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
1-MethylethylideneCH3CCH3 (g)C[C]C316.5303.6± 2.1kJ/mol42.0797 ±
0.0024		40852-89-9*0

Representative Geometry of CH3CCH3 (g)

spin ON           spin OFF
          

Top contributors to the provenance of ΔfH° of CH3CCH3 (g)

The 20 contributors listed below account only for 68.3% of the provenance of ΔfH° of CH3CCH3 (g).
A total of 60 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
6.52685.5 CH3CCH3 (g, singlet) → CH3CCH3 (g, triplet) ΔrH°(0 K) = 897 ± 420 cm-1Ruscic W1RO
5.62685.2 CH3CCH3 (g, singlet) → CH3CCH3 (g, triplet) ΔrH°(0 K) = 873 ± 450 cm-1Ruscic G4
5.52687.5 CH3CCH3 (g, singlet) + CH2 (g, singlet) → 2 CH3CH (g, singlet) ΔrH°(0 K) = 0.21 ± 0.85 kcal/molRuscic W1RO
5.52685.4 CH3CCH3 (g, singlet) → CH3CCH3 (g, triplet) ΔrH°(0 K) = 721 ± 455 cm-1Ruscic CBS-n
4.92687.2 CH3CCH3 (g, singlet) + CH2 (g, singlet) → 2 CH3CH (g, singlet) ΔrH°(0 K) = 0.58 ± 0.90 kcal/molRuscic G4
4.92687.4 CH3CCH3 (g, singlet) + CH2 (g, singlet) → 2 CH3CH (g, singlet) ΔrH°(0 K) = 0.58 ± 0.90 kcal/molRuscic CBS-n
4.92687.1 CH3CCH3 (g, singlet) + CH2 (g, singlet) → 2 CH3CH (g, singlet) ΔrH°(0 K) = 0.86 ± 0.90 kcal/molRuscic G3X
4.72685.1 CH3CCH3 (g, singlet) → CH3CCH3 (g, triplet) ΔrH°(0 K) = 917 ± 490 cm-1Ruscic G3X
4.02687.3 CH3CCH3 (g, singlet) + CH2 (g, singlet) → 2 CH3CH (g, singlet) ΔrH°(0 K) = 0.90 ± 1.00 kcal/molRuscic CBS-n
3.62685.3 CH3CCH3 (g, singlet) → CH3CCH3 (g, triplet) ΔrH°(0 K) = 894 ± 560 cm-1Ruscic CBS-n
2.32053.8 CH3CH (g, singlet) + CH4 (g) → CH2 (g, singlet) + CH3CH3 (g) ΔrH°(0 K) = 12.75 ± 0.9 kcal/molRuscic W1RO
2.22054.8 CH3CH (g, singlet) + CH3 (g) → CH2 (g, singlet) + CH3CH2 (g) ΔrH°(0 K) = 8.96 ± 0.9 kcal/molRuscic W1RO
1.82053.4 CH3CH (g, singlet) + CH4 (g) → CH2 (g, singlet) + CH3CH3 (g) ΔrH°(0 K) = 12.58 ± 1.0 kcal/molRuscic G4
1.82053.7 CH3CH (g, singlet) + CH4 (g) → CH2 (g, singlet) + CH3CH3 (g) ΔrH°(0 K) = 12.48 ± 1.0 kcal/molRuscic CBS-n
1.82054.7 CH3CH (g, singlet) + CH3 (g) → CH2 (g, singlet) + CH3CH2 (g) ΔrH°(0 K) = 8.78 ± 1.0 kcal/molRuscic CBS-n
1.82054.4 CH3CH (g, singlet) + CH3 (g) → CH2 (g, singlet) + CH3CH2 (g) ΔrH°(0 K) = 8.61 ± 1.0 kcal/molRuscic G4
1.52053.3 CH3CH (g, singlet) + CH4 (g) → CH2 (g, singlet) + CH3CH3 (g) ΔrH°(0 K) = 12.28 ± 1.1 kcal/molRuscic G3X
1.52054.3 CH3CH (g, singlet) + CH3 (g) → CH2 (g, singlet) + CH3CH2 (g) ΔrH°(0 K) = 8.77 ± 1.1 kcal/molRuscic G3X
1.32050.5 CH3CH (g, singlet) → CH2CH2 (g) ΔrH°(0 K) = -74.64 ± 1.2 kcal/molRuscic W1RO
1.12050.4 CH3CH (g, singlet) → CH2CH2 (g) ΔrH°(0 K) = -74.88 ± 1.3 kcal/molRuscic CBS-n

Top 10 species with enthalpies of formation correlated to the ΔfH° of CH3CCH3 (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
100.0 1-MethylethylideneCH3CCH3 (g, singlet)C[C]C316.5302.6± 2.1kJ/mol42.0797 ±
0.0024		40852-89-9*2
79.2 1-Methyl-1-ethylium-1-yl[CH3CCH3]+ (g)C[C+]C1058.71046.1± 2.6kJ/mol42.0792 ±
0.0024		121408-19-3*0
76.4 Isopropylidene anion[CH3CCH3]- (g)C[C-]C282.9268.8± 2.7kJ/mol42.0803 ±
0.0024		*121408-19-3*0
67.6 EthylideneCH3CH (g, singlet)[CH]C373.80366.57± 0.87kJ/mol28.0532 ±
0.0016		4218-50-2*2
45.7 1-MethylethylideneCH3CCH3 (g, triplet)C[C]C327.0313.9± 1.6kJ/mol42.0797 ±
0.0024		40852-89-9*1
33.9 EthylideneCH3CH (g)[CH]C361.35354.37± 0.76kJ/mol28.0532 ±
0.0016		4218-50-2*0
33.9 EthylideneCH3CH (g, triplet)[CH]C361.35354.35± 0.76kJ/mol28.0532 ±
0.0016		4218-50-2*1
23.4 PropylideneCH3CH2CH (g, triplet)CC[CH]349.5335.8± 1.4kJ/mol42.0797 ±
0.0024		6700-78-3*1
20.4 1,3-PropanediylCH2CH2CH2 (g, triplet)[CH2]C[CH2]320.1308.2± 1.7kJ/mol42.0797 ±
0.0024		32458-33-6*1
16.1 Ethylidene anion[CH3CH]- (g)[CH-]C325.8318.5± 1.9kJ/mol28.0537 ±
0.0016		35829-99-3*0

Most Influential reactions involving CH3CCH3 (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
1.0002686.1 CH3CCH3 (g) → CH3CCH3 (g, singlet) ΔrH°(0 K) = 0 ± 0 cm-1triv, Ruscic W1RO, Ruscic G4
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.