Selected ATcT [1, 2] enthalpy of formation based on version 1.172 of the Thermochemical Network [3]

This version of ATcT results[3] was generated by additional expansion of version 1.156 to include species relevant to a study of photodissociation of formamide[4].

Methyliumyl

Formula: [CH2]+ (g)
CAS RN: 15091-72-2
ATcT ID: 15091-72-2*0
SMILES: [CH2+]
InChI: InChI=1S/CH2/h1H2/q+1
InChIKey: CCOXZMOGYFFTRT-UHFFFAOYSA-N
Hills Formula: C1H2+

2D Image:

[CH2+]
Aliases: [CH2]+; Methyliumyl; Methyliumyl ion; Methyliumyl cation; Methyliumyl ion (1+); Methylene cation; Methylen ion (1+); Carbene cation; Carbene ion (1+); Carbon dihydride cation; Carbon dihydride ion (1+); Methaniumyl; CH2+
Relative Molecular Mass: 14.02603 ± 0.00081

   ΔfH°(0 K)   ΔfH°(298.15 K)UncertaintyUnits
1393.2001394.059± 0.099kJ/mol

3D Image of [CH2]+ (g)

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Top contributors to the provenance of ΔfH° of [CH2]+ (g)

The 20 contributors listed below account only for 56.8% of the provenance of ΔfH° of [CH2]+ (g).
A total of 181 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
12.02415.1 CH2 (g, triplet) → [CH2]+ (g) ΔrH°(0 K) = 83772 ± 3 cm-1Willitsch 2002, Willitsch 2003
8.62412.9 CH2 (g, triplet) → C (g) + 2 H (g) ΔrH°(0 K) = 179.80 ± 0.06 kcal/molFeller 2016, note unc2
6.32412.8 CH2 (g, triplet) → C (g) + 2 H (g) ΔrH°(0 K) = 179.76 ± 0.07 kcal/molFeller 2014
5.02430.1 CH3 (g) → CH2 (g, triplet) H (g) ΔrH°(0 K) = 109.26 ± 0.08 kcal/molFeller 2016, est unc, note unc2
3.12454.8 CH2 (g, triplet) → CH (g) H (g) ΔrH°(0 K) = 418.04 ± 0.35 kJ/molCsaszar 2003
2.32427.1 CH3 (g) → [CH2]+ (g) H (g) ΔrH°(0 K) = 15.120 ± 0.006 eVLitorja 1998
2.02375.1 H2 (g) C (graphite) → CH4 (g) ΔrG°(1165 K) = 37.521 ± 0.068 kJ/molSmith 1946, note COf, 3rd Law
1.82429.8 CH3 (g) → CH2 (g, triplet) H (g) ΔrH°(0 K) = 457.05 ± 0.56 kJ/molHarding 2008
1.72411.9 CH2 (g, triplet) → C (g) + 2 H (g) ΔrH°(0 K) = 752.45 ± 0.56 kJ/molHarding 2008
1.42429.4 CH3 (g) → CH2 (g, triplet) H (g) ΔrH°(0 K) = 109.22 ± 0.15 kcal/molKarton 2008
1.32411.5 CH2 (g, triplet) → C (g) + 2 H (g) ΔrH°(0 K) = 179.86 ± 0.15 kcal/molKarton 2008
1.32434.1 [CH2]- (g) → C- (g) + 2 H (g) ΔrH°(0 K) = 165.69 ± 0.12 kcal/molFeller 2016, note unc2
1.32412.1 CH2 (g, triplet) → C (g) + 2 H (g) ΔrH°(0 K) = 753.03 ± 0.62 (×1.044) kJ/molCsaszar 2003
1.22455.5 CH2 (g, singlet) → CH (g) H (g) ΔrH°(0 K) = 90.97 ± 0.12 kcal/molFeller 2014
1.22454.4 CH2 (g, triplet) → CH (g) H (g) ΔrH°(0 K) = 417.96 ± 0.56 kJ/molHarding 2008
1.12429.6 CH3 (g) → CH2 (g, triplet) H (g) ΔrH°(0 K) = 457.05 ± 0.70 kJ/molHarding 2008
1.12411.7 CH2 (g, triplet) → C (g) + 2 H (g) ΔrH°(0 K) = 752.43 ± 0.70 kJ/molHarding 2008
1.12960.1 CH3OH (g) → CH2 (g, triplet) H2O (g) ΔrH°(0 K) = 81.77 ± 0.17 kcal/molNguyen 2015a
1.12454.12 CH2 (g, triplet) → CH (g) H (g) ΔrH°(0 K) = 99.75 ± 0.08 (×1.756) kcal/molFeller 2014
1.02414.9 CH2 (g, singlet) → C (g) + 2 H (g) ΔrH°(0 K) = 170.98 ± 0.11 (×1.445) kcal/molFeller 2014

Top 10 species with enthalpies of formation correlated to the ΔfH° of [CH2]+ (g)

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
93.3 MethyleneCH2 (g, triplet)[CH2]391.066391.612± 0.093kJ/mol14.02658 ±
0.00081
2465-56-7*1
93.3 MethyleneCH2 (g)[CH2]391.066391.612± 0.093kJ/mol14.02658 ±
0.00081
2465-56-7*0
80.7 MethyleneCH2 (g, singlet)[CH2]428.73429.14± 0.11kJ/mol14.02658 ±
0.00081
2465-56-7*2
78.9 KeteneCH2CO (g, ortho singlet)C=C=O-45.22-48.40± 0.11kJ/mol42.0367 ±
0.0016
463-51-4*22
78.9 KeteneCH2CO (g, para singlet)C=C=O-45.34-48.40± 0.11kJ/mol42.0367 ±
0.0016
463-51-4*21
78.9 KeteneCH2CO (g)C=C=O-45.34-48.40± 0.11kJ/mol42.0367 ±
0.0016
463-51-4*0
78.9 KeteneCH2CO (g, singlet)C=C=O-45.34-48.40± 0.11kJ/mol42.0367 ±
0.0016
463-51-4*2
78.6 Ketene cation[CH2CO]+ (g)C=C=[O+]882.23879.06± 0.11kJ/mol42.0361 ±
0.0016
64999-16-2*0
40.2 Methylene anion[CH2]- (g)[CH2-]328.17328.60± 0.18kJ/mol14.02713 ±
0.00081
50928-07-9*0
33.0 CarbonC (g)[C]711.381716.866± 0.039kJ/mol12.01070 ±
0.00080
7440-44-0*0

Most Influential reactions involving [CH2]+ (g)

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
0.9842415.1 CH2 (g, triplet) → [CH2]+ (g) ΔrH°(0 K) = 83772 ± 3 cm-1Willitsch 2002, Willitsch 2003
0.3533328.5 CH3CCH3 (g, singlet) [CH2]+ (g) → [CH3CCH3]+ (g) CH2 (g, singlet) ΔrH°(0 K) = -2.295 ± 0.027 eVRuscic W1RO
0.1073328.2 CH3CCH3 (g, singlet) [CH2]+ (g) → [CH3CCH3]+ (g) CH2 (g, singlet) ΔrH°(0 K) = -2.315 ± 0.049 eVRuscic G4
0.1023328.4 CH3CCH3 (g, singlet) [CH2]+ (g) → [CH3CCH3]+ (g) CH2 (g, singlet) ΔrH°(0 K) = -2.318 ± 0.050 eVRuscic CBS-n
0.0715895.6 CH2(NN) (g) → [CH2]+ (g) N2 (g) ΔrH°(0 K) = 11.109 ± 0.040 eVRuscic W1RO
0.0673328.1 CH3CCH3 (g, singlet) [CH2]+ (g) → [CH3CCH3]+ (g) CH2 (g, singlet) ΔrH°(0 K) = -2.282 ± 0.062 eVRuscic G3X
0.0593328.3 CH3CCH3 (g, singlet) [CH2]+ (g) → [CH3CCH3]+ (g) CH2 (g, singlet) ΔrH°(0 K) = -2.289 ± 0.066 eVRuscic CBS-n
0.0292427.1 CH3 (g) → [CH2]+ (g) H (g) ΔrH°(0 K) = 15.120 ± 0.006 eVLitorja 1998
0.0215895.3 CH2(NN) (g) → [CH2]+ (g) N2 (g) ΔrH°(0 K) = 11.107 ± 0.073 eVRuscic G4
0.0205895.5 CH2(NN) (g) → [CH2]+ (g) N2 (g) ΔrH°(0 K) = 11.137 ± 0.075 eVRuscic CBS-n
0.0135895.2 CH2(NN) (g) → [CH2]+ (g) N2 (g) ΔrH°(0 K) = 11.063 ± 0.093 eVRuscic G3X
0.0115895.4 CH2(NN) (g) → [CH2]+ (g) N2 (g) ΔrH°(0 K) = 11.128 ± 0.099 eVRuscic CBS-n
0.0064374.2 CH2CO (g) → [CH2]+ (g) CO (g) ΔrH°(0 K) = 13.729 ± 0.008 eVMcCulloh 1976a
0.0032415.2 CH2 (g, triplet) → [CH2]+ (g) ΔrH°(0 K) = 10.385 ± 0.006 eVCoudert 2018
0.0024374.1 CH2CO (g) → [CH2]+ (g) CO (g) ΔrH°(0 K) = 13.743 ± 0.005 (×2.65) eVRuscic 1999
0.0012415.4 CH2 (g, triplet) → [CH2]+ (g) ΔrH°(0 K) = 10.396 ± 0.003 (×3.221) eVHerzberg 1959, Herzberg 1961a, Herzberg 1971
0.0012416.11 CH2 (g, triplet) → [CH2]+ (g) ΔrH°(0 K) = 10.382 ± 0.010 eVLau 2005
0.0012415.3 CH2 (g, triplet) → [CH2]+ (g) ΔrH°(0 K) = 10.393 ± 0.011 eVLitorja 1998
0.0002427.2 CH3 (g) → [CH2]+ (g) H (g) ΔrH°(0 K) = 15.09 ± 0.03 (×1.189) eVChupka 1968a
0.0002427.3 CH3 (g) → [CH2]+ (g) H (g) ΔrH°(0 K) = 15.121 ± 0.040 eVRuscic 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. 1.172 of the Thermochemical Network (2024); available at ATcT.anl.gov
4   K. L. Caster, N. A. Seifert, B. Ruscic, A. W. Jasper, and K. Prozument,
Dynamics of HCN, NHC, and HNCO Formation in the 193 nm Photodissociation of Formamide
J. Phys. Chem. A (in press) (2024) [DOI: 10.1021/acs.jpca.4c02232]
5   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]
6   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 [5] and Ruscic and Bross[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.