Selected ATcT [1, 2] enthalpy of formation based on version 1.124 of the Thermochemical Network [3]

This version of ATcT results was generated by additional expansion of version 1.122x [4] to include additional information relevant to the study of thermophysical and thermochemical properties of CH2 and CH3 using nonrigid rotor anharmonic oscillator (NRRAO) partition functions [5], the development and benchmarking of a state-of-the-art computational approach that aims to reproduce total atomization energies of small molecules within 10–15 cm^-1 [6], as well as the study of the reversible reaction C₂H₃ + H₂ ⇌ C₂H₄ + H ⇌ C₂H₅ [7]

Methoxymethylene

Formula: CH3OCH (g, gauche triplet)

CAS RN: 19527-10-7

ATcT ID: 19527-10-7*1

SMILES: CO[CH]

InChI: InChI=1S/C2H4O/c1-3-2/h1H,2H3

InChIKey: QJVFBSULGFNYKF-UHFFFAOYSA-N

Hills Formula: C2H4O1

2D Image:

Aliases: CH3OCH; Methoxymethylene; Methoxycarbene

Relative Molecular Mass: 44.0526 ± 0.0017

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
245.3	235.8	± 1.4	kJ/mol

3D Image of CH3OCH (g, gauche triplet)

spin ON spin OFF

Top contributors to the provenance of Δ_fH° of CH3OCH (g, gauche triplet)

The 14 contributors listed below account for 90.3% of the provenance of Δ_fH° of CH3OCH (g, gauche triplet).

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
13.7	4006.5	CH3OCH (g, gauche triplet) + CH4 (g) → CH3OCH3 (g) + CH2 (g, triplet)	Δ_rH°(0 K) = 10.86 ± 0.85 kcal/mol	Ruscic W1RO
12.2	4006.2	CH3OCH (g, gauche triplet) + CH4 (g) → CH3OCH3 (g) + CH2 (g, triplet)	Δ_rH°(0 K) = 11.19 ± 0.90 kcal/mol	Ruscic G4
12.2	4006.4	CH3OCH (g, gauche triplet) + CH4 (g) → CH3OCH3 (g) + CH2 (g, triplet)	Δ_rH°(0 K) = 11.76 ± 0.90 kcal/mol	Ruscic CBS-n
12.2	4006.1	CH3OCH (g, gauche triplet) + CH4 (g) → CH3OCH3 (g) + CH2 (g, triplet)	Δ_rH°(0 K) = 10.30 ± 0.90 kcal/mol	Ruscic G3X
9.9	4006.3	CH3OCH (g, gauche triplet) + CH4 (g) → CH3OCH3 (g) + CH2 (g, triplet)	Δ_rH°(0 K) = 11.04 ± 1.0 kcal/mol	Ruscic CBS-n
5.1	3977.7	CH3COH (g, anti singlet) → CH3COH (g, gauche triplet)	Δ_rH°(0 K) = 30.64 ± 0.50 kcal/mol	Schreiner 2011, est unc
4.2	3994.5	CH3OCH (g, anti singlet) + CH3COH (g, gauche triplet) → CH3OCH (g, gauche triplet) + CH3COH (g, anti singlet)	Δ_rH°(0 K) = -2.88 ± 0.85 kcal/mol	Ruscic W1RO
3.8	3994.2	CH3OCH (g, anti singlet) + CH3COH (g, gauche triplet) → CH3OCH (g, gauche triplet) + CH3COH (g, anti singlet)	Δ_rH°(0 K) = -2.67 ± 0.90 kcal/mol	Ruscic G4
3.8	3994.4	CH3OCH (g, anti singlet) + CH3COH (g, gauche triplet) → CH3OCH (g, gauche triplet) + CH3COH (g, anti singlet)	Δ_rH°(0 K) = -2.67 ± 0.90 kcal/mol	Ruscic CBS-n
3.8	3994.1	CH3OCH (g, anti singlet) + CH3COH (g, gauche triplet) → CH3OCH (g, gauche triplet) + CH3COH (g, anti singlet)	Δ_rH°(0 K) = -2.63 ± 0.90 kcal/mol	Ruscic G3X
3.0	3994.3	CH3OCH (g, anti singlet) + CH3COH (g, gauche triplet) → CH3OCH (g, gauche triplet) + CH3COH (g, anti singlet)	Δ_rH°(0 K) = -2.24 ± 1.0 kcal/mol	Ruscic CBS-n
2.3	4159.1	CH3OCH3 (g) + 3 O2 (g) → 2 CO2 (g) + 3 H2O (cr,l)	Δ_rH°(298.15 K) = -349.06 ± 0.11 kcal/mol	Pilcher 1964
2.0	3977.6	CH3COH (g, anti singlet) → CH3COH (g, gauche triplet)	Δ_rH°(0 K) = 30.52 ± 0.80 kcal/mol	Matus 2006, est unc
1.3	3972.6	CH3COH (g, gauche triplet) → 2 C (g) + O (g) + 4 H (g)	Δ_rH°(0 K) = 560.92 ± 1 kcal/mol	Matus 2006

Top 10 species with enthalpies of formation correlated to the Δ_fH° of CH3OCH (g, gauche 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	Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units	Relative Molecular Mass	ATcT ID
36.0	1-Hydroxyethylidene	CH3COH (g, gauche triplet)	184.9	175.5	± 1.4	kJ/mol	44.0526 ± 0.0017	30967-49-8*1
24.0	Methoxymethylene	CH3OCH (g, anti singlet)	129.12	118.59	± 0.78	kJ/mol	44.0526 ± 0.0017	19527-10-7*21
24.0	Methoxymethylene	CH3OCH (g, singlet)	129.12	118.62	± 0.78	kJ/mol	44.0526 ± 0.0017	19527-10-7*2
24.0	Methoxymethylene	CH3OCH (g)	129.12	118.62	± 0.78	kJ/mol	44.0526 ± 0.0017	19527-10-7*0
20.3	Methoxymethane	CH3OCH3 (g)	-166.51	-184.01	± 0.37	kJ/mol	46.0684 ± 0.0017	115-10-6*0
8.6	Methoxymethylene	CH3OCH (g, syn singlet)	144.7	134.3	± 1.4	kJ/mol	44.0526 ± 0.0017	19527-10-7*22
5.9	Methoxyethane	CH3CH2OCH3 (g)	-194.78	-217.67	± 0.57	kJ/mol	60.0950 ± 0.0025	540-67-0*0
5.7	Methylene	CH2 (g, triplet)	391.054	391.600	± 0.096	kJ/mol	14.02658 ± 0.00081	2465-56-7*1
5.7	Methylene	CH2 (g)	391.054	391.600	± 0.096	kJ/mol	14.02658 ± 0.00081	2465-56-7*0
5.6	1-Hydroxyethylidene	CH3COH (g, syn singlet)	69.97	59.46	± 0.86	kJ/mol	44.0526 ± 0.0017	30967-49-8*22

Most Influential reactions involving CH3OCH (g, gauche 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
0.148	3994.5	CH3OCH (g, anti singlet) + CH3COH (g, gauche triplet) → CH3OCH (g, gauche triplet) + CH3COH (g, anti singlet)	Δ_rH°(0 K) = -2.88 ± 0.85 kcal/mol	Ruscic W1RO
0.148	4006.5	CH3OCH (g, gauche triplet) + CH4 (g) → CH3OCH3 (g) + CH2 (g, triplet)	Δ_rH°(0 K) = 10.86 ± 0.85 kcal/mol	Ruscic W1RO
0.132	3994.4	CH3OCH (g, anti singlet) + CH3COH (g, gauche triplet) → CH3OCH (g, gauche triplet) + CH3COH (g, anti singlet)	Δ_rH°(0 K) = -2.67 ± 0.90 kcal/mol	Ruscic CBS-n
0.132	3994.2	CH3OCH (g, anti singlet) + CH3COH (g, gauche triplet) → CH3OCH (g, gauche triplet) + CH3COH (g, anti singlet)	Δ_rH°(0 K) = -2.67 ± 0.90 kcal/mol	Ruscic G4
0.132	3994.1	CH3OCH (g, anti singlet) + CH3COH (g, gauche triplet) → CH3OCH (g, gauche triplet) + CH3COH (g, anti singlet)	Δ_rH°(0 K) = -2.63 ± 0.90 kcal/mol	Ruscic G3X
0.132	4006.1	CH3OCH (g, gauche triplet) + CH4 (g) → CH3OCH3 (g) + CH2 (g, triplet)	Δ_rH°(0 K) = 10.30 ± 0.90 kcal/mol	Ruscic G3X
0.132	4006.2	CH3OCH (g, gauche triplet) + CH4 (g) → CH3OCH3 (g) + CH2 (g, triplet)	Δ_rH°(0 K) = 11.19 ± 0.90 kcal/mol	Ruscic G4
0.132	4006.4	CH3OCH (g, gauche triplet) + CH4 (g) → CH3OCH3 (g) + CH2 (g, triplet)	Δ_rH°(0 K) = 11.76 ± 0.90 kcal/mol	Ruscic CBS-n
0.107	3994.3	CH3OCH (g, anti singlet) + CH3COH (g, gauche triplet) → CH3OCH (g, gauche triplet) + CH3COH (g, anti singlet)	Δ_rH°(0 K) = -2.24 ± 1.0 kcal/mol	Ruscic CBS-n
0.107	4006.3	CH3OCH (g, gauche triplet) + CH4 (g) → CH3OCH3 (g) + CH2 (g, triplet)	Δ_rH°(0 K) = 11.04 ± 1.0 kcal/mol	Ruscic CBS-n

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 21^st 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. 1.124 of the Thermochemical Network, Argonne National Laboratory, Lemont, Illinois 2022; available at ATcT.anl.gov [DOI: 10.17038/CSE/1885923]
4		Y. Ren, L. Zhou, A. Mellouki, V. Daële, M. Idir, S. S. Brown, B. Ruscic, Robert S. Paton, M. R. McGillen, and A. R. Ravishankara, Reactions of NO3 with Aromatic Aldehydes: Gas-Phase Kinetics and Insights into the Mechanism of the Reaction. Atmos. Chem. Phys. 21, 13537-13551 (2021) [DOI: 10.5194/acp2021-228]
5		B. Ruscic and D. H. Bross, Active Thermochemical Tables: The Thermophysical and Thermochemical Properties of Methyl, CH3, and Methylene, CH2, Corrected for Nonrigid Rotor and Anharmonic Oscillator Effects. Mol. Phys. e1969046 (2021) [DOI: 10.1080/00268976.2021.1969046]
6		J. H. Thorpe, J. L. Kilburn, D. Feller, P. B. Changala, D. H. Bross, B. Ruscic, and J. F. Stanton, Elaborated Thermochemical Treatment of HF, CO, N2, and H2O: Insight into HEAT and Its Extensions J. Chem. Phys. 155, 184109 (2021) [DOI: 10.1063/5.0069322]
7		T. L. Nguyen, D. H. Bross, B. Ruscic, G. B. Ellison, and J. F. Stanton, Mechanism, Thermochemistry, and Kinetics of the Reversible Reactions: C2H3 + H2 ⇌ C2H4 + H ⇌ C2H5. Faraday Discuss. , (Advance Article) (2022) [DOI: 10.1039/D1FD00124H]
8		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]
9		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 [8,9]).
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.