7 246.1 ± 1.1 kJ/mol 53.0830 ± 0.0032 65114-67-2*0 n-Hexane CH3CH2CH2CH2CH2CH3 (cr,l) -179.81 -198.46 ± 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) -11.01 -23.64 ± 0.93 kJ/mol 45.0605 ± 0.0017 4422-54-2*2 Vinyl alcohol cation [CH2CHOH]+ (g, anti) 778.5 767.3 ± 1.2 kJ/mol 44.0520 ± 0.0017 57239-63-1*2 1-Hydroxyethylidene CH3COH (g, syn singlet) 69.97 59.46 ± 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 Trioxidanylium [HOOO]+ (g, trans) 1070.4 1064.1 ± 1.4 kJ/mol 49.00559 ± 0.00090 74241-49-9*1 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 Oxoethylidene HCC(O)H (g, singlet) 275.4 272.6 ± 1.7 kJ/mol 42.0367 ± 0.0016 39920-84-8*2 Ethyl hydroperoxide CH3CH2OOH (g) -142.9 -161.4 ± 1.2 kJ/mol 62.0678 ± 0.0018 3031-74-1*0 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) -122.03 -125.37 ± 0.55 kJ/mol 45.0174 ± 0.0010 16499-21-1*2 Chloryl hydride HCl(O)O (g) 197.7 191.2 ± 1.6 kJ/mol 68.4594 ± 0.0011 174365-32-3*0 Water anion [(H)(OH)]- (g, vdW ?) 31.3 29.8 ± 3.1 kJ/mol 18.01583 ± 0.00033 12259-30-2*100 1-Methoxyethenol CH2C(OH)OCH3 (g, anti-syn) -284.3 -303.7 ± 1.2 kJ/mol 74.0785 ± 0.0025 4453-91-2*1 1-Propene-1,2-diol CH3C(OH)CHOH (g, cis) -311.4 -329.8 ± 1.2 kJ/mol 74.0785 ± 0.0025 7333-03-1*1 1-Propene-1,2-diol CH3C(OH)CHOH (g, trans) -293.2 -309.8 ± 1.3 kJ/mol 74.0785 ± 0.0025 7333-03-1*2 (Formyloxy)methyl HC(O)OCH2 (g, anti) -135.9 -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) 122.9 104.5 ± 1.4 kJ/mol 44.0763 ± 0.0017 34285-60-4*0 Ethylideneamidogen CH3CHN (g) 209.6 199.2 ± 1.1 kJ/mol 42.0599 ± 0.0016 28445-33-2*0 (Methyleneamino)methyl CH2NCH2 (g) 244.2 233.5 ± 1.3 kJ/mol 42.0599 ± 0.0016 56391-78-7*0 2-Aziridinyl NH(CHCH2) (g, syn) 360.7 348.5 ± 1.8 kJ/mol 42.0599 ± 0.0016 *23838-09-7*1 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 Iodomethane CH3I (l) -12.29 ± 0.20 kJ/mol 141.93899 ± 0.00083 74-88-4*590 Iodide I- (aq) -56.831 ± 0.090 kJ/mol 126.905019 ± 0.000030 20461-54-5*800 Difluoromethylene CF2 (g, triplet) 43.31 44.03 ± 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) -302.83 -309.60 ± 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 ± 1.4 kJ/mol 66.00691 ± 0.00085 479587-30-9*2 Dibromophosgene CBr2O (g) -97.99 -113.93 ± 0.37 kJ/mol 187.8181 ± 0.0022 593-95-3*0 Benzene C6H6 (cr,l) 50.84 49.29 ± 0.22 kJ/mol 78.1118 ± 0.0048 71-43-2*500 o-Benzyne C6H4 (g) 468.20 459.29 ± 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 Hydrogen bromide HBr (aq) -120.88 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*800 Cycloheptane CH2(CH2CH2CH2CH2CH2C (g) -72.49 -117.99 ± 0.53 kJ/mol 98.1861 ± 0.0057 291-64-5*0 Dinitrogen pentoxide O2NONO2 (g) 24.35 14.77 ± 0.30 kJ/mol 108.0105 ± 0.0015 10102-03-1*0 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) 697.0 700.3 ± 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) 285.19 278.69 ± 0.94 kJ/mol 53.0627 ± 0.0024 14668-82-7*1 1-Cyanoethylidene CH3CCN (g, triplet) 437.5 433.8 ± 1.5 kJ/mol 53.0627 ± 0.0024 498544-34-6*1 Bromonium [HBrH]+ (g) 924.2 913.4 ± 3.0 kJ/mol 81.9193 ± 0.0010 36658-54-5*0 Isocyanomethylene HCNC (g, singlet) 582.3 583.6 ± 1.7 kJ/mol 39.0361 ± 0.0016 78694-65-2*1 2-Methyl-2-cyclopropen-1-ylidene CH3C(CHC) (g, singlet) 448.0 441.8 ± 1.2 kJ/mol 52.0746 ± 0.0032 185841-59-2*2 1,2,3-Butatrien-1-ylium [CH2CCCH]+ (g, triplet) 1425.8 1426.1 ± 1.3 kJ/mol 51.0661 ± 0.0032 81932-79-8*1 But-1-en-3-yn-1-ide [HCCCHCH]- (g, cis) 419.7 418.5 ± 1.2 kJ/mol 51.0672 ± 0.0032 119611-65-3*2 But-3-en-1-yn-1-ide [CH2CHCC]- (g, singlet) 326.6 323.6 ± 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) -278.0 -279.3 ± 2.0 kJ/mol 60.08430 ± 0.00067 7631-86-9*0 Silylidyne SiH (g) 371.31 373.11 ± 0.76 kJ/mol 29.09344 ± 0.00031 13774-94-2*0 Benzvalene ((CHCH)(CH(CHCH)CH)) (g) 404.4 386.7 ± 1.2 kJ/mol 78.1118 ± 0.0048 659-85-8*0 Bromo hypobromite BrOBr (g) 120.9 104.4 ± 1.2 kJ/mol 175.8074 ± 0.0020 21308-80-5*0 Bromide Br- (aq) -120.88 ± 0.14 kJ/mol 79.90455 ± 0.00100 24959-67-9*800 2-Naphthalenyl C6H4(CHCCHCH) (g) 416.7 397.1 ± 1.4 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) 231.88 203.07 ± 0.80 kJ/mol 178.2292 ± 0.0112 85-01-8*0 Aniline C6H5NH2 (g) 108.83 86.81 ± 0.72 kJ/mol 93.1265 ± 0.0048 62-53-3*0 Pyruvic acid CH3C(O)C(O)OH (g) -521.1 -535.5 ± 1.1 kJ/mol 88.0621 ± 0.0026 127-17-3*0 Sulfuric acid OS(O)(OH)2 (cr,l) -811.81 -813.80 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*500 Hydroxyaminiumyl [NOH]+ (g) 1161.1 1158.2 ± 1.4 kJ/mol 31.01353 ± 0.00032 63559-88-6*0 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 Dioxyamidogen HNOO (g, cis) 240.5 233.8 ± 1.8 kJ/mol 47.01348 ± 0.00061 71843-95-3*2 Peroxynitrous acid HOONO (g, cis, perp) -0.14 -7.19 ± 0.53 kJ/mol 63.01288 ± 0.00091 14691-52-2*2 Dihydrogen fluoride anion [HFH]- (g, triplet) 133.2 131.9 ± 1.6 kJ/mol 21.01483 ± 0.00014 117339-92-1*1 Dioxiranylidene C(OO) (g) 190.3 191.1 ± 1.4 kJ/mol 44.00950 ± 0.00100 138832-57-2*0 Methylidyne CH (g, doublet) 592.837 596.171 ± 0.097 kJ/mol 13.01864 ± 0.00080 3315-37-5*1 2-Hydrotrioxy cation [OO(H)O]+ (g) 1298.2 1291.5 ± 1.5 kJ/mol 49.00559 ± 0.00090 *74241-49-9*0 Chlorine difluoride cation [FClF]+ (g) 998.9 996.7 ± 1.7 kJ/mol 73.44896 ± 0.00090 32629-46-2*0 Deuterium atom D (g) 219.804 221.717 ± 0.000 kJ/mol 2.01410177800 ± 0.00000000040 16873-17-9*0 Methylammonium [CH3NH3]+ (g) 628.5 609.6 ± 1.4 kJ/mol 32.06453 ± 0.00091 17000-00-9*0 Aminomethylene CHNH2 (g) 245.9 238.1 ± 1.5 kJ/mol 29.04126 ± 0.00083 35430-17-2*0 Methyleneamidogen anion [CH2N]- (g) 192.86 189.10 ± 0.88 kJ/mol 28.03387 ± 0.00082 28892-56-0*0 (Z)-Iminomethyl HCNH (g, cis) 294.54 291.05 ± 0.89 kJ/mol 28.03332 ± 0.00082 54980-11-9*0 Aminomethylidyne CNH2 (g) 372.0 368.4 ± 1.1 kJ/mol 28.03332 ± 0.00082 84654-89-7*0 Hydrogen difluoride cation [FFH]+ (g) 1174.3 1171.3 ± 1.5 kJ/mol 39.004198 ± 0.000070 *126950-54-7*0 Xenon cation Xe+ (g) 1170.354 1170.354 ± 0.0062 kJ/mol 131.2895 ± 0.0200 24203-25-6*0 Ethynylamidogen HCCNH (g) 395.50 393.47 ± 0.97 kJ/mol 40.0440 ± 0.0016 73456-14-1*0 Methyleneoxonium CH2OH2 (g) 152.46 144.15 ± 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 Chlorine chlorite ClOClO (g, gauche) 168.6 166.2 ± 1.3 kJ/mol 102.9042 ± 0.0019 105206-44-8*3 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 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 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 Bifluoride [FFH]- (g, triplet) -68.0 -67.6 ± 1.6 kJ/mol 39.005295 ± 0.000070 *18130-74-0*1 Cycloprop-2-enyl CH(CHCH) (g) 490.29 485.74 ± 0.58 kJ/mol 39.0559 ± 0.0024 28933-84-8*0 2-Propen-1-yl-3-ylidene CH2CHC (g) 556.63 554.37 ± 0.89 kJ/mol 39.0559 ± 0.0024 202744-74-9*0 2-Propynylidyne anion [CCCH]- (g) 540.07 544.85 ± 0.82 kJ/mol 37.0406 ± 0.0024 82893-67-2*0 Chlorosyl hydride HClO (g) 141.9 139.0 ± 1.7 kJ/mol 52.46004 ± 0.00095 71572-35-5*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) 97.21 73.22 ± 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 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 1089.8 ± 1.2 kJ/mol 53.0820 ± 0.0032 *65114-67-2*2 Oxofluoronium [FO]+ (g) 1342.66 1342.61 ± 0.80 kJ/mol 34.99725 ± 0.00030 12763-67-6*0 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) -176.15 -227.94 ± 0.50 kJ/mol 128.2551 ± 0.0073 111-84-2*0 Ethanol CH3CH2OH (cr,l) -269.74 -277.51 ± 0.21 kJ/mol 46.0684 ± 0.0017 64-17-5*500 Oxygen anion monohydrate [(HOH)O]- (g) -239.0 -244.3 ± 3.0 kJ/mol 34.01523 ± 0.00062 31748-17-1*0 Vinyl alcohol cation [CH2CHOH]+ (g, syn) 786.56 775.34 ± 0.80 kJ/mol 44.0520 ± 0.0017 57239-63-1*1 Vinoxy cation [CH2CHO]+ (g, triplet) 1020.2 1013.2 ± 1.5 kJ/mol 43.0441 ± 0.0016 *35731-40-9*1 Vinoxide [CH2CHO]- (g) -152.96 -160.02 ± 0.57 kJ/mol 43.0452 ± 0.0016 35731-40-9*0 Oxiranyl anion [CH2(CHO)]- (g, singlet) 121.3 113.3 ± 1.5 kJ/mol 43.0452 ± 0.0016 72722-59-9*2 Ketene CH2CO (g, singlet) -45.36 -48.42 ± 0.11 kJ/mol 42.0367 ± 0.0016 463-51-4*2 COC vdW (CO)(C) (g, triplet) 589.7 598.5 ± 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 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 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 -214.0 ± 1.5 kJ/mol 73.0706 ± 0.0025 2887-49-2*1 Glyoxal OCHCHO (g) -207.80 -213.36 ± 0.55 kJ/mol 58.0361 ± 0.0017 107-22-2*0 1-Aminoethenyl CH2CNH2 (g) 294.7 286.0 ± 1.1 kJ/mol 42.0599 ± 0.0016 180385-92-6*0 Dimethylmethyleneammonium [(CH3)2NCH2]+ (g) 696.7 671.7 ± 1.3 kJ/mol 58.1018 ± 0.0025 28149-27-1*0 Trichloromethide [CCl3]- (g) -123.2 -122.7 ± 2.0 kJ/mol 118.3693 ± 0.0028 14478-07-0*0 2-Hydrotrioxy anion [OO(H)O]- (g) 27.5 21.8 ± 1.4 kJ/mol 49.00669 ± 0.00090 *89965-38-8*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) -61.14 ± 0.99 kJ/mol 165.8322 ± 0.0039 127-18-4*500 Trichloroethene CHClCCl2 (g) -10.9 -14.2 ± 1.5 kJ/mol 131.3874 ± 0.0031 79-01-6*0 Hydrogen fluoride HF (aq) -334.70 ± 0.15 kJ/mol 20.006343 ± 0.000070 7664-39-3*800 Triiodide [I3]- (aq) -51.30 ± 0.80 kJ/mol 380.713959 ± 0.000090 14900-04-0*800 Bromodichloromethane CHCl2Br (g) -35.0 -46.7 ± 1.2 kJ/mol 163.8280 ± 0.0022 75-27-4*0 Peroxychlorous acid HOOClO (g, syn) 95.4 89.4 ± 2.0 kJ/mol 84.4588 ± 0.0013 177778-92-6*1 Difluorodibromomethane CF2Br2 (g) -360.4 -378.5 ± 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) -411.12 -424.31 ± 0.46 kJ/mol 130.9194 ± 0.0013 1511-62-2*0 Fluoride F- (aq) -334.70 ± 0.15 kJ/mol 18.99895178 ± 0.00000050 16984-48-8*800 Nitrosodioxaziridine ONN(OO) (g, trans) 413.7 407.7 ± 1.8 kJ/mol 76.01168 ± 0.00091 132871-99-9*1 Trioxidaniumyl [HOOOH]+ (g, t, t) 925.5 916.3 ± 1.5 kJ/mol 50.01353 ± 0.00091 161321-37-5*2 1,2-Difluoroethane CH2FCH2F (g) -434.39 -447.82 ± 0.80 kJ/mol 66.0500 ± 0.0016 624-72-6*0 Fluoro(fluorooxy)methylene FCOF (g, trans) -37.5 -39.1 ± 1.4 kJ/mol 66.00691 ± 0.00085 479587-30-9*1 Benzenium [CH2(CHCHCHCHCH)]+ (g) 887.7 867.7 ± 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 Benzylium [C6H5CH2]+ (g) 929.69 910.19 ± 0.55 kJ/mol 91.1299 ± 0.0056 6711-19-9*0 Fluorohydrochlorine cation [FClH]+ (g) 975.3 972.3 ± 2.0 kJ/mol 55.45849 ± 0.00090 70110-64-4*0 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 ± 1.2 kJ/mol 140.5667 ± 0.0057 98-88-4*0 Perchloric acid HOCl(O)(O)O (g) 11.7 0.3 ± 1.3 kJ/mol 100.4582 ± 0.0015 7601-90-3*0 Dioxosilane SiO2 (cr, quartz) -906.75 -911.73 ± 0.64 kJ/mol 60.08430 ± 0.00067 7631-86-9*505 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) 321.3 310.6 ± 1.6 kJ/mol 111.5487 ± 0.0049 3474-40-6*0 p-Chlorophenyl C6H4Cl (g) 324.2 313.4 ± 1.6 kJ/mol 111.5487 ± 0.0049 2396-00-1*0 o-Chlorophenyl C6H4Cl (g) 328.5 317.8 ± 1.6 kJ/mol 111.5487 ± 0.0049 3474-42-8*0 Bromobenzene cation [C6H5Br]+ (g) 995.1 973.6 ± 1.3 kJ/mol 157.0074 ± 0.0049 55450-33-4*0 Iodobenzene C6H5I (cr,l) 113.6 113.6 ± 1.1 kJ/mol 204.0084 ± 0.0048 591-50-4*500 Nitrobenzene C6H5N(O)O (g) 82.1 62.1 ± 1.4 kJ/mol 123.1094 ± 0.0049 98-95-3*0 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 Formaldonitrone CH2NHO (g) 78.4 67.1 ± 1.4 kJ/mol 45.04066 ± 0.00088 67353-84-8*0 (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 Vinylvinylidene CH2CHCHC (g, singlet) 494.1 488.8 ± 1.7 kJ/mol 52.0746 ± 0.0032 148759-16-4*2 But-1-en-3-yn-1-ide [HCCCHCH]- (g, trans) 422.3 421.0 ± 1.3 kJ/mol 51.0672 ± 0.0032 119611-65-3*1 Tetrahedryl anion [C(CH(CHCH))]- (g) 634.5 630.7 ± 1.6 kJ/mol 51.0672 ± 0.0032 138805-00-2*0 Silicon carbide SiC (g) 740.4 745.3 ± 2.4 kJ/mol 40.09620 ± 0.00085 409-21-2*0 Silicon carbide SiC (cr, alpha-hex) -70.7 -71.7 ± 1.5 kJ/mol 40.09620 ± 0.00085 409-21-2*501 Silanide [SiH3]- (g) 69.4 63.8 ± 1.4 kJ/mol 31.10987 ± 0.00037 15807-96-2*0 Dimethylsilanone CH3Si(O)CH3 (g) -237.2 -252.7 ± 2.3 kJ/mol 74.1539 ± 0.0017 47956-45-6*0 Dimethylsilane CH3SiH2CH3 (g) -66.1 -87.6 ± 1.2 kJ/mol 60.1704 ± 0.0017 1111-74-6*0 Hydroxysilyl anion [SiH2OH]- (g, syn) -219.3 -227.3 ± 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 Chlorine fluoride cation [ClF]+ (g) 1165.52 1165.70 ± 0.49 kJ/mol 54.45055 ± 0.00090 12432-44-9*0 Ethylamidogen anion [CH3CH2NH]- (g) 106.47 88.82 ± 0.82 kJ/mol 44.0763 ± 0.0017 54448-40-7*0 Diacetylide [CCCCH]- (g) 460.9 465.9 ± 1.0 kJ/mol 49.0513 ± 0.0032 59012-21-4*0 Oxygen cation monohydrate [(HOH)O]+ (g) 1153.3 1147.8 ± 3.3 kJ/mol 34.01413 ± 0.00062 *31748-17-1*0 Oxywater (H2O)O (g) 64.9 58.4 ± 1.3 kJ/mol 34.01468 ± 0.00062 171363-09-0*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 1,3-Butadiyne-1,4-diyl CCCC (g) 1052.35 1062.32 ± 0.65 kJ/mol 48.0428 ± 0.0032 78015-07-3*0 Chlorosyl chloride ClClO (g) 134.5 133.2 ± 1.4 kJ/mol 86.9048 ± 0.0018 86825-56-1*0 Hydrogen difluoride (F)(HF) (g, perp) -187.4 -187.1 ± 1.6 kJ/mol 39.004746 ± 0.000070 12528-21-1*2 Ethylene cation [CH2CH2]+ (g) 1075.21 1067.99 ± 0.12 kJ/mol 28.0526 ± 0.0016 34470-02-5*0 Trihydrogen dioxide anion [HOHOH]- (g) -487.4 -495.7 ± 1.1 kJ/mol 35.02317 ± 0.00064 12501-19-8*0 Vinylidene CCH2 (g, triplet) 610.45 610.15 ± 0.50 kJ/mol 26.0373 ± 0.0016 2143-69-3*1 Iminomethide [HCNH]- (g, trans) 237.4 233.6 ± 1.8 kJ/mol 28.03387 ± 0.00082 90623-30-6*1 Ammonium nitrate (NH4)NO3 (cr,l) -350.21 -365.17 ± 0.18 kJ/mol 80.04344 ± 0.00095 6484-52-2*500 Cyanogen iodide anion [ICN]- (g) 86.5 88.9 ± 8.1 kJ/mol 152.92246 ± 0.00080 1356929-44-6*0 Methanol CH3OH (cr,l) -235.28 -238.62 ± 0.16 kJ/mol 32.04186 ± 0.00090 67-56-1*500 Formaldehyde cation [CH2O]+ (g) 944.853 941.232 ± 0.097 kJ/mol 30.02543 ± 0.00087 54288-05-0*0 Hydrogen fluoride HF (aq, 10 H2O) -321.70 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*815 Nitrous acid HONO (g, cis) -71.36 -77.71 ± 0.26 kJ/mol 47.01348 ± 0.00061 7782-77-6*2 Isoformyl anion [COH]- (g, triplet) 267.4 268.0 ± 1.6 kJ/mol 29.01859 ± 0.00086 81747-63-9*2 Azidonitrene NNNN (g, Cs) 692.1 687.5 ± 1.4 kJ/mol 56.02696 ± 0.00028 147363-92-6*2 Carbonic acid C(O)(OH)2 (g) -602.53 -611.84 ± 0.75 kJ/mol 62.0248 ± 0.0012 463-79-6*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 Ammonia NH3 (aq, undissoc) -80.882 ± 0.053 kJ/mol 17.03056 ± 0.00022 7664-41-7*1000 Nitronium [ONO]+ (g) 961.80 958.25 ± 0.20 kJ/mol 46.00499 ± 0.00060 14522-82-8*0 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 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 Oxochloronium [ClO]+ (g) 1150.86 1150.70 ± 0.66 kJ/mol 51.45155 ± 0.00095 12301-79-0*0 Hydroxydioxonitrate [HON(O)O]- (g) -193.2 -197.5 ± 2.4 kJ/mol 63.01343 ± 0.00091 58875-09-5*0 1,3-Butadienyl anion [CH2CHCHCH]- (g) 265.3 255.0 ± 1.5 kJ/mol 53.0830 ± 0.0032 65114-68-3*0 n-Decane CH3(CH2)8CH3 (g) -192.08 -248.82 ± 0.80 kJ/mol 142.2817 ± 0.0081 124-18-5*0 Ethyloxoniumyl [CH3CH2OH]+ (g) 783.3 766.4 ± 1.7 kJ/mol 46.0679 ± 0.0017 34480-55-2*0 1-Hydroxyethyl CH3CHOH (g, gauche-syn) -41.50 -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-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 Acetaldehyde cation [CH3CHO]+ (g) 831.96 821.99 ± 0.23 kJ/mol 44.0520 ± 0.0017 36505-03-0*0 1-Hydroxyethylidene CH3COH (g, gauche triplet) 184.9 175.5 ± 1.4 kJ/mol 44.0526 ± 0.0017 30967-49-8*1 Methoxymethylene CH3OCH (g, gauche triplet) 245.3 235.8 ± 1.4 kJ/mol 44.0526 ± 0.0017 19527-10-7*1 1-Hydroxyethenyl CH2COH (g) 121.32 114.94 ± 0.87 kJ/mol 43.0446 ± 0.0016 81847-74-7*0 Peroxyimidogen NOO (g) 405.4 403.4 ± 1.9 kJ/mol 46.00554 ± 0.00060 *60488-31-5*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) 141.1 135.0 ± 1.6 kJ/mol 43.0452 ± 0.0016 72722-59-9*1 Acetic acid CH3C(O)OH (aq) -485.10 ± 0.27 kJ/mol 60.0520 ± 0.0017 64-19-7*800 Ketenyl anion [HCCO]- (g) -48.47 -47.55 ± 0.82 kJ/mol 41.0293 ± 0.0016 64066-01-9*0 Dicarbon monoxide anion [CCO]- (g) 154.18 157.82 ± 0.83 kJ/mol 40.0213 ± 0.0016 87191-88-6*0 Dicarbon monoxide CCO (g, singlet) 440.22 444.55 ± 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 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 Hydrogen fluoride HF (aq, 30 H2O) -321.90 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*820 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) 1215.6 1212.9 ± 1.3 kJ/mol 43.02423 ± 0.00086 114766-65-3*0 Oxadiazirene O(NN) (g) 351.7 349.9 ± 1.7 kJ/mol 44.01288 ± 0.00033 227934-45-4*0 Dihydrogen cation [H2]+ (g) 1488.364 1488.480 ± 0.000 kJ/mol 2.01533 ± 0.00014 12184-90-6*0 1,2-Ethenediol HOCHCHOH (g, trans) -254.0 -266.4 ± 1.3 kJ/mol 60.0520 ± 0.0017 1571-60-4*2 Acetyl chloride CH3C(O)Cl (l) -272.09 ± 0.39 kJ/mol 78.4973 ± 0.0019 75-36-5*500 Methyl formate HC(O)OCH3 (l) -388.57 ± 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") -182.21 -191.03 ± 0.85 kJ/mol 59.0440 ± 0.0017 13799-69-4*1 NON NON (g) 545.5 542.6 ± 1.7 kJ/mol 44.01288 ± 0.00033 227934-46-5*0 2-Methoxy-2-oxoethyl CH2C(O)OCH3 (g, anti) -172.9 -188.1 ± 1.7 kJ/mol 73.0706 ± 0.0025 54668-31-4*2 (Acetyloxy)methyl CH3C(O)OCH2 (g, anti) -173.9 -186.9 ± 1.7 kJ/mol 73.0706 ± 0.0025 2887-49-2*2 Hydroxyoxoethenyl HOCCO (g) 24.5 22.7 ± 1.7 kJ/mol 57.0281 ± 0.0017 702699-39-6*0 Isocyanomethylidyne CNC (g) 672.2 676.5 ± 1.7 kJ/mol 38.0281 ± 0.0016 53590-27-5*0 Cyanomethylidyne CCN (g) 684.7 689.1 ± 2.1 kJ/mol 38.0281 ± 0.0016 4120-02-9*0 Tetrachloromethane CCl4 (l) -104.62 -124.04 ± 0.41 kJ/mol 153.8215 ± 0.0037 56-23-5*500 Hydrogen chloride HCl (aq) -166.989 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*800 Dichloromethylene anion [CCl2]- (g) 75.99 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) 346.24 346.54 ± 0.89 kJ/mol 48.4713 ± 0.0012 2108-20-5*1 1,2-Dichloroethane CH2ClCH2Cl (cr,l) -165.66 ± 0.56 kJ/mol 98.9586 ± 0.0024 107-06-2*500 Chloride Cl- (aq) -166.989 ± 0.023 kJ/mol 35.45325 ± 0.00090 16887-00-6*800 1,1-Dichloroethane CH3CHCl2 (cr,l) -163.76 ± 0.48 kJ/mol 98.9586 ± 0.0024 75-34-3*500 1,1,2-Trichloroethane CH2ClCHCl2 (l) -187.6 ± 1.1 kJ/mol 133.4033 ± 0.0031 79-00-5*500 Pentachloroethane CHCl2CCl3 (g) -150.5 -156.5 ± 1.9 kJ/mol 202.2928 ± 0.0048 76-01-7*0 Chloroform CHCl3 (l) -130.95 ± 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) 148.39 148.67 ± 0.43 kJ/mol 32.01704 ± 0.00080 13453-52-6*0 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) -97.5 -95.7 ± 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 Benzene cation [C6H6]+ (g) 992.64 976.17 ± 0.22 kJ/mol 78.1113 ± 0.0048 34504-50-2*0 Peroxychlorite [OClOO]- (g) -34.4 -34.4 ± 2.0 kJ/mol 83.4514 ± 0.0013 852472-63-0*0 Triiodide [I3]- (g) -254.3 -257.5 ± 3.4 kJ/mol 380.713959 ± 0.000090 14900-04-0*0 1-Chloro ozone ClOOO (g, cis vdW) 226.3 223.0 ± 2.3 kJ/mol 83.4509 ± 0.0013 141801-66-3*101 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) 179.5 169.1 ± 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 2-Oxopropylium [CH3C(O)CH2]+ (g) 784.7 770.9 ± 1.7 kJ/mol 57.0707 ± 0.0024 54088-52-7*0 2,3-Butanedione CH3C(O)C(O)CH3 (g) -310.56 -327.13 ± 0.63 kJ/mol 86.0892 ± 0.0033 431-03-8*0 1,2-Dibromoethane CH2BrCH2Br (g) -11.6 -38.5 ± 1.2 kJ/mol 187.8612 ± 0.0026 106-93-4*0 Dioxymethylidyne COO (g) 299.8 301.1 ± 1.7 kJ/mol 44.00950 ± 0.00100 791121-04-5*0 Fluorosyl fluoride FFO (g, triplet) 192.8 193.3 ± 2.3 kJ/mol 53.99621 ± 0.00030 86825-57-2*1 (Hydroxyimino)methyl HCNOH (g, trans-trans) 250.1 244.0 ± 1.9 kJ/mol 44.03272 ± 0.00087 206442-92-4*1 Trifluoromethide [CF3]- (g) -637.5 -639.4 ± 1.8 kJ/mol 69.00646 ± 0.00080 54128-17-5*0 Diiodide [I2]- (g) -178.13 -180.72 ± 0.48 kJ/mol 253.809489 ± 0.000060 12190-71-5*0 1-Isocyanoethylidene CH3CNC (g, triplet) 545.5 540.7 ± 1.6 kJ/mol 53.0627 ± 0.0024 *498544-34-6*1 3-Imino-2-propen-1-ylidene CHCHCNH (g, anti-triplet) 571.8 566.9 ± 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) 469.5 461.3 ± 1.5 kJ/mol 53.0627 ± 0.0024 287-24-1*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 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 Dibromide [Br2]- (g) -196.9 -211.0 ± 2.2 kJ/mol 159.8085 ± 0.0020 12595-70-9*0 Dioxygen O2 (g, singlet) 94.410 94.383 ± 0.000 kJ/mol 31.99880 ± 0.00060 7782-44-7*2 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) 587.5 591.4 ± 1.6 kJ/mol 56.17100 ± 0.00060 12597-35-2*0 Fluoronium [(HF)(H)]+ (g, triplet) 1490.1 1491.4 ± 1.9 kJ/mol 21.01373 ± 0.00014 12206-67-6*1 Disiloxane SiH3OSiH3 (g) -330.3 -347.4 ± 2.3 kJ/mol 78.21804 ± 0.00079 13597-73-4*0 Tetramethylsilane Si(CH3)4 (g) -184.3 -214.7 ± 2.1 kJ/mol 88.2236 ± 0.0033 75-76-3*0 Trimethylsilyl Si(CH3)3 (g) 47.9 25.8 ± 2.1 kJ/mol 73.1891 ± 0.0025 16571-41-8*0 Dihydrogen fluoride anion [(F)(HH)]- (g, singlet) -257.0 -260.1 ± 1.9 kJ/mol 21.01483 ± 0.00014 *117339-92-1*2 Chlorohydrofluorine cation [ClFH]+ (g) 1000.8 998.1 ± 2.1 kJ/mol 55.45849 ± 0.00090 70110-63-3*0 1,2,3,5-Hexatetraene CH2CCCHCHCH2 (g, trans) 391.7 380.0 ± 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 Azanylium [NH2]+ (g) 1266.57 1264.49 ± 0.11 kJ/mol 16.02207 ± 0.00016 15194-15-7*0 Dioxygenyl ion monohydrate [(H2O)(O2)]+ (g) 828.5 821.5 ± 2.1 kJ/mol 50.01353 ± 0.00091 11083-61-7*0 Diazenide [NNH]- (g, vdW) 175.6 176.7 ± 1.6 kJ/mol 29.02197 ± 0.00016 71004-29-0*100 2-Cyclopropyn-1-ylidene C(CC) (g, triplet) 898.8 905.7 ± 1.6 kJ/mol 36.0321 ± 0.0024 102508-15-6*1 Helium hydride cation [HeH]+ (g) 1350.148 1348.258 ± 0.000 kJ/mol 5.009993 ± 0.000070 17009-49-3*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 Fluorochlorate [ClF]- (g) -256.03 -255.43 ± 0.81 kJ/mol 54.45165 ± 0.00090 12272-56-9*0 Sulfuric acid OS(O)(OH)2 (aq, 2500 H2O) -895.08 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*898 Hydrogen atom H (ad, 1 Pt(111) fcc) -22.3 -25.6 ± 1.5 kJ/mol 1.007940 ± 0.000070 12385-13-6*1001001 Hydrogen atom H (ad, 4 Pt(111) fcc) -33.4 -36.7 ± 1.5 kJ/mol 1.007940 ± 0.000070 12385-13-6*1001004 Trioxidanyl HOOO (g, cis) 26.36 23.09 ± 0.19 kJ/mol 49.00614 ± 0.00090 12500-78-6*2 Methyleneoxonium cation [CH2OH2]+ (g) 827.7 818.3 ± 1.7 kJ/mol 32.04131 ± 0.00090 *177788-17-9*0 Hydroxymethanide [CH2OH]- (g) 9.5 2.9 ± 1.7 kJ/mol 31.03447 ± 0.00088 55830-71-2*0 Formaldehyde CH2O (g, singlet) -105.389 -109.229 ± 0.096 kJ/mol 30.02598 ± 0.00087 50-00-0*2 Hydroxymethylene cation [HCOH]+ (g, cis) 986.4 982.8 ± 1.6 kJ/mol 30.02543 ± 0.00087 135395-06-1*2 Hydroxymethylene cation [HCOH]+ (g, gauche quartet) 1482.1 1479.4 ± 1.9 kJ/mol 30.02543 ± 0.00087 135395-06-1*3 Hydroxymethylene anion [HCOH]- (g, cis) 160.2 157.5 ± 1.7 kJ/mol 30.02653 ± 0.00087 207914-87-2*2 Hydroxymethylene anion [HCOH]- (g, gauche quartet) 334.0 334.8 ± 2.1 kJ/mol 30.02653 ± 0.00087 207914-87-2*3 Aquacarbon H2OC (g, singlet vdW) 467.6 465.5 ± 1.9 kJ/mol 30.02598 ± 0.00087 81434-73-3*102 Aquacarbon cation [H2OC]+ (g) 1196.1 1193.0 ± 1.7 kJ/mol 30.02543 ± 0.00087 *81434-73-3*0 Azidonitrene NNNN (g, C2h) 660.8 657.6 ± 1.6 kJ/mol 56.02696 ± 0.00028 147363-92-6*1 Peroxyformic acid HC(O)OOH (g, gauche) -265.2 -273.0 ± 1.5 kJ/mol 62.0248 ± 0.0012 107-32-4*3 Nitrous acid HONO (g) -72.970 -78.627 ± 0.079 kJ/mol 47.01348 ± 0.00061 7782-77-6*0 Deuterium atom cation D+ (g) 1532.210 1534.123 ± 0.000 kJ/mol 2.01355319809 ± 0.00000000040 14464-47-2*0 Propyne cation [CH3CCH]+ (g) 1192.62 1186.90 ± 0.38 kJ/mol 40.0633 ± 0.0024 34526-53-9*0 Cyclopropylidene C(CH2CH2) (g, triplet) 544.7 535.9 ± 1.5 kJ/mol 40.0639 ± 0.0024 2143-70-6*2 Chlorine difluoride ClFF (g) 22.5 23.9 ± 1.9 kJ/mol 73.44951 ± 0.00090 91483-78-2*0 Propynylidene cation [HCCCH]+ (g) 1410.9 1413.5 ± 1.3 kJ/mol 38.0474 ± 0.0024 75123-91-0*0 Propynylidene HCCCH (g, trans singlet) 597.4 599.2 ± 1.1 kJ/mol 38.0480 ± 0.0024 67152-18-5*4 Propadienylidenide [CH2CC]- (g) 381.17 382.07 ± 0.41 kJ/mol 38.0485 ± 0.0024 109292-49-1*0 1,2-Propadien-1-ylium-1-yl [CH2CC]+ (g) 1561.7 1562.9 ± 1.4 kJ/mol 38.0474 ± 0.0024 110714-00-6*0 Dioxaziridinyl cation [N(OO)]+ (g) 1365.8 1363.3 ± 1.7 kJ/mol 46.00499 ± 0.00060 *66252-29-7*0 Aminooxy cation [NH2O]+ (g) 945.99 938.86 ± 0.77 kJ/mol 32.02147 ± 0.00034 *51375-41-8*0 Ethane cation [CH3CH3]+ (g) 1043.14 1029.13 ± 0.59 kJ/mol 30.0685 ± 0.0017 34488-65-8*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 Cyclohexane CH2(CH2CH2CH2CH2CH2) (l) -131.77 -155.90 ± 0.29 kJ/mol 84.1595 ± 0.0049 110-82-7*500 Nitric acid HON(O)O (cr,l) -178.99 -173.27 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*500 1,5-Hexadiene CH2CHCH2CH2CHCH2 (g) 108.54 83.95 ± 0.39 kJ/mol 82.1436 ± 0.0049 592-42-7*0 2-Hydroxyethyl CH2CH2OH (g, staggered-anti) -6.0 -18.4 ± 1.5 kJ/mol 45.0605 ± 0.0017 4422-54-2*3 Bifluoride [FHF]- (g) -705.22 -709.07 ± 0.35 kJ/mol 39.005295 ± 0.000070 18130-74-0*0 Ethoxy CH3CH2O (g) 1.26 -12.16 ± 0.43 kJ/mol 45.0605 ± 0.0017 2154-50-9*0 Trifluoride ion [F3]- (g) -348.9 -349.7 ± 2.6 kJ/mol 56.9957582 ± 0.0000015 25730-99-8*0 Ethylene anion [CH2CH2]- (g, anti ?) 232.1 224.5 ± 2.0 kJ/mol 28.0537 ± 0.0016 34527-91-8*1 Dioxaziridinyl anion [N(OO)]- (g) 295.9 293.4 ± 1.6 kJ/mol 46.00609 ± 0.00060 66252-31-1*0 Peroxyimidogen cation [NOO]+ (g) 1409.7 1406.8 ± 1.9 kJ/mol 46.00499 ± 0.00060 *60488-32-6*0 Dicarbon monoxide cation [CCO]+ (g) 1433.9 1439.0 ± 2.1 kJ/mol 40.0203 ± 0.0016 12287-08-0*0 C=O-C cation [COC]+ (g, quartet) 1816.9 1820.9 ± 2.0 kJ/mol 40.0203 ± 0.0016 83483-98-1*2 Peroxyimidogen anion [NOO]- (g) 165.0 162.7 ± 1.7 kJ/mol 46.00609 ± 0.00060 60488-31-5*0 Oxirene anion [O(CHCH)]- (g) 288.3 285.3 ± 2.2 kJ/mol 42.0372 ± 0.0016 *157-18-6*0 Trioxidaniumyl [HOOOH]+ (g, c, t) 935.2 926.1 ± 1.5 kJ/mol 50.01353 ± 0.00091 161321-37-5*3 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 Nirous oxide cation [NNO]+ (g) 1329.70 1326.80 ± 0.12 kJ/mol 44.01233 ± 0.00033 12269-46-4*0 Chlorite [OClO]- (g) -105.51 -107.69 ± 0.37 kJ/mol 67.4520 ± 0.0011 14998-27-7*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) -77.4 -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 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 Fluoroniumyl ion [HF]+ (g) 1275.555 1275.787 ± 0.022 kJ/mol 20.005795 ± 0.000070 12381-92-9*0 Acetylene anion [HCCH]- (g, trans ?) 356.9 356.7 ± 1.9 kJ/mol 26.0378 ± 0.0016 50443-89-5*1 Hydrofluorate ion [HF]- (g) -75.6 -75.1 ± 1.8 kJ/mol 20.006892 ± 0.000070 37249-79-9*0 Oxadiazirine anion [O(NN)]- (g) 95.1 95.5 ± 2.9 kJ/mol 44.01343 ± 0.00033 350586-31-1*0 Ammonium hydroxide NH4OH (aq) -362.826 ± 0.062 kJ/mol 35.04584 ± 0.00047 1336-21-6*800 Glyoxal OCHCHO (g, cis) -189.35 -194.80 ± 0.71 kJ/mol 58.0361 ± 0.0017 107-22-2*2 Ethynediol HOCCOH (g) -18.3 -22.1 ± 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 Dihydrogen fluoride anion [(HF)(H)]- (g, singlet) -61.9 -60.5 ± 3.2 kJ/mol 21.01483 ± 0.00014 117339-92-1*2 Dimethylaminylium [(CH3)2N]+ (g) 1040.7 1025.2 ± 1.8 kJ/mol 44.0752 ± 0.0017 49784-85-2*0 Trioxodinitrate anion [ONN(O)O]- (g, vdW) -104.2 -107.5 ± 1.9 kJ/mol 76.01223 ± 0.00091 194856-62-7*100 Ethylimidogen CH3CH2N (g) 306.1 291.5 ± 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 Dichloromethylene CCl2 (g, triplet) 313.99 315.20 ± 0.90 kJ/mol 82.9161 ± 0.0020 1605-72-7*1 Chloromethyliumyl [CHCl]+ (g) 1207.4 1207.7 ± 2.0 kJ/mol 48.4708 ± 0.0012 89877-51-0*0 Chloromethylene anion [CHCl]- (g) 203.54 204.35 ± 0.94 kJ/mol 48.4719 ± 0.0012 75466-08-9*0 Hydrogen peroxide cation [H2O2]+ (g, cis) 931.04 924.18 ± 0.98 kJ/mol 34.01413 ± 0.00062 12325-10-9*2 Chlorohydroxymethyl CH(Cl)OH (g, anti-gauche) -46.2 -51.8 ± 2.0 kJ/mol 65.4787 ± 0.0012 147139-06-8*2 Hydrogen fluoride HF (aq, 20 H2O) -321.85 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*818 1,1,1,2-Tetrachloroethane CH2ClCCl3 (cr,l) -193.5 ± 1.1 kJ/mol 167.8481 ± 0.0039 630-20-6*500 Hexachloroethane CCl3CCl3 (cr,l) -214.1 ± 2.8 kJ/mol 236.7376 ± 0.0056 67-72-1*500 3-Chloro-3-methyl-3H-diazirine (NN)CClCH3 (g) 251.5 239.6 ± 2.7 kJ/mol 90.5114 ± 0.0019 4222-21-3*0 trans-1,2-Dichloroethene CHClCHCl (g, trans) 5.64 0.22 ± 0.56 kJ/mol 96.9427 ± 0.0024 156-60-5*0 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) 95.93 96.47 ± 0.61 kJ/mol 32.01759 ± 0.00080 71267-42-0*0 Polytetrafluoroethylene CF2CF2 (s) -830.20 ± 0.55 kJ/mol 100.0150 ± 0.0016 9002-84-0*591 Nitrosyl fluoride FNO (g) -85.47 -87.84 ± 0.79 kJ/mol 49.00454 ± 0.00031 7789-25-5*0 trans-1,2-Difluoroethene CHFCHF (g, trans) -299.60 -306.03 ± 0.89 kJ/mol 64.0341 ± 0.0016 1630-78-0*0 Fluoroethynide [CCF]- (g) 133.3 137.5 ± 1.5 kJ/mol 43.0204 ± 0.0016 85905-56-2*0 Formyl fluoride cation [CHFO]+ (g) 816.6 813.3 ± 1.3 kJ/mol 48.01589 ± 0.00086 99766-68-4*0 Formyl fluoride [FCO]- (g) -405.1 -403.7 ± 1.6 kJ/mol 47.00905 ± 0.00085 62227-71-8*0 Fluoroisoformyl cation [COF]+ (g) 1347.4 1349.5 ± 1.9 kJ/mol 47.00795 ± 0.00085 *1871-25-6*0 Chlorine oxide peroxide OClOO (g, vdW) 226.5 227.4 ± 2.5 kJ/mol 83.4509 ± 0.0013 141801-67-4*100 Nitrogen hydride oxide NH3O (g) 71.2 60.0 ± 1.5 kJ/mol 33.02996 ± 0.00037 38544-48-8*0 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 Hydroxyaminylium [HNOH]+ (g, cis) 1048.5 1041.3 ± 2.6 kJ/mol 32.02147 ± 0.00034 66097-71-0*2 Iodine I (g, 2P1/2) 198.109 197.709 ± 0.0021 kJ/mol 126.904470 ± 0.000030 14362-44-8*2 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 Fluorodioxidenium [FOO]+ (g) 1221.9 1219.5 ± 2.0 kJ/mol 50.99665 ± 0.00060 139584-95-5*0 Hydroxyamidogen anion [HNOH]- (g) 90.6 84.8 ± 2.8 kJ/mol 32.02257 ± 0.00034 *66097-71-0*0 1-Chloro ozone anion [ClOOO]- (g, perp) -109.0 -111.5 ± 2.2 kJ/mol 83.4514 ± 0.0013 224299-15-4*3 Iminomethide [HCNH]- (g, cis) 252.7 248.9 ± 1.8 kJ/mol 28.03387 ± 0.00082 90623-30-6*2 Dihydrogen fluoride (H)(HF) (g) -55.9 -54.9 ± 1.6 kJ/mol 21.01428 ± 0.00014 12592-22-2*1 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 Nitrosyl nitrate ON(O2)NO (g, perp) 70.7 62.4 ± 1.7 kJ/mol 92.0111 ± 0.0012 *15969-55-8*0 1-Chloro ozone anion [ClOOO]- (g, cis) -66.9 -68.8 ± 2.1 kJ/mol 83.4514 ± 0.0013 224299-15-4*1 Hydrogen cyanide cation [HCN]+ (g) 1442.53 1442.06 ± 0.20 kJ/mol 27.02483 ± 0.00081 12601-62-6*0 Carbamoyl HNCOH (g, trans-trans) 74.1 67.7 ± 2.7 kJ/mol 44.03272 ± 0.00087 *2858-51-7*1 Formaldiminoxy CH2NO (g) 160.9 153.9 ± 1.5 kJ/mol 44.03272 ± 0.00087 2683-96-7*0 Fluorodioxidanide [FOO]- (g) -256.8 -256.1 ± 1.9 kJ/mol 50.99775 ± 0.00060 23553-17-5*0 Formaldoxime CH2NOH (g, cis) 50.6 39.8 ± 1.8 kJ/mol 45.04066 ± 0.00088 75-17-2*2 Oxaziridine CH2(NHO) (g) 115.5 103.7 ± 2.1 kJ/mol 45.04066 ± 0.00088 6827-26-5*0 Fluorosyl fluoride anion [FFO]- (g, doublet) -147.1 -146.8 ± 3.0 kJ/mol 53.99675 ± 0.00030 *86825-57-2*2 Cyanoethynyl CCCN (g) 715.7 722.1 ± 1.2 kJ/mol 50.0388 ± 0.0024 62435-43-2*0 (E)-Diazene anion [HNNH]- (g, trans) 265.5 258.7 ± 2.0 kJ/mol 30.02991 ± 0.00020 *59952-06-6*0 Ammonium hydroxide NH4OH (cr,l) -360.45 -361.53 ± 0.57 kJ/mol 35.04584 ± 0.00047 1336-21-6*500 (Z)-Diazene cation [HNNH]+ (g, cis) 1157.0 1150.2 ± 1.3 kJ/mol 30.02881 ± 0.00020 86631-37-0*0 2-Methylene-2H-azirine (CHN)CCH2 (g) 404.2 396.9 ± 1.7 kJ/mol 53.0627 ± 0.0024 110027-86-6*0 Nitrilomethylium [CN]+ (g) 1783.13 1786.61 ± 0.48 kJ/mol 26.01689 ± 0.00080 12539-57-0*0 Hydrogen fluoride HF (aq, 22 H2O) -321.86 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*902 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 Dioxofluorine OFO (g) 524.0 523.2 ± 1.0 kJ/mol 50.99720 ± 0.00060 175861-93-5*0 2-Isocyanovinyl CHCHNC (g, syn) 544.6 542.6 ± 1.7 kJ/mol 52.0547 ± 0.0024 225798-14-1*2 Cyanomethylene HCCN (g, singlet) 529.5 530.5 ± 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 Perchloryloxy OCl(O)(O)O (g) 248.4 240.8 ± 1.8 kJ/mol 99.4503 ± 0.0015 12133-63-0*0 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) 1429.8 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 1-Buten-3-ynylium [HCCCHCH]+ (g, trans) 1482.3 1479.8 ± 1.5 kJ/mol 51.0661 ± 0.0032 84654-85-3*1 1-Hydrazinylium-1-yl [NNH2]+ (g) 1143.4 1136.4 ± 1.4 kJ/mol 30.02881 ± 0.00020 63986-30-1*0 Dihydrooxooxygen cation [(H2O)O]+ (g) 994.8 988.1 ± 1.6 kJ/mol 34.01413 ± 0.00062 177329-59-8*0 3-Buten-1-ynylium [CH2CHCC]+ (g, triplet) 1572.6 1570.2 ± 1.7 kJ/mol 51.0661 ± 0.0032 103928-84-3*1 3-Methylene-1-cyclopropen-1-ylium [CH2C(CHC)]+ (g, singlet) 1398.7 1395.4 ± 1.7 kJ/mol 51.0661 ± 0.0032 117469-28-0*2 Tetraoxidanyl (HO2)(O2) (g, vdW) 2.1 0.4 ± 2.9 kJ/mol 65.0055 ± 0.0012 69696-93-1*100 Butyraldehyde CH3CH2CH2CHO (g) -185.31 -205.67 ± 0.85 kJ/mol 72.1057 ± 0.0033 123-72-8*0 Perchlorate [OCl(O)(O)O]- (g) -263.9 -272.8 ± 2.1 kJ/mol 99.4508 ± 0.0015 14797-73-0*0 Chloroallene CH2CCHCl (g) 181.8 175.2 ± 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 Methylcyclopentane CH3CH(CH2CH2CH2CH2) (g) -68.59 -106.12 ± 0.37 kJ/mol 84.1595 ± 0.0049 96-37-7*0 Dioxosilane SiO2 (cr,l) -906.75 -911.73 ± 0.64 kJ/mol 60.08430 ± 0.00067 7631-86-9*500 Dioxosilane SiO2 (vitr) -826.30 -902.23 ± 0.65 kJ/mol 60.08430 ± 0.00067 7631-86-9*520 Ethynylene cation [C2]+ (g) 1964.94 1971.53 ± 0.40 kJ/mol 24.0209 ± 0.0016 12595-79-8*0 Silicon carbide cation [SiC]+ (g) 1602.0 1606.7 ± 2.6 kJ/mol 40.09565 ± 0.00085 78393-58-5*0 Silyliumyl [SiH2]+ (g) 1155.50 1153.88 ± 0.96 kJ/mol 30.10083 ± 0.00033 28149-31-7*0 Disilanyl anion [SiH3SiH2]- (g) 63.5 51.1 ± 2.2 kJ/mol 61.21125 ± 0.00069 53199-49-8*0 Disilene SiH2SiH2 (g, triplet) 393.3 384.8 ± 2.3 kJ/mol 60.20276 ± 0.00066 15435-77-5*1 Di-mu-hydrodihydrodisilicon HSi(HSiHH) (g, cis-singlet) 385.5 375.1 ± 2.7 kJ/mol 60.20276 ± 0.00066 129970-82-7*22 Bromine dioxide OBrO (g) 165.6 156.0 ± 2.1 kJ/mol 111.9028 ± 0.0012 21255-83-4*0 (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 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 Ethylammoniumyl [CH3CH2NH2]+ (g) 827.5 807.5 ± 1.6 kJ/mol 45.0832 ± 0.0017 41857-50-5*0 Diazenide [NNH]- (g, triplet) 347.4 344.6 ± 1.6 kJ/mol 29.02197 ± 0.00016 71004-29-0*1 2-Methyl-2-propanamine (CH3)3CNH2 (g) -86.98 -120.63 ± 0.55 kJ/mol 73.1369 ± 0.0033 75-64-9*0 Trioxidanylium [HOOO]+ (g, cis) 1085.2 1078.9 ± 1.4 kJ/mol 49.00559 ± 0.00090 74241-49-9*2 Aminyliumyl [NH]+ (g) 1659.04 1659.96 ± 0.24 kJ/mol 15.014131 ± 0.000099 19067-62-0*0 Biphenyl C6H5C6H5 (g) 207.1 178.9 ± 1.1 kJ/mol 154.2078 ± 0.0096 92-52-4*0 Helium He (g, triplet) 1912.302 1912.302 ± 0.000 kJ/mol 4.0026020 ± 0.0000020 7440-59-7*1 Helium cation He+ (g) 2372.322 2372.322 ± 0.000 kJ/mol 4.0020534 ± 0.0000020 14234-48-1*0 Neonium [NeH]+ (g) 1324.88 1323.07 ± 0.89 kJ/mol 21.18709 ± 0.00060 12200-65-6*0 Kryptonium [KrH]+ (g) 1106.33 1104.55 ± 0.69 kJ/mol 84.8074 ± 0.1000 37276-90-7*0 Hydroxylamine NH2OH (g, cis) -15.4 -25.9 ± 1.4 kJ/mol 33.02996 ± 0.00037 7803-49-8*2 Monosulfur cation S+ (g) 1276.48 1278.27 ± 0.14 kJ/mol 32.0655 ± 0.0060 14701-12-3*0 Oxosulfur [SO]+ (g) 999.33 999.93 ± 0.13 kJ/mol 48.0649 ± 0.0060 767269-11-4*0 Hydrosulfide [SH]- (g) -80.51 -80.51 ± 0.19 kJ/mol 33.0745 ± 0.0060 15035-72-0*0 Hydroxylamine cation [NH2OH]+ (g) 857.7 847.9 ± 1.6 kJ/mol 33.02941 ± 0.00037 62675-55-2*0 Sulfuric acid OS(O)(OH)2 (aq, 75 H2O) -887.10 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*825 Sulfuric acid OS(O)(OH)2 (aq, 7000 H2O) -899.14 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*846 Hydrogen sulfate [OHS(O)(O)O]- (g) -942.4 -952.8 ± 1.9 kJ/mol 97.0721 ± 0.0061 14996-02-2*0 Fluorine atom cation F+ (g) 1758.300 1760.599 ± 0.017 kJ/mol 18.99785462 ± 0.00000050 14701-13-4*0 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 Hydroperoxyimidogen HOON (g, trans) 103.4 99.8 ± 2.4 kJ/mol 47.01348 ± 0.00061 877456-58-1*1 Cyclopropenyliumdiyl [CH(CC)]+ (g) 1692.1 1695.1 ± 1.9 kJ/mol 37.0395 ± 0.0024 127476-05-5*0 Cyclopropynyl anion [CH(CC)]- (g) 518.12 521.10 ± 0.88 kJ/mol 37.0406 ± 0.0024 136861-42-2*0 Nitric acid cation [HON(O)O]+ (g) 1029.16 1020.10 ± 0.69 kJ/mol 63.01233 ± 0.00091 272109-63-4*0 Chlorine difluoride cation [ClFF]+ (g) 1346.3 1344.9 ± 2.1 kJ/mol 73.44896 ± 0.00090 86825-59-4*0 2-Butynylium [CH3CCCH2]+ (g, triplet) 1258.7 1251.4 ± 1.6 kJ/mol 53.0820 ± 0.0032 64235-83-2*1 Trifluorine cation [F3]+ (g) 1529.5 1527.4 ± 2.3 kJ/mol 56.9946610 ± 0.0000015 64710-22-1*0 1-Methylene-2-propenylium [CH2CHCCH2]+ (g, singlet) 1059.4 1049.3 ± 1.7 kJ/mol 53.0820 ± 0.0032 62698-26-4*2 1-Methylene-2-propenylium [CH2CHCCH2]+ (g, triplet) 1256.3 1246.6 ± 1.7 kJ/mol 53.0820 ± 0.0032 62698-26-4*1 Hydroxyimidogen anion [NOH]- (g) 229.8 227.4 ± 2.2 kJ/mol 31.01463 ± 0.00032 *35337-59-8*0 1,3-Butadienylium [CH2CHCHCH]+ (g, singlet) 1133.6 1123.6 ± 2.5 kJ/mol 53.0820 ± 0.0032 86181-69-3*2 Chlorine difluoride anion [ClFF]- (g) -319.0 -319.0 ± 2.2 kJ/mol 73.45005 ± 0.00090 91419-41-9*0 3-Methanetetrayl-1,2-cyclopropanediylidene CC(CC) (g) 1154.8 1164.2 ± 1.9 kJ/mol 48.0428 ± 0.0032 78015-08-4*0 Cyclopentene CH2(CH2CHCHCH2) (l) 7.06 ± 0.51 kJ/mol 68.1170 ± 0.0040 142-29-0*590 Formaldehyde anion [CH2O]- (g) -26.7 -28.3 ± 2.0 kJ/mol 30.02653 ± 0.00087 27837-46-3*0 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 Formaldehyde CH2O (g, triplet) 196.002 192.699 ± 0.096 kJ/mol 30.02598 ± 0.00087 50-00-0*1 Ethanium [C2H7]+ (g, classical Cs I) 888.7 870.3 ± 1.8 kJ/mol 31.0764 ± 0.0017 24669-33-8*2 Ethanium [C2H7]+ (g, classical Cs II) 895.1 877.3 ± 1.9 kJ/mol 31.0764 ± 0.0017 24669-33-8*3 1-Hydroxyethanide [CH3CHOH]- (g) -20.3 -33.7 ± 2.2 kJ/mol 45.0610 ± 0.0017 88032-18-2*0 Hydrogen difluoride cation [FFH]+ (g, singlet) 1174.3 1171.3 ± 1.5 kJ/mol 39.004198 ± 0.000070 *126950-54-7*2 (Methylmethylene)oxonium [CH3OCH2]+ (g) 685.8 671.6 ± 2.2 kJ/mol 45.0600 ± 0.0017 23653-97-6*0 Methoxymethyl anion [CH3OCH2]- (g) 23.3 10.3 ± 2.3 kJ/mol 45.0610 ± 0.0017 61192-30-1*0 Hydrogen fluoride HF (aq, 18 H2O) -321.83 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*901 Acetaldehyde anion [CH3CHO]- (g) -62.2 -72.5 ± 2.2 kJ/mol 44.0531 ± 0.0017 60427-04-5*0 Nitric acid HON(O)O (aq, 1 H2O) -186.83 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*801 Triazirine HN(NN) (g) 464.1 457.6 ± 2.6 kJ/mol 43.02816 ± 0.00022 157-29-9*0 Nitric acid HON(O)O (aq, 3 H2O) -197.77 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*805 Ethylene anion [CH2CH2]- (g, syn ?) 231.6 225.5 ± 2.0 kJ/mol 28.0537 ± 0.0016 34527-91-8*2 Cyanogen bromide anion [BrCN]- (g) 57.7 54.1 ± 3.8 kJ/mol 105.9220 ± 0.0013 54092-05-6*0 Dioxygen O2 (g, triplet) 0.000 0.000 ± 0.000 kJ/mol 31.99880 ± 0.00060 7782-44-7*1 Ketene cation [CH2CO]+ (g) 882.21 879.04 ± 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 1-Ethylium-1-yl [CH3CH]+ (g) 1182.0 1174.7 ± 3.2 kJ/mol 28.0526 ± 0.0016 85944-79-2*0 Oxoethenylium [HCCO]+ (g) 1139.7 1142.4 ± 2.1 kJ/mol 41.0282 ± 0.0016 92056-63-8*0 Ethylidene anion [CH3CH]- (g) 325.7 318.4 ± 1.8 kJ/mol 28.0537 ± 0.0016 35829-99-3*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 Methyl hydroperoxide cation [CH3OOH]+ (g) 833.7 819.7 ± 2.0 kJ/mol 48.0407 ± 0.0010 112465-88-0*0 Methoxyoxoniumylidene [CH3OO]+ (g) 1012.62 1003.78 ± 0.68 kJ/mol 47.0328 ± 0.0010 86475-50-5*0 Aminooxy anion [NH2O]- (g) 47.3 40.4 ± 1.7 kJ/mol 32.02257 ± 0.00034 51375-41-8*0 Formic acid HC(O)OH (cr,l) -431.51 -424.67 ± 0.20 kJ/mol 46.0254 ± 0.0010 64-18-6*500 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 ± 1.5 kJ/mol 46.0259 ± 0.0010 93207-29-5*0 2-Cyclopropyn-1-ylidenemethyl anion [CC(CC)]- (g) 800.9 809.8 ± 1.7 kJ/mol 48.0433 ± 0.0032 289679-90-9*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 Ozone cation [OOO]+ (g) 1352.880 1350.541 ± 0.041 kJ/mol 47.99765 ± 0.00090 12596-82-6*0 Hydrogen bromide HBr (aq, 600 H2O) -120.39 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*834 Nirous oxide anion [NNO]- (g) 99.3 96.7 ± 1.9 kJ/mol 44.01343 ± 0.00033 12274-12-3*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 Chlorosyl chloride anion [ClClO]- (g) -185.4 -184.7 ± 2.3 kJ/mol 86.9053 ± 0.0018 *86825-55-0*0 Oxazirinyl cation [C(NO)]+ (g) 1565.5 1566.2 ± 2.3 kJ/mol 42.01629 ± 0.00086 *228850-18-8*0 Oxazirinyl anion [C(NO)]- (g) 448.2 449.0 ± 2.4 kJ/mol 42.01739 ± 0.00086 28269-68-3*0 Acetic acid CH3C(O)OH (cr,l) -484.02 -483.59 ± 0.18 kJ/mol 60.0520 ± 0.0017 64-19-7*500 Acetic acid CH3C(O)OH (aq, 75 H2O) -484.61 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*825 Acetic acid CH3C(O)OH (aq, 1500 H2O) -484.81 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*840 Chloryl chloride ClCl(O)O (g) 126.1 122.1 ± 1.7 kJ/mol 102.9042 ± 0.0019 117489-73-3*0 Chloroniumyl ion [HCl]+ (g) 1137.798 1137.732 ± 0.0051 kJ/mol 36.46009 ± 0.00090 12258-94-5*0 Acetylene anion [HCCH]- (g, cis ?) 380.1 380.4 ± 1.9 kJ/mol 26.0378 ± 0.0016 50443-89-5*2 Ethyl formate HC(O)OCH2CH3 (cr,l) -426.0 ± 1.1 kJ/mol 74.0785 ± 0.0025 109-94-4*500 Hypofluorous acid anion [HOF]- (g, quartet) 155.3 154.7 ± 2.6 kJ/mol 36.00629 ± 0.00031 36505-07-4*2 Propionic acid CH3CH2C(O)OH (g, anti) -415.5 -433.1 ± 1.3 kJ/mol 74.0785 ± 0.0025 79-09-4*2 (1Z)-Ethanimine CH3CHNH (g, cis) 58.8 44.2 ± 1.4 kJ/mol 43.0678 ± 0.0016 56003-82-8*0 (E)-2-Iminoethylium [CH2CHNH]+ (g, anti-singlet) 1108.3 1097.6 ± 3.0 kJ/mol 42.0594 ± 0.0016 91127-33-2*22 2-Iminoethyl anion [CH2CHNH]- (g, syn) 104.5 93.5 ± 2.1 kJ/mol 42.0604 ± 0.0016 73843-87-5*1 Cyanogen cation [NCCN]+ (g) 1598.24 1600.45 ± 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) 479.2 482.9 ± 2.0 kJ/mol 38.0287 ± 0.0016 *53590-27-5*0 Methylammoniumyl [CH3NH2]+ (g) 865.89 851.96 ± 0.26 kJ/mol 31.05659 ± 0.00088 34516-31-9*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) 720.3 724.4 ± 2.1 kJ/mol 38.0281 ± 0.0016 439586-06-8*0 Hydrogen bromide HBr (aq, 1250 H2O) -120.53 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*954 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 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 Methylamine anion [CH3NH2]- (g) 84.2 69.3 ± 2.8 kJ/mol 31.05769 ± 0.00088 81096-79-9*0 Trichloromethylium [CCl3]+ (g) 856.13 854.61 ± 0.93 kJ/mol 118.3683 ± 0.0028 27130-34-3*0 Dichloromethyliumyl [CCl2]+ (g) 1122.0 1122.9 ± 1.8 kJ/mol 82.9156 ± 0.0020 55945-51-2*0 Ammonium bromide (NH4)Br (cr) -253.64 -270.22 ± 0.15 kJ/mol 97.9425 ± 0.0010 12124-97-9*510 Hydrogen chloride HCl (aq, 1000 H2O) -166.562 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*839 Aminomethyl anion [CH2NH2]- (g) 209.5 199.2 ± 2.1 kJ/mol 30.04975 ± 0.00085 74215-21-7*0 Dioxodiazoxane ONONO (g, t, c) 109.4 105.3 ± 1.8 kJ/mol 76.01168 ± 0.00091 122413-35-8*2 Methylaminilium [CH3NH]+ (g) 1135.2 1125.3 ± 2.1 kJ/mol 30.04865 ± 0.00085 49784-84-1*0 1,1,1-Trichloroethane CH3CCl3 (l) -183.85 -177.20 ± 0.52 kJ/mol 133.4033 ± 0.0031 71-55-6*500 Methyliumylamino [CH2NH]+ (g) 1056.1 1049.3 ± 1.7 kJ/mol 29.04071 ± 0.00083 65130-65-6*0 Azanidylmethyl [CH2NH]- (g) 224.4 217.2 ± 2.2 kJ/mol 29.04181 ± 0.00083 127593-73-1*0 Fluorosyl fluoride anion [FFO]- (g, quartet) -56.6 -55.7 ± 2.4 kJ/mol 53.99675 ± 0.00030 *86825-57-2*1 Vinyl chloride CH2CHCl (cr,l) -3.61 0.96 ± 0.91 kJ/mol 62.4979 ± 0.0018 75-01-4*500 Chloromethane cation [CH3Cl]+ (g) 1014.55 1007.78 ± 0.16 kJ/mol 50.4867 ± 0.0012 12538-71-5*0 Hydrogen bromide HBr (aq, 5000 H2O) -120.69 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*844 Aminomethyliumyl [CHNH2]+ (g) 1039.5 1031.9 ± 2.3 kJ/mol 29.04071 ± 0.00083 89302-94-3*0 Hydrogen chloride HCl (aq, 1250 H2O) -166.603 ± 0.024 kJ/mol 36.46064 ± 0.00090 7647-01-0*954 Bromofluoromethane CH2FBr (g) -197.4 -211.9 ± 4.9 kJ/mol 112.9290 ± 0.0013 373-52-4*0 Aminomethylene anion [CHNH2]- (g) 353.0 346.1 ± 2.3 kJ/mol 29.04181 ± 0.00083 207914-86-1*0 Fluorodibromomethane CHFBr2 (g) -159.7 -179.3 ± 4.9 kJ/mol 191.8250 ± 0.0022 1868-53-7*0 Difluorochlorobromomethane CF2ClBr (g) -428.9 -439.9 ± 4.9 kJ/mol 165.3642 ± 0.0016 353-59-3*0 Dichlorofluorobromomethane CCl2FBr (g) -228.3 -238.3 ± 4.9 kJ/mol 181.8185 ± 0.0022 353-58-2*0 Dibromofluorochloromethane CBr2FCl (g) -169.9 -186.8 ± 4.9 kJ/mol 226.2698 ± 0.0023 353-55-9*0 Krypton cation Kr+ (g) 1350.757 1350.756 ± 0.000 kJ/mol 83.7995 ± 0.1000 16915-28-9*0 Hydrogen fluoride HF (aq, 40 H2O) -321.94 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*821 Hydrogen chloride HCl (aq, 1500 H2O) -166.634 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*840 Hydrogen carbonate [HOC(O)O]- (aq) -689.858 ± 0.040 kJ/mol 61.0174 ± 0.0012 71-52-3*800 1,2-Difluoroacetylene cation [FCCF]+ (g) 1081.7 1084.5 ± 1.3 kJ/mol 62.0177 ± 0.0016 268566-70-7*0 Difluorophosgene cation [CF2O]+ (g) 653.43 650.67 ± 0.51 kJ/mol 66.00636 ± 0.00085 73256-56-1*0 Methylimidogen anion [CH3N]- (g) 321.1 313.5 ± 1.4 kJ/mol 29.04181 ± 0.00083 82539-34-2*0 Hydrogen chloride HCl (aq, 140 H2O) -165.944 ± 0.024 kJ/mol 36.46064 ± 0.00090 7647-01-0*907 Chloro(chlorooxy)methylene ClCOCl (g, cis) 73.5 73.7 ± 3.6 kJ/mol 98.9155 ± 0.0020 479587-31-0*2 Chlorohydroxymethylene ClCOH (g, trans) 14.0 11.1 ± 2.5 kJ/mol 64.4707 ± 0.0012 147723-60-2*1 (Chlorooxy)methylene HCOCl (g, cis) 119.2 117.9 ± 2.7 kJ/mol 64.4707 ± 0.0012 331419-80-8*2 Dibromophosgene CBr2O (l) -144.37 ± 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 Methyleneaminylium [CH2N]+ (g, triplet) 1456.7 1453.1 ± 2.1 kJ/mol 28.03277 ± 0.00082 53518-13-1*1 Phenylium [C6H5]+ (g, singlet) 1149.15 1136.37 ± 0.85 kJ/mol 77.1034 ± 0.0048 17333-73-2*2 Hydrogen chloride HCl (aq, 74 H2O) -165.544 ± 0.024 kJ/mol 36.46064 ± 0.00090 7647-01-0*953 Trioxidanylium [HOOO]+ (g) 1070.4 1064.2 ± 1.4 kJ/mol 49.00559 ± 0.00090 74241-49-9*0 iso-Proplylide [CH3CHCH3]- (g) 128.8 110.4 ± 1.5 kJ/mol 43.0882 ± 0.0024 25012-80-0*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 Deuterium hydride cation [HD]+ (g) 1490.498 1490.587 ± 0.000 kJ/mol 3.021493 ± 0.000070 12181-16-7*0 Cycloheptane CH2(CH2CH2CH2CH2CH2C (cr,l) -126.63 -156.52 ± 0.51 kJ/mol 98.1861 ± 0.0057 291-64-5*500 Tribromine Br3 (g) 156.0 134.3 ± 3.2 kJ/mol 239.7120 ± 0.0030 11094-39-6*0 Hypochlorous acid cation [HOCl]+ (g) 998.94 995.90 ± 0.90 kJ/mol 52.45949 ± 0.00095 71606-47-8*0 Ethylbenzene C6H5CH2CH3 (cr,l) -12.35 ± 0.54 kJ/mol 106.1650 ± 0.0064 100-41-4*500 Triiodine cation [I3]+ (g) 946.1 941.0 ± 4.1 kJ/mol 380.712861 ± 0.000090 12596-32-6*0 Phenylacetylene C6H5CCH (cr,l) 273.97 ± 0.73 kJ/mol 102.1332 ± 0.0064 536-74-3*500 Phenyloxoniumylidene [C6H5O]+ (g) 901.5 887.2 ± 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 Carbon tetracation [C]+4 (g) 14993.620 14998.767 ± 0.053 kJ/mol 12.00851 ± 0.00080 16092-62-9*0 Peroxychloric acid HOOCl(O)O (g) 76.6 68.4 ± 2.5 kJ/mol 100.4582 ± 0.0015 177778-91-5*0 Fluorobenzene C6H5F (cr,l) -152.13 -149.72 ± 0.88 kJ/mol 96.1023 ± 0.0048 462-06-6*500 Nitrate [ON(O)O]- (aq) -206.56 ± 0.18 kJ/mol 62.00549 ± 0.00090 14797-55-8*800 Carbon C (g, triplet) 711.404 716.889 ± 0.044 kJ/mol 12.01070 ± 0.00080 7440-44-0*1 Bromobenzene C6H5Br (cr,l) 60.3 ± 1.3 kJ/mol 157.0079 ± 0.0049 108-86-1*500 Tribromide [Br3]- (g) -287.5 -308.5 ± 1.9 kJ/mol 239.7125 ± 0.0030 14522-80-6*0 Carbon C (g, singlet) 833.335 838.482 ± 0.044 kJ/mol 12.01070 ± 0.00080 7440-44-0*2 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) -244.60 -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 chloride HCl (aq, 75 H2O) -165.554 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*825 Nitrosyl nitrate ONONO2 (g, trans) 48.3 40.4 ± 1.8 kJ/mol 92.0111 ± 0.0012 15969-55-8*1 Propionaldehyde CH3CH2CHO (cr,l) -218.02 -216.57 ± 0.28 kJ/mol 58.0791 ± 0.0025 123-38-6*500 Ethyl nitrite CH3CH2ONO (g) -81.29 -98.69 ± 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) 267.68 242.24 ± 0.98 kJ/mol 92.1384 ± 0.0056 121-46-0*0 Aminomethyliumylidene [CNH2]+ (g) 1168.3 1165.1 ± 2.2 kJ/mol 28.03277 ± 0.00082 86784-42-1*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 Acrolein CH2CHCHO (g, cis) -46.4 -56.8 ± 1.4 kJ/mol 56.0633 ± 0.0024 107-02-8*2 2-Chloro ozone anion [ClO(O)O]- (g) -103.6 -105.9 ± 3.2 kJ/mol 83.4514 ± 0.0013 *141801-67-4*0 Diazenium [NH2NH]+ (g) 968.65 957.38 ± 0.73 kJ/mol 31.03675 ± 0.00025 37369-93-0*0 Ethenedione cation [OCCO]+ (g) 909.5 912.7 ± 2.0 kJ/mol 56.0197 ± 0.0017 12541-99-0*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 Water H2O (l, eq.press.) -285.797 ± 0.025 kJ/mol 18.01528 ± 0.00033 7732-18-5*589 2-(Methylidyneamino)ethenyl CHCHNCH (g, syn-triplet) 637.1 632.3 ± 2.0 kJ/mol 53.0627 ± 0.0024 123416-74-0*22 Cyclopropylide [CH(CH2CH2)]- (g) 264.8 252.0 ± 1.7 kJ/mol 41.0723 ± 0.0024 1724-45-4*0 1-Cyanovinylium [CH2CCN]+ (g) 1318.3 1317.1 ± 2.2 kJ/mol 52.0542 ± 0.0024 85399-09-3*0 Hydrogen fluoride HF (aq, 60 H2O) -321.98 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*823 Hydroxyoxoammoniumyl [HONO]+ (g) 984.1 977.7 ± 1.7 kJ/mol 47.01293 ± 0.00061 80371-48-8*0 Hypochlorous acid anion [HOCl]- (g) 198.7 198.4 ± 2.5 kJ/mol 52.46059 ± 0.00095 34524-94-2*0 Tetraoxygen O4 (g, C2h singlet) 145.8 142.2 ± 3.8 kJ/mol 63.9976 ± 0.0012 12596-83-7*22 Butatriene cation [CH2CCCH2]+ (g) 1210.5 1204.7 ± 1.3 kJ/mol 52.0740 ± 0.0032 65513-85-1*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 1-Propenylidene CH3CHC (g, triplet) 630.3 622.8 ± 1.7 kJ/mol 40.0639 ± 0.0024 70277-78-0*2 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 Fluoronium [HFH]+ (g) 774.04 771.10 ± 0.91 kJ/mol 21.01373 ± 0.00014 12206-67-6*0 Tetroxidane HOOOOH (g) -34.0 -44.5 ± 1.8 kJ/mol 66.0135 ± 0.0012 29683-94-1*0 1-Buten-3-yn-1-yl HCCCHCH (g, cis) 547.7 545.0 ± 1.2 kJ/mol 51.0666 ± 0.0032 2810-61-9*2 Triazirinylium ion [N(NN)]+ (g) 1608.8 1605.9 ± 1.6 kJ/mol 42.01967 ± 0.00021 92220-05-8*0 3-Buten-1-ynylium [CH2CHCC]+ (g, singlet) 1603.8 1602.8 ± 1.7 kJ/mol 51.0661 ± 0.0032 103928-84-3*2 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 Dinitrogen pentoxide O2NONO2 (cr,l) -41.12 ± 0.38 kJ/mol 108.0105 ± 0.0015 10102-03-1*500 1,3-Cyclobutadien-1-ylium [C(CHCHCH)]+ (g, singlet) 1388.2 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 Phenyl hydroperoxide C6H5OOH (g) 13.4 -5.7 ± 2.1 kJ/mol 110.1106 ± 0.0049 36112-26-2*0 Tetranitrogen cation [NNNN]+ (g) 1392.8 1392.5 ± 1.5 kJ/mol 56.02641 ± 0.00028 12185-04-5*0 Methylcyclopentane CH3CH(CH2CH2CH2CH2) (cr,l) -116.54 -137.90 ± 0.36 kJ/mol 84.1595 ± 0.0049 96-37-7*500 Hydrooxonitrate [HNO]- (g) 78.62 75.70 ± 0.99 kJ/mol 31.01463 ± 0.00032 66057-02-1*0 Dioxosilane SiO2 (cr, cristobalite) -904.05 -908.91 ± 0.69 kJ/mol 60.08430 ± 0.00067 7631-86-9*510 Chlorosyl chloride cation [ClClO]+ (g) 1132.6 1130.8 ± 2.0 kJ/mol 86.9043 ± 0.0018 *86825-56-1*0 Methanol anion [CH3OH]- (g) -89.1 -99.8 ± 2.8 kJ/mol 32.04241 ± 0.00090 68474-04-4*0 Silylene anion [SiH2]- (g) 167.1 165.5 ± 1.4 kJ/mol 30.10193 ± 0.00033 54991-62-7*0 Silyliumylidene [SiH]+ (g) 1134.7 1135.9 ± 1.1 kJ/mol 29.09289 ± 0.00031 31241-66-4*0 Disilene cation [SiH2SiH2]+ (g) 1069.5 1060.4 ± 2.0 kJ/mol 60.20221 ± 0.00066 108492-63-3*0 Di-mu-hydrodihydrodisilicon cation [HSi(HSiHH)]+ (g, trans) 1180.1 1172.5 ± 3.3 kJ/mol 60.20221 ± 0.00066 *129970-82-7*1 Di-mu-hydrodihydrodisilicon anion [HSi(HSiHH)]- (g, trans) 288.3 279.8 ± 3.4 kJ/mol 60.20331 ± 0.00066 *129970-83-8*1 mu-Hydrotrihydrodisilicon Si(HSiH3) (g, triplet) 459.2 451.0 ± 2.5 kJ/mol 60.20276 ± 0.00066 497967-55-2*1 Hydrogen fluoride HF (aq, 5 H2O) -321.33 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*809 Isocyanomethylium [CH2NC]+ (g) 1272.8 1270.6 ± 2.2 kJ/mol 40.0435 ± 0.0016 78269-43-9*0 Bromine atom Br (g, 2P3/2) 117.910 111.847 ± 0.056 kJ/mol 79.90400 ± 0.00100 10097-32-2*1 Ammonium chloride (NH4)Cl (cr) -311.553 -314.714 ± 0.062 kJ/mol 53.49120 ± 0.00095 12125-02-9*510 Dewar benzene (CHCH)(CHCHCHCH) (g) 422.1 405.1 ± 1.7 kJ/mol 78.1118 ± 0.0048 5649-95-6*0 2-Propenylidyne anion [CH2CHC]- (g) 464.6 460.9 ± 1.7 kJ/mol 39.0565 ± 0.0024 120126-89-8*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 1,2-Hexadien-4-yne CH2CCHCCCH3 (g) 407.4 397.4 ± 1.7 kJ/mol 78.1118 ± 0.0048 34783-10-3*0 3-Methylene-1-penten-4-yne CH2CHC(CH2)CCH (g, trans) 362.5 349.9 ± 2.2 kJ/mol 78.1118 ± 0.0048 6929-96-0*1 2-Propen-3-yliumylidene [CHCHCH]+ (g) 1494.5 1491.5 ± 1.7 kJ/mol 39.0554 ± 0.0024 84654-86-4*0 Ammonium radical NH4 (g) 190.01 179.42 ± 0.43 kJ/mol 18.03850 ± 0.00029 92075-50-8*0 2-Propenylidene anion [CHCHCH]- (g) 536.0 532.6 ± 1.7 kJ/mol 39.0565 ± 0.0024 98705-30-7*0 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 Ethylaminylium [CH3CH2NH]+ (g, syn-triplet) 1092.2 1076.3 ± 2.4 kJ/mol 44.0752 ± 0.0017 54387-08-5*11 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 Hypofluorous acid cation [HOF]+ (g) 1142.02 1139.01 ± 0.87 kJ/mol 36.00519 ± 0.00031 90243-22-4*0 Anthracene C6H4(CH(CC(C4H4)CH)) (g) 255.96 226.94 ± 0.98 kJ/mol 178.2292 ± 0.0112 120-12-7*0 Anthracene C6H4(CH(CC(C4H4)CH)) (cr,l) 150.59 124.78 ± 0.92 kJ/mol 178.2292 ± 0.0112 120-12-7*500 Phenanthrene C6H4(C2H2(CC(C4H4))) (cr,l) 136.24 110.97 ± 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) 334.73 312.78 ± 0.94 kJ/mol 178.2292 ± 0.0112 501-65-5*500 Imidogen anion [NH]- (g) 322.62 322.67 ± 0.16 kJ/mol 15.015229 ± 0.000099 23841-33-0*0 Bicyclo[1.1.0]buta-1,1-diene-2,4-diyl C(CCH)C (g) 990.3 993.6 ± 2.0 kJ/mol 49.0507 ± 0.0032 *99417-53-5*0 Benzoic acid C6H5C(O)OH (g) -274.30 -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 Argonium [ArH]+ (g) 1151.9 1150.2 ± 1.5 kJ/mol 40.9554 ± 0.0010 12254-68-1*0 Monosulfur anion S- (g) 76.49 78.54 ± 0.14 kJ/mol 32.0665 ± 0.0060 14337-03-2*0 2-Cyclopropyn-1-ylidene C(CC) (g, singlet) 993.2 1000.0 ± 2.5 kJ/mol 36.0321 ± 0.0024 102508-15-6*2 Fluorosyl fluoride cation [FFO]+ (g, quartet) 1413.1 1413.4 ± 3.5 kJ/mol 53.99566 ± 0.00030 *86825-50-5*1 Dibromine Br2 (aq) -2.25 ± 0.18 kJ/mol 159.8080 ± 0.0020 7726-95-6*800 Thiodioxy SOO (g) 206.8 204.6 ± 2.1 kJ/mol 64.0648 ± 0.0060 164034-62-2*0 2-Cyclopropyn-1-yl anion [C(CC)]- (g) 664.7 672.0 ± 1.6 kJ/mol 36.0326 ± 0.0024 500574-36-7*0 Sulfur oxide peroxide OSOO (g, cis) -25.9 -30.2 ± 2.3 kJ/mol 80.0642 ± 0.0061 175799-68-5*2 Propynylidene HCCCH (g) 543.50 546.49 ± 0.65 kJ/mol 38.0480 ± 0.0024 67152-18-5*0 Sulfuric acid OS(O)(OH)2 (aq, 50 H2O) -886.59 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*822 Sulfuric acid OS(O)(OH)2 (aq, 10000 H2O) -900.56 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*850 1-Cyclopropene-1,2-diyl CH2(CC) (g) 791.1 790.6 ± 1.5 kJ/mol 38.0480 ± 0.0024 202744-75-0*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 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 Trioxirane O(OO) (g) 272.7 270.1 ± 1.3 kJ/mol 47.99820 ± 0.00090 153851-84-4*0 Trihydrogen H(HH) (g, 2p 2A2" Ry) 756.931 754.146 ± 0.015 kJ/mol 3.02382 ± 0.00021 12184-91-7*2 Formyloxidanyl HC(O)O (g) -125.84 -127.20 ± 0.55 kJ/mol 45.0174 ± 0.0010 16499-21-1*0 Dioxiranyl HC(OO) (g) 217.3 213.8 ± 2.0 kJ/mol 45.0174 ± 0.0010 120595-16-6*0 Ammonium hydroxide NH4OH (aq, 10 H2O) -365.99 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*815 1,2-Butadienylium [CH3CHCCH]+ (g, triplet) 1315.5 1307.4 ± 1.7 kJ/mol 53.0820 ± 0.0032 *65114-67-2*1 Ethoxyethane CH3CH2OCH2CH3 (cr,l) -266.19 -278.51 ± 0.60 kJ/mol 74.1216 ± 0.0033 60-29-7*500 Peroxyhypochlorous acid cation [HOOCl]+ (g, trans) 1030.4 1024.6 ± 2.5 kJ/mol 68.4589 ± 0.0011 *67952-07-2*1 1,3-Butadienylium [CH2CHCHCH]+ (g, triplet) 1255.9 1246.5 ± 2.3 kJ/mol 53.0820 ± 0.0032 86181-69-3*1 Ammonium hydroxide NH4OH (aq, 3 H2O) -365.12 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*805 Ammonium hydroxide NH4OH (aq, 5000 H2O) -366.30 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*844 Hydroxyoxoammoniumyl [HONO]+ (g, trans) 984.1 977.7 ± 1.7 kJ/mol 47.01293 ± 0.00061 80371-48-8*1 Ammonium hydroxide NH4OH (aq, 1 H2O) -363.81 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*801 Glycolaldehyde HC(O)CH2OH (g, anti-anti) -292.3 -304.9 ± 1.7 kJ/mol 60.0520 ± 0.0017 141-46-8*21 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 Oxadiazirine cation [O(NN)]+ (g) 1509.9 1507.2 ± 2.4 kJ/mol 44.01233 ± 0.00033 *227934-45-4*0 Methyl acetate CH3C(O)OCH3 (l) -445.61 ± 0.57 kJ/mol 74.0785 ± 0.0025 79-20-9*500 Ammonium hydroxide NH4OH (aq, 10000 H2O) -366.24 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*850 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 1-Hydroxy-2-propanone CH3C(O)CH2OH (g, gauche-anti) -338.1 -356.3 ± 1.7 kJ/mol 74.0785 ± 0.0025 116-09-6*31 1-Hydroxy-2-propanone CH3C(O)CH2OH (g, anti-syn) -329.8 -349.7 ± 1.7 kJ/mol 74.0785 ± 0.0025 116-09-6*22 Ammonium hydroxide NH4OH (aq, 50000 H2O) -366.01 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*855 Methoxyoxomethyl CH3OCO (g, syn-staggered) -151.6 -160.7 ± 1.5 kJ/mol 59.0440 ± 0.0017 16481-04-2*2 Hydrogen peroxide H2O2 (cr,l) -193.098 -187.281 ± 0.079 kJ/mol 34.01468 ± 0.00062 7722-84-1*500 Oxygen difluoride cation [FOF]+ (g) 1292.12 1289.59 ± 0.66 kJ/mol 53.99566 ± 0.00030 39432-25-2*0 1-Ethenylium-1-yl [CCH2]+ (g) 1507.1 1507.1 ± 2.1 kJ/mol 26.0367 ± 0.0016 80541-07-7*0 Ammonium hydroxide NH4OH (aq, 100000 H2O) -365.85 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*861 Propionic acid CH3CH2C(O)OH (cr,l) -505.35 -509.50 ± 0.18 kJ/mol 74.0785 ± 0.0025 79-09-4*500 NON cation [NON]+ (g) 1444.0 1444.2 ± 2.8 kJ/mol 44.01233 ± 0.00033 *227934-46-5*0 Ethylene glycol (CH2OH)2 (cr,l) -448.63 -455.15 ± 0.37 kJ/mol 62.0678 ± 0.0018 107-21-1*500 Hydrochlorate ion [HCl]- (g) -25.2 -24.2 ± 2.5 kJ/mol 36.46119 ± 0.00090 63099-75-2*0 Hydrogen difluoride cation [(HF)(F)]+ (g, triplet) 1267.5 1265.4 ± 4.1 kJ/mol 39.004198 ± 0.000070 *126950-54-7*1 NON anion [NON]- (g) 495.3 492.8 ± 2.5 kJ/mol 44.01343 ± 0.00033 *227934-47-6*0 Oxalic acid (C(O)OH)2 (cr) -819.54 -829.63 ± 0.42 kJ/mol 90.0349 ± 0.0020 144-62-7*500 Dimethylamine (CH3)2NH (l) -43.31 ± 0.37 kJ/mol 45.0837 ± 0.0017 124-40-3*500 Trioxidanyl HOOO (g) 25.36 23.27 ± 0.13 kJ/mol 49.00614 ± 0.00090 12500-78-6*0 Oxygen difluoride anion [FOF]- (g) -202.0 -201.9 ± 2.7 kJ/mol 53.99675 ± 0.00030 *7783-41-7*0 Difluorodioxidanium [FOOF]+ (g, trans) 1283.7 1279.1 ± 2.3 kJ/mol 69.99506 ± 0.00060 *7783-44-0*1 (E)-2-Iminoethylium [CH2CHNH]+ (g, anti-triplet) 1148.6 1138.9 ± 3.3 kJ/mol 42.0594 ± 0.0016 91127-33-2*12 1-Iminoethylium [CH3CNH]+ (g, singlet) 833.6 823.1 ± 3.0 kJ/mol 42.0594 ± 0.0016 *128365-64-0*2 1-Iminoethanide [CH3CNH]- (g, anti) 185.6 175.2 ± 3.2 kJ/mol 42.0604 ± 0.0016 *128365-65-1*2 1-Iminoethylium [CH3CNH]+ (g, anti-triplet) 1342.1 1333.2 ± 3.9 kJ/mol 42.0594 ± 0.0016 *128365-64-0*12 N-Methylenemethaniminium [CH2NCH2]+ (g, singlet) 904.3 893.3 ± 3.1 kJ/mol 42.0594 ± 0.0016 88333-01-1*2 Nitrous acid anion [HONO]- (g, cis) -105.82 -110.44 ± 0.78 kJ/mol 47.01403 ± 0.00061 256393-36-9*2 (Methylimino)methanide [CH3NCH]- (g, trans) 222.9 212.1 ± 3.2 kJ/mol 42.0604 ± 0.0016 *64709-60-0*1 Aziridine NH(CH2CH2) (cr,l) 92.10 ± 0.88 kJ/mol 43.0678 ± 0.0016 151-56-4*500 2-Aziridinylium [NH(CHCH2)]+ (g, singlet) 1010.6 998.6 ± 3.3 kJ/mol 42.0594 ± 0.0016 *91127-35-4*2 2-Aziridinide [NH(CHCH2)]- (g, anti) 315.9 303.8 ± 3.5 kJ/mol 42.0604 ± 0.0016 111127-93-6*2 2-Aziridinyl NH(CHCH2) (g, anti) 364.3 352.1 ± 2.1 kJ/mol 42.0599 ± 0.0016 *23838-09-7*2 2-Aziridinylium [NH(CHCH2)]+ (g, anti-triplet) 1304.6 1292.9 ± 4.2 kJ/mol 42.0594 ± 0.0016 *91127-35-4*12 Trimethylamine (CH3)3N (l) -48.73 ± 0.86 kJ/mol 59.1103 ± 0.0025 75-50-3*500 Cyanogen anion [NCCN]- (g) 281.5 284.7 ± 2.2 kJ/mol 52.0354 ± 0.0016 11118-88-0*0 Diisocyanogen cation [CNNC]+ (g, trans) 1825.3 1828.1 ± 3.2 kJ/mol 52.0343 ± 0.0016 *78800-21-2*1 Isoprene CH2C(CH3)CHCH2 (cr,l) 48.95 ± 0.69 kJ/mol 68.1170 ± 0.0040 78-79-5*500 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 Cyanamide NH2CN (cr) 58.92 ± 0.54 kJ/mol 42.04006 ± 0.00082 420-04-2*500 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 Methylamine CH3NH2 (l) -45.27 ± 0.44 kJ/mol 31.05714 ± 0.00088 74-89-5*500 Dihydrogen H2 (g, ortho) 1.417 0.019 ± 0.000 kJ/mol 2.01588 ± 0.00014 1333-74-0*1 Chlorine chlorite ClOClO (g, cis) 177.4 175.1 ± 2.2 kJ/mol 102.9042 ± 0.0019 105206-44-8*2 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 Ammonium hydroxide NH4OH (aq, 100 H2O) -366.36 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*828 Nitrosyl nitrite anion [ONONO]- (g, t, t) -103.0 -106.2 ± 2.8 kJ/mol 76.01223 ± 0.00091 *122413-35-8*1 n-Heptane CH3(CH2)5CH3 (cr,l) -201.43 -223.88 ± 0.46 kJ/mol 100.2019 ± 0.0057 142-82-5*500 Trioxidane HOOOH (g) -81.95 -90.55 ± 0.62 kJ/mol 50.01408 ± 0.00091 14699-99-1*0 Peroxyhypochlorite [ClOO]- (g) -252.78 -251.75 ± 0.34 kJ/mol 67.4520 ± 0.0011 224299-14-3*0 n-Octane CH3(CH2)6CH3 (cr,l) -226.23 -249.35 ± 0.54 kJ/mol 114.2285 ± 0.0065 111-65-9*500 Nitric acid trihydrate (HON(O)O)(H2O)3 (cr,l) -1062.00 -1055.15 ± 0.20 kJ/mol 117.0587 ± 0.0019 13444-83-2*500 Nitric acid monohydrate (HON(O)O)(H2O) (cr,l) -479.12 -472.63 ± 0.19 kJ/mol 81.0282 ± 0.0012 13444-82-1*500 n-Nonane CH3(CH2)7CH3 (cr,l) -247.52 -274.38 ± 0.49 kJ/mol 128.2551 ± 0.0073 111-84-2*500 Methanol dimer (CH3OH)2 (g) -398.5 -419.2 ± 1.4 kJ/mol 64.0837 ± 0.0018 42845-44-3*0 Hydroxylamine NH2OH (aq, undissoc) -97.1 ± 2.2 kJ/mol 33.02996 ± 0.00037 7803-49-8*1000 Chlorodioxidanyl ClOO (g) 100.36 99.27 ± 0.34 kJ/mol 67.4515 ± 0.0011 17376-09-9*0 n-Decane CH3(CH2)8CH3 (cr,l) -272.66 -300.21 ± 0.80 kJ/mol 142.2817 ± 0.0081 124-18-5*500 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) -23.45 ± 0.51 kJ/mol 96.9427 ± 0.0024 75-35-4*500 Peroxynitrous acid HOONO (g) -5.76 -11.59 ± 0.36 kJ/mol 63.01288 ± 0.00091 14691-52-2*0 1,5-Hexadiene CH2CHCH2CH2CHCH2 (cr,l) 54.59 ± 0.31 kJ/mol 82.1436 ± 0.0049 592-42-7*500 Hydrazoic acid cation [HNNN]+ (g) 1333.63 1327.95 ± 0.83 kJ/mol 43.02761 ± 0.00022 58852-14-5*0 Dichloromethane CH2Cl2 (l) -122.78 ± 0.36 kJ/mol 84.9320 ± 0.0020 75-09-2*590 Hydrazoic acid anion [HNNN]- (g, trans) 309.0 302.7 ± 2.3 kJ/mol 43.02871 ± 0.00022 203264-98-6*1 Dioxodiazoxane ONONO (g, c, p) 125.7 120.4 ± 2.1 kJ/mol 76.01168 ± 0.00091 122413-35-8*3 Ammonium hydroxide NH4OH (aq, 2 H2O) -364.66 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*803 Ammonium hydroxide NH4OH (aq, 20 H2O) -366.19 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*818 Dihydrogen cation [H2]+ (g, ortho) 1489.060 1488.480 ± 0.000 kJ/mol 2.01533 ± 0.00014 12184-90-6*1 Tribromofluoromethane CBr3F (g) -99.2 -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 Difluoromethylene anion [CF2]- (g) -211.15 -209.97 ± 0.58 kJ/mol 50.00805 ± 0.00080 66212-40-6*0 Peroxychlorous acid HOOClO (g, anti) 102.7 96.9 ± 2.5 kJ/mol 84.4588 ± 0.0013 177778-92-6*2 Fluoromethylidyne anion [CF]- (g) 200.8 204.3 ± 1.9 kJ/mol 31.00965 ± 0.00080 33412-12-3*0 Carbonate [OC(O)O]-2 (g) -223.4 -226.6 ± 2.5 kJ/mol 60.0100 ± 0.0012 3812-32-6*0 Azide [NNN]- (aq) 272.57 ± 0.48 kJ/mol 42.02077 ± 0.00021 14343-69-2*800 Carbon dioxide CO2 (aq, undissoc) -413.195 ± 0.019 kJ/mol 44.00950 ± 0.00100 124-38-9*1000 Ammonium hydroxide NH4OH (aq, 500 H2O) -366.38 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*833 Paraformaldehyde CH2O (cr, paraformaldehyde) -179.2 ± 1.6 kJ/mol 30.02598 ± 0.00087 30525-89-4*500 Difluorovinylidene CCF2 (g) 129.4 130.6 ± 2.2 kJ/mol 62.0182 ± 0.0016 41895-33-4*0 Fluoroethynylium [CCF]+ (g) 1536.3 1541.0 ± 2.3 kJ/mol 43.0193 ± 0.0016 268566-69-4*0 Bromoacetylene HCCBr (g) 281.7 275.2 ± 1.6 kJ/mol 104.9333 ± 0.0019 593-61-3*0 Chlorine hydride oxide HCl(O)(O)O (g) 163.9 154.0 ± 2.4 kJ/mol 84.4588 ± 0.0013 1027055-52-2*0 Perchloryl cation [OCl(O)O]+ (g) 1252.1 1246.4 ± 2.5 kJ/mol 83.4504 ± 0.0013 23594-88-9*0 Propane cation [CH3CH2CH3]+ (g) 974.7 954.6 ± 1.7 kJ/mol 44.0951 ± 0.0025 34479-70-4*0 Peroxyhypochlorous acid anion [HOOCl]- (g, cis quartet) -32.1 -33.9 ± 2.6 kJ/mol 68.4600 ± 0.0011 *67952-08-3*2 Chloro(chlorooxy)methylene ClCOCl (g, trans singlet) 98. 101. ± 15. kJ/mol 98.9155 ± 0.0020 479587-31-0*11 Trifluorine F3 (g) 80.6 81.9 ± 2.6 kJ/mol 56.9952096 ± 0.0000015 73455-86-4*0 Chlorooxomethylium [ClCO]+ (g) 783.7 783.8 ± 2.2 kJ/mol 63.4623 ± 0.0012 38264-03-8*0 2-Iodoethanol ICH2CH2OH (l) -207.2 ± 2.4 kJ/mol 171.9650 ± 0.0017 624-76-0*590 1,3-Butadiyne cation [HCCCCH]+ (g) 1440.21 1442.08 ± 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 Oxygen atom hexacation [O]+6 (g) 42035.28 42037.14 ± 0.12 kJ/mol 15.99611 ± 0.00030 14158-22-6*0 o-Benzyne C6H4 (g, triplet) 625.7 616.4 ± 1.1 kJ/mol 76.0960 ± 0.0048 462-80-6*1 Hydraziniumyl [NH2NH2]+ (g) 886.6 873.3 ± 2.0 kJ/mol 32.04469 ± 0.00031 20771-51-1*0 m-Benzyne C6H4 (g) 527.0 518.6 ± 1.2 kJ/mol 76.0960 ± 0.0048 1828-89-3*0 p-Benzyne cation [C6H4]+ (g) 1425.0 1417.7 ± 2.1 kJ/mol 76.0954 ± 0.0048 121058-09-1*0 Cyclobutane CH2(CH2CH2CH2) (l) 3.92 ± 0.39 kJ/mol 56.1063 ± 0.0032 287-23-0*590 p-Benzyne C6H4 (g) 587.1 577.6 ± 1.2 kJ/mol 76.0960 ± 0.0048 3355-34-8*0 Toluene C6H5CH3 (l) 19.80 12.05 ± 0.31 kJ/mol 92.1384 ± 0.0056 108-88-3*500 Tetraoxidanyl HOOOO (g, cis) 53.1 46.1 ± 5.1 kJ/mol 65.0055 ± 0.0012 69696-93-1*2 Hydrazine NH2NH2 (cr,l) 57.31 50.75 ± 0.18 kJ/mol 32.04524 ± 0.00031 302-01-2*500 Cyclopentadienylium [CH(CHCHCHCH)]+ (g) 1088.33 1075.46 ± 0.92 kJ/mol 65.0927 ± 0.0040 29661-18-5*0 2,4,5-Trioxa-1,3-diazabicyclo[1.1.1]pentane N(O3)N (g) 602.5 593.3 ± 2.1 kJ/mol 76.01168 ± 0.00091 224950-18-9*0 Cycloheptene CH2(CHCHCH2CH2CH2CH2 (cr,l) -25.2 -46.3 ± 1.7 kJ/mol 96.1702 ± 0.0057 628-92-2*500 Triiodine I3 (g) 153.4 149.4 ± 3.6 kJ/mol 380.713410 ± 0.000090 12596-31-5*0 Cycloheptatriene CH2(CHCHCHCHCHCH) (cr,l) 154.11 145.33 ± 0.96 kJ/mol 92.1384 ± 0.0056 544-25-2*500 Phenylethene C6H5CHCH2 (cr,l) 104.46 ± 0.48 kJ/mol 104.1491 ± 0.0064 100-42-5*500 Benzonitrile C6H5CN (cr,l) 161.22 163.59 ± 0.91 kJ/mol 103.1213 ± 0.0056 100-47-0*500 Isocyanobenzene C6H5NC (g) 321.1 307.2 ± 1.7 kJ/mol 103.1213 ± 0.0056 931-54-4*0 Phenol C6H5OH (cr,l) -146.42 -162.27 ± 0.65 kJ/mol 94.1112 ± 0.0048 108-95-2*500 1-Methyl-1-ethylium-1-yl [CH3CCH3]+ (g) 1058.2 1045.7 ± 1.9 kJ/mol 42.0792 ± 0.0024 121408-19-3*0 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 Tetraoxodinitrogen cation [O2NNO2]+ (g) 1030.7 1025.2 ± 2.6 kJ/mol 92.0105 ± 0.0012 64476-91-1*0 Carbon dication [C]+2 (g) 4150.474 4155.620 ± 0.044 kJ/mol 12.00960 ± 0.00080 16092-61-8*0 Isopropylidene anion [CH3CCH3]- (g) 282.5 268.4 ± 2.0 kJ/mol 42.0803 ± 0.0024 *121408-19-3*0 Hydrogen chloride HCl (aq, 2439 H2O) -166.712 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*951 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 Iodine monochloride ICl (cr) -36.511 -35.537 ± 0.063 kJ/mol 162.35717 ± 0.00090 7790-99-0*510 o-Tolualdehyde CH3C6H4C(O)H (cr, l, ortho) -119.4 ± 1.1 kJ/mol 120.1485 ± 0.0064 529-20-4*500 Fluorobenzene anion [C6H5F]- (g) -18.7 -30.5 ± 1.8 kJ/mol 96.1029 ± 0.0048 34561-55-2*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 o-Chlorophenylium [C6H4Cl]+ (g) 1167.9 1158.6 ± 2.5 kJ/mol 111.5481 ± 0.0049 137963-70-3*0 Methoxymethylene CH3OCH (g, syn singlet) 144.7 134.3 ± 1.4 kJ/mol 44.0526 ± 0.0017 19527-10-7*22 Iodobenzene cation [C6H5I]+ (g) 1023.46 1008.02 ± 0.99 kJ/mol 204.0078 ± 0.0048 38406-85-8*0 Methylcyclopropane CH3CH(CH2CH2) (l) 1.96 ± 0.59 kJ/mol 56.1063 ± 0.0032 594-11-6*590 1,3-Propanediyl CH2CH2CH2 (g, triplet) 320.1 308.2 ± 1.6 kJ/mol 42.0797 ± 0.0024 32458-33-6*1 Nitrobenzene C6H5N(O)O (cr,l) 7.1 ± 1.4 kJ/mol 123.1094 ± 0.0049 98-95-3*500 Dihydrogen fluoride (HF)(H) (g) -56.5 -54.2 ± 1.7 kJ/mol 21.01428 ± 0.00014 12592-22-2*2 Carbon dioxide anion [CO2]- (g) -340.6 -340.1 ± 2.2 kJ/mol 44.01005 ± 0.00100 14485-07-5*0 Pyridine N(CHCHCHCHCH) (cr,l) 102.25 100.22 ± 0.39 kJ/mol 79.0999 ± 0.0040 110-86-1*500 Dioxiranylidene cation [C(OO)]+ (g) 1409.1 1410.3 ± 2.6 kJ/mol 44.00895 ± 0.00100 *138832-57-2*0 Nitromethane CH3N(O)O (cr,l) -114.09 -112.91 ± 0.43 kJ/mol 61.0401 ± 0.0010 75-52-5*500 Hydrogen fluoride HF (aq, 50 H2O) -321.96 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*822 Dioxygen difluoride OOF2 (g) 75.1 71.6 ± 3.6 kJ/mol 69.99561 ± 0.00060 183051-89-0*0 2-Hydroxyethenyl CHCHOH (g, cis-cis) 143.8 137.3 ± 1.0 kJ/mol 43.0446 ± 0.0016 108665-16-3*11 2-Hydroxyethenyl CHCHOH (g, trans-trans) 147.2 140.9 ± 1.2 kJ/mol 43.0446 ± 0.0016 108665-16-3*22 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 Bromoniumyl [HBr]+ (g) 1097.79 1089.94 ± 0.13 kJ/mol 80.9114 ± 0.0010 12258-64-9*0 cis-1,2-Diiodoethene CHICHI (g, cis) 217.45 209.17 ± 0.35 kJ/mol 279.8462 ± 0.0016 590-26-1*0 trans-1,2-Diiodoethene CHICHI (g, trans) 215.11 207.72 ± 0.35 kJ/mol 279.8462 ± 0.0016 590-27-2*0 2-Hydroxyethenyl CHCHOH (g, cis-trans) 150.5 144.5 ± 1.6 kJ/mol 43.0446 ± 0.0016 108665-16-3*12 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) -801.6 -823.7 ± 2.7 kJ/mol 118.0880 ± 0.0034 110-15-6*0 Tetrazete N(NNN) (g, D2h) 764.9 759.0 ± 1.8 kJ/mol 56.02696 ± 0.00028 42851-09-2*0 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 Dioxiranylidene anion [C(OO)]- (g, ?) -110.2 -109.7 ± 3.0 kJ/mol 44.01005 ± 0.00100 *138832-58-3*0 Isocyanogen iodide INC (g) 341.7 342.0 ± 4.9 kJ/mol 152.92191 ± 0.00080 66004-32-8*0 Acrolein CH2CHCHO (cr,l) -95.7 ± 1.4 kJ/mol 56.0633 ± 0.0024 107-02-8*500 Ethenedione anion [OCCO]- (g) -149.7 -147.1 ± 1.7 kJ/mol 56.0207 ± 0.0017 77783-15-4*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 Acetamide CH3C(O)NH2 (cr,l) -315.86 ± 0.53 kJ/mol 59.0672 ± 0.0017 60-35-5*500 Dioxymethylidyne cation [COO]+ (g, doublet) 1436.6 1439.1 ± 2.7 kJ/mol 44.00895 ± 0.00100 *791121-04-5*2 1-Propenylium [CH3CHCH]+ (g, cis) 1231.9 1221.6 ± 1.7 kJ/mol 41.0713 ± 0.0024 50457-58-4*2 1-Propenylide [CH3CHCH]- (g, cis) 204.0 192.7 ± 1.8 kJ/mol 41.0723 ± 0.0024 65887-20-9*2 Dioxymethylidyne cation [(C)(OO)]+ (g, vdW quartet) 1388.2 1391.7 ± 3.2 kJ/mol 44.00895 ± 0.00100 *791121-04-5*101 Acrylonitrile CH2CHCN (g, triplet) 446.4 441.0 ± 1.7 kJ/mol 53.0627 ± 0.0024 107-13-1*2 Acrylonitrile CH2CHCN (cr,l) 146.32 153.99 ± 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 Carbon dioxide cation [CO2]+ (g, quartet) 1335.0 1335.5 ± 2.4 kJ/mol 44.00895 ± 0.00100 12181-61-2*1 Cyclopropylium [CH(CH2CH2)]+ (g) 1104.9 1093.4 ± 2.4 kJ/mol 41.0713 ± 0.0024 1724-43-2*0 Carbon monoxide anion [CO]- (g) 30.0 33.7 ± 2.3 kJ/mol 28.01065 ± 0.00085 12539-63-8*0 Tetraazatetrahedrane N(N(N)N) (g, Td) 763.7 757.2 ± 1.7 kJ/mol 56.02696 ± 0.00028 12596-63-3*0 Acetonitrile CH3CN (cr,l) 40.62 ± 0.22 kJ/mol 41.0520 ± 0.0016 75-05-8*500 Isocyanogen iodide anion [INC]- (g) 123.0 125.2 ± 9.3 kJ/mol 152.92246 ± 0.00080 *66004-32-8*0 (Z)-Diazene anion [HNNH]- (g, cis) 280.0 273.3 ± 2.0 kJ/mol 30.02991 ± 0.00020 *86631-37-0*0 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 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 Hydrogen fluoride HF (aq, 23 H2O) -321.87 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*903 Vinylvinylidene CH2CHCHC (g, triplet, trans) 690.5 684.4 ± 2.7 kJ/mol 52.0746 ± 0.0032 148759-16-4*11 Hydrogen difluoride cation [FHF]+ (g, triplet ?) 1241. 1238. ± 16. kJ/mol 39.004198 ± 0.000070 126950-54-7*1 1-Buten-3-ynylium [HCCCHCH]+ (g, cis) 1483.1 1480.5 ± 1.7 kJ/mol 51.0661 ± 0.0032 84654-85-3*2 Carbon monoxide CO (g, triplet) 465.578 469.285 ± 0.026 kJ/mol 28.01010 ± 0.00085 630-08-0*1 Bicyclo[1.1.0]buta-1,3-dien-4-ylium-2-yl [C(CC)C]+ (g) 2087.7 2097.5 ± 2.3 kJ/mol 48.0423 ± 0.0032 289679-91-0*0 2-Cyclopropyn-1-ylidenemethyliumyl [CC(CC)]+ (g) 2239.8 2247.7 ± 2.3 kJ/mol 48.0423 ± 0.0032 289679-92-1*0 Isodiazene anion [NNH2]- (g) 380.9 374.1 ± 2.1 kJ/mol 30.02991 ± 0.00020 *63986-30-1*0 2-Cyclopropen-1-ylidenemethylium [CHC(CHCH)]+ (g, triplet) 1433.1 1429.3 ± 1.9 kJ/mol 51.0661 ± 0.0032 112936-36-4*1 Isocyanogen bromide BrNC (g) 341.0 335.3 ± 3.5 kJ/mol 105.9214 ± 0.0013 65997-98-0*0 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 Hydrogen iodide HI (aq) -56.831 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*800 Butyraldehyde CH3CH2CH2CHO (cr,l) -235.83 -239.36 ± 0.84 kJ/mol 72.1057 ± 0.0033 123-72-8*500 Ammonium hydroxide NH4OH (aq, 50 H2O) -366.32 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*822 Dioxohydrazine ONNO (g, cis) 172.93 171.17 ± 0.14 kJ/mol 60.01228 ± 0.00062 16824-89-8*2 Disilicon cation [Si2]+ (g) 1349.9 1353.5 ± 2.7 kJ/mol 56.17045 ± 0.00060 12597-36-3*0 Dioxosilane cation [SiO2]+ (g) 946.3 946.2 ± 2.8 kJ/mol 60.08375 ± 0.00067 59458-81-0*0 Silicate [SiO2]- (g) -477.5 -478.3 ± 2.6 kJ/mol 60.08485 ± 0.00067 53095-83-3*0 1-Propynylium [CH3CC]+ (g) 1547.1 1545.1 ± 3.1 kJ/mol 39.0554 ± 0.0024 24858-94-4*0 Chloryl ion [OClO]+ (g) 1100.26 1097.60 ± 0.53 kJ/mol 67.4510 ± 0.0011 25052-55-5*0 Oxobromonium [BrO]+ (g) 1139.9 1132.1 ± 1.6 kJ/mol 95.9029 ± 0.0010 142315-39-7*0 Oxosilicate [SiO]- (g) -106.1 -104.9 ± 2.6 kJ/mol 44.08545 ± 0.00042 12503-59-2*0 Cycloprop-1-enylium [CH2(CHC)]+ (g) 1502.3 1498.0 ± 2.1 kJ/mol 39.0554 ± 0.0024 117067-78-4*0 Silicon carbide SiC (cr, beta-cubic) -72.1 -73.1 ± 1.5 kJ/mol 40.09620 ± 0.00085 409-21-2*502 Silane cation [SiH4]+ (g) 1104.7 1097.6 ± 1.6 kJ/mol 32.11671 ± 0.00041 34826-51-2*0 Silylium [SiH3]+ (g) 989.75 984.17 ± 0.94 kJ/mol 31.10877 ± 0.00037 41753-67-7*0 Silylidyne anion [SiH]- (g) 248.5 249.7 ± 1.1 kJ/mol 29.09399 ± 0.00031 68865-96-3*0 Disilanylium [SiH3SiH2]+ (g) 981.8 970.4 ± 2.6 kJ/mol 61.21015 ± 0.00069 86860-82-4*0 Cycloprop-2-enylide [CH(CHCH)]- (g) 514.9 511.9 ± 2.2 kJ/mol 39.0565 ± 0.0024 20829-57-6*0 Dioxohydrazine ONNO (g) 172.93 171.17 ± 0.14 kJ/mol 60.01228 ± 0.00062 16824-89-8*0 1-Disilanylium-1-yl [SiH3SiH]+ (g) 1124.1 1116.5 ± 2.3 kJ/mol 60.20221 ± 0.00066 108492-64-4*0 Di-mu-hydrodihydrodisilicon cation [HSi(HSiHH)]+ (g, cis) 1194.2 1184.6 ± 3.5 kJ/mol 60.20221 ± 0.00066 *129970-82-7*2 Di-mu-hydrodihydrodisilicon anion [HSi(HSiHH)]- (g, cis) 296.5 289.0 ± 3.5 kJ/mol 60.20331 ± 0.00066 *129970-83-8*2 Ethynylene C2 (g, triplet) 827.228 833.933 ± 0.092 kJ/mol 24.0214 ± 0.0016 12070-15-4*1 Ammonium hydroxide NH4OH (aq, 4 H2O) -365.42 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*807 2-Propen-3-ylium-1-ylidyne [CHCHC]+ (g) 1791.1 1792.7 ± 2.6 kJ/mol 38.0474 ± 0.0024 161054-36-0*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 1,3-Butadiynyl anion [CCCC]- (g) 677.3 686.4 ± 1.1 kJ/mol 48.0433 ± 0.0032 59158-53-1*0 2,4-Hexadiyne CH3CCCCCH3 (cr,l) 319.05 312.69 ± 0.99 kJ/mol 78.1118 ± 0.0048 2809-69-0*500 Ethynylaminylium [HCCNH]+ (g, triplet) 1278.0 1277.6 ± 2.6 kJ/mol 40.0435 ± 0.0016 103835-08-1*1 Ammonia anion [NH3]- (g) 94.3 87.3 ± 2.4 kJ/mol 17.03111 ± 0.00022 37353-00-7*0 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 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 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 Oxoethylidene anion [HCC(O)H]- (g, anti-gauche) 86.9 83.6 ± 2.1 kJ/mol 42.0372 ± 0.0016 106543-38-8*1 1,3-Pentadiyne HCCCCCH3 (cr,l) 385.0 ± 5.0 kJ/mol 64.0853 ± 0.0040 4911-55-1*500 Hydronium radical (H2O)(H) (g, vdW) -18.5 -21.5 ± 2.1 kJ/mol 19.02322 ± 0.00037 12168-76-2*100 1-Aminoethylium [CH3CHNH2]+ (g) 683.2 664.6 ± 2.3 kJ/mol 44.0752 ± 0.0017 *30208-36-7*0 1-Propanamine CH3CH2CH2NH2 (cr,l) -93.77 -101.38 ± 0.40 kJ/mol 59.1103 ± 0.0025 107-10-8*500 2-Propanamine CH3CH(CH3)NH2 (cr,l) -101.55 -112.16 ± 0.52 kJ/mol 59.1103 ± 0.0025 75-31-0*500 Hydrogen fluoride HF (aq, 55 H2O) -321.97 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*905 Naphthalene C6H4(C4H4) (cr,l) 94.62 75.03 ± 0.59 kJ/mol 128.1705 ± 0.0080 91-20-3*500 Propenediylidene anion [CHCHC]- (g) 588.8 590.0 ± 2.3 kJ/mol 38.0485 ± 0.0024 *161054-36-0*0 Hydroxymethyleneoxonium [CH2OOH]+ (g) 792.92 782.78 ± 0.65 kJ/mol 47.0328 ± 0.0010 77144-12-8*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 Ethyl hydroperoxide CH3CH2OOH (cr,l) -210. ± 20. kJ/mol 62.0678 ± 0.0018 3031-74-1*500 Aniline C6H5NH2 (cr,l) 37.29 31.04 ± 0.64 kJ/mol 93.1265 ± 0.0048 62-53-3*500 Cyclopropenylidene anion [C(CHCH)]- (g) 544.3 543.9 ± 2.2 kJ/mol 38.0485 ± 0.0024 *16165-40-5*0 Isocyanic fluoride FNC (g) 301.1 302.9 ± 1.8 kJ/mol 45.01584 ± 0.00080 16992-26-0*0 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 Deuterium hydride HD (g) 0.328 0.319 ± 0.000 kJ/mol 3.022042 ± 0.000070 13983-20-5*0 Xenonium [XeH]+ (g) 1038.13 1036.35 ± 0.89 kJ/mol 132.2974 ± 0.0200 37276-91-8*0 Pyruvic acid CH3C(O)C(O)OH (cr,l) -588.51 ± 0.74 kJ/mol 88.0621 ± 0.0026 127-17-3*500 Sulfur dioxide OSO (aq, undissoc) -322.82 ± 0.14 kJ/mol 64.0648 ± 0.0060 7446-09-5*1000 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 1148.49 ± 0.20 kJ/mol 33.0734 ± 0.0060 12273-42-6*0 Bromosyl bromide BrBrO (g) 180.3 164.5 ± 2.1 kJ/mol 175.8074 ± 0.0020 68322-97-4*0 Formic acid HC(O)OH (aq) -425.48 ± 0.45 kJ/mol 46.0254 ± 0.0010 64-18-6*800 Sulfuric acid OS(O)(OH)2 (aq, 70 H2O) -887.02 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*824 Nitrogen atom dianion [N]-2 (g) 1062.8 1065.0 ± 2.8 kJ/mol 14.007837 ± 0.000070 16727-21-2*0 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 -520.64 ± 0.89 kJ/mol 82.0801 ± 0.0061 7782-99-2*0 Sulfurous acid S(O)(OH)2 (aq, undissoc) -608.62 ± 0.14 kJ/mol 82.0801 ± 0.0061 7782-99-2*1000 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 ± 3.8 kJ/mol 390.1560 ± 0.0040 12596-95-1*0 Platinum hydride PtH (g) 457.1 456.2 ± 9.2 kJ/mol 196.0859 ± 0.0020 13966-55-7*0 Hydrogen atom H (ad, Pt(111)) -37.0 -38.7 ± 1.1 kJ/mol 1.007940 ± 0.000070 12385-13-6*1000000 Hydrogen atom H (ad, 4 Pt(111)) -33.4 -35.1 ± 1.5 kJ/mol 1.007940 ± 0.000070 12385-13-6*1000004 Isocyanogen chloride ClNC (g) 314.7 316.4 ± 2.4 kJ/mol 61.4701 ± 0.0012 75754-69-7*0 Ammonia NH3 (aq, 3 H2O) -78.86 ± 0.41 kJ/mol 17.03056 ± 0.00022 7664-41-7*805 Hydrogen iodide HI (aq, 5130 H2O) -56.648 ± 0.089 kJ/mol 127.912410 ± 0.000076 10034-85-2*958 Difluorodioxidanium [FOOF]+ (g, cis) 1287.2 1283.0 ± 2.3 kJ/mol 69.99506 ± 0.00060 *7783-44-0*2 Fluorine atom pentacation [F]+5 (g) 30617.6 30619.4 ± 1.8 kJ/mol 18.99566030 ± 0.00000050 14701-05-4*0 Cyclopentadiene CH2(CHCHCHCH) (l) 110.08 ± 0.59 kJ/mol 66.1011 ± 0.0040 542-92-7*590 Isocyanogen cation [CNCN]+ (g) 1654.1 1656.5 ± 1.4 kJ/mol 52.0343 ± 0.0016 133415-63-1*0 Chlorine atom pentacation [Cl]+5 (g) 19147. 19149. ± 11. kJ/mol 35.44996 ± 0.00090 20337-89-7*0 Diisocyanogen cation [CNNC]+ (g, cis) 1838.6 1842.6 ± 3.1 kJ/mol 52.0343 ± 0.0016 *78800-21-2*2 Water H2O (cr) -286.268 -292.708 ± 0.025 kJ/mol 18.01528 ± 0.00033 7732-18-5*510 sec-Butylium [CH3CH2CHCH3]+ (g) 792.7 769.0 ± 1.6 kJ/mol 57.1137 ± 0.0033 16548-59-7*0 2-Methylpentane CH3CH2CH2CH(CH3)2 (cr,l) -180.14 -203.79 ± 0.73 kJ/mol 86.1754 ± 0.0049 107-83-5*500 3-Methylpentane CH3CH2CH(CH3)CH2CH3 (cr,l) -177.59 -201.86 ± 0.76 kJ/mol 86.1754 ± 0.0049 96-14-0*500 Formaldehyde CH2O (g, para singlet) -105.389 -109.229 ± 0.096 kJ/mol 30.02598 ± 0.00087 50-00-0*21 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 Trioxodinitrate anion [ONN(O)O]- (g, non-vdW) -87.3 -93.0 ± 2.2 kJ/mol 76.01223 ± 0.00091 194856-62-7*1 2,2-Dimethylbutane CH3CH2C(CH3)3 (cr,l) -187.90 -213.62 ± 0.75 kJ/mol 86.1754 ± 0.0049 75-83-2*500 Peroxyhypochlorous acid cation [HOOCl]+ (g, cis) 1050.8 1045.2 ± 2.5 kJ/mol 68.4589 ± 0.0011 *67952-07-2*2 Fluorine atom F (g, 2P3/2) 77.252 79.037 ± 0.017 kJ/mol 18.99840320 ± 0.00000050 14762-94-8*1 Oxygen atom tetracation [O]+4 (g) 17719.207 17721.064 ± 0.025 kJ/mol 15.99721 ± 0.00030 14127-65-2*0 Hydrogen peroxide cation [H2O2]+ (g, trans, ortho) 897.29 890.31 ± 0.51 kJ/mol 34.01413 ± 0.00062 12325-10-9*11 Peroxyformate [HC(O)OO]- (g, anti) -320.9 -326.7 ± 1.8 kJ/mol 61.0174 ± 0.0012 104960-05-6*2 Peroxyformyl HC(O)OO (g, anti) -90.6 -96.1 ± 1.8 kJ/mol 61.0168 ± 0.0012 56240-83-6*2 Nitrosyl nitrite anion [ONONO]- (g, t, c) -100.2 -103.4 ± 2.9 kJ/mol 76.01223 ± 0.00091 *122413-35-8*2 Ammonia NH3 (aq, 4 H2O) -79.33 ± 0.41 kJ/mol 17.03056 ± 0.00022 7664-41-7*807 Hydroxylamine NH2OH (cr,l) -107.46 ± 0.60 kJ/mol 33.02996 ± 0.00037 7803-49-8*500 Ammonia NH3 (aq, 5 H2O) -79.63 ± 0.41 kJ/mol 17.03056 ± 0.00022 7664-41-7*809 1,3-Butadiyne-1,4-diyl CCCC (g, triplet) 1052.35 1062.32 ± 0.65 kJ/mol 48.0428 ± 0.0032 78015-07-3*1 Ammonia NH3 (aq, 10 H2O) -80.16 ± 0.41 kJ/mol 17.03056 ± 0.00022 7664-41-7*815 Dihydrogen H2 (g, para) -0.000 -0.058 ± 0.000 kJ/mol 2.01588 ± 0.00014 1333-74-0*2 Hypochloroperoxoous acid, hydroxy ester HOOOCl (g, anti) 48.8 41.8 ± 2.5 kJ/mol 84.4588 ± 0.0013 928652-99-7*2 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 Polyoxymethylene CH2O (cr, polyoxymethylene) -170.85 ± 0.21 kJ/mol 30.02598 ± 0.00087 9002-81-7*500 Bromomethane CH3Br (l) -56.63 -59.65 ± 0.17 kJ/mol 94.9385 ± 0.0013 74-83-9*590 Ammonia NH3 (aq, 20 H2O) -80.38 ± 0.41 kJ/mol 17.03056 ± 0.00022 7664-41-7*818 Ammonia NH3 (aq, 50 H2O) -80.52 ± 0.41 kJ/mol 17.03056 ± 0.00022 7664-41-7*822 Hydroxylamine NH2OH (g) -33.07 -43.44 ± 0.42 kJ/mol 33.02996 ± 0.00037 7803-49-8*0 Formylimidogen HC(O)N (g, singlet) 245.3 242.1 ± 3.3 kJ/mol 43.02478 ± 0.00086 42288-92-6*2 Dioxofluorine anion [OFO]- (g) 155.9 154.4 ± 2.5 kJ/mol 50.99775 ± 0.00060 *175861-93-5*0 Fluorine atom hexacation [F]+6 (g) 45781.5 45783.3 ± 1.8 kJ/mol 18.99511172 ± 0.00000050 14701-04-3*0 Ammonium hydroxide NH4OH (aq, undissoc) -366.678 ± 0.061 kJ/mol 35.04584 ± 0.00047 1336-21-6*1000 Hydrazoic acid anion [HNNN]- (g, cis) 316.2 310.0 ± 2.3 kJ/mol 43.02871 ± 0.00022 203264-98-6*2 1-Hydroxyethyl CH3CHOH (g) -42.86 -56.29 ± 0.47 kJ/mol 45.0605 ± 0.0017 2348-46-1*0 Chlorodioxidenium [ClOO]+ (g) 1215.1 1212.9 ± 6.3 kJ/mol 67.4510 ± 0.0011 64710-10-7*0 Hydroxyoxoammoniumyl [HONO]+ (g, cis) 1014.8 1008.5 ± 2.0 kJ/mol 47.01293 ± 0.00061 80371-48-8*2 Ammonia NH3 (aq, 100 H2O) -80.56 ± 0.41 kJ/mol 17.03056 ± 0.00022 7664-41-7*828 Hydrazoic acid HNNN (aq, undissoc) 257.59 ± 0.48 kJ/mol 43.02816 ± 0.00022 7782-79-8*1000 Hydrazoic acid HNNN (aq) 272.57 ± 0.48 kJ/mol 43.02816 ± 0.00022 7782-79-8*800 Carbonic acid C(O)(OH)2 (aq, undissoc) -698.991 ± 0.030 kJ/mol 62.0248 ± 0.0012 463-79-6*1000 Ethyl bromide CH3CH2Br (l) -55.73 -91.26 ± 0.26 kJ/mol 108.9651 ± 0.0019 74-96-4*500 Methylaminyliumyl [CH3N]+ (g, doublet ?) 1388.3 1381.9 ± 2.3 kJ/mol 29.04071 ± 0.00083 56924-51-7*1 Ammonia NH3 (aq, 500 H2O) -80.58 ± 0.41 kJ/mol 17.03056 ± 0.00022 7664-41-7*833 Vinyl iodide CH2CHI (g) 139.6 130.8 ± 1.2 kJ/mol 153.9497 ± 0.0016 593-66-8*0 Ammonia NH3 (aq, 1000 H2O) -80.57 ± 0.41 kJ/mol 17.03056 ± 0.00022 7664-41-7*839 Difluorovinylidene cation [CCF2]+ (g) 1181.5 1183.0 ± 2.3 kJ/mol 62.0177 ± 0.0016 268566-71-8*0 Ammonia NH3 (aq, 5000 H2O) -80.50 ± 0.41 kJ/mol 17.03056 ± 0.00022 7664-41-7*844 Formaldehyde CH2O (aq) -171.20 ± 0.59 kJ/mol 30.02598 ± 0.00087 50-00-0*800 Ammonia NH3 (aq, 10000 H2O) -80.44 ± 0.41 kJ/mol 17.03056 ± 0.00022 7664-41-7*850 2-Hydroxyethylium [CH2CH2OH]+ (g, gauche) 1024.6 1012.0 ± 2.0 kJ/mol 45.0600 ± 0.0017 38607-31-7*1 Oxygen atom heptacation [O]+7 (g) 113369.48 113371.34 ± 0.12 kJ/mol 15.99556 ± 0.00030 14274-89-6*0 Chloro(chlorooxy)methylene ClCOCl (g, trans triplet) 101.1 104.7 ± 4.8 kJ/mol 98.9155 ± 0.0020 479587-31-0*12 Ammonia NH3 (aq, 50000 H2O) -80.22 ± 0.41 kJ/mol 17.03056 ± 0.00022 7664-41-7*855 Carbon suboxide OCCCO (cr,l) -131.3 -116.2 ± 1.1 kJ/mol 68.0309 ± 0.0025 504-64-3*500 Ammonia NH3 (aq, 100000 H2O) -80.05 ± 0.41 kJ/mol 17.03056 ± 0.00022 7664-41-7*861 Acetaldehyde CH3CHO (cr,l) -187.05 -191.77 ± 0.29 kJ/mol 44.0526 ± 0.0017 75-07-0*500 m-Benzyne C6H4 (g, triplet) 614.7 605.3 ± 1.4 kJ/mol 76.0960 ± 0.0048 1828-89-3*1 Propylene cation [CH3CHCH2]+ (g) 975.14 961.61 ± 0.19 kJ/mol 42.0792 ± 0.0024 34504-10-4*0 Cyclopropane cation [CH2(CH2CH2)]+ (g) 1022.3 1006.9 ± 1.6 kJ/mol 42.0792 ± 0.0024 34496-93-0*0 Hydrazine monohydrate (NH2NH2)(H2O) (l) -242.56 ± 0.19 kJ/mol 50.06052 ± 0.00053 7803-57-8*500 Tropylide [CH(CHCHCHCHCHCH)]- (g) 261.5 245.2 ± 2.0 kJ/mol 91.1310 ± 0.0056 34464-18-1*0 Dihydrogen anion [H2]- (g) 253.8 254.7 ± 1.2 kJ/mol 2.01643 ± 0.00014 12184-89-3*0 Bicyclo[1.1.0]buta-1,3-diene-2,4-diyl C(CC)C (g, singlet) 1047.19 1054.79 ± 0.68 kJ/mol 48.0428 ± 0.0032 12184-80-4*2 Carbon trication [C]+3 (g) 8770.942 8776.088 ± 0.050 kJ/mol 12.00905 ± 0.00080 14067-06-2*0 Tribromine cation [Br3]+ (g) 1036.2 1013.5 ± 2.5 kJ/mol 239.7115 ± 0.0030 33105-86-1*0 1,3-Butadiyn-4-ylium-1-yl [CCCC]+ (g) 2109.9 2120.6 ± 2.8 kJ/mol 48.0423 ± 0.0032 124708-46-9*0 Carbon pentacation [C]+5 (g) 52824.604 52829.751 ± 0.053 kJ/mol 12.00796 ± 0.00080 14280-11-6*0 Tetraoxodinitrate anion [O2NNO2]- (g) -184.6 -187.8 ± 2.4 kJ/mol 92.0116 ± 0.0012 63552-02-3*0 Peroxyhypochlorous acid anion [HOOCl]- (g, trans quartet) -2.8 -3.3 ± 2.6 kJ/mol 68.4600 ± 0.0011 *67952-08-3*1 Carbon hexacation [C]+6 (g) 100101.758 100106.905 ± 0.053 kJ/mol 12.00741 ± 0.00080 16249-02-8*0 Carbide [C]-4 (g) 2709.5 2714.7 ± 2.7 kJ/mol 12.01289 ± 0.00080 12385-15-8*0 Dioxaziridine HN(OO) (g) 277.6 270.9 ± 1.9 kJ/mol 47.01348 ± 0.00061 67394-35-8*0 Fluorine atom octacation [F]+8 (g) 155686.5 155688.3 ± 1.8 kJ/mol 18.99401456 ± 0.00000050 15721-58-1*0 Methyl acetate CH3C(O)OCH3 (g) -394.15 -413.02 ± 0.57 kJ/mol 74.0785 ± 0.0025 79-20-9*0 Tribromide [Br3]- (aq) -129.55 ± 0.23 kJ/mol 239.7125 ± 0.0030 14522-80-6*800 Nitrosyl nitrate ONONO2 (g, cis-perp) 60.4 52.5 ± 1.9 kJ/mol 92.0111 ± 0.0012 15969-55-8*2 Iodine monochloride ICl (l) -24.048 ± 0.063 kJ/mol 162.35717 ± 0.00090 7790-99-0*590 Acetylene anion [HCCH]- (g) 356.9 356.7 ± 1.9 kJ/mol 26.0378 ± 0.0016 50443-89-5*0 Methyl formate HC(O)OCH3 (g) -346.94 -359.98 ± 0.65 kJ/mol 60.0520 ± 0.0017 107-31-3*0 Ethyl formate HC(O)OCH2CH3 (g) -375.1 -393.9 ± 1.0 kJ/mol 74.0785 ± 0.0025 109-94-4*0 Succinic acid (CH2C(O)OH)2 (cr,l) -918.47 -940.19 ± 0.12 kJ/mol 118.0880 ± 0.0034 110-15-6*500 1,2-Dibromoethane CH2BrCH2Br (cr,l) -80.3 ± 1.2 kJ/mol 187.8612 ± 0.0026 106-93-4*500 1,3-Butadien-2-ol CH2C(OH)CHCH2 (g, s-cis, syn) -42.7 -59.3 ± 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 Trioxygen difluoride FOOOF (g) 112.3 107.1 ± 1.1 kJ/mol 85.99501 ± 0.00090 16829-28-0*0 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 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 Dioxofluorine cation [OFO]+ (g) 1667.0 1664.8 ± 2.8 kJ/mol 50.99665 ± 0.00060 223566-05-0*0 1-Methylethenylium [CH3CCH2]+ (g) 995.2 986.0 ± 1.9 kJ/mol 41.0713 ± 0.0024 50457-57-3*0 (Hydroxyimino)methyl HCNOH (g, trans-cis) 258.8 252.7 ± 2.0 kJ/mol 44.03272 ± 0.00087 206442-92-4*2 1-Methylethenyl anion [CH3CCH2]- (g) 199.3 188.2 ± 2.0 kJ/mol 41.0723 ± 0.0024 65887-19-6*0 Oxygen atom trication [O]+3 (g) 10249.929 10252.880 ± 0.018 kJ/mol 15.99775 ± 0.00030 14127-64-1*0 Chlorine atom hexacation [Cl]+6 (g) 28501. 28503. ± 11. kJ/mol 35.44941 ± 0.00090 22541-73-7*0 Trihydrogen (H)(HH) (g, vdW) 215.9 218.3 ± 1.1 kJ/mol 3.02382 ± 0.00021 12184-91-7*100 Cyanoacetylene cation [HCCCN]+ (g) 1495.46 1497.76 ± 0.62 kJ/mol 51.0462 ± 0.0024 85398-68-1*0 Isocyanoacetylene cation [HCCNC]+ (g) 1567.7 1570.3 ± 1.3 kJ/mol 51.0462 ± 0.0024 145076-03-5*0 Chlorine trifluoride cation [FCl(F)F]+ (g) 1053.4 1049.2 ± 2.3 kJ/mol 92.44736 ± 0.00090 478167-77-0*0 Cyanoethynylium [CCCN]+ (g) 1867.6 1874.3 ± 3.2 kJ/mol 50.0383 ± 0.0024 104233-69-4*0 Hydrogen fluoride HF (aq, 3 H2O) -320.71 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*805 Acetylene HCCH (g, cis-triplet) 599.1 599.0 ± 1.5 kJ/mol 26.0373 ± 0.0016 74-86-2*11 1-Propenylium [CH3CHCH]+ (g, trans) 1233.8 1223.4 ± 2.0 kJ/mol 41.0713 ± 0.0024 50457-58-4*1 1-Propenylide [CH3CHCH]- (g, trans) 210.4 199.3 ± 2.0 kJ/mol 41.0723 ± 0.0024 65887-20-9*1 Hydrogen bromide HBr (aq, 2570 H2O) -120.62 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*952 Acetoxy CH3C(O)O (g) -182.21 -190.92 ± 0.85 kJ/mol 59.0440 ± 0.0017 13799-69-4*0 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 2-(Methylidyneamino)ethenyl CHCHNCH (g, singlet) 600.7 596.4 ± 1.2 kJ/mol 53.0627 ± 0.0024 123416-74-0*1 Ketene CH2CO (g, para singlet) -45.36 -48.42 ± 0.11 kJ/mol 42.0367 ± 0.0016 463-51-4*21 Trioxirane cation [O(OO)]+ (g) 1444.5 1442.4 ± 2.2 kJ/mol 47.99765 ± 0.00090 *153851-84-4*0 2-Chloro ozone ClO(O)O (g) 265.7 265.1 ± 3.7 kJ/mol 83.4509 ± 0.0013 *141801-66-3*0 Deuterium molecule cation [D2]+ (g) 1492.286 1492.361 ± 0.000 kJ/mol 4.02765497609 ± 0.00000000080 12184-84-8*0 Tetraoxygen O4 (g, D2h singlet) 69.8 65.1 ± 4.4 kJ/mol 63.9976 ± 0.0012 12596-83-7*21 Ammonium oxide (NH4)2O (cr,l) -428.46 -430.45 ± 0.61 kJ/mol 52.07640 ± 0.00065 12161-77-2*500 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 Trihydrogen H(HH) (g, 2s 2A1' Ry) 745.878 743.094 ± 0.062 kJ/mol 3.02382 ± 0.00021 12184-91-7*1 Fluorine atom trication [F]+3 (g) 11182.871 11186.696 ± 0.032 kJ/mol 18.99675746 ± 0.00000050 14700-88-0*0 Fluorine atom tetracation [F]+4 (g) 19594.3 19596.6 ± 1.7 kJ/mol 18.99620888 ± 0.00000050 14700-79-9*0 Chlorine atom dication [Cl]+2 (g) 3668.475 3670.081 ± 0.013 kJ/mol 35.45160 ± 0.00090 15723-23-6*0 Fluorosyl fluoride FFO (g, singlet) 227. 225. ± 21. kJ/mol 53.99621 ± 0.00030 86825-57-2*2 Carbon monoxide CO (g, singlet) -113.804 -110.524 ± 0.026 kJ/mol 28.01010 ± 0.00085 630-08-0*2 Deuteride D- (g) 146.991 148.904 ± 0.0021 kJ/mol 2.01465035791 ± 0.00000000040 14452-69-8*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) 524.6 515.9 ± 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 Hydrogen peroxide cation [H2O2]+ (g, cis, para) 931.04 924.18 ± 0.98 kJ/mol 34.01413 ± 0.00062 12325-10-9*22 Propionic acid CH3CH2C(O)OH (g) -435.93 -453.82 ± 0.59 kJ/mol 74.0785 ± 0.0025 79-09-4*0 But-3-en-1-yn-1-ide [CH2CHCC]- (g, triplet) 559.0 558.4 ± 2.2 kJ/mol 51.0672 ± 0.0032 58870-47-6*1 Water H2O (g, para) -238.898 -241.801 ± 0.025 kJ/mol 18.01528 ± 0.00033 7732-18-5*2 Chlorine atom tetracation [Cl]+4 (g) 12615.5 12617.1 ± 4.6 kJ/mol 35.45051 ± 0.00090 22541-74-8*0 Oxoniumyl ion [H2O]+ (g, ortho) 978.501 975.597 ± 0.026 kJ/mol 18.01473 ± 0.00033 56583-62-1*1 Silicon cation Si+ (g) 1236.89 1241.01 ± 0.59 kJ/mol 28.08495 ± 0.00030 14067-07-3*0 Silicon atom dication [Si]+2 (g) 2814.02 2817.00 ± 0.59 kJ/mol 28.08440 ± 0.00030 14175-55-4*0 Silicon atom trication [Si]+3 (g) 6045.60 6048.58 ± 0.59 kJ/mol 28.08385 ± 0.00030 14175-56-5*0 Nitrous acid anion [HONO]- (g, trans) -105.4 -109.4 ± 1.8 kJ/mol 47.01403 ± 0.00061 256393-36-9*1 Dioxosilane SiO2 (cr, tridymite) -901.5 -906.3 ± 1.4 kJ/mol 60.08430 ± 0.00067 7631-86-9*515 Oxosilyliumyl [SiO]+ (g) 1022.0 1023.2 ± 2.9 kJ/mol 44.08435 ± 0.00042 12359-18-1*0 Dinitrogen dimer (N2)2 (g) -0.88 0.84 ± 0.67 kJ/mol 56.02696 ± 0.00028 154680-01-0*0 Trihydrogen cation [H3]+ (g, para) 1110.304 1106.697 ± 0.013 kJ/mol 3.02327 ± 0.00021 28132-48-1*2 Fluorine atom heptacation [F]+7 (g) 63649.3 63651.1 ± 1.8 kJ/mol 18.99456314 ± 0.00000050 14700-77-7*0 Ethynylene C2 (g, singlet) 820.005 826.577 ± 0.092 kJ/mol 24.0214 ± 0.0016 12070-15-4*2 Oxygen atom octacation [O]+8 (g) 197447.75 197449.60 ± 0.12 kJ/mol 15.99501 ± 0.00030 21450-98-6*0 Ammonia NH3 (aq) -77.030 ± 0.056 kJ/mol 17.03056 ± 0.00022 7664-41-7*800 mu-Hydrotetrahydrodisilicon cation [SiH2(HSiH2)]+ (g) 981.8 969.1 ± 2.9 kJ/mol 61.21015 ± 0.00069 160896-65-1*0 Di-mu-hydrotrihydrodisilicon cation [SiH2(HSiHH)]+ (g) 1033.9 1020.6 ± 2.9 kJ/mol 61.21015 ± 0.00069 *160896-65-1*0 Disilene anion [SiH2SiH2]- (g) 178.4 170.0 ± 3.1 kJ/mol 60.20331 ± 0.00066 157379-08-3*0 Silylsilylene anion [SiH3SiH]- (g) 160.1 151.4 ± 3.1 kJ/mol 60.20331 ± 0.00066 286949-98-2*0 Silylsilylene SiH3SiH (g, triplet) 381.3 372.4 ± 2.7 kJ/mol 60.20276 ± 0.00066 50420-90-1*1 mu-Hydrotrihydrodisilicon SiH2(HSiH) (g) 317.7 307.7 ± 2.2 kJ/mol 60.20276 ± 0.00066 497967-56-3*0 Ammonia NH3 (aq, 1 H2O) -75.73 ± 0.57 kJ/mol 17.03056 ± 0.00022 7664-41-7*801 mu-Hydrotrihydrodisilicon cation [Si(HSiH3)]+ (g) 1160.1 1152.0 ± 2.6 kJ/mol 60.20221 ± 0.00066 *497967-55-2*0 Hydroxymethylene HCOH (g) 112.68 108.92 ± 0.27 kJ/mol 30.02598 ± 0.00087 19710-56-6*0 Silyloxoniumylidene [SiH3O]+ (g, triplet) 1096.1 1089.8 ± 2.9 kJ/mol 47.10817 ± 0.00047 152720-17-7*1 2-Propen-1-ylium-1-ylidene [CH2CHC]+ (g) 1373.2 1369.6 ± 2.0 kJ/mol 39.0554 ± 0.0024 88000-25-3*0 Hydroxysilylium [SiH2OH]+ (g) 600.1 591.5 ± 2.9 kJ/mol 47.10817 ± 0.00047 66639-72-3*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 Nitrogen atom anion N- (g) 488.2 490.5 ± 2.3 kJ/mol 14.007289 ± 0.000070 17778-87-9*0 Nitrogen atom N (g, quartet) 470.580 472.442 ± 0.024 kJ/mol 14.006740 ± 0.000070 17778-88-0*1 2-Iminoethyl CH2CHNH (g, syn) 221.6 210.3 ± 1.8 kJ/mol 42.0599 ± 0.0016 73843-90-0*1 Nitrogen atom dication [N]+2 (g) 4728.994 4731.822 ± 0.025 kJ/mol 14.005643 ± 0.000070 17439-59-7*0 1,5-Hexadiyne HCCCH2CH2CCH (cr,l) 385.9 ± 1.9 kJ/mol 78.1118 ± 0.0048 628-16-0*500 2-Iminoethyl anion [CH2CHNH]- (g, anti) 110.6 100.1 ± 2.3 kJ/mol 42.0604 ± 0.0016 73843-87-5*2 Isocyanogen bromide anion [BrNC]- (g) 104.8 101.6 ± 4.6 kJ/mol 105.9220 ± 0.0013 *238754-53-5*0 Fluorine atom dication [F]+2 (g) 5132.471 5134.255 ± 0.021 kJ/mol 18.99730604 ± 0.00000050 14701-07-6*0 Oxonium [H3O]+ (g, para) 605.88 599.13 ± 0.17 kJ/mol 19.02267 ± 0.00037 13968-08-6*2 2-Iminoethylium [CH2CHNH]+ (g, singlet) 1108.3 1097.6 ± 3.0 kJ/mol 42.0594 ± 0.0016 73843-91-1*2 Ethynylaminylium [HCCNH]+ (g, singlet) 1350.8 1349.0 ± 2.5 kJ/mol 40.0435 ± 0.0016 103835-08-1*2 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 2-Oxo-1-ethylium-1-yl [HCC(O)H]+ (g, syn-quartet) 1292.0 1288.7 ± 2.4 kJ/mol 42.0361 ± 0.0016 214464-96-7*12 3-Ethenylidenecyclobutene CH2CC(CHCHCH2) (g) 406.5 392.4 ± 2.3 kJ/mol 78.1118 ± 0.0048 813466-23-8*0 3,4-Hexadien-1-yne HCCCHCCHCH3 (g) 418.6 407.5 ± 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 (E)-2-Iminoethylium [CH2CHNH]+ (g, anti) 1108.3 1094.8 ± 3.0 kJ/mol 42.0594 ± 0.0016 91127-33-2*0 Oxoethylidene anion [HCC(O)H]- (g, syn-gauche) 92.3 89.0 ± 2.3 kJ/mol 42.0372 ± 0.0016 106543-38-8*2 Oxygen atom pentacation [O]+5 (g) 28708.788 28710.645 ± 0.053 kJ/mol 15.99666 ± 0.00030 14127-66-3*0 Nitrogen atom trication [N]+3 (g) 9306.68 9308.55 ± 0.23 kJ/mol 14.005094 ± 0.000070 18396-22-0*0 Nitrogen atom tetracation [N]+4 (g) 16781.74 16783.60 ± 0.23 kJ/mol 14.004546 ± 0.000070 14452-70-1*0 mu-Oxodichlorine cation [ClOCl]+ (g) 1130.45 1126.84 ± 0.63 kJ/mol 86.9043 ± 0.0018 51174-96-0*0 Bromodioxy BrOO (g) 116.7 107.7 ± 3.7 kJ/mol 111.9028 ± 0.0012 67177-47-3*0 Nitrogen atom pentacation [N]+5 (g) 26226.70 26228.56 ± 0.23 kJ/mol 14.003997 ± 0.000070 20508-99-0*0 mu-Oxodichlorate anion [ClOCl]- (g) -147.8 -147.7 ± 2.5 kJ/mol 86.9053 ± 0.0018 365546-30-1*0 (Z)-2-Iminoethylium [CH2CHNH]+ (g, syn) 1151.7 1143.0 ± 3.3 kJ/mol 42.0594 ± 0.0016 91127-34-3*0 Oxygen atom dication [O]+2 (g) 4949.459 4953.000 ± 0.013 kJ/mol 15.99830 ± 0.00030 14127-63-0*0 2-Aminoethylium [CH2CH2NH2]+ (g, triplet) 1042.5 1025.9 ± 2.4 kJ/mol 44.0752 ± 0.0017 54088-54-9*1 2-Aminoethyl anion [CH2CH2NH2]- (g) 148.9 131.8 ± 2.1 kJ/mol 44.0763 ± 0.0017 71857-14-2*0 (Z)-2-Iminoethylium [CH2CHNH]+ (g, syn-triplet) 1151.7 1143.0 ± 3.3 kJ/mol 42.0594 ± 0.0016 91127-34-3*11 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 Nitrogen atom hexacation [N]+6 (g) 79493.10 79494.96 ± 0.23 kJ/mol 14.003449 ± 0.000070 15721-56-9*0 1,2-Diphenylethane C6H5CH2CH2C6H5 (g) 180.78 142.30 ± 0.76 kJ/mol 182.2610 ± 0.0112 103-29-7*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) 1192.6 1174.6 ± 3.4 kJ/mol 127.1620 ± 0.0080 79319-68-9*0 Biphenyl C6H5C6H5 (l) 113.9 ± 1.1 kJ/mol 154.2078 ± 0.0096 92-52-4*590 Buckminsterfullerene C60 (g) 2524.7 2520.0 ± 6.5 kJ/mol 720.6420 ± 0.0480 99685-96-8*0 Buckminsterfullerene C60 (cr,l) 2329.6 2339.0 ± 6.5 kJ/mol 720.6420 ± 0.0480 99685-96-8*500 Chlorine atom trication [Cl]+3 (g) 7487.2 7490.2 ± 3.3 kJ/mol 35.45105 ± 0.00090 16547-50-5*0 Cyclobutatrienyl CH(CCC) (g) 961.9 965.4 ± 2.4 kJ/mol 49.0507 ± 0.0032 *99417-52-4*0 Methylene CH2 (g) 391.054 391.600 ± 0.096 kJ/mol 14.02658 ± 0.00081 2465-56-7*0 Helium anion He- (g, 1s.2s.2p 4P) 1904.822 1904.822 ± 0.000 kJ/mol 4.0031506 ± 0.0000020 14452-58-5*3 Helium anion He- (g, 2p3 4S3/2) 5724.96 5724.96 ± 0.32 kJ/mol 4.0031506 ± 0.0000020 14452-58-5*4 Dihelium cation [He2]+ (g) 2143.643 2139.915 ± 0.018 kJ/mol 8.0046554 ± 0.0000040 12184-99-5*0 Dihelium anion [He2]- (g, quartet 4Pig) 1714.9 1711.2 ± 1.9 kJ/mol 8.0057526 ± 0.0000040 90188-47-9*1 Ammonia NH3 (aq, 2 H2O) -78.02 ± 0.41 kJ/mol 17.03056 ± 0.00022 7664-41-7*803 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) 21529.81 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 Sulfur atom dication [S]+2 (g) 3528.25 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 Chlorine atom Cl (g, 2P3/2) 119.621 121.228 ± 0.0011 kJ/mol 35.45270 ± 0.00090 22537-15-1*1 Dioxathiirane S(OO) (g) 167.3 164.9 ± 2.3 kJ/mol 64.0648 ± 0.0060 191663-73-7*0 Difluorine cation [F2]+ (g) 1514.301 1514.475 ± 0.013 kJ/mol 37.9962578 ± 0.0000010 12184-86-0*0 Sulfur trioxide OS(O)O (cr,l) -454.29 ± 0.37 kJ/mol 80.0642 ± 0.0061 7446-11-9*500 Formic acid HC(O)OH (aq, undissoc) -425.38 ± 0.45 kJ/mol 46.0254 ± 0.0010 64-18-6*1000 3-Oxidedioxathiirane OS(OO) (g) -127.8 -132.8 ± 2.2 kJ/mol 80.0642 ± 0.0061 2243010-16-2*0 Trioxathietane S(OOO) (g) 263.7 258.6 ± 2.3 kJ/mol 80.0642 ± 0.0061 *2243010-16-2*0 Oxadithiirane O(SS) (g) 136.5 134.4 ± 2.5 kJ/mol 80.1314 ± 0.0120 488092-02-0*0 Sulfanylideneoxidaniumthiolate SOS (g) 220.9 219.1 ± 2.0 kJ/mol 80.1314 ± 0.0120 401811-43-6*0 Hydrogen peroxide H2O2 (g, para) -129.411 -135.397 ± 0.061 kJ/mol 34.01468 ± 0.00062 7722-84-1*2 Sulfuric acid OS(O)(OH)2 (aq, 115 H2O) -887.62 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*893 Sulfuric acid OS(O)(OH)2 (aq) -878.84 -909.08 ± 0.14 kJ/mol 98.0795 ± 0.0061 7664-93-9*800 Sulfuric acid OS(O)(OH)2 (aq, 40 H2O) -886.27 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*821 Sulfuric acid OS(O)(OH)2 (aq, 700 H2O) -891.17 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*835 Sulfuric acid OS(O)(OH)2 (aq, 800 H2O) -891.54 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*837 Sulfuric acid OS(O)(OH)2 (aq, 1500 H2O) -893.33 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*840 Sulfuric acid OS(O)(OH)2 (aq, 2000 H2O) -894.29 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*841 Sulfuric acid OS(O)(OH)2 (aq, 3000 H2O) -895.75 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*842 Sulfuric acid OS(O)(OH)2 (aq, 5000 H2O) -897.78 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*844 Sulfuric acid OS(O)(OH)2 (aq, 45 H2O) -886.44 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*906 Sulfuric acid OS(O)(OH)2 (aq, 60 H2O) -886.83 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*823 Sulfuric acid OS(O)(OH)2 (aq, 80 H2O) -887.18 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*826 Sulfuric acid OS(O)(OH)2 (aq, 90 H2O) -887.32 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*827 Sulfuric acid OS(O)(OH)2 (aq, 750 H2O) -891.36 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*836 Sulfuric acid OS(O)(OH)2 (aq, 1250 H2O) -892.79 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*954 Sulfuric acid OS(O)(OH)2 (aq, 6000 H2O) -898.51 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*845 Sulfuric acid OS(O)(OH)2 (aq, 7500 H2O) -899.42 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*847 Sulfuric acid OS(O)(OH)2 (aq, 8000 H2O) -899.69 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*848 Sulfuric acid OS(O)(OH)2 (aq, 9000 H2O) -900.15 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*849 Sulfuric acid monohydrate (OS(O)(OH)2)(H2O) (cr,l) -1126.24 -1127.40 ± 0.14 kJ/mol 116.0948 ± 0.0062 10193-30-3*500 Sulfuric acid dihydrate (OS(O)(OH)2)(H2O)2 (cr,l) -1422.05 -1426.84 ± 0.15 kJ/mol 134.1100 ± 0.0063 13451-10-0*500 Sulfuric acid trihydrate (OS(O)(OH)2)(H2O)3 (cr,l) -1715.99 -1720.11 ± 0.16 kJ/mol 152.1253 ± 0.0064 40835-65-2*500 Sulfuric acid tetrahydrate (OS(O)(OH)2)(H2O)4 (cr,l) -2006.84 -2010.87 ± 0.18 kJ/mol 170.1406 ± 0.0065 37006-20-5*500 Nitride [N]-3 (g) 1879.1 1881.0 ± 4.4 kJ/mol 14.008386 ± 0.000070 18851-77-9*0 Dihydrogen cation [H2]+ (g, para) 1488.364 1488.480 ± 0.000 kJ/mol 2.01533 ± 0.00014 12184-90-6*2 Sulfurous acid S(O)(OH)2 (aq) -635.3 ± 4.0 kJ/mol 82.0801 ± 0.0061 7782-99-2*800 Water trimer (H2O)3 (g) -762.63 -776.73 ± 0.20 kJ/mol 54.04584 ± 0.00099 31014-12-7*0 Nitrosodioxaziridine ONN(OO) (g) 413.7 408.2 ± 1.8 kJ/mol 76.01168 ± 0.00091 132871-99-9*0 Acetic acid CH3C(O)OH (aq, 20 H2O) -484.10 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*818 Hydrogen iodide HI (aq, 75 H2O) -55.968 ± 0.099 kJ/mol 127.912410 ± 0.000076 10034-85-2*825 Hydrogen fluoride HF (aq, 25 H2O) -321.88 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*819 Oxoniumyl ion [H2O]+ (g, para) 978.750 975.599 ± 0.026 kJ/mol 18.01473 ± 0.00033 56583-62-1*2 Acetic acid CH3C(O)OH (aq, 25 H2O) -484.23 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*819 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 Nitric acid HON(O)O (aq, 20 H2O) -205.94 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*818 Dichloromethylene CCl2 (g) 229.88 231.07 ± 0.64 kJ/mol 82.9161 ± 0.0020 1605-72-7*0 Acetic acid CH3C(O)OH (aq, 30 H2O) -484.31 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*820 Hydrazine anion [NH2NH2]- (g) 232.3 217.9 ± 4.1 kJ/mol 32.04579 ± 0.00031 65391-88-0*0 Hydrogen bromide HBr (aq, 1500 H2O) -120.55 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*840 Acetic acid CH3C(O)OH (aq, 40 H2O) -484.43 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*821 Acetic acid CH3C(O)OH (aq, 50 H2O) -484.51 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*822 Acetic acid CH3C(O)OH (aq, 55.51 H2O) -484.54 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*891 Hydrogen bromide HBr (aq, 150 H2O) -120.05 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*829 1,3-Butadienyl CH2CHCHCH (g, gauche-cis) 385.5 375.3 ± 2.0 kJ/mol 53.0825 ± 0.0032 86181-68-2*22 Acetic acid CH3C(O)OH (aq, 111 H2O) -484.67 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*892 Ethoxyethene CH2CHOCH2CH3 (g) -118.0 -136.5 ± 1.5 kJ/mol 72.1057 ± 0.0033 109-92-2*0 Hydrogen iodide HI (aq, 100000 H2O) -56.784 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*861 Acetic acid CH3C(O)OH (aq, 200 H2O) -484.74 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*830 Acetic acid CH3C(O)OH (aq, 300 H2O) -484.76 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*831 Cyclopentadienide [CH(CHCHCHCH)]- (g) 100.8 87.8 ± 1.1 kJ/mol 65.0937 ± 0.0040 12127-83-2*0 Formic acid HC(O)OH (aq, 10 H2O) -425.20 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*815 Ammonium hydroxide NH4OH (aq, 555.1 H2O) -366.37 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*895 Acetic acid CH3C(O)OH (aq, 400 H2O) -484.78 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*832 Acetic acid CH3C(O)OH (aq, 500 H2O) -484.79 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*833 trans-Cycloheptene CH2(CHCHCH2CH2CH2CH2 (g) 141.9 103.8 ± 1.9 kJ/mol 96.1702 ± 0.0057 45509-99-7*0 Cyclopropane CH2(CH2CH2) (l) 41.44 35.76 ± 0.52 kJ/mol 42.0797 ± 0.0024 75-19-4*500 Acetic acid CH3C(O)OH (aq, 555.1 H2O) -484.79 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*895 Acetic acid CH3C(O)OH (aq, 600 H2O) -484.79 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*834 Nitric acid HON(O)O (aq, 2 H2O) -193.76 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*803 Ethenol CH2CHOH (g) -113.38 -123.72 ± 0.38 kJ/mol 44.0526 ± 0.0017 557-75-5*0 mu-Oxodioxodinitrogen [ONONO]+ (g, t, t) 984.0 981.1 ± 3.2 kJ/mol 76.01113 ± 0.00091 87950-63-8*1 Ethoxyethene CH2CHOCH2CH3 (g, cis-perp) -111.5 -135.4 ± 2.3 kJ/mol 72.1057 ± 0.0033 109-92-2*21 Vinyl alcohol cation [CH2CHOH]+ (g) 778.5 767.6 ± 1.2 kJ/mol 44.0520 ± 0.0017 57239-63-1*0 Hydrogen chloride HCl (aq, 500 H2O) -166.403 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*833 Acetic acid CH3C(O)OH (aq, 700 H2O) -484.80 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*835 Hydrogen chloride HCl (aq, 2400 H2O) -166.708 ± 0.024 kJ/mol 36.46064 ± 0.00090 7647-01-0*896 Hydrogen fluoride HF (aq, 200 H2O) -322.09 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*830 Hydrogen bromide HBr (aq, 3 H2O) -102.59 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*805 Acetic acid CH3C(O)OH (aq, 800 H2O) -484.80 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*837 Acetic acid CH3C(O)OH (aq, 900 H2O) -484.80 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*838 Phenol cation [C6H5OH]+ (g) 746.17 727.38 ± 0.64 kJ/mol 94.1107 ± 0.0048 40932-22-7*0 Phenol anion [C6H5OH]- (g) 22.8 7.8 ± 4.9 kJ/mol 94.1118 ± 0.0048 38752-11-3*0 Acetic acid CH3C(O)OH (aq, 1000 H2O) -484.81 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*839 1,3-Butadienylium [CH2CHCHCH]+ (g) 1133.6 1123.6 ± 2.5 kJ/mol 53.0820 ± 0.0032 86181-69-3*0 1-Hydroxyethylidene CH3COH (g, singlet) 57.35 47.04 ± 0.77 kJ/mol 44.0526 ± 0.0017 30967-49-8*2 1-Hydroxyethylidene CH3COH (g) 57.35 47.04 ± 0.77 kJ/mol 44.0526 ± 0.0017 30967-49-8*0 Acetic acid CH3C(O)OH (aq, 2000 H2O) -484.82 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*841 Hydroperoxonium [H2OOH]+ (g) 738.2 727.9 ± 1.2 kJ/mol 35.02207 ± 0.00064 70850-26-9*0 Benzaldehyde cation [C6H5C(O)H]+ (g) 896.4 879.7 ± 1.8 kJ/mol 106.1214 ± 0.0056 80226-59-1*0 Benzaldehyde anion [C6H5C(O)H]- (g) -55.6 -73.3 ± 2.7 kJ/mol 106.1225 ± 0.0056 34473-57-9*0 Acetic acid CH3C(O)OH (aq, 5000 H2O) -484.70 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*844 Hydrogen fluoride HF (aq, 45 H2O) -321.95 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*906 Nitrogen atom N (g, doublet) 700.555 702.458 ± 0.024 kJ/mol 14.006740 ± 0.000070 17778-88-0*2 Benzoyl anion [C6H5CO]- (g) 69.7 57.1 ± 4.0 kJ/mol 105.1145 ± 0.0056 78944-74-8*0 Acetic acid CH3C(O)OH (aq, 10000 H2O) -484.84 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*850 Acetic acid CH3C(O)OH (aq, 20000 H2O) -484.85 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*852 Acetic acid CH3C(O)OH (aq, 50000 H2O) -484.86 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*855 Nitric acid HON(O)O (aq, 25 H2O) -206.01 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*819 Acetic acid CH3C(O)OH (aq, 100000 H2O) -484.87 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*861 Ammonium hydroxide NH4OH (aq, 3.5 H2O) -365.29 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*806 Tetraoxidanyl HOOOO (g) 2.1 0.4 ± 2.9 kJ/mol 65.0055 ± 0.0012 69696-93-1*0 Ammonium hydroxide NH4OH (aq, 600 H2O) -366.37 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*834 1,1-Ethenediol CH2C(OH)2 (g) -307.66 -320.20 ± 0.83 kJ/mol 60.0520 ± 0.0017 10375-04-9*0 1,1-Ethenediol CH2C(OH)2 (g, syn-syn C2v) -302.5 -315.8 ± 1.9 kJ/mol 60.0520 ± 0.0017 10375-04-9*2 Ammonium hydroxide NH4OH (aq, 25 H2O) -366.23 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*819 m-Tolualdehyde CH3C6H4C(O)H (cr, l, meta) -125.6 ± 1.3 kJ/mol 120.1485 ± 0.0064 620-23-5*500 Ethoxyethene CH2CHOCH2CH3 (g, trans-trans) -111.0 -133.2 ± 2.6 kJ/mol 72.1057 ± 0.0033 109-92-2*1 Hydrogen chloride HCl (aq, 3000 H2O) -166.738 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*842 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 Methoxymethylene CH3OCH (g, singlet) 129.12 118.62 ± 0.78 kJ/mol 44.0526 ± 0.0017 19527-10-7*2 Hydrogen iodide HI (aq, 5 H2O) -47.73 ± 0.32 kJ/mol 127.912410 ± 0.000076 10034-85-2*809 Cyanogen NCCN (cr,l) 273.93 289.18 ± 0.42 kJ/mol 52.0349 ± 0.0016 460-19-5*500 Hydrogen iodide HI (aq, 1500 H2O) -56.525 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*840 Hydrogen bromide HBr (aq, 55.51 H2O) -119.57 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*891 Glycolaldehyde HC(O)CH2OH (g) -304.47 -317.50 ± 0.90 kJ/mol 60.0520 ± 0.0017 141-46-8*0 Hydrogen iodide HI (aq, 40 H2O) -55.701 ± 0.095 kJ/mol 127.912410 ± 0.000076 10034-85-2*821 1-Aziridinide [N(CH2CH2)]- (g) 243.9 231.5 ± 3.3 kJ/mol 42.0604 ± 0.0016 1358579-49-3*0 Carbon dianion [C]-2 (g) 1027.5 1033.0 ± 4.9 kJ/mol 12.01180 ± 0.00080 50802-47-6*0 Carbon trianion [C]-3 (g) 1813.2 1818.6 ± 5.9 kJ/mol 12.01235 ± 0.00080 50802-48-7*0 Hydrogen chloride HCl (aq, 55.51 H2O) -165.293 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*891 2-Aziridinyl NH(CHCH2) (g) 360.7 349.2 ± 1.8 kJ/mol 42.0599 ± 0.0016 *23838-09-7*0 Formic acid HC(O)OH (aq, 40 H2O) -425.23 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*821 Methoxymethylene CH3OCH (g) 129.12 118.62 ± 0.78 kJ/mol 44.0526 ± 0.0017 19527-10-7*0 Formic acid HC(O)OH (aq, 50 H2O) -425.25 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*822 1-Methylethylidene CH3CCH3 (g) 316.03 303.13 ± 0.98 kJ/mol 42.0797 ± 0.0024 40852-89-9*0 Iminomethyl HCNH (g) 275.81 272.21 ± 0.56 kJ/mol 28.03332 ± 0.00082 15691-95-9*0 Iminomethide [HCNH]- (g) 237.4 233.6 ± 1.8 kJ/mol 28.03387 ± 0.00082 90623-30-6*0 Formic acid HC(O)OH (aq, 55.51 H2O) -425.26 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*891 Chloromethylene CHCl (g) 320.36 320.65 ± 0.89 kJ/mol 48.4713 ± 0.0012 2108-20-5*0 Hydrogen chloride HCl (aq, 555.1 H2O) -166.430 ± 0.024 kJ/mol 36.46064 ± 0.00090 7647-01-0*895 Hydrogen bromide HBr (aq, 2000 H2O) -120.59 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*841 Formic acid HC(O)OH (aq, 75 H2O) -425.28 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*825 Dinitrogen tetraoxide O2NNO2 (cr,l) -37.83 -26.98 ± 0.19 kJ/mol 92.0111 ± 0.0012 10544-72-6*500 Carbon C (g, quintuplet) 1114.967 1120.114 ± 0.044 kJ/mol 12.01070 ± 0.00080 7440-44-0*3 Hydrogen fluoride HF (aq, 7500 H2O) -325.00 ± 0.17 kJ/mol 20.006343 ± 0.000070 7664-39-3*847 Peroxyformyl HC(O)OO (g) -100.64 -105.74 ± 0.93 kJ/mol 61.0168 ± 0.0012 56240-83-6*0 Hydrogen fluoride HF (aq, 35 H2O) -321.92 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*904 Pyridiniumyl [N(CHCHCHCHCH)]+ (g) 1051.34 1035.40 ± 0.61 kJ/mol 79.0994 ± 0.0040 16399-94-3*0 Pyridine anion [N(CHCHCHCHCH)]- (g) 214.4 200.9 ± 3.2 kJ/mol 79.1005 ± 0.0040 12169-63-0*0 Hydrogen bromide HBr (aq, 800 H2O) -120.44 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*837 Water H2O (cr, l, eq.press.) -286.269 -285.797 ± 0.025 kJ/mol 18.01528 ± 0.00033 7732-18-5*499 Nitric acid HON(O)O (aq, 4 H2O) -200.30 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*807 Water H2O (cr, eq.press.) -286.270 -292.710 ± 0.025 kJ/mol 18.01528 ± 0.00033 7732-18-5*509 Acetone enol CH3C(OH)CH2 (g) -151.35 -168.16 ± 0.69 kJ/mol 58.0791 ± 0.0025 29456-04-0*0 Acetone enol CH3C(OH)CH2 (g, anti) -145.3 -162.6 ± 1.9 kJ/mol 58.0791 ± 0.0025 29456-04-0*2 Hydrogen chloride HCl (aq, 3500 H2O) -166.752 ± 0.024 kJ/mol 36.46064 ± 0.00090 7647-01-0*899 Hydroxyamidogen HNOH (g) 101.26 94.43 ± 0.80 kJ/mol 32.02202 ± 0.00034 13940-32-4*0 Iodine monochloride ICl (cr,l) -36.511 -35.537 ± 0.063 kJ/mol 162.35717 ± 0.00090 7790-99-0*500 Perchloric acid cation [HOCl(O)(O)O]+ (g) 1190.2 1180.6 ± 3.3 kJ/mol 100.4577 ± 0.0015 91712-47-9*0 1-Propen-2-ol-1-yl CH3C(OH)CH (g) 101.57 90.21 ± 0.87 kJ/mol 57.0712 ± 0.0024 1976041-84-5*0 1-Propen-2-ol-1-yl CH3C(OH)CH (g, cis-cis) 106.5 94.5 ± 1.9 kJ/mol 57.0712 ± 0.0024 1976041-84-5*12 1-Propen-2-ol-1-yl CH3C(OH)CH (g, trans-trans) 114.0 102.8 ± 1.9 kJ/mol 57.0712 ± 0.0024 1976041-84-5*21 1-Propen-2-ol-1-yl CH3C(OH)CH (g, cis-trans) 115.1 104.3 ± 1.9 kJ/mol 57.0712 ± 0.0024 1976041-84-5*22 Ammonium hydroxide NH4OH (aq, 8 H2O) -365.91 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*813 Isocyanogen anion [CNCN]- (g) 386.6 388.7 ± 3.3 kJ/mol 52.0354 ± 0.0016 *83951-85-3*0 Ethylene anion [CH2CH2]- (g) 232.1 225.6 ± 2.0 kJ/mol 28.0537 ± 0.0016 34527-91-8*0 Hydrogen iodide HI (aq, 20 H2O) -55.09 ± 0.12 kJ/mol 127.912410 ± 0.000076 10034-85-2*818 Formic acid HC(O)OH (aq, 111 H2O) -425.31 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*892 Hydrogen fluoride HF (aq, 300 H2O) -322.18 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*831 Formic acid HC(O)OH (aq, 200 H2O) -425.34 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*830 Hypochloroperoxoous acid, hydroxy ester HOOOCl (g) 48.5 41.7 ± 1.8 kJ/mol 84.4588 ± 0.0013 928652-99-7*0 Trihydrogen H(HH) (g, Ry) 745.878 743.199 ± 0.062 kJ/mol 3.02382 ± 0.00021 12184-91-7*0 Peroxyformate [HC(O)OO]- (g) -341.15 -346.59 ± 0.98 kJ/mol 61.0174 ± 0.0012 104960-05-6*0 Methyl nitrite CH3ONO (g, trans) -52.43 -64.38 ± 0.89 kJ/mol 61.0401 ± 0.0010 624-91-9*1 Methyl nitrite CH3ONO (cr,l) -88.77 ± 0.56 kJ/mol 61.0401 ± 0.0010 624-91-9*500 Hydrogen fluoride HF (aq, 500 H2O) -322.37 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*833 2-Hydroxyethenyl CHCHOH (g) 138.00 132.18 ± 0.72 kJ/mol 43.0446 ± 0.0016 108665-16-3*0 Ethyl nitrite CH3CH2ONO (g, gauche-trans) -80.2 -98.5 ± 1.9 kJ/mol 75.0666 ± 0.0017 109-95-5*2 Ethyl nitrite CH3CH2ONO (g, gauche-cis) -78.2 -97.1 ± 1.9 kJ/mol 75.0666 ± 0.0017 109-95-5*3 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 Propyl nitrite CH3CH2CH2ONO (g, gauche-gauche-trans II) -94.9 -119.5 ± 2.5 kJ/mol 89.0932 ± 0.0025 543-67-9*4 Propyl nitrite CH3CH2CH2ONO (g, trans-gauche-trans) -94.9 -119.2 ± 2.5 kJ/mol 89.0932 ± 0.0025 543-67-9*5 Propyl nitrite CH3CH2CH2ONO (g, trans-gauche-cis) -93.0 -118.0 ± 2.5 kJ/mol 89.0932 ± 0.0025 543-67-9*6 Propyl nitrite CH3CH2CH2ONO (g, gauche-gauche-cis) -92.7 -117.8 ± 2.5 kJ/mol 89.0932 ± 0.0025 543-67-9*7 Propyl nitrite CH3CH2CH2ONO (g, gauche-gauche-cis II) -91.3 -116.2 ± 2.8 kJ/mol 89.0932 ± 0.0025 543-67-9*8 1,2-Dibromoethene CHBrCHBr (g) 121.2 101.0 ± 2.0 kJ/mol 185.8453 ± 0.0026 540-49-8*0 Propylidene anion [CH3CH2CH]- (g) 300.9 286.7 ± 3.2 kJ/mol 42.0803 ± 0.0024 *121408-55-7*0 1-Methoxyethenol CH2C(OH)OCH3 (g) -284.3 -302.8 ± 1.2 kJ/mol 74.0785 ± 0.0025 4453-91-2*0 Hydrogen iodide HI (aq, 500 H2O) -56.362 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*833 Isoformyl anion [COH]- (g) 55.7 58.4 ± 1.8 kJ/mol 29.01859 ± 0.00086 81747-63-9*0 2,2,4-Trimethylpentane (CH3)2CHCH2C(CH3)3 (g) -171.0 -223.5 ± 1.5 kJ/mol 114.2285 ± 0.0065 540-84-1*0 Chlorohydroxymethyl CH(Cl)OH (g) -54.9 -60.6 ± 1.1 kJ/mol 65.4787 ± 0.0012 147139-06-8*0 Hydrogen bromide HBr (aq, 2500 H2O) -120.62 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*898 Hydrogen bromide HBr (aq, 20 H2O) -118.40 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*818 Hydrogen fluoride HF (aq, 500000 H2O) -333.06 ± 0.17 kJ/mol 20.006343 ± 0.000070 7664-39-3*866 Hydrogen iodide HI (aq, 555.1 H2O) -56.383 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*895 Hydrogen chloride HCl (aq, 400 H2O) -166.336 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*832 Hydrogen bromide HBr (aq, 200 H2O) -120.14 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*830 Hydrogen iodide HI (aq, 600 H2O) -56.395 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*834 Chloroethane CH3CH2Cl (cr,l) -134.34 -135.96 ± 0.25 kJ/mol 64.5138 ± 0.0019 75-00-3*500 Ammonium hydroxide NH4OH (aq, 700 H2O) -366.37 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*835 Hydrogen fluoride HF (aq, 4000 H2O) -324.15 ± 0.14 kJ/mol 20.006343 ± 0.000070 7664-39-3*843 Aminomethylidyne anion [CNH2]- (g, triplet) 481.6 478.1 ± 3.2 kJ/mol 28.03387 ± 0.00082 96808-04-7*1 Ethoxyethene CH2CHOCH2CH3 (g, trans-perp) -109.0 -132.2 ± 2.3 kJ/mol 72.1057 ± 0.0033 109-92-2*11 Ammonium hydroxide NH4OH (aq, 5 H2O) -365.62 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*809 1,1-Dibromoethane CH3CHBr2 (cr,l) -67.2 ± 1.3 kJ/mol 187.8612 ± 0.0026 557-91-5*500 1-Hydroxy-2-propanone CH3C(O)CH2OH (g) -354.56 -373.89 ± 0.84 kJ/mol 74.0785 ± 0.0025 116-09-6*0 Isocyanogen chloride cation [ClNC]+ (g) 1481.0 1482.3 ± 3.9 kJ/mol 61.4696 ± 0.0012 956475-91-5*0 Nitrosyl nitrate ONONO2 (g) 48.3 40.4 ± 1.8 kJ/mol 92.0111 ± 0.0012 15969-55-8*0 Formic acid HC(O)OH (aq, 300 H2O) -425.35 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*831 3-Buten-2-one CH3C(O)CHCH2 (g) -95.40 -110.94 ± 0.85 kJ/mol 70.0898 ± 0.0032 78-94-4*0 Hydrogen chloride HCl (aq, 4000 H2O) -166.763 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*843 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 Formic acid HC(O)OH (aq, 400 H2O) -425.35 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*832 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 Hydrogen bromide HBr (aq, 700 H2O) -120.42 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*835 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 Hydrogen iodide HI (aq, 50 H2O) -55.809 ± 0.095 kJ/mol 127.912410 ± 0.000076 10034-85-2*822 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 Formic acid HC(O)OH (aq, 500 H2O) -425.35 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*833 Hydrogen iodide HI (aq, 3 H2O) -36.92 ± 0.56 kJ/mol 127.912410 ± 0.000076 10034-85-2*805 Nitric acid HON(O)O (aq, 5 H2O) -201.96 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*809 Hydrogen chloride HCl (aq, 700 H2O) -166.487 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*835 Ammonium hydroxide NH4OH (aq, 20000 H2O) -366.18 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*852 Ammonium hydroxide NH4OH (aq, 30 H2O) -366.25 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*820 Hydrogen iodide HI (aq, 2000 H2O) -56.558 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*841 1,2-Propadien-1-one anion [CH2CCO]- (g) 49.7 48.5 ± 3.1 kJ/mol 54.0479 ± 0.0024 159171-62-7*0 Fluorosyl fluoride anion [FFO]- (g) -147.1 -146.8 ± 3.0 kJ/mol 53.99675 ± 0.00030 *86825-57-2*0 Hydrogen fluoride HF (aq, 250 H2O) -322.13 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*908 Hydrogen bromide HBr (aq, 2 H2O) -93.05 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*803 1-Oxo-2-propyn-1-ylium [HCCCO]+ (g) 1001.7 1003.1 ± 3.0 kJ/mol 53.0389 ± 0.0024 53474-99-0*0 3-Oxo-1,2-propadien-1-yl anion [HCCCO]- (g) 179.4 182.0 ± 3.2 kJ/mol 53.0400 ± 0.0024 557113-97-0*0 Oxiranylium [CH2(CHO)]+ (g) 901.3 893.3 ± 1.4 kJ/mol 43.0441 ± 0.0016 57789-76-1*0 2-Aziridinylium [NH(CHCH2)]+ (g) 1010.6 998.6 ± 3.3 kJ/mol 42.0594 ± 0.0016 *91127-35-4*0 Dioxymethylene HCOO (g) 341.8 339.8 ± 3.0 kJ/mol 45.0174 ± 0.0010 438586-67-5*0 Formylethynyl anion [CCCHO]- (g) 100.4 101.7 ± 3.4 kJ/mol 53.0400 ± 0.0024 85905-64-2*0 Diazanide [NH2NH]- (g) 249.3 239.3 ± 3.1 kJ/mol 31.03785 ± 0.00025 25415-88-7*0 2-Cyclopropen-1-one cation [OC(CHCH)]+ (g) 1078.6 1075.5 ± 2.0 kJ/mol 54.0468 ± 0.0024 100815-68-7*0 Formic acid HC(O)OH (aq, 555.1 H2O) -425.35 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*895 Hydrogen bromide HBr (aq, 30 H2O) -118.97 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*820 Oxiranyl anion [CH2(CHO)]- (g) 121.3 113.4 ± 1.5 kJ/mol 43.0452 ± 0.0016 72722-59-9*0 Hydrogen chloride HCl (aq, 5000 H2O) -166.793 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*844 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 Isourea NHC(OH)NH2 (g) -156.2 -172.8 ± 2.6 kJ/mol 60.05534 ± 0.00091 4744-36-9*0 Hydrogen cyanide anion [HCN]- (g) 129.527 129.048 ± 0.089 kJ/mol 27.02593 ± 0.00081 12334-27-9*0 Hydrogen chloride HCl (aq, 7000 H2O) -166.822 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*846 Carbamoyl anion [NH2CO]- (g) -81.9 -87.8 ± 3.1 kJ/mol 44.03327 ± 0.00087 78944-69-1*0 Formic acid HC(O)OH (aq, 12 H2O) -425.20 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*816 Carbamoyl HNCOH (g) 74.1 68.3 ± 2.7 kJ/mol 44.03272 ± 0.00087 *2858-51-7*0 Carbamoyl HNCOH (g, trans-cis) 76.4 69.9 ± 3.2 kJ/mol 44.03272 ± 0.00087 *2858-51-7*2 Carbamoyl HNCOH (g, cis-trans) 96.3 90.1 ± 3.2 kJ/mol 44.03272 ± 0.00087 *2858-51-7*3 Carbamoyl HNCOH (g, cis-cis) 110.9 104.8 ± 3.2 kJ/mol 44.03272 ± 0.00087 *2858-51-7*4 Trioxidaniumyl [HOOOH]+ (g) 925.5 916.6 ± 1.5 kJ/mol 50.01353 ± 0.00091 161321-37-5*0 Hydrogen chloride HCl (aq, 10 H2O) -161.148 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*815 (Hydroxyimino)methyl HCNOH (g) 250.1 244.3 ± 1.9 kJ/mol 44.03272 ± 0.00087 206442-92-4*0 Hydroxyaminylium [HNOH]+ (g) 1019.5 1012.3 ± 2.5 kJ/mol 32.02147 ± 0.00034 66097-71-0*0 2-Aziridinylium [NH(CHCH2)]+ (g, triplet) 1304.6 1292.9 ± 4.2 kJ/mol 42.0594 ± 0.0016 *91127-35-4*1 (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 Hydrogen iodide HI (aq, 6 H2O) -49.969 ± 0.095 kJ/mol 127.912410 ± 0.000076 10034-85-2*811 Nitric acid HON(O)O (aq, 55.51 H2O) -206.04 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*891 Hydrogen chloride HCl (aq, 10000 H2O) -166.847 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*850 Methane anion [CH4]- (g) 27.3 19.4 ± 5.1 kJ/mol 16.04301 ± 0.00085 27680-53-1*0 Ammonium hydroxide NH4OH (aq, 1.5 H2O) -364.33 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*802 Isocyanic acid anion [HNCO]- (g) -54.3 -57.4 ± 3.0 kJ/mol 43.02533 ± 0.00086 *444010-28-0*0 Formaldoxime CH2NOH (g) 30.5 19.9 ± 1.3 kJ/mol 45.04066 ± 0.00088 75-17-2*0 Carbonylmethyloxonium [CH3OCO]+ (g) 561.3 553.1 ± 3.1 kJ/mol 59.0435 ± 0.0017 24434-00-2*0 Formic acid HC(O)OH (aq, 600 H2O) -425.36 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*834 Peroxyhypochlorous acid anion [HOOCl]- (g, quartet) -32.1 -33.9 ± 2.6 kJ/mol 68.4600 ± 0.0011 *67952-08-3*0 Hydrogen bromide HBr (aq, 1 H2O) -72.05 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*801 Hydrogen chloride HCl (aq, 12 H2O) -162.010 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*816 Diisocyanogen anion [CNNC]- (g) 456.8 462.5 ± 3.6 kJ/mol 52.0354 ± 0.0016 *78800-22-3*0 Diisocyanogen cation [CNNC]+ (g) 1825.3 1828.5 ± 3.2 kJ/mol 52.0343 ± 0.0016 *78800-21-2*0 Methoxyoxomethyl CH3OCO (g) -152.6 -160.3 ± 1.2 kJ/mol 59.0440 ± 0.0017 16481-04-2*0 Methoxyoxomethyl CH3OCO (g, anti-eclipsed) -151.7 -159.8 ± 2.1 kJ/mol 59.0440 ± 0.0017 16481-04-2*3 Ammonium hydroxide NH4OH (aq, 40 H2O) -366.30 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*821 Pentachloroethylium [CCl3CCl2]+ (g) 838.1 836.5 ± 3.3 kJ/mol 201.2844 ± 0.0048 *7094-17-9*0 Hydrogen chloride HCl (aq, 50 H2O) -165.186 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*822 Pentachloroethanide [CCl3CCl2]- (g) -281.8 -280.3 ± 3.9 kJ/mol 201.2854 ± 0.0048 263019-83-6*0 Cyanic acid cation [HOCN]+ (g) 1135.7 1133.2 ± 2.9 kJ/mol 43.02423 ± 0.00086 59780-31-3*0 Acetyloxoniumylidene [CH3C(O)O]+ (g, triplet) 892.3 883.8 ± 2.9 kJ/mol 59.0435 ± 0.0017 67057-47-0*1 Hydrobromate ion [HBr]- (g) -5.9 -12.4 ± 4.3 kJ/mol 80.9125 ± 0.0010 85532-97-4*0 Fluorine atom nonacation [F]+9 (g) 262121.1 262122.9 ± 1.8 kJ/mol 18.99346598 ± 0.00000050 35424-07-8*0 Hydrogen iodide HI (aq, 700 H2O) -56.416 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*835 Cyanic acid anion [HOCN]- (g) -9.2 -9.6 ± 3.1 kJ/mol 43.02533 ± 0.00086 58199-47-6*0 Hydrogen chloride HCl (aq, 40 H2O) -164.926 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*821 1-Cyanoethylidene CH3CCN (g) 437.5 433.8 ± 1.5 kJ/mol 53.0627 ± 0.0024 498544-34-6*0 Hydrogen bromide HBr (aq, 40 H2O) -119.29 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*821 Hydrogen bromide HBr (aq, 10 H2O) -116.28 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*815 Ammonium hydroxide NH4OH (aq, 15 H2O) -366.12 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*817 Oxoiodonium [IO]+ (g) 1066.1 1064.1 ± 1.9 kJ/mol 142.90332 ± 0.00030 81182-81-2*0 Hydrogen iodide HI (aq, 100 H2O) -56.048 ± 0.097 kJ/mol 127.912410 ± 0.000076 10034-85-2*828 Hydrogen isocyanide anion [HNC]- (g) 191.62 191.80 ± 0.32 kJ/mol 27.02593 ± 0.00081 96913-22-3*0 Hydrogen bromide HBr (aq, 300 H2O) -120.24 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*831 3-Imino-2-propen-1-ylidene CHCHCNH (g) 530.7 526.3 ± 1.2 kJ/mol 53.0627 ± 0.0024 916765-05-4*0 Hydrogen iodide HI (aq, 2500 H2O) -56.584 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*898 3-Imino-2-propen-1-ylidene CHCHCNH (g, triplet) 571.8 567.0 ± 1.6 kJ/mol 53.0627 ± 0.0024 916765-05-4*2 Hydrogen fluoride HF (aq, 1000 H2O) -322.72 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*839 Hydrogen bromide HBr (aq, 75 H2O) -119.74 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*825 1,2-Butadiene CH3CHCCH2 (cr,l) 137.79 138.84 ± 0.64 kJ/mol 54.0904 ± 0.0032 590-19-2*500 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 2-(Methylidyneamino)ethenyl CHCHNCH (g) 600.7 596.4 ± 1.2 kJ/mol 53.0627 ± 0.0024 123416-74-0*0 Oxooxoniumylmethoxy [OC(O)O]+ (g) 1178.3 1177.6 ± 5.8 kJ/mol 60.0084 ± 0.0012 952586-28-6*0 2-(Methylidyneamino)ethenyl CHCHNCH (g, triplet) 634.5 630.4 ± 1.6 kJ/mol 53.0627 ± 0.0024 123416-74-0*2 Formic acid HC(O)OH (aq, 700 H2O) -425.36 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*835 Formic acid HC(O)OH (aq, 800 H2O) -425.36 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*837 Nitric acid HON(O)O (aq, 7 H2O) -203.79 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*812 Hydrogen chloride HCl (aq, 20000 H2O) -166.885 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*852 1,2-Dichloroethene CHClCHCl (g) 3.81 -1.51 ± 0.55 kJ/mol 96.9427 ± 0.0024 540-59-0*0 Ketene CH2CO (g, ortho singlet) -45.24 -48.42 ± 0.11 kJ/mol 42.0367 ± 0.0016 463-51-4*22 Acetate [CH3C(O)O]- (aq) -485.10 ± 0.27 kJ/mol 59.0446 ± 0.0017 71-50-1*800 Diazoethenylidene cation [NNCC]+ (g) 1771.1 1773.1 ± 3.5 kJ/mol 52.0343 ± 0.0016 *130760-10-0*0 Diatomic bromine cation [Br2]+ (g) 1060.31 1045.36 ± 0.23 kJ/mol 159.8075 ± 0.0020 12595-71-0*0 Hydrogen iodide HI (aq, 7 H2O) -51.307 ± 0.099 kJ/mol 127.912410 ± 0.000076 10034-85-2*812 Formic acid HC(O)OH (aq, 900 H2O) -425.36 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*838 Propylidyne CH3CH2C (g) 492.6 483.0 ± 1.2 kJ/mol 41.0718 ± 0.0024 85056-54-8*0 Chlorine atom dianion [Cl]-2 (g) 406.6 408.2 ± 4.8 kJ/mol 35.45380 ± 0.00090 33944-49-9*0 2-Cyanovinyl CHCHCN (g) 447.79 445.38 ± 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) 263.7 261.4 ± 1.8 kJ/mol 52.0553 ± 0.0024 *85398-67-0*0 Formic acid HC(O)OH (aq, 1000 H2O) -425.37 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*839 (Formyloxy)methyl HC(O)OCH2 (g) -151.5 -159.6 ± 1.1 kJ/mol 59.0440 ± 0.0017 3122-12-1*0 2-Isocyanovinyl CHCHNC (g) 543.2 541.8 ± 1.7 kJ/mol 52.0547 ± 0.0024 225798-14-1*0 Formic acid HC(O)OH (aq, 15 H2O) -425.20 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*817 Formic acid HC(O)OH (aq, 20 H2O) -425.20 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*818 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 Carboxymethyl CH2C(O)OH (g) -226.7 -236.6 ± 1.1 kJ/mol 59.0440 ± 0.0017 2887-46-9*0 Hydrogen bromide HBr (aq, 900 H2O) -120.47 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*838 Isocyanomethyliumyl [HCNC]+ (g) 1505.9 1507.8 ± 3.3 kJ/mol 39.0355 ± 0.0016 99045-54-2*0 Isocyanomethylene anion [HCNC]- (g) 400.5 401.3 ± 2.1 kJ/mol 39.0366 ± 0.0016 144141-01-5*0 Isocyanomethylene HCNC (g) 582.3 584.5 ± 1.7 kJ/mol 39.0361 ± 0.0016 78694-65-2*0 Trihydrogen HHH (g, TS) 254.5 250.7 ± 1.2 kJ/mol 3.02382 ± 0.00021 12184-91-7*200 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) 224.3 230.2 ± 3.5 kJ/mol 52.0320 ± 0.0024 109292-50-4*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 Hydrogen iodide HI (aq, 3000 H2O) -56.605 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*842 Ammonium hydroxide NH4OH (aq, 55.51 H2O) -366.32 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*891 Dichlorovinylidene CCCl2 (g) 424.3 427.5 ± 3.0 kJ/mol 94.9268 ± 0.0024 20394-25-6*0 Chlorovinylidene CCHCl (g) 429.2 430.9 ± 2.9 kJ/mol 60.4820 ± 0.0018 70277-82-6*0 Hydrogen fluoride HF (aq, 600 H2O) -322.44 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*834 Diazoethenylidene anion [NNCC]- (g) 529.6 532.2 ± 3.5 kJ/mol 52.0354 ± 0.0016 *130760-11-1*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 Ethylidene CH3CH (g) 361.27 354.29 ± 0.46 kJ/mol 28.0532 ± 0.0016 4218-50-2*0 Dioxodiazoxane ONONO (g) 93.0 88.2 ± 1.3 kJ/mol 76.01168 ± 0.00091 122413-35-8*0 Hydrogen chloride HCl (aq, 15 H2O) -162.855 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*817 1,3-Cyclobutadiene cation [CH(CHCHCH)]+ (g) 1215.7 1207.4 ± 3.0 kJ/mol 52.0740 ± 0.0032 34531-09-4*0 Diazene HNNH (g, trans-cis-iso equilib) 207.12 199.98 ± 0.41 kJ/mol 30.02936 ± 0.00020 3618-05-1*0 Nitrous acid anion [HONO]- (g) -105.82 -109.29 ± 0.78 kJ/mol 47.01403 ± 0.00061 256393-36-9*0 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 Ammonium hydroxide NH4OH (aq, 750 H2O) -366.37 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*836 3H-diazirin-3-ylidene-methylene CC(NN) (g) 837.3 839.9 ± 2.4 kJ/mol 52.0349 ± 0.0016 204253-88-3*0 Fluoromethane cation [CH3F]+ (g) 981.78 974.28 ± 0.62 kJ/mol 34.03237 ± 0.00083 59122-96-2*0 Fluoromethane CH3F (l) -245.78 ± 0.45 kJ/mol 34.03292 ± 0.00083 593-53-3*590 Nitric acid HON(O)O (aq, 100 H2O) -206.06 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*828 Formic acid HC(O)OH (aq, 5 H2O) -425.31 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*809 Vinylvinylidene CH2CHCHC (g) 494.1 488.8 ± 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 Hydrogen fluoride HF (aq, 22.2 H2O) -321.86 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*888 Vinylvinylidene CH2CHCHC (g, triplet, cis) 695.4 689.0 ± 3.3 kJ/mol 52.0746 ± 0.0032 148759-16-4*12 Vinylvinylidene cation [CH2CHCHC]+ (g) 1429.8 1424.5 ± 2.0 kJ/mol 52.0740 ± 0.0032 161054-20-2*0 Vinylvinylidene cation [CH2CHCHC]+ (g, cis) 1437.9 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 Cyclopropylidene C(CH2CH2) (g) 474.93 466.91 ± 0.85 kJ/mol 40.0639 ± 0.0024 2143-70-6*0 Chloromethane CH3Cl (l) -106.52 -102.56 ± 0.16 kJ/mol 50.4872 ± 0.0012 74-87-3*590 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 Dicarbon monoxide CCO (g) 377.12 381.16 ± 0.83 kJ/mol 40.0208 ± 0.0016 12071-23-7*0 Nitric acid HON(O)O (aq, 10 H2O) -205.02 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*815 (Acetyloxy)methyl CH3C(O)OCH2 (g) -200.2 -214.0 ± 1.5 kJ/mol 73.0706 ± 0.0025 2887-49-2*0 Bromomethane cation [CH3Br]+ (g) 996.21 981.29 ± 0.17 kJ/mol 94.9380 ± 0.0013 12538-70-4*0 Hydrogen chloride HCl (aq, 200 H2O) -166.102 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*830 COC vdW (CO)(C) (g) 589.7 598.5 ± 1.5 kJ/mol 40.0208 ± 0.0016 *12071-24-8*0 Ammonium hydroxide NH4OH (aq, 800 H2O) -366.37 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*837 Diazene HNNH (g, trans-cis equilib) 207.12 199.98 ± 0.41 kJ/mol 30.02936 ± 0.00020 3618-05-1*1 Hydrogen peroxide cation [H2O2]+ (g, trans, para) 897.32 890.31 ± 0.51 kJ/mol 34.01413 ± 0.00062 12325-10-9*12 1,2,3-Butatrien-1-ylium [CH2CCCH]+ (g) 1271.8 1270.0 ± 1.1 kJ/mol 51.0661 ± 0.0032 81932-79-8*0 Isocyanomethane CH3NC (cr,l) 146.5 ± 2.2 kJ/mol 41.0520 ± 0.0016 593-75-9*500 Hydrogen iodide HI (aq, 8 H2O) -52.23 ± 0.12 kJ/mol 127.912410 ± 0.000076 10034-85-2*813 Ammonium hydroxide NH4OH (aq, 900 H2O) -366.37 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*838 Nitric acid HON(O)O (aq, 500 H2O) -206.17 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*833 Hydrogen fluoride HF (aq, 18.5 H2O) -321.83 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*887 Iodomethane cation [CH3I]+ (g) 944.68 935.28 ± 0.18 kJ/mol 141.93844 ± 0.00083 12538-72-6*0 1-Buten-3-yn-1-yl HCCCHCH (g) 547.26 544.74 ± 0.87 kJ/mol 51.0666 ± 0.0032 2810-61-9*0 1-Buten-3-ynylium [HCCCHCH]+ (g) 1482.3 1480.2 ± 1.5 kJ/mol 51.0661 ± 0.0032 84654-85-3*0 But-1-en-3-yn-1-ide [HCCCHCH]- (g) 419.7 419.1 ± 1.2 kJ/mol 51.0672 ± 0.0032 119611-65-3*0 Hydrogen fluoride HF (aq, 400 H2O) -322.28 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*832 2-Propenylidene CHCHCH2 (g, triplet) 417.4 410.5 ± 1.5 kJ/mol 40.0639 ± 0.0024 19527-08-3*1 Nitrato [ON(O)O]+ (g) 1290.61 1285.90 ± 0.86 kJ/mol 62.00439 ± 0.00090 133057-96-2*0 Formic acid HC(O)OH (aq, 2000 H2O) -425.37 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*841 Fluoroform CHF3 (l) -704.76 ± 0.41 kJ/mol 70.01385 ± 0.00080 75-46-7*590 3-Buten-1-ynylium [CH2CHCC]+ (g) 1572.6 1570.2 ± 1.7 kJ/mol 51.0661 ± 0.0032 103928-84-3*0 But-3-en-1-yn-1-ide [CH2CHCC]- (g) 326.6 323.6 ± 1.4 kJ/mol 51.0672 ± 0.0032 58870-47-6*0 Trihydrogen cation [H3]+ (g, ortho) 1110.577 1106.695 ± 0.013 kJ/mol 3.02327 ± 0.00021 28132-48-1*1 2-Propenylidene CHCHCH2 (g) 417.4 410.5 ± 1.5 kJ/mol 40.0639 ± 0.0024 19527-08-3*0 Ammonium hydroxide NH4OH (aq, 2.5 H2O) -364.91 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*804 2-Propenylidene CHCHCH2 (g, triplet syn) 419.0 411.5 ± 2.3 kJ/mol 40.0639 ± 0.0024 19527-08-3*12 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 Hydrogen fluoride HF (aq, 5000 H2O) -324.44 ± 0.14 kJ/mol 20.006343 ± 0.000070 7664-39-3*844 C=O-C cation [COC]+ (g) 1585.8 1592.9 ± 2.7 kJ/mol 40.0203 ± 0.0016 83483-98-1*0 Formic acid HC(O)OH (aq, 5000 H2O) -425.38 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*844 2-Cyclopropen-1-ylidenemethylium [CHC(CHCH)]+ (g) 1346.4 1343.8 ± 1.8 kJ/mol 51.0661 ± 0.0032 112936-36-4*0 Hydrogen iodide HI (aq, 111 H2O) -56.077 ± 0.095 kJ/mol 127.912410 ± 0.000076 10034-85-2*892 Formic acid HC(O)OH (aq, 10000 H2O) -425.38 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*850 Formic acid HC(O)OH (aq, 20000 H2O) -425.39 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*852 Formic acid HC(O)OH (aq, 50000 H2O) -425.40 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*855 1,3-Cyclobutadien-1-ylium [C(CHCHCH)]+ (g) 1388.2 1383.3 ± 1.9 kJ/mol 51.0661 ± 0.0032 81913-77-1*0 Hydrogen bromide HBr (aq, 4000 H2O) -120.67 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*843 Diazene cation [HNNH]+ (g, trans-iso-cis equilib) 1132.49 1125.83 ± 0.64 kJ/mol 30.02881 ± 0.00020 76986-17-9*0 Nitric acid HON(O)O (aq, 555.1 H2O) -206.18 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*895 Cyclobutenide [CH2(CHCHCH)]- (g) 320.3 307.9 ± 3.2 kJ/mol 53.0830 ± 0.0032 60211-42-9*0 Nitric acid HON(O)O (aq, 15 H2O) -205.71 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*817 Difluorodioxidanium [FOOF]+ (g) 1283.7 1280.1 ± 2.3 kJ/mol 69.99506 ± 0.00060 *7783-44-0*0 Formic acid HC(O)OH (aq, 100000 H2O) -425.43 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*861 Hydrogen iodide HI (aq, 9 H2O) -52.90 ± 0.16 kJ/mol 127.912410 ± 0.000076 10034-85-2*814 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 Hydrogen bromide HBr (aq, 5 H2O) -111.07 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*809 Diazene cation [HNNH]+ (g, trans-cis equilib) 1132.49 1125.55 ± 0.64 kJ/mol 30.02881 ± 0.00020 76986-17-9*1 Dioxoethylium [OCHCO]+ (g) 688.7 690.0 ± 3.0 kJ/mol 57.0276 ± 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 Ethanedial anion [OCHCO]- (g) -188.7 -190.2 ± 3.1 kJ/mol 57.0287 ± 0.0017 1994332-01-2*0 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 Cyanomethylium [CH2CN]+ (g) 1256.69 1254.05 ± 0.65 kJ/mol 40.0435 ± 0.0016 34430-18-7*0 Isocyanogen bromide cation [BrNC]+ (g) 1469.7 1464.0 ± 5.9 kJ/mol 105.9209 ± 0.0013 238754-53-5*0 Oxirene O(CHCH) (g) 273.19 271.03 ± 0.92 kJ/mol 42.0367 ± 0.0016 157-18-6*0 Ammonium hydroxide NH4OH (aq, 300 H2O) -366.38 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*831 2-Aziridinylium [NH(CHCH2)]+ (g, syn-triplet) 1334.7 1323.7 ± 4.9 kJ/mol 42.0594 ± 0.0016 *91127-35-4*11 Isofulminic acid cation [HONC]+ (g) 1376.9 1374.8 ± 2.9 kJ/mol 43.02423 ± 0.00086 117800-60-9*0 Dichlorine cation [Cl2]+ (g) 1108.307 1108.286 ± 0.0062 kJ/mol 70.9049 ± 0.0018 12595-90-3*0 Silicon atom tetracation [Si]+4 (g) 10401.12 10404.11 ± 0.59 kJ/mol 28.08331 ± 0.00030 22537-24-2*0 Silicon anion Si- (g) 316.30 319.28 ± 0.59 kJ/mol 28.08605 ± 0.00030 14337-02-1*0 Oxirene O(CHCH) (g, triplet) 387.9 384.5 ± 1.4 kJ/mol 42.0367 ± 0.0016 157-18-6*1 Hydrogen peroxide H2O2 (g, ortho) -129.390 -135.397 ± 0.061 kJ/mol 34.01468 ± 0.00062 7722-84-1*1 Disilicon anion [Si2]- (g) 375.2 379.0 ± 1.8 kJ/mol 56.17155 ± 0.00060 64236-73-3*0 Diazene anion [HNNH]- (g, trans-cis-iso equilib) 265.5 258.7 ± 2.0 kJ/mol 30.02991 ± 0.00020 100429-75-2*0 Hydroxyoxoethenylium [HOCCO]+ (g) 866.4 865.2 ± 3.5 kJ/mol 57.0276 ± 0.0017 *1994332-00-1*0 Ethynediolide [HOCCO]- (g) -132.9 -134.0 ± 3.5 kJ/mol 57.0287 ± 0.0017 1994332-00-1*0 2-Aziridinide [NH(CHCH2)]- (g) 315.9 303.8 ± 3.5 kJ/mol 42.0604 ± 0.0016 111127-93-6*0 Hydrogen bromide HBr (aq, 555.1 H2O) -120.37 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*895 Cyanogen bromide cation [BrCN]+ (g) 1331.1 1324.8 ± 1.4 kJ/mol 105.9209 ± 0.0013 34749-77-4*0 Ethynol cation [HCCOH]+ (g) 1063.8 1061.2 ± 2.9 kJ/mol 42.0361 ± 0.0016 84005-02-7*0 Hydrogen iodide HI (aq, 800 H2O) -56.437 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*837 Bromoform CHBr3 (l) 7.5 ± 1.1 kJ/mol 252.7306 ± 0.0031 75-25-2*590 Hydrogen fluoride HF (aq, 100000 H2O) -330.14 ± 0.17 kJ/mol 20.006343 ± 0.000070 7664-39-3*861 Hydrogen iodide HI (aq, 10 H2O) -53.38 ± 0.17 kJ/mol 127.912410 ± 0.000076 10034-85-2*815 Cyanogen iodide cation [ICN]+ (g) 1271.3 1271.2 ± 1.7 kJ/mol 152.92136 ± 0.00080 34749-78-5*0 Silicon carbide anion [SiC]- (g) 509.8 514.5 ± 4.4 kJ/mol 40.09675 ± 0.00085 86017-99-4*0 Acetylide [C2]-2 (g) 843.0 849.6 ± 3.2 kJ/mol 24.0225 ± 0.0016 34846-56-5*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 Silicon carbide SiC (cr,l) -70.7 -71.7 ± 1.5 kJ/mol 40.09620 ± 0.00085 409-21-2*500 Tetrafluorosilane cation [SiF4]+ (g) -137.3 -141.7 ± 5.9 kJ/mol 104.07856 ± 0.00030 62859-94-3*0 Difluoromethane CH2F2 (l) -468.98 ± 0.35 kJ/mol 52.02339 ± 0.00081 75-10-5*590 (Methylamino)methyl anion [CH3NHCH2]- (g) 201.8 184.9 ± 3.1 kJ/mol 44.0763 ± 0.0017 *31277-25-5*0 Formylimidogen HC(O)N (g, triplet) 245.2 242.1 ± 4.6 kJ/mol 43.02478 ± 0.00086 42288-92-6*1 Hydrogen chloride HCl (aq, 800 H2O) -166.516 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*837 Water anion [H2O]- (g) -50.1 -53.0 ± 4.3 kJ/mol 18.01583 ± 0.00033 12259-30-2*0 Fluorosyl fluoride FFO (g) 192.8 193.3 ± 2.3 kJ/mol 53.99621 ± 0.00030 86825-57-2*0 Dioxohydrazine ONNO (g, trans) 192.3 188.7 ± 1.8 kJ/mol 60.01228 ± 0.00062 16824-89-8*1 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 Silylene SiH2 (g) 271.44 269.77 ± 0.86 kJ/mol 30.10138 ± 0.00033 13825-90-6*0 Diazene anion [HNNH]- (g, trans-cis equilib) 265.5 258.7 ± 2.0 kJ/mol 30.02991 ± 0.00020 100429-75-2*1 Hydrogen fluoride HF (aq, 20000 H2O) -326.67 ± 0.17 kJ/mol 20.006343 ± 0.000070 7664-39-3*852 Peroxyformic acid HC(O)OOH (g) -279.22 -288.36 ± 0.88 kJ/mol 62.0248 ± 0.0012 107-32-4*0 Oxonium [H3O]+ (aq) -285.796 ± 0.025 kJ/mol 19.02267 ± 0.00037 13968-08-6*800 Disilane cation [SiH3SiH3]+ (g) 1030.4 1017.6 ± 2.2 kJ/mol 62.21809 ± 0.00073 96301-43-8*0 Hydrogen chloride HCl (aq, 50000 H2O) -166.922 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*855 Formic acid HC(O)OH (aq, 7 H2O) -425.24 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*812 Hydrazoic acid anion [HNNN]- (g) 309.0 303.1 ± 2.3 kJ/mol 43.02871 ± 0.00022 203264-98-6*0 Formic acid HC(O)OH (aq, 25 H2O) -425.21 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*819 Hydrodioxonitrogen cation [HN(O)O]+ (g) 1130.3 1123.6 ± 3.0 kJ/mol 47.01293 ± 0.00061 252986-76-8*0 Hydrogen chloride HCl (aq, 100000 H2O) -166.947 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*861 Ethynol HCCOH (g, t-c triplet) 406.4 403.2 ± 3.2 kJ/mol 42.0367 ± 0.0016 32038-79-2*12 2-Aziridinide [NH(CHCH2)]- (g, syn) 329.9 317.8 ± 4.0 kJ/mol 42.0604 ± 0.0016 111127-93-6*1 Disilene SiH2SiH2 (g) 288.7 280.0 ± 1.9 kJ/mol 60.20276 ± 0.00066 15435-77-5*0 1-Methylene-2-propenylium [CH2CHCCH2]+ (g) 1059.4 1049.3 ± 1.7 kJ/mol 53.0820 ± 0.0032 62698-26-4*0 Formic acid HC(O)OH (aq, 3 H2O) -425.43 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*805 Ethanimine CH3CHNH (g) 55.71 41.07 ± 0.73 kJ/mol 43.0678 ± 0.0016 20729-41-3*0 Chlorine atom heptacation [Cl]+7 (g) 39520. 39522. ± 11. kJ/mol 35.44886 ± 0.00090 22537-27-5*0 Silylsilylene SiH3SiH (g) 317.2 309.4 ± 2.0 kJ/mol 60.20276 ± 0.00066 50420-90-1*0 Ammonium hydroxide NH4OH (aq, 4000 H2O) -366.31 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*843 Hydrazoic acid HNNN (cr,l) 261.45 ± 0.65 kJ/mol 43.02816 ± 0.00022 7782-79-8*500 Dinitrogen anion [N2]- (g) 192.5 192.5 ± 1.7 kJ/mol 28.01403 ± 0.00014 12185-02-3*0 Ethynol HCCOH (g, t-t triplet) 409.4 406.3 ± 3.2 kJ/mol 42.0367 ± 0.0016 32038-79-2*13 Hydrodioxonitrate [HN(O)O]- (g) -61.8 -68.2 ± 3.2 kJ/mol 47.01403 ± 0.00061 61508-71-2*0 Ammonium hydroxide NH4OH (aq, 75 H2O) -366.34 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*825 Ethynol HCCOH (g, c-t triplet) 455.5 452.2 ± 3.2 kJ/mol 42.0367 ± 0.0016 32038-79-2*14 Peroxychlorous acid HOOClO (g) 95.4 89.8 ± 2.0 kJ/mol 84.4588 ± 0.0013 177778-92-6*0 Di-mu-hydrodihydrodisilicon HSi(HSiHH) (g) 374.6 364.3 ± 2.4 kJ/mol 60.20276 ± 0.00066 129970-82-7*0 Di-mu-hydrodihydrodisilicon HSi(HSiHH) (g, trans) 374.6 364.2 ± 2.4 kJ/mol 60.20276 ± 0.00066 129970-82-7*1 Di-mu-hydrodihydrodisilicon HSi(HSiHH) (g, trans-triplet) 544.1 536.1 ± 3.7 kJ/mol 60.20276 ± 0.00066 129970-82-7*11 Di-mu-hydrodihydrodisilicon cation [HSi(HSiHH)]+ (g) 1180.1 1172.5 ± 3.3 kJ/mol 60.20221 ± 0.00066 *129970-82-7*0 Di-mu-hydrodihydrodisilicon anion [HSi(HSiHH)]- (g) 288.3 280.2 ± 3.4 kJ/mol 60.20331 ± 0.00066 *129970-83-8*0 Ethynol HCCOH (g, c-c triplet) 464.1 460.9 ± 3.2 kJ/mol 42.0367 ± 0.0016 32038-79-2*15 Nitric acid HON(O)O (aq, 30 H2O) -206.04 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*820 Hydrogen bromide HBr (aq, 2640 H2O) -120.62 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*957 Hydrogen chloride HCl (aq, 20 H2O) -163.675 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*818 Ethylideneammoniumylidene [CH3CHN]+ (g, triplet) 1309.9 1300.3 ± 3.0 kJ/mol 42.0594 ± 0.0016 91127-36-5*1 Chlorous acid cation [HOClO]+ (g) 996.6 991.6 ± 3.1 kJ/mol 68.4589 ± 0.0011 *99559-66-7*0 Ethylideneazanide [CH3CHN]- (g) 147.7 137.5 ± 3.2 kJ/mol 42.0604 ± 0.0016 144810-43-5*0 Hydrogen fluoride HF (aq, 15 H2O) -321.80 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*817 Trioxygen difluoride FOOOF (g, cis) 113.5 107.7 ± 2.0 kJ/mol 85.99501 ± 0.00090 16829-28-0*2 Hydrogen bromide HBr (aq, 100 H2O) -119.89 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*828 Hydrogen bromide HBr (aq, 12 H2O) -117.06 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*816 Hydrogen chloride HCl (aq, 25 H2O) -164.169 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*819 Formic acid HC(O)OH (aq, 6 H2O) -425.27 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*811 Fluorosyl fluoride cation [FFO]+ (g) 1413.1 1413.4 ± 3.5 kJ/mol 53.99566 ± 0.00030 *86825-50-5*0 Hydrogen chloride HCl (aq, 900 H2O) -166.541 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*838 Ammonium hydroxide NH4OH (aq, 400 H2O) -366.38 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*832 Formic acid HC(O)OH (aq, 30 H2O) -425.21 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*820 Hydroxysilyl anion [SiH2OH]- (g) -219.3 -227.1 ± 2.1 kJ/mol 47.10927 ± 0.00047 78450-47-2*0 Hydroxysilyl anion [SiH2OH]- (g, anti) -219.0 -226.9 ± 2.7 kJ/mol 47.10927 ± 0.00047 78450-47-2*2 Bromine atom Br (g, 2P1/2) 161.994 155.931 ± 0.056 kJ/mol 79.90400 ± 0.00100 10097-32-2*2 Nitric acid HON(O)O (aq, 50 H2O) -206.05 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*822 Oxide [O]-2 (g) 651. 653. ± 15. kJ/mol 16.00050 ± 0.00030 16833-27-5*0 2-Butynylium [CH3CCCH2]+ (g) 1085.8 1077.6 ± 1.3 kJ/mol 53.0820 ± 0.0032 64235-83-2*0 Benzvalene cation [((CHCH)(CH(CHCH)CH) (g) 1200.2 1184.8 ± 2.7 kJ/mol 78.1113 ± 0.0048 81050-63-7*0 Hydrogen iodide HI (aq, 30 H2O) -55.51 ± 0.11 kJ/mol 127.912410 ± 0.000076 10034-85-2*820 Dioxyamidogen HNOO (g, trans) 251.2 244.6 ± 2.5 kJ/mol 47.01348 ± 0.00061 71843-95-3*1 Hydrogen iodide HI (aq, 4000 H2O) -56.630 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*843 Hydrogen iodide HI (aq, 1250 H2O) -56.500 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*954 Nitrosyl nitrite anion [ONONO]- (g) -103.0 -106.1 ± 2.8 kJ/mol 76.01223 ± 0.00091 *122413-35-8*0 Oxiranylidene CH2(CO) (g) 213.5 209.3 ± 1.4 kJ/mol 42.0367 ± 0.0016 50983-85-2*0 Hydrogen fluoride HF (aq, 55.51 H2O) -321.97 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*891 1,3-Butadienyl CH2CHCHCH (g) 372.22 363.00 ± 0.87 kJ/mol 53.0825 ± 0.0032 86181-68-2*0 2-Iminoethyl CH2CHNH (g) 219.27 208.59 ± 0.87 kJ/mol 42.0599 ± 0.0016 73843-90-0*0 1,3-Butadienyl CH2CHCHCH (g, trans-cis) 374.9 364.4 ± 2.0 kJ/mol 53.0825 ± 0.0032 86181-68-2*12 2-Iminoethylium [CH2CHNH]+ (g) 1108.3 1097.6 ± 3.0 kJ/mol 42.0594 ± 0.0016 73843-91-1*0 Butadienylacetylene CH2CHCHCHCCH (g) 358.8 346.3 ± 1.9 kJ/mol 78.1118 ± 0.0048 10420-90-3*0 Hydrogen bromide HBr (aq, 400 H2O) -120.31 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*832 (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 Hydrogen fluoride HF (aq, 75 H2O) -322.00 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*825 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 Trioxodinitrate anion [ONN(O)O]- (g) -104.2 -107.5 ± 1.9 kJ/mol 76.01223 ± 0.00091 194856-62-7*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 Hydrogen chloride HCl (aq, 111 H2O) -165.819 ± 0.024 kJ/mol 36.46064 ± 0.00090 7647-01-0*892 Propargylallene CH2CCHCH2CCH (g, cis) 432.3 420.7 ± 2.2 kJ/mol 78.1118 ± 0.0048 33142-15-3*2 Ammonium hydroxide NH4OH (aq, 1500 H2O) -366.36 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*840 Hydrogen iodide HI (aq, 400 H2O) -56.324 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*832 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 Hydrogen iodide HI (aq, 7000 H2O) -56.671 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*846 1,2,3,5-Hexatetraene CH2CCCHCHCH2 (g, cis) 400.5 388.9 ± 2.3 kJ/mol 78.1118 ± 0.0048 60239-33-0*2 2-Iminoethylium [CH2CHNH]+ (g, triplet) 1148.6 1140.1 ± 3.3 kJ/mol 42.0594 ± 0.0016 73843-91-1*1 Chlorine atom Cl (g, 2P1/2) 130.176 131.783 ± 0.0011 kJ/mol 35.45270 ± 0.00090 22537-15-1*2 Carbonylbis(oxy) OC(O)O (g) -143.5 -144.6 ± 3.0 kJ/mol 60.0089 ± 0.0012 16518-45-9*0 Hydrogen iodide HI (aq, 4 H2O) -44.15 ± 0.30 kJ/mol 127.912410 ± 0.000076 10034-85-2*807 Isocyanogen chloride anion [ClNC]- (g) 103.0 107.4 ± 3.9 kJ/mol 61.4707 ± 0.0012 923019-39-0*0 Peroxychlorous acid HOOClO (g, perp ?) 101.5 95.4 ± 3.6 kJ/mol 84.4588 ± 0.0013 177778-92-6*3 Hydrogen bromide HBr (aq, 7000 H2O) -120.72 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*846 Chlorous acid anion [HOClO]- (g) -154.3 -156.1 ± 3.3 kJ/mol 68.4600 ± 0.0011 99559-66-7*0 1,3-Butadienyl CH2CHCHCH (g, cis-trans) 384.0 374.5 ± 2.0 kJ/mol 53.0825 ± 0.0032 86181-68-2*21 Ethynylamidogen anion [HCCNH]- (g) 233.9 230.7 ± 3.2 kJ/mol 40.0446 ± 0.0016 64066-03-1*0 Hydroxymethylene cation [HCOH]+ (g) 971.9 968.3 ± 1.4 kJ/mol 30.02543 ± 0.00087 135395-06-1*0 Formic acid HC(O)OH (aq, 8 H2O) -425.22 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*813 Ethynylaminylium [HCCNH]+ (g) 1278.0 1277.6 ± 2.6 kJ/mol 40.0435 ± 0.0016 103835-08-1*0 1-Methylallyl CH3CHCHCH2 (g) 152.57 136.10 ± 0.80 kJ/mol 55.0984 ± 0.0032 15819-46-2*0 Hydrogen iodide HI (aq, 10000 H2O) -56.697 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*850 Hydrogen fluoride HF (aq, 37 H2O) -321.93 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*890 1-Methyl-1-propenyl CH3CCHCH3 (g) 239.98 224.60 ± 0.67 kJ/mol 55.0984 ± 0.0032 71790-71-1*0 Nitric acid HON(O)O (aq, 5000 H2O) -206.38 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*844 1-Methyl-1-propenyl CH3CCHCH3 (g, cis) 243.3 227.0 ± 1.9 kJ/mol 55.0984 ± 0.0032 71790-71-1*2 Ammonium hydroxide NH4OH (aq, 200 H2O) -366.37 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*830 Hydrogen iodide HI (aq, 300 H2O) -56.278 ± 0.092 kJ/mol 127.912410 ± 0.000076 10034-85-2*831 1-Butenyl CH3CH2CHCH (g) 263.39 246.33 ± 0.69 kJ/mol 55.0984 ± 0.0032 2669-61-6*0 Hydrogen fluoride HF (aq, 700 H2O) -322.52 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*835 1-Butenyl CH3CH2CHCH (g, gauche) 263.8 246.6 ± 1.9 kJ/mol 55.0984 ± 0.0032 2669-61-6*3 2-Hydroxyethyl CH2CH2OH (g) -13.07 -26.33 ± 0.49 kJ/mol 45.0605 ± 0.0017 4422-54-2*0 Hydroperoxonium [H2OOH]+ (g, cis) 762.5 752.7 ± 2.0 kJ/mol 35.02207 ± 0.00064 70850-26-9*2 1-Propen-1-yl-3-ylidene CHCHCH (g) 656.7 653.3 ± 1.1 kJ/mol 39.0559 ± 0.0024 84654-90-0*0 Ethylamine CH3CH2NH2 (cr,l) -76.88 ± 0.68 kJ/mol 45.0837 ± 0.0017 75-04-7*500 Formic acid HC(O)OH (aq, 9 H2O) -425.21 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*814 Tetraoxidanyl HOOOO (g, trans) 76.7 69.5 ± 6.1 kJ/mol 65.0055 ± 0.0012 69696-93-1*1 Water dimer cation [(H2O)2]+ (g) 556.9 546.4 ± 3.0 kJ/mol 36.03001 ± 0.00066 158061-35-9*0 Acetic acid CH3C(O)OH (aq, undissoc) -484.79 ± 0.27 kJ/mol 60.0520 ± 0.0017 64-19-7*1000 2-Iminoethyl anion [CH2CHNH]- (g) 104.5 94.0 ± 2.1 kJ/mol 42.0604 ± 0.0016 73843-87-5*0 1-Aminoethyl anion [CH3CHNH2]- (g) 174.4 156.8 ± 3.2 kJ/mol 44.0763 ± 0.0017 59263-55-7*0 Ammonium hydroxide NH4OH (aq, 4.5 H2O) -365.53 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*808 Oxoethylidene HCC(O)H (g) 261.1 258.3 ± 1.1 kJ/mol 42.0367 ± 0.0016 39920-84-8*0 Cyanic fluoride cation [FCN]+ (g) 1294.3 1294.7 ± 1.1 kJ/mol 45.01529 ± 0.00080 62532-69-8*0 Ethylaminylium [CH3CH2NH]+ (g, triplet) 1092.3 1077.1 ± 2.4 kJ/mol 44.0752 ± 0.0017 54387-08-5*1 Ethylaminylium [CH3CH2NH]+ (g, anti-triplet) 1094.7 1079.0 ± 2.9 kJ/mol 44.0752 ± 0.0017 54387-08-5*12 Cyanic fluoride anion [FCN]- (g) -20.6 -18.6 ± 2.9 kJ/mol 45.01639 ± 0.00080 34507-50-1*0 Hydrogen bromide HBr (aq, 1000 H2O) -120.49 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*839 1,2-Difluoroethene CHFCHF (g) -302.83 -308.93 ± 0.89 kJ/mol 64.0341 ± 0.0016 1691-13-0*0 Formic acid HC(O)OH (aq, 4 H2O) -425.37 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*807 N-Methylethanamine CH3CH2NHCH3 (cr,l) -75.1 ± 2.3 kJ/mol 59.1103 ± 0.0025 624-78-2*500 Nitrosodioxaziridine ONN(OO) (g, cis) 413.9 408.1 ± 3.2 kJ/mol 76.01168 ± 0.00091 132871-99-9*2 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 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 2-Methyl-2-propanamine (CH3)3CNH2 (l) -150.56 ± 0.54 kJ/mol 73.1369 ± 0.0033 75-64-9*590 Ammonium hydroxide NH4OH (aq, 7000 H2O) -366.28 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*846 Oxoethylidene anion [HCC(O)H]- (g) 86.9 84.2 ± 2.1 kJ/mol 42.0372 ± 0.0016 106543-38-8*0 Hydrogen iodide HI (aq, 150 H2O) -56.140 ± 0.097 kJ/mol 127.912410 ± 0.000076 10034-85-2*829 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 ± 3.1 kJ/mol 128.1711 ± 0.0080 34509-91-6*0 1-Iminoethyl CH3CNH (g) 233.0 222.9 ± 1.1 kJ/mol 42.0599 ± 0.0016 128365-64-0*0 Diazenide [NNH]- (g) 175.6 176.7 ± 1.6 kJ/mol 29.02197 ± 0.00016 71004-29-0*0 Acetic acid CH3C(O)OH (aq, 0.5 H2O) -483.01 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*923 Hydrogen iodide HI (aq, 25 H2O) -55.35 ± 0.11 kJ/mol 127.912410 ± 0.000076 10034-85-2*819 Hydrogen peroxide H2O2 (aq) -190.69 ± 0.30 kJ/mol 34.01468 ± 0.00062 7722-84-1*800 Hydrogen fluoride HF (aq, 2000 H2O) -323.40 ± 0.12 kJ/mol 20.006343 ± 0.000070 7664-39-3*841 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 Peroxyhypochlorous acid cation [HOOCl]+ (g) 1030.4 1024.6 ± 2.5 kJ/mol 68.4589 ± 0.0011 *67952-07-2*0 Hydrogen bromide HBr (aq, 500 H2O) -120.35 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*833 Hydrogen fluoride HF (aq, 3000 H2O) -323.84 ± 0.12 kJ/mol 20.006343 ± 0.000070 7664-39-3*842 Methanediol CH2(OH)2 (g) -379.16 -392.55 ± 0.74 kJ/mol 48.0413 ± 0.0010 463-57-0*0 1-Iminoethyl CH3CNH (g, syn) 252.3 242.3 ± 2.1 kJ/mol 42.0599 ± 0.0016 128365-64-0*1 1-Iminoethylium [CH3CNH]+ (g) 833.6 823.1 ± 3.0 kJ/mol 42.0594 ± 0.0016 *128365-64-0*0 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 Hydrogen iodide HI (aq, 12 H2O) -54.03 ± 0.17 kJ/mol 127.912410 ± 0.000076 10034-85-2*816 1-Iminoethylium [CH3CNH]+ (g, triplet) 1342.1 1333.2 ± 3.9 kJ/mol 42.0594 ± 0.0016 *128365-64-0*1 Difluorovinylidene anion [CCF2]- (g) -88.2 -87.1 ± 2.3 kJ/mol 62.0188 ± 0.0016 107693-92-5*0 Hydrogen iodide HI (aq, 200 H2O) -56.199 ± 0.097 kJ/mol 127.912410 ± 0.000076 10034-85-2*830 Methylaminyliumyl [CH3N]+ (g, quartet) 1423.0 1416.1 ± 2.3 kJ/mol 29.04071 ± 0.00083 56924-51-7*2 Dibromovinylidene CCBr2 (g) 509.9 498.8 ± 4.1 kJ/mol 183.8294 ± 0.0026 261771-36-2*0 Ammonium hydroxide NH4OH (aq, 2000 H2O) -366.35 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*841 Butadiynylium [CCCCH]+ (g) 1781.2 1787.7 ± 3.2 kJ/mol 49.0502 ± 0.0032 76108-67-3*0 Fluorovinylidene CCHF (g) 298.9 300.1 ± 3.1 kJ/mol 44.0277 ± 0.0016 70302-00-0*0 (Dimethylamino)methyl anion [(CH3)2NCH2]- (g) 190.5 166.3 ± 3.3 kJ/mol 58.1029 ± 0.0025 125231-49-4*0 1-Iminoethylium [CH3CNH]+ (g, syn-triplet) 1378.2 1368.7 ± 4.3 kJ/mol 42.0594 ± 0.0016 *128365-64-0*11 Hydrogen fluoride HF (aq, 10000 H2O) -325.44 ± 0.17 kJ/mol 20.006343 ± 0.000070 7664-39-3*850 Hydrogen fluoride HF (aq, 100 H2O) -322.03 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*828 1-Iminoethanide [CH3CNH]- (g) 185.6 175.5 ± 3.2 kJ/mol 42.0604 ± 0.0016 *128365-65-1*0 Helium He (g, singlet) 0.000 0.000 ± 0.000 kJ/mol 4.0026020 ± 0.0000020 7440-59-7*2 Acetic acid CH3C(O)OH (aq, 1 H2O) -482.91 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*801 1-Iminoethanide [CH3CNH]- (g, syn) 193.1 182.5 ± 3.6 kJ/mol 42.0604 ± 0.0016 *128365-65-1*1 Helium dication [He]+2 (g) 7622.839 7622.839 ± 0.000 kJ/mol 4.0015048 ± 0.0000020 12587-46-1*0 Carbonate [OC(O)O]-2 (aq) -675.155 ± 0.055 kJ/mol 60.0100 ± 0.0012 3812-32-6*800 Acetic acid CH3C(O)OH (aq, 1.5 H2O) -482.85 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*802 Ammonium hydroxide NH4OH (aq, 3000 H2O) -366.33 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*842 Bromovinylidene CCHBr (g) 466.1 460.1 ± 3.8 kJ/mol 104.9333 ± 0.0019 161957-27-3*0 Methoxyethene CH2CHOCH3 (g) -89.5 -106.8 ± 1.1 kJ/mol 58.0791 ± 0.0025 107-25-5*0 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 Difluorophosgene anion [CF2O]- (g) -602.3 -604.2 ± 3.2 kJ/mol 66.00745 ± 0.00085 474815-26-4*0 Hydrohelate [HeH]- (g) 143.256 139.027 ± 0.0021 kJ/mol 5.011091 ± 0.000070 12325-01-8*0 1,2-Butadienylium [CH3CHCCH]+ (g) 1099.2 1089.8 ± 1.2 kJ/mol 53.0820 ± 0.0032 *65114-67-2*0 Hydrogen chloride HCl (aq, 150 H2O) -165.977 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*829 Diiodine cation [I2]+ (g) 963.523 960.408 ± 0.018 kJ/mol 253.808391 ± 0.000060 28712-14-3*0 Nitric acid HON(O)O (aq, 10000 H2O) -206.43 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*850 Hydroxyformyl HOCO (g) -181.18 -183.73 ± 0.42 kJ/mol 45.0174 ± 0.0010 2564-86-5*0 Fluoro(fluorooxy)methylene FCOF (g) -134.8 -136.0 ± 1.4 kJ/mol 66.00691 ± 0.00085 479587-30-9*0 Acetic acid CH3C(O)OH (aq, 2 H2O) -482.87 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*803 Nitric acid HON(O)O (aq, 50000 H2O) -206.50 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*855 Acetic acid CH3C(O)OH (aq, 2.5 H2O) -482.96 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*804 Methylaminyliumyl [CH3N]+ (g ?) 1388.3 1381.9 ± 2.3 kJ/mol 29.04071 ± 0.00083 56924-51-7*0 Acetic acid CH3C(O)OH (aq, 3 H2O) -483.04 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*805 2-Hydroxyethylium [CH2CH2OH]+ (g) 1019.1 1007.0 ± 1.5 kJ/mol 45.0600 ± 0.0017 38607-31-7*0 Hydrogen peroxide cation [H2O2]+ (g) 897.29 890.31 ± 0.51 kJ/mol 34.01413 ± 0.00062 12325-10-9*0 Neon decacation [Ne]+10 (g) 338828.3 338828.3 ± 1.4 kJ/mol 20.17421 ± 0.00060 32218-07-8*0 Neon hydride NeH (g) 215.989 211.755 ± 0.024 kJ/mol 21.18764 ± 0.00060 17438-52-7*0 Fluorine atom F (g, 2P1/2) 82.087 83.872 ± 0.017 kJ/mol 18.99840320 ± 0.00000050 14762-94-8*2 Hydroneonate [NeH]- (g) 143.096 142.084 ± 0.035 kJ/mol 21.18819 ± 0.00060 75514-98-6*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) -242.79 ± 0.24 kJ/mol 98.9155 ± 0.0020 75-44-5*501 N-Methylenemethaniminium [CH2NCH2]+ (g) 904.3 893.3 ± 3.1 kJ/mol 42.0594 ± 0.0016 88333-01-1*0 Phosgene CCl2O (cr, l, II+liquid) -255.49 -242.79 ± 0.24 kJ/mol 98.9155 ± 0.0020 75-44-5*502 Krypton dication [Kr]+2 (g) 3701.124 3701.124 ± 0.013 kJ/mol 83.7989 ± 0.1000 18469-91-5*0 1,3-Butadiyne-1,4-diyl CCCC (g, singlet) 1084.09 1093.89 ± 0.84 kJ/mol 48.0428 ± 0.0032 78015-07-3*2 Xenon dication [Xe]+2 (g) 3194.14 3194.14 ± 0.36 kJ/mol 131.2889 ± 0.0200 14066-95-6*0 N-Methylenemethaniminium [CH2NCH2]+ (g, triplet) 1157.1 1147.2 ± 4.0 kJ/mol 42.0594 ± 0.0016 88333-01-1*1 Hydrogen bromide HBr (aq, 50 H2O) -119.49 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*822 Hydrogen iodide HI (aq, 900 H2O) -56.454 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*838 Hydrogen chloride HCl (aq, 30 H2O) -164.500 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*820 Hydrogen iodide HI (aq, 15 H2O) -54.592 ± 0.092 kJ/mol 127.912410 ± 0.000076 10034-85-2*817 Acetic acid CH3C(O)OH (aq, 4 H2O) -483.15 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*807 Chloro(chlorooxy)methylene ClCOCl (g) 73.5 73.9 ± 3.6 kJ/mol 98.9155 ± 0.0020 479587-31-0*0 Chloro(chlorooxy)methylene ClCOCl (g, trans) 98. 105. ± 15. kJ/mol 98.9155 ± 0.0020 479587-31-0*1 Acetic acid CH3C(O)OH (aq, 4.5 H2O) -483.18 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*808 Sulfur atom hexacation [S]+6 (g) 26947.2 26949.0 ± 3.4 kJ/mol 32.0627 ± 0.0060 22537-26-4*0 Bicyclo[1.1.0]buta-1,3-diene-2,4-diyl C(CC)C (g, triplet) 1133.1 1141.0 ± 2.7 kJ/mol 48.0428 ± 0.0032 12184-80-4*1 Sulfur atom dianion [S]-2 (g) 454.1 455.9 ± 3.2 kJ/mol 32.0671 ± 0.0060 18496-25-8*0 Hydroxymethylene anion [HCOH]- (g) 147.2 144.2 ± 1.6 kJ/mol 30.02653 ± 0.00087 207914-87-2*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 O--HH Complex (H2)(O) (g, vdW Cinfv ?) 247.6 248.9 ± 2.7 kJ/mol 18.01528 ± 0.00033 *7732-18-5*101 Isocyanic fluoride cation [FNC]+ (g) 1618.2 1618.8 ± 4.0 kJ/mol 45.01529 ± 0.00080 *16992-26-0*0 Formic acid cation [HC(O)OH]+ (g) 721.93 715.40 ± 0.25 kJ/mol 46.0248 ± 0.0010 50614-05-6*0 Sulfonyl cation [OSO]+ (g) 897.07 894.81 ± 0.13 kJ/mol 64.0643 ± 0.0060 12439-77-9*0 Imidogen NH (g, triplet) 358.74 358.79 ± 0.16 kJ/mol 15.014680 ± 0.000099 13774-92-0*1 Sulfur dioxide OSO (cr,l) -331.4 -320.1 ± 1.9 kJ/mol 64.0648 ± 0.0060 7446-09-5*500 N-?Methylidynemethanaminium [CH3NCH]+ (g) 881.0 870.2 ± 3.0 kJ/mol 42.0594 ± 0.0016 64709-60-0*0 Hydrogen bromide HBr (aq, 10000 H2O) -120.74 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*850 Formic acid anion [HC(O)OH]- (g) -256.2 -262.3 ± 1.8 kJ/mol 46.0259 ± 0.0010 19066-82-1*0 Hydrogen bromide HBr (aq, 15 H2O) -117.76 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*817 Oxosulfate [SO]- (g) -102.59 -101.83 ± 0.50 kJ/mol 48.0659 ± 0.0060 12269-52-2*0 Acetic acid CH3C(O)OH (aq, 5 H2O) -483.22 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*809 Sulfur trioxide cation [OS(O)O]+ (g) 847.66 844.75 ± 0.68 kJ/mol 80.0637 ± 0.0061 12710-95-1*0 Hydroperoxyimidogen HOON (g, cis) 111.9 109.0 ± 2.8 kJ/mol 47.01348 ± 0.00061 877456-58-1*2 Sulfite [OS(O)O]-2 (g) -275.1 -280.7 ± 4.4 kJ/mol 80.0653 ± 0.0061 14265-45-3*0 Hydroxyformyl anion [HOCO]- (g) -319.55 -321.41 ± 0.57 kJ/mol 45.0180 ± 0.0010 78944-70-4*0 Chlorohydroxymethylene ClCOH (g, cis) 14.4 11.5 ± 3.2 kJ/mol 64.4707 ± 0.0012 147723-60-2*2 Sulfur oxide peroxide OSOO (g) -25.9 -30.2 ± 2.3 kJ/mol 80.0642 ± 0.0061 175799-68-5*0 Chlorohydroxymethylene ClCOH (g) 14.0 11.3 ± 2.5 kJ/mol 64.4707 ± 0.0012 147723-60-2*0 Sulfur oxide peroxide OSOO (g, trans) -3.4 -7.0 ± 3.0 kJ/mol 80.0642 ± 0.0061 175799-68-5*1 Ammonium hydroxide NH4OH (aq, 6 H2O) -365.75 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*811 (Chlorooxy)methylene HCOCl (g, trans) 155.5 155.3 ± 3.7 kJ/mol 64.4707 ± 0.0012 331419-80-8*1 Nitrogen atom heptacation [N]+7 (g) 143853.26 143855.13 ± 0.23 kJ/mol 14.002900 ± 0.000070 40549-08-4*0 Disulfur oxide cation [SSO]+ (g) 970.67 969.39 ± 0.61 kJ/mol 80.1309 ± 0.0120 135758-60-0*0 Oxothioxosulfate [SSO]- (g) -231.81 -233.42 ± 0.87 kJ/mol 80.1319 ± 0.0120 12143-07-6*0 (Chlorooxy)methylene HCOCl (g) 119.2 117.9 ± 2.7 kJ/mol 64.4707 ± 0.0012 331419-80-8*0 Nitrosodioxaziridine ONN(OO) (g, gauche) 415.4 409.5 ± 2.8 kJ/mol 76.01168 ± 0.00091 132871-99-9*3 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 Imidogen NH (g, singlet) 509.34 509.39 ± 0.17 kJ/mol 15.014680 ± 0.000099 13774-92-0*2 (Methylimino)methyl CH3NCH (g) 277.9 267.8 ± 1.1 kJ/mol 42.0599 ± 0.0016 117928-23-1*0 Acetic acid CH3C(O)OH (aq, 6 H2O) -483.28 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*811 (Methylimino)methyl CH3NCH (g, cis) 297.0 287.0 ± 2.0 kJ/mol 42.0599 ± 0.0016 117928-23-1*2 Sulfuric acid cation [OS(O)(OH)2]+ (g) 401.4 388.4 ± 3.3 kJ/mol 98.0789 ± 0.0061 247933-66-0*0 (Methylimino)methanide [CH3NCH]- (g) 222.9 212.2 ± 3.2 kJ/mol 42.0604 ± 0.0016 *64709-60-0*0 (Methylimino)methanide [CH3NCH]- (g, cis) 236.5 225.6 ± 3.6 kJ/mol 42.0604 ± 0.0016 *64709-60-0*2 Chloroformyl anion [ClCO]- (g) -356.5 -352.9 ± 3.2 kJ/mol 63.4633 ± 0.0012 41976-93-6*0 Difluorodioxidane anion [FOOF]- (g) -251. -251. ± 28. kJ/mol 69.99615 ± 0.00060 *7783-45-1*0 Sulfate [SO4]-2 (aq) -909.08 ± 0.14 kJ/mol 96.0647 ± 0.0061 14808-79-8*800 Nitric acid HON(O)O (aq, 2000 H2O) -206.31 ± 0.18 kJ/mol 63.01288 ± 0.00091 7697-37-2*841 Isocyanic fluoride anion [FNC]- (g) 74.1 75.8 ± 5.7 kJ/mol 45.01639 ± 0.00080 357426-78-9*0 Sulfuric acid OS(O)(OH)2 (aq, 10 H2O) -880.34 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*815 Sulfuric acid OS(O)(OH)2 (aq, 12 H2O) -881.95 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*816 Sulfuric acid OS(O)(OH)2 (aq, 15 H2O) -883.44 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*817 Sulfuric acid OS(O)(OH)2 (aq, 20 H2O) -884.73 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*818 Sulfuric acid OS(O)(OH)2 (aq, 25 H2O) -885.40 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*819 Sulfuric acid OS(O)(OH)2 (aq, 30 H2O) -885.80 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*820 Hydrogen bromide HBr (aq, 111 H2O) -119.94 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*892 Formate [HC(O)O]- (aq) -425.48 ± 0.45 kJ/mol 45.0180 ± 0.0010 71-47-6*800 Hydrogen chloride HCl (aq, 300 H2O) -166.253 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*831 Sulfuric acid OS(O)(OH)2 (aq, 150 H2O) -888.00 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*829 Sulfuric acid OS(O)(OH)2 (aq, 200 H2O) -888.44 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*830 Sulfuric acid OS(O)(OH)2 (aq, 300 H2O) -889.18 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*831 Sulfuric acid OS(O)(OH)2 (aq, 400 H2O) -889.79 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*832 Sulfuric acid OS(O)(OH)2 (aq, 500 H2O) -890.31 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*833 Sulfuric acid OS(O)(OH)2 (aq, 600 H2O) -890.80 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*834 Hydrogen iodide HI (aq, 20000 H2O) -56.734 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*852 Hydrogen bromide HBr (aq, 20000 H2O) -120.78 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*852 Sulfuric acid OS(O)(OH)2 (aq, 900 H2O) -891.86 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*838 Trihydrogen H(HH) (g, TS) 477.4 474.7 ± 2.3 kJ/mol 3.02382 ± 0.00021 12184-91-7*201 Hydrogen iodide HI (aq, 50000 H2O) -56.768 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*855 Hydrogen iodide HI (aq, 55.51 H2O) -55.860 ± 0.095 kJ/mol 127.912410 ± 0.000076 10034-85-2*891 Sulfuric acid OS(O)(OH)2 (aq, 4000 H2O) -896.92 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*843 Acetic acid CH3C(O)OH (aq, 7 H2O) -483.36 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*812 Propynylidene HCCCH (g, singlet) 597.7 599.5 ± 1.3 kJ/mol 38.0480 ± 0.0024 67152-18-5*2 Hydrogen peroxide cation [H2O2]+ (g, cis, ortho) 931.06 924.18 ± 0.98 kJ/mol 34.01413 ± 0.00062 12325-10-9*21 Sulfuric acid OS(O)(OH)2 (aq, 20000 H2O) -903.14 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*852 Sulfuric acid OS(O)(OH)2 (aq, 50000 H2O) -905.84 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*855 Sulfuric acid OS(O)(OH)2 (aq, 100000 H2O) -907.13 ± 0.13 kJ/mol 98.0795 ± 0.0061 7664-93-9*861 2-Iodoethanol ICH2CH2OH (g) -131.9 -150.1 ± 2.5 kJ/mol 171.9650 ± 0.0017 624-76-0*0 Hydrogen chloride HCl (aq, 2000 H2O) -166.680 ± 0.023 kJ/mol 36.46064 ± 0.00090 7647-01-0*841 Acetic acid CH3C(O)OH (aq, 8 H2O) -483.44 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*813 Chlorine chlorite ClOClO (g) 168.6 166.4 ± 1.3 kJ/mol 102.9042 ± 0.0019 105206-44-8*0 Acetic acid CH3C(O)OH (aq, 9 H2O) -483.52 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*814 Acetic acid CH3C(O)OH (aq, 10 H2O) -483.60 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*815 Cyanogen chloride cation [ClCN]+ (g) 1326.25 1327.58 ± 0.97 kJ/mol 61.4696 ± 0.0012 37612-72-9*0 Methoxyethene CH2CHOCH3 (g, trans) -82.1 -99.2 ± 2.4 kJ/mol 58.0791 ± 0.0025 107-25-5*1 Hydrogen fluoride HF (aq, 900 H2O) -322.66 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*838 Acetic acid CH3C(O)OH (aq, 12 H2O) -483.75 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*816 Formaldehyde CH2O (g, ortho singlet) -105.263 -109.229 ± 0.096 kJ/mol 30.02598 ± 0.00087 50-00-0*22 Hydrogen bromide HBr (aq, 25 H2O) -118.74 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*819 Hydrogen bromide HBr (aq, 50000 H2O) -120.82 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*855 Hydrogen fluoride HF (aq, 800 H2O) -322.59 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*837 Hydrogen fluoride HF (aq, undissoc) -321.40 ± 0.17 kJ/mol 20.006343 ± 0.000070 7664-39-3*1000 Hydrogen fluoride HF (aq, 264.3 H2O) -322.14 ± 0.11 kJ/mol 20.006343 ± 0.000070 7664-39-3*909 1-Aminoethenylium [CH2CNH2]+ (g) 900.0 889.1 ± 3.0 kJ/mol 42.0594 ± 0.0016 *139597-26-5*0 Propargylenide [HCCCH]- (g) 434.4 437.7 ± 1.1 kJ/mol 38.0485 ± 0.0024 82906-05-6*0 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 1-Aminoethenide [CH2CNH2]- (g) 215.9 205.2 ± 3.2 kJ/mol 42.0604 ± 0.0016 139597-26-5*0 Hypobromous acid cation [HOBr]+ (g) 975.16 964.54 ± 0.54 kJ/mol 96.9108 ± 0.0010 154804-02-1*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 Carbon C (diamond) 2.390 1.862 ± 0.044 kJ/mol 12.01070 ± 0.00080 7440-44-0*501 Hydrogen fluoride HF (aq, 50000 H2O) -328.59 ± 0.17 kJ/mol 20.006343 ± 0.000070 7664-39-3*855 Hydrogen bromide HBr (aq, 100000 H2O) -120.82 ± 0.14 kJ/mol 80.9119 ± 0.0010 10035-10-6*861 Sulfite [OS(O)O]-2 (aq) -635.3 ± 4.0 kJ/mol 80.0653 ± 0.0061 14265-45-3*800 Sulfurous acid S(O)(OH)2 (aq, 100 H2O) -612.21 ± 0.14 kJ/mol 82.0801 ± 0.0061 7782-99-2*828 Sulfurous acid S(O)(OH)2 (aq, 150 H2O) -612.93 ± 0.14 kJ/mol 82.0801 ± 0.0061 7782-99-2*829 Sulfurous acid S(O)(OH)2 (aq, 200 H2O) -613.47 ± 0.14 kJ/mol 82.0801 ± 0.0061 7782-99-2*830 Sulfurous acid S(O)(OH)2 (aq, 250 H2O) -613.90 ± 0.14 kJ/mol 82.0801 ± 0.0061 7782-99-2*908 Sulfurous acid S(O)(OH)2 (aq, 300 H2O) -614.27 ± 0.14 kJ/mol 82.0801 ± 0.0061 7782-99-2*831 Sulfurous acid S(O)(OH)2 (aq, 400 H2O) -614.87 ± 0.14 kJ/mol 82.0801 ± 0.0061 7782-99-2*832 Sulfurous acid S(O)(OH)2 (aq, 500 H2O) -615.38 ± 0.14 kJ/mol 82.0801 ± 0.0061 7782-99-2*833 Sulfurous acid S(O)(OH)2 (aq, 750 H2O) -616.32 ± 0.14 kJ/mol 82.0801 ± 0.0061 7782-99-2*836 Sulfurous acid S(O)(OH)2 (aq, 1000 H2O) -617.01 ± 0.14 kJ/mol 82.0801 ± 0.0061 7782-99-2*839 Sulfurous acid S(O)(OH)2 (aq, 1500 H2O) -618.10 ± 0.14 kJ/mol 82.0801 ± 0.0061 7782-99-2*840 Sulfurous acid S(O)(OH)2 (aq, 2000 H2O) -618.85 ± 0.14 kJ/mol 82.0801 ± 0.0061 7782-99-2*841 Sulfurous acid S(O)(OH)2 (aq, 3000 H2O) -619.89 ± 0.14 kJ/mol 82.0801 ± 0.0061 7782-99-2*842 Sulfurous acid S(O)(OH)2 (aq, 3500 H2O) -620.30 ± 0.14 kJ/mol 82.0801 ± 0.0061 7782-99-2*899 Sulfurous acid S(O)(OH)2 (aq, 4000 H2O) -620.63 ± 0.14 kJ/mol 82.0801 ± 0.0061 7782-99-2*843 Sulfurous acid S(O)(OH)2 (aq, 5000 H2O) -621.22 ± 0.14 kJ/mol 82.0801 ± 0.0061 7782-99-2*844 Sulfurous acid S(O)(OH)2 (aq, 7500 H2O) -622.20 ± 0.14 kJ/mol 82.0801 ± 0.0061 7782-99-2*847 Sulfurous acid S(O)(OH)2 (aq, 10000 H2O) -622.79 ± 0.14 kJ/mol 82.0801 ± 0.0061 7782-99-2*850 Sulfonic acid SH(O)(O)OH (g) -482.1 -494.6 ± 1.4 kJ/mol 82.0801 ± 0.0061 *7782-99-2*0 Acetic acid CH3C(O)OH (aq, 15 H2O) -483.92 ± 0.33 kJ/mol 60.0520 ± 0.0017 64-19-7*817 Bisulfite cation [OS(OH)O]+ (g) 556.0 547.3 ± 3.2 kJ/mol 81.0716 ± 0.0061 43637-78-1*0 Chlorine trifluoride anion [FCl(F)F]- (g) -480.4 -481.9 ± 3.5 kJ/mol 92.44846 ± 0.00090 184289-50-7*0 Ethane anion [CH3CH3]- (g) 41.8 26.5 ± 4.4 kJ/mol 30.0696 ± 0.0017 54064-82-3*0 Formic acid HC(O)OH (aq, 0.25 H2O) -424.95 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*924 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 Ethylimidogen anion [CH3CH2N]- (g) 277.3 263.5 ± 3.6 kJ/mol 43.0684 ± 0.0016 82539-33-1*0 Platinum dimer cation [Pt2]+ (g) 1661.0 1659.7 ± 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 Ammonium hydroxide NH4OH (aq, 12 H2O) -366.06 ± 0.41 kJ/mol 35.04584 ± 0.00047 1336-21-6*816 Platinum hydride cation [PtH]+ (g) 1336. 1355. ± 22. kJ/mol 196.0854 ± 0.0020 87882-39-1*0 Ethylimidogen cation [CH3CH2N]+ (g, quartet) 1394.6 1381.4 ± 3.7 kJ/mol 43.0673 ± 0.0016 *82539-33-1*1 Hydrogen atom H (ad, Pt(111) fcc) -37.0 -40.2 ± 1.1 kJ/mol 1.007940 ± 0.000070 12385-13-6*1001000 Formic acid HC(O)OH (aq, 0.5 H2O) -425.16 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*923 Cyanogen chloride anion [ClCN]- (g) 46.9 51.2 ± 3.1 kJ/mol 61.4707 ± 0.0012 12281-43-5*0 Hydrogen iodide HI (aq, 1000 H2O) -56.471 ± 0.090 kJ/mol 127.912410 ± 0.000076 10034-85-2*839 1-Aziridinylium [N(CH2CH2)]+ (g, triplet) 1265.6 1253.9 ± 3.1 kJ/mol 42.0594 ± 0.0016 91127-35-4*1 Hydrogen atom H (ad, Pt(111) atop) -32. -34. ± 20. kJ/mol 1.007940 ± 0.000070 12385-13-6*1002000 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 HC(O)OH (aq, 1 H2O) -425.44 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*801 Formic acid HC(O)OH (aq, 1.5 H2O) -425.54 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*802 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 Formic acid HC(O)OH (aq, 2 H2O) -425.51 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*803 Formic acid HC(O)OH (aq, 2.5 H2O) -425.47 ± 0.60 kJ/mol 46.0254 ± 0.0010 64-18-6*804 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 1391.172 ± 0.018 kJ/mol 79.8955 ± 0.0020 17596-58-6*0 Argon atom dication [Ar]+2 (g) 4186.429 4186.468 ± 0.013 kJ/mol 39.94690 ± 0.00100 15056-24-3*0 Argon dimer Ar2 (g) -1.013 -6.347 ± 0.0051 kJ/mol 79.8960 ± 0.0020 12595-59-4*0 Argon anion Ar- (g, 2S1/2) 25. 25. ± 28. kJ/mol 39.94855 ± 0.00100 16544-90-4*1 Neon anion Ne- (g) 13. 13. ± 29. kJ/mol 20.18025 ± 0.00060 20205-95-2*0 Argon anion Ar- (g) 25. 25. ± 28. kJ/mol 39.94855 ± 0.00100 16544-90-4*0 Helium anion He- (g, 1s2.2s 2S1/2) 51. 51. ± 130. kJ/mol 4.0031506 ± 0.0000020 14452-58-5*1 Helium anion He- (g) 51. 51. ± 130. kJ/mol 4.0031506 ± 0.0000020 14452-58-5*0 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 ± 0.099 kJ/mol 39.94855 ± 0.00100 16544-90-4*2 Krypton anion Kr- (g) 110. 110. ± 350. kJ/mol 83.8005 ± 0.1000 20205-93-0*0 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
References
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B. Ruscic, R. E. Pinzon, M. L. Morton, G. von Laszewski, S. Bittner, S. G. Nijsure, K. A. Amin, M. Minkoff, and A. F. Wagner,
Introduction to Active Thermochemical Tables: Several "Key" Enthalpies of Formation Revisited.
J. Phys. Chem. A 108 , 9979-9997 (2004)
[DOI: 10.1021/jp047912y]
2
B. Ruscic, R. E. Pinzon, G. von Laszewski, D. Kodeboyina, A. Burcat, D. Leahy, D. Montoya, and A. F. Wagner,
Active Thermochemical Tables: Thermochemistry for the 21st Century.
J. Phys. Conf. Ser. 16 , 561-570 (2005)
[DOI: 10.1088/1742-6596/16/1/078]
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B. Ruscic and D. H. Bross, Active Thermochemical Tables (ATcT) values based on ver. 1.124 of the Thermochemical Network, Argonne National Laboratory, Lemont, Illinois 2022; available at ATcT.anl.gov [DOI: 10.17038/CSE/1885923 ]
4
Y. Ren, L. Zhou, A. Mellouki, V. Daële, M. Idir, S. S. Brown, B. Ruscic, Robert S. Paton, M. R. McGillen, and A. R. Ravishankara,
Reactions of NO3 with Aromatic Aldehydes: Gas-Phase Kinetics and Insights into the Mechanism of the Reaction.
Atmos. Chem. Phys. 21 , 13537-13551 (2021)
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5
B. Ruscic and D. H. Bross,
Active Thermochemical Tables: The Thermophysical and Thermochemical Properties of Methyl, CH3, and Methylene, CH2, Corrected for Nonrigid Rotor and Anharmonic Oscillator Effects.
Mol. Phys. e1969046 (2021)
[DOI: 10.1080/00268976.2021.1969046]
6
J. H. Thorpe, J. L. Kilburn, D. Feller, P. B. Changala, D. H. Bross, B. Ruscic, and J. F. Stanton,
Elaborated Thermochemical Treatment of HF, CO, N2, and H2O: Insight into HEAT and Its Extensions
J. Chem. Phys. 155 , 184109 (2021)
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T. L. Nguyen, D. H. Bross, B. Ruscic, G. B. Ellison, and J. F. Stanton,
Mechanism, Thermochemistry, and Kinetics of the Reversible Reactions: C2H3 + H2 ⇌ C2H4 + H ⇌ C2H5.
Faraday Discuss. , (Advance Article) (2022)
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8
B. Ruscic,
Uncertainty Quantification in Thermochemistry, Benchmarking Electronic Structure Computations, and Active Thermochemical Tables.
Int. J. Quantum Chem. 114 , 1097-1101 (2014)
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B. Ruscic and D. H. Bross,
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 [8,9 ]).
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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