Selected ATcT [1, 2] enthalpy of formation based on version 1.122 of the Thermochemical Network [3]

This version of ATcT results was partially described in Ruscic et al. [4], and was also used for the initial development of high-accuracy ANLn composite electronic structure methods [5].

Species Name Formula Image    ΔfH°(0 K)    ΔfH°(298.15 K) Uncertainty Units Relative
Molecular
Mass		 ATcT ID
MethyleneCH2 (g, triplet)[CH2]390.96391.52± 0.12kJ/mol14.02658 ±
0.00081		2465-56-7*1

Representative Geometry of CH2 (g, triplet)

spin ON           spin OFF
          

Top contributors to the provenance of ΔfH° of CH2 (g, triplet)

The 20 contributors listed below account only for 49.7% of the provenance of ΔfH° of CH2 (g, triplet).
A total of 263 contributors would be needed to account for 90% of the provenance.

Please note: The list is limited to 20 most important contributors or, if less, a number sufficient to account for 90% of the provenance. The Reference acts as a further link to the relevant references and notes for the measurement. The Measured Quantity is normaly given in the original units; in cases where we have reinterpreted the original measurement, the listed value may differ from that given by the authors. The quoted uncertainty is the a priori uncertainty used as input when constructing the initial Thermochemical Network, and corresponds either to the value proposed by the original authors or to our estimate; if an additional multiplier is given in parentheses immediately after the prior uncertainty, it corresponds to the factor by which the prior uncertainty needed to be multiplied during the ATcT analysis in order to make that particular measurement consistent with the prevailing knowledge contained in the Thermochemical Network.

Contribution
(%)		TN
ID		 Reaction Measured Quantity Reference
6.01676.8 CH2 (g, triplet) → C (g) + 2 H (g) ΔrH°(0 K) = 179.76 ± 0.07 (×1.354) kcal/molFeller 2014
4.21710.8 CH2 (g, triplet) → CH (g) + H (g) ΔrH°(0 K) = 417.85 ± 0.35 kJ/molCsaszar 2003
3.01675.9 CH2 (g, triplet) → C (g) + 2 H (g) ΔrH°(0 K) = 752.45 ± 0.56 kJ/molHarding 2008
2.91678.9 CH2 (g, singlet) → C (g) + 2 H (g) ΔrH°(0 K) = 170.98 ± 0.11 (×1.164) kcal/molFeller 2014
2.91690.8 CH3 (g) → CH2 (g, triplet) + H (g) ΔrH°(0 K) = 457.05 ± 0.56 kJ/molHarding 2008
2.71688.1 CH3 (g) → [CH2]+ (g) + H (g) ΔrH°(0 K) = 15.120 ± 0.006 eVLitorja 1998
2.41676.1 CH2 (g, triplet) → C (g) + 2 H (g) ΔrH°(0 K) = 753.03 ± 0.62 kJ/molCsaszar 2003
2.41675.5 CH2 (g, triplet) → C (g) + 2 H (g) ΔrH°(0 K) = 179.86 ± 0.15 kcal/molKarton 2008
2.31690.4 CH3 (g) → CH2 (g, triplet) + H (g) ΔrH°(0 K) = 109.22 ± 0.15 kcal/molKarton 2008
2.21697.12 CH (g) → C (g) + H (g) ΔrH°(0 K) = 80.01 ± 0.04 kcal/molFeller 2014
2.01642.1 2 H2 (g) + C (graphite) → CH4 (g) ΔrG°(1165 K) = 37.521 ± 0.068 kJ/molSmith 1946, note COf, 3rd Law
2.01710.12 CH2 (g, triplet) → CH (g) + H (g) ΔrH°(0 K) = 99.75 ± 0.08 (×1.509) kcal/molFeller 2014
1.91675.7 CH2 (g, triplet) → C (g) + 2 H (g) ΔrH°(0 K) = 752.43 ± 0.70 kJ/molHarding 2008
1.81690.6 CH3 (g) → CH2 (g, triplet) + H (g) ΔrH°(0 K) = 457.05 ± 0.70 kJ/molHarding 2008
1.71711.5 CH2 (g, singlet) → CH (g) + H (g) ΔrH°(0 K) = 90.97 ± 0.12 kcal/molFeller 2014
1.71675.8 CH2 (g, triplet) → C (g) + 2 H (g) ΔrH°(0 K) = 752.44 ± 0.74 kJ/molHarding 2008
1.61690.7 CH3 (g) → CH2 (g, triplet) + H (g) ΔrH°(0 K) = 457.04 ± 0.74 kJ/molHarding 2008
1.61675.6 CH2 (g, triplet) → C (g) + 2 H (g) ΔrH°(0 K) = 752.39 ± 0.75 kJ/molTajti 2004, est unc
1.61710.4 CH2 (g, triplet) → CH (g) + H (g) ΔrH°(0 K) = 418.04 ± 0.56 kJ/molHarding 2008
1.61690.5 CH3 (g) → CH2 (g, triplet) + H (g) ΔrH°(0 K) = 457.54 ± 0.75 kJ/molTajti 2004, est unc

Top 10 species with enthalpies of formation correlated to the ΔfH° of CH2 (g, triplet)

Please note: The correlation coefficients are obtained by renormalizing the off-diagonal elements of the covariance matrix by the corresponding variances.
The correlation coefficient is a number from -1 to 1, with 1 representing perfectly correlated species, -1 representing perfectly anti-correlated species, and 0 representing perfectly uncorrelated species.

Correlation
Coefficent
(%)		Species Name Formula Image    ΔfH°(0 K)    ΔfH°(298.15 K) Uncertainty Units Relative
Molecular
Mass		 ATcT ID
100.0 MethyleneCH2 (g)[CH2]390.96391.52± 0.12kJ/mol14.02658 ±
0.00081		2465-56-7*0
95.5 Methyliumyl[CH2]+ (g)[CH2+]1393.091393.95± 0.13kJ/mol14.02603 ±
0.00081		15091-72-2*0
90.6 MethyleneCH2 (g, singlet)[CH2]428.62429.03± 0.13kJ/mol14.02658 ±
0.00081		2465-56-7*2
88.9 KeteneCH2CO (g, singlet)C=C=O-45.45-48.57± 0.13kJ/mol42.0367 ±
0.0016		463-51-4*2
88.9 KeteneCH2CO (g)C=C=O-45.45-48.57± 0.13kJ/mol42.0367 ±
0.0016		463-51-4*0
88.8 Ketene cation[CH2CO]+ (g)C=C=[O+]882.12879.10± 0.13kJ/mol42.0361 ±
0.0016		64999-16-2*0
42.4 MethylidyneCH (g)[CH]592.78596.12± 0.11kJ/mol13.01864 ±
0.00080		3315-37-5*0
42.4 MethylidyneCH (g, doublet)[CH]592.78596.12± 0.11kJ/mol13.01864 ±
0.00080		3315-37-5*1
37.0 Carbon atomC (g)[C]711.401716.886± 0.050kJ/mol12.01070 ±
0.00080		7440-44-0*0
37.0 Carbon atomC (g, triplet)[C]711.401716.886± 0.050kJ/mol12.01070 ±
0.00080		7440-44-0*1

Most Influential reactions involving CH2 (g, triplet)

Please note: The list, which is based on a hat (projection) matrix analysis, is limited to no more than 20 largest influences.

Influence
Coefficient		 TN
ID		 Reaction Measured Quantity Reference
1.0001684.1 CH2 (g, triplet) → CH2 (g) ΔrH°(0 K) = 0.0 ± 0.0 cm-1triv
0.9881679.3 CH2 (g, triplet) → [CH2]+ (g) ΔrH°(0 K) = 83772 ± 3 cm-1Willitsch 2002, Willitsch 2003
0.7481685.1 CH2 (g, triplet) → CH2 (g, singlet) ΔrH°(0 K) = 3147 ± 5 cm-1Jensen 1988, Jacox 1994
0.7281681.1 [CH2]- (g) → CH2 (g, triplet) ΔrH°(0 K) = 0.652 ± 0.006 eVLeopold 1985, Bunker 1985
0.2603947.2 [C6H5]+ (g, triplet) + CH2 (g, singlet) → [C6H5]+ (g, singlet) + CH2 (g, triplet) ΔrH°(0 K) = -34.10 ± 1.5 kcal/molRuscic G3B3
0.1131710.8 CH2 (g, triplet) → CH (g) + H (g) ΔrH°(0 K) = 417.85 ± 0.35 kJ/molCsaszar 2003
0.1023947.1 [C6H5]+ (g, triplet) + CH2 (g, singlet) → [C6H5]+ (g, singlet) + CH2 (g, triplet) ΔrH°(298.15 K) = -137 ± 10 kJ/molNicolaides 1997
0.0952504.6 CCCH (g) + CH2 (g, triplet) → HCCCH (g, triplet) + CH (g) ΔrH°(0 K) = 24.91 ± 3 kJ/molAguilera-Iparraguirre 2008, est unc
0.0831685.4 CH2 (g, triplet) → CH2 (g, singlet) ΔrH°(0 K) = 3156 ± 15 cm-1Bunker 1986, note CH2
0.0741676.8 CH2 (g, triplet) → C (g) + 2 H (g) ΔrH°(0 K) = 179.76 ± 0.07 (×1.354) kcal/molFeller 2014
0.0662872.5 CCO (g, triplet) + CH4 (g) → CH2 (g, triplet) + CH2CO (g) ΔrH°(0 K) = 8.04 ± 0.9 kcal/molRuscic W1RO
0.0651681.2 [CH2]- (g) → CH2 (g, triplet) ΔrH°(0 K) = 0.65 ± 0.02 eVSears 1983
0.0541710.12 CH2 (g, triplet) → CH (g) + H (g) ΔrH°(0 K) = 99.75 ± 0.08 (×1.509) kcal/molFeller 2014
0.0541681.12 [CH2]- (g) → CH2 (g, triplet) ΔrH°(0 K) = 0.653 ± 0.022 eVBoese 2004
0.0532872.4 CCO (g, triplet) + CH4 (g) → CH2 (g, triplet) + CH2CO (g) ΔrH°(0 K) = 9.05 ± 1.0 kcal/molRuscic CBS-n
0.0532872.2 CCO (g, triplet) + CH4 (g) → CH2 (g, triplet) + CH2CO (g) ΔrH°(0 K) = 8.55 ± 1.0 kcal/molRuscic G4
0.0481690.8 CH3 (g) → CH2 (g, triplet) + H (g) ΔrH°(0 K) = 457.05 ± 0.56 kJ/molHarding 2008
0.0471798.9 CH3CH (g, triplet) + CH3 (g) → CH2 (g, triplet) + CH3CH2 (g) ΔrH°(0 K) = 2.78 ± 0.9 kcal/molRuscic W1RO
0.0461685.2 CH2 (g, triplet) → CH2 (g, singlet) ΔrH°(0 K) = 3165 ± 20 cm-1McKellar 1983
0.0451797.8 CH3CH (g, triplet) + CH4 (g) → CH2 (g, triplet) + C2H6 (g) ΔrH°(0 K) = 6.58 ± 0.9 kcal/molRuscic W1RO
References
1   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]
3   B. Ruscic and D. H. Bross,
Active Thermochemical Tables (ATcT) values based on ver. 1.122 of the Thermochemical Network (2016); available at ATcT.anl.gov
4   B. Ruscic,
Active Thermochemical Tables: Sequential Bond Dissociation Enthalpies of Methane, Ethane, and Methanol and the Related Thermochemistry.
J. Phys. Chem. A 119, 7810-7837 (2015) [DOI: 10.1021/acs.jpca.5b01346]
5   S. J. Klippenstein, L. B. Harding, and B. Ruscic,
Ab initio Computations and Active Thermochemical Tables Hand in Hand: Heats of Formation of Core Combustion Species.
J. Phys. Chem. A 121, 6580-6602 (2017) [DOI: 10.1021/acs.jpca.7b05945]
6   B. Ruscic,
Uncertainty Quantification in Thermochemistry, Benchmarking Electronic Structure Computations, and Active Thermochemical Tables.
Int. J. Quantum Chem. 114, 1097-1101 (2014) [DOI: 10.1002/qua.24605]
Formula
The aggregate state is given in parentheses following the formula, such as: g - gas-phase, cr - crystal, l - liquid, etc.
Uncertainties
The listed uncertainties correspond to estimated 95% confidence limits, as customary in thermochemistry (see, for example, Ruscic [6]).
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.