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

This version of ATcT results was generated from an expansion of version 1.122e [4] to include results centered on the determination of the appearance energy of CH3+ from CH4. [5].

Species Name Formula Image    ΔfH°(0 K)    ΔfH°(298.15 K) Uncertainty Units Relative
Molecular
Mass
ATcT ID
Methylium[CH3]+ (g)[CH3+]1099.3401095.396± 0.057kJ/mol15.03397 ±
0.00083
14531-53-4*0

Representative Geometry of [CH3]+ (g)

spin ON           spin OFF
          

Top contributors to the provenance of ΔfH° of [CH3]+ (g)

The 9 contributors listed below account for 75.7% of the provenance of ΔfH° of [CH3]+ (g).

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
56.61888.1 H2 (g) C (graphite) → CH4 (g) ΔrG°(1165 K) = 37.521 ± 0.068 kJ/molSmith 1946, note COf, 3rd Law
7.11909.1 CH4 (g) → [CH3]+ (g) H (g) ΔrH°(0 K) = 14.32272 ± 0.00020 eVChang 2017
3.21887.4 CH4 (g) + 2 O2 (g) → CO2 (g) + 2 H2O (cr,l) ΔrH°(298.15 K) = -890.61 ± 0.21 kJ/molDale 2002
2.2118.2 1/2 O2 (g) H2 (g) → H2O (cr,l) ΔrH°(298.15 K) = -285.8261 ± 0.040 kJ/molRossini 1939, Rossini 1931, Rossini 1931b, note H2Oa, Rossini 1930
2.11887.6 CH4 (g) + 2 O2 (g) → CO2 (g) + 2 H2O (cr,l) ΔrH°(298.15 K) = -890.44 ± 0.26 kJ/molGOMB Ref Calorimeter, Alexandrov 2002
1.11887.5 CH4 (g) + 2 O2 (g) → CO2 (g) + 2 H2O (cr,l) ΔrH°(298.15 K) = -890.43 ± 0.35 kJ/molAlexandrov 2002a, Alexandrov 2002
1.11887.1 CH4 (g) + 2 O2 (g) → CO2 (g) + 2 H2O (cr,l) ΔrH°(303.15 K) = -889.849 ± 0.350 kJ/molRossini 1931a, Rossini 1931b, Prosen 1945, Rossini 1940, note CH4
1.01900.13 CH3 (g) → C (g) + 3 H (g) ΔrH°(0 K) = 289.11 ± 0.10 kcal/molFeller 2016, note unc2
0.91939.1 CH3 (g) → CH2 (g, triplet) H (g) ΔrH°(0 K) = 109.26 ± 0.08 kcal/molFeller 2016, est unc, note unc2

Top 10 species with enthalpies of formation correlated to the ΔfH° of [CH3]+ (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
94.5 MethaneCH4 (g)C-66.557-74.526± 0.055kJ/mol16.04246 ±
0.00085
74-82-8*0
91.9 MethylCH3 (g)[CH3]149.872146.458± 0.060kJ/mol15.03452 ±
0.00083
2229-07-4*0
78.9 Methane cation[CH4]+ (g)[CH4+]1150.6731144.290± 0.066kJ/mol16.04191 ±
0.00085
20741-88-2*0
31.8 IodomethaneCH3I (g)CI24.5014.97± 0.18kJ/mol141.93899 ±
0.00083
74-88-4*0
31.8 Methyl iodide cation[CH3I]+ (g)C[I+]944.79935.40± 0.18kJ/mol141.93844 ±
0.00083
12538-72-6*0
28.9 BromomethaneCH3Br (g)CBr-20.88-36.28± 0.18kJ/mol94.9385 ±
0.0013
74-83-9*0
28.7 IodomethaneCH3I (l)CI-12.18± 0.20kJ/mol141.93899 ±
0.00083
74-88-4*590
27.9 Methyl bromide cation[CH3Br]+ (g)C[Br+]996.24981.32± 0.18kJ/mol94.9380 ±
0.0013
12538-70-4*0
27.3 BromomethaneCH3Br (l)CBr-56.60-59.61± 0.19kJ/mol94.9385 ±
0.0013
74-83-9*590
25.4 Carbon atomC (g)[C]711.399716.884± 0.047kJ/mol12.01070 ±
0.00080
7440-44-0*0

Most Influential reactions involving [CH3]+ (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
0.9091909.1 CH4 (g) → [CH3]+ (g) H (g) ΔrH°(0 K) = 14.32272 ± 0.00020 eVChang 2017
0.6714360.1 CH3Br (g) → [CH3]+ (g) Br (g) ΔrH°(0 K) = 12.834 ± 0.002 eVSong 2001
0.4994382.2 CH3I (g) → [CH3]+ (g) I (g) ΔrH°(0 K) = 12.251 ± 0.0024 eVLee 2007
0.4261903.1 CH3 (g) → [CH3]+ (g) ΔrH°(0 K) = 79370.4 ± 3 cm-1Schulenburg 2006, note CH3
0.4261903.2 CH3 (g) → [CH3]+ (g) ΔrH°(0 K) = 79369.9 ± 3 cm-1Schulenburg 2006, note CH3
0.2804382.1 CH3I (g) → [CH3]+ (g) I (g) ΔrH°(0 K) = 12.248 ± 0.003 (×1.067) eVBodi 2009
0.0931903.4 CH3 (g) → [CH3]+ (g) ΔrH°(0 K) = 79363 ± 3 (×2.134) cm-1Blush 1993, note CH3
0.0454382.3 CH3I (g) → [CH3]+ (g) I (g) ΔrH°(0 K) = 12.243 ± 0.008 eVLee 2007, Bodi 2009
0.0361909.3 CH4 (g) → [CH3]+ (g) H (g) ΔrH°(0 K) = 14.323 ± 0.001 eVWeitzel 1999, Weitzel 2001
0.0254382.5 CH3I (g) → [CH3]+ (g) I (g) ΔrH°(0 K) = 12.24 ± 0.01 (×1.067) eVMintz 1976
0.0222061.5 [CH2CH]+ (g) CH4 (g) → [CH3]+ (g) CH2CH2 (g) ΔrH°(0 K) = 25.61 ± 0.9 kcal/molRuscic W1RO, Lago 2006
0.0172061.2 [CH2CH]+ (g) CH4 (g) → [CH3]+ (g) CH2CH2 (g) ΔrH°(0 K) = 25.05 ± 1.0 kcal/molRuscic G4
0.0172061.4 [CH2CH]+ (g) CH4 (g) → [CH3]+ (g) CH2CH2 (g) ΔrH°(0 K) = 26.05 ± 1.0 kcal/molRuscic CBS-n
0.0142434.8 [CH3O]+ (g) → [CH3]+ (g) O (g) ΔrH°(0 K) = 67.81 ± 1.50 kcal/molRuscic W1RO
0.0122434.4 [CH3O]+ (g) → [CH3]+ (g) O (g) ΔrH°(0 K) = 68.24 ± 1.60 kcal/molRuscic G4
0.0122434.7 [CH3O]+ (g) → [CH3]+ (g) O (g) ΔrH°(0 K) = 67.43 ± 1.60 kcal/molRuscic CBS-n
0.0121909.8 CH4 (g) → [CH3]+ (g) H (g) ΔrH°(0 K) = 14.321 ± 0.001 (×1.719) eVBodi 2009a
0.0111891.4 [CH5]+ (g) → [CH3]+ (g) H2 (g) ΔrH°(0 K) = 42.0 ± 1 kcal/molMuller 1997
0.0102434.3 [CH3O]+ (g) → [CH3]+ (g) O (g) ΔrH°(0 K) = 68.35 ± 1.72 kcal/molRuscic G3X
0.0093509.1 CH3OO (g) → [CH3]+ (g) O2 (g) ΔrH°(0 K) = 11.16 ± 0.05 eVMeloni 2006


References (for your convenience, also available in RIS and BibTex format)
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. 1.122g of the Thermochemical Network (2019); available at ATcT.anl.gov
4   J. P. Porterfield, D. H. Bross, B. Ruscic, J. H. Thorpe, T. L. Nguyen, J. H. Baraban, J. F. Stanton, J. W. Daily, and G. B. Ellison,
Thermal Decomposition of Potential Ester Biofuels, Part I: Methyl Acetate and Methyl Butanoate.
J. Chem. Phys. A 121, 4658-4677 (2017) [DOI: 10.1021/acs.jpca.7b02639] (Veronica Vaida Festschrift)
5   Y.-C. Chang, B. Xiong, D. H. Bross, B. Ruscic, and C. Y. Ng,
A Vacuum Ultraviolet laser Pulsed Field Ionization-Photoion Study of Methane (CH4): Determination of the Appearance Energy of Methylium From Methane with Unprecedented Precision and the Resulting Impact on the Bond Dissociation Energies of CH4 and CH4+.
Phys. Chem. Chem. Phys. 19, 9592-9605 (2017) [DOI: 10.1039/c6cp08200a] (part of 2017 PCCP Hot Articles collection)
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.