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
Methanium[CH5]+ (g)[CH5+]921.95911.70± 0.45kJ/mol17.04985 ±
0.00087
15135-49-6*0

Representative Geometry of [CH5]+ (g)

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Top contributors to the provenance of ΔfH° of [CH5]+ (g)

The 20 contributors listed below account only for 60.4% of the provenance of ΔfH° of [CH5]+ (g).
A total of 77 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
13.53603.14 HC(O)OH (g, syn) → [HOCO]+ (g) H (g) ΔrH°(0 K) = 1187.3 ± 1.0 kJ/molShuman 2010a
8.63603.2 HC(O)OH (g, syn) → [HOCO]+ (g) H (g) ΔrH°(0 K) = 12.316 ± 0.013 eVRuscic 1989
6.51897.3 [CH5]+ (g) CO (g) → [HCO]+ (g) CH4 (g) ΔrH°(441 K) = -11.5 ± 0.4 kcal/molSzulejko 1993, 2nd Law, note unc5
4.21897.2 [CH5]+ (g) CO (g) → [HCO]+ (g) CH4 (g) ΔrG°(441 K) = -8.6 ± 0.5 kcal/molSzulejko 1993, 3rd Law, note unc5
3.63603.4 HC(O)OH (g, syn) → [HOCO]+ (g) H (g) ΔrH°(0 K) = 12.30 ± 0.02 eVShuman 2010a, est unc
3.63603.6 HC(O)OH (g, syn) → [HOCO]+ (g) H (g) ΔrH°(0 K) = 12.31 ± 0.02 eVVillem 1975, Akopyan 1976, AE corr
3.63603.1 HC(O)OH (g, syn) → [HOCO]+ (g) H (g) ΔrH°(0 K) = 12.30 ± 0.02 eVRuscic 1989
1.61898.8 [CH5]+ (g) H2O (g) → [H3O]+ (g) CH4 (g) ΔrH°(0 K) = -34.21 ± 0.8 kcal/molRuscic W1RO
1.63603.5 HC(O)OH (g, syn) → [HOCO]+ (g) H (g) ΔrH°(0 K) = 12.29 ± 0.03 eVWarneck 1974
1.51990.2 [C2H7]+ (g) CH4 (g) → [CH5]+ (g) CH3CH3 (g) ΔrG°(334 K) = 10.5 ± 0.7 kcal/molSzulejko 1993, 3rd Law, note unc5
1.31890.8 [CH5]+ (g) → CH4 (g) H+ (g) ΔrH°(0 K) = 129.28 ± 0.90 kcal/molRuscic W1RO
1.23604.8 [HOCO]+ (g) → CO2 (g) H+ (g) ΔrH°(0 K) = 128.00 ± 0.90 kcal/molRuscic W1RO
1.11535.3 [NNH]+ (g) CO2 (g) → N2 (g) [HOCO]+ (g) ΔrG°(561 K) = -12.6 ± 0.6 (×1.269) kcal/molSzulejko 1993, 3rd Law, note unc5
1.11984.5 [C2H7]+ (g, bridged C2) CH4 (g) → [CH5]+ (g) CH3CH3 (g) ΔrH°(0 K) = 10.71 ± 0.8 kcal/molRuscic W1RO
1.11888.1 H2 (g) C (graphite) → CH4 (g) ΔrG°(1165 K) = 37.521 ± 0.068 kJ/molSmith 1946, note COf, 3rd Law
1.03540.2 HC(O)OH (cr,l) + 1/2 O2 (g) → CO2 (g) H2O (cr,l) ΔrH°(298.15 K) = -60.807 ± 0.074 kcal/molLebedeva 1964
1.01891.4 [CH5]+ (g) → [CH3]+ (g) H2 (g) ΔrH°(0 K) = 42.0 ± 1 kcal/molMuller 1997
1.01890.13 [CH5]+ (g) → CH4 (g) H+ (g) ΔrH°(0 K) = 128.5 ± 1.0 kcal/molKomornicki 1992, note unc2
1.01890.12 [CH5]+ (g) → CH4 (g) H+ (g) ΔrH°(0 K) = 129.4 ± 1 kcal/molMuller 1997
1.01898.4 [CH5]+ (g) H2O (g) → [H3O]+ (g) CH4 (g) ΔrH°(0 K) = -34.79 ± 1.0 kcal/molRuscic G4

Top 10 species with enthalpies of formation correlated to the ΔfH° of [CH5]+ (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
96.6 Hydroxyoxomethylium[HOCO]+ (g)O[C+]=O600.65597.57± 0.44kJ/mol45.0169 ±
0.0010
638-71-1*0
24.8 Formic acidHC(O)OH (g, syn)C(=O)O-371.10-378.42± 0.22kJ/mol46.0254 ±
0.0010
64-18-6*1
24.8 Formic acidHC(O)OH (g)C(=O)O-371.10-378.40± 0.22kJ/mol46.0254 ±
0.0010
64-18-6*0
21.1 Formic acid cation[HC(O)OH]+ (g, syn)[CH+](=O)O721.87714.79± 0.26kJ/mol46.0248 ±
0.0010
50614-05-6*1
21.1 Formic acid cation[HC(O)OH]+ (g)[CH+](=O)O721.87715.34± 0.26kJ/mol46.0248 ±
0.0010
50614-05-6*0
17.0 Formic acidHC(O)OH (cr,l)C(=O)O-431.55-424.72± 0.20kJ/mol46.0254 ±
0.0010
64-18-6*500
13.3 Formic acidHC(O)OH (g, anti)C(=O)O-354.76-361.86± 0.38kJ/mol46.0254 ±
0.0010
64-18-6*2
13.3 MethaneCH4 (g)C-66.557-74.526± 0.055kJ/mol16.04246 ±
0.00085
74-82-8*0
12.6 Methylium[CH3]+ (g)[CH3+]1099.3401095.396± 0.057kJ/mol15.03397 ±
0.00083
14531-53-4*0
12.4 Ethanium[C2H7]+ (g, bridged C2)[CH3+][H][CH3]874.34858.07± 0.62kJ/mol31.0764 ±
0.0017
24669-33-8*1

Most Influential reactions involving [CH5]+ (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
0.2531895.5 [CH5]+ (g) CO2 (g) → [HOCO]+ (g) CH4 (g) ΔrG°(296 K) = 7.92 ± 0.20 kJ/molBohme 1973a, 3rd Law, note unc
0.2291895.7 [CH5]+ (g) CO2 (g) → [HOCO]+ (g) CH4 (g) ΔrG°(296 K) = 7.82 ± 0.21 kJ/molHemsworth 1973, 3rd Law, note unc
0.2091895.6 [CH5]+ (g) CO2 (g) → [HOCO]+ (g) CH4 (g) ΔrG°(296 K) = 7.72 ± 0.22 kJ/molBohme 1973a, 3rd Law, note unc
0.1611895.4 [CH5]+ (g) CO2 (g) → [HOCO]+ (g) CH4 (g) ΔrG°(296 K) = 7.78 ± 0.25 kJ/molBohme 1973a, 3rd Law, note unc
0.0871895.3 [CH5]+ (g) CO2 (g) → [HOCO]+ (g) CH4 (g) ΔrG°(296 K) = 7.86 ± 0.34 kJ/molBohme 1973a, 3rd Law, note unc
0.0701897.3 [CH5]+ (g) CO (g) → [HCO]+ (g) CH4 (g) ΔrH°(441 K) = -11.5 ± 0.4 kcal/molSzulejko 1993, 2nd Law, note unc5
0.0571990.2 [C2H7]+ (g) CH4 (g) → [CH5]+ (g) CH3CH3 (g) ΔrG°(334 K) = 10.5 ± 0.7 kcal/molSzulejko 1993, 3rd Law, note unc5
0.0451897.2 [CH5]+ (g) CO (g) → [HCO]+ (g) CH4 (g) ΔrG°(441 K) = -8.6 ± 0.5 kcal/molSzulejko 1993, 3rd Law, note unc5
0.0441984.5 [C2H7]+ (g, bridged C2) CH4 (g) → [CH5]+ (g) CH3CH3 (g) ΔrH°(0 K) = 10.71 ± 0.8 kcal/molRuscic W1RO
0.0331538.1 [NNH]+ (g) CH4 (g) → [CH5]+ (g) N2 (g) ΔrH°(0 K) = -12.2 ± 1.0 kcal/molKomornicki 1992, est unc
0.0281984.4 [C2H7]+ (g, bridged C2) CH4 (g) → [CH5]+ (g) CH3CH3 (g) ΔrH°(0 K) = 11.75 ± 1.0 kcal/molRuscic CBS-n
0.0281984.2 [C2H7]+ (g, bridged C2) CH4 (g) → [CH5]+ (g) CH3CH3 (g) ΔrH°(0 K) = 11.24 ± 1.0 kcal/molRuscic G4
0.0261895.11 [CH5]+ (g) CO2 (g) → [HOCO]+ (g) CH4 (g) ΔrG°(296 K) = 1.869 ± 0.149 kcal/molBohme 1980, 3rd Law, note unc
0.0191984.1 [C2H7]+ (g, bridged C2) CH4 (g) → [CH5]+ (g) CH3CH3 (g) ΔrH°(0 K) = 11.58 ± 1.2 kcal/molRuscic G3X
0.0191898.8 [CH5]+ (g) H2O (g) → [H3O]+ (g) CH4 (g) ΔrH°(0 K) = -34.21 ± 0.8 kcal/molRuscic W1RO
0.0161984.3 [C2H7]+ (g, bridged C2) CH4 (g) → [CH5]+ (g) CH3CH3 (g) ΔrH°(0 K) = 11.55 ± 1.3 kcal/molRuscic CBS-n
0.0151990.1 [C2H7]+ (g) CH4 (g) → [CH5]+ (g) CH3CH3 (g) ΔrH°(334 K) = 11.9 ± 0.7 (×1.957) kcal/molSzulejko 1993, 2nd Law, note unc5
0.0131890.8 [CH5]+ (g) → CH4 (g) H+ (g) ΔrH°(0 K) = 129.28 ± 0.90 kcal/molRuscic W1RO
0.0121898.4 [CH5]+ (g) H2O (g) → [H3O]+ (g) CH4 (g) ΔrH°(0 K) = -34.79 ± 1.0 kcal/molRuscic G4
0.0121898.7 [CH5]+ (g) H2O (g) → [H3O]+ (g) CH4 (g) ΔrH°(0 K) = -35.17 ± 1.0 kcal/molRuscic CBS-n


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.