Selected ATcT [1, 2] enthalpy of formation based on version 1.176 of the Thermochemical Network [3]

This version of ATcT results[3] was generated by additional expansion of version 1.172 to include species related to Criegee intermediates that are involved in several ongoing studies[4].

Methoxymethylene

Formula: CH3OCH (g, syn singlet)

CAS RN: 19527-10-7

ATcT ID: 19527-10-7*22

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
144.8	134.4	± 1.4	kJ/mol

3D Image of CH3OCH (g, syn singlet)

spin ON spin OFF

Top contributors to the provenance of Δ_fH° of CH3OCH (g, syn singlet)

The 20 contributors listed below account only for 89.8% of the provenance of Δ_fH° of CH3OCH (g, syn singlet).
A total of 21 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
8.3	4250.5	CH3OCH (g, anti singlet) → CH3OCH (g, syn singlet)	Δ_rH°(0 K) = 1337 ± 300 cm-1	Ruscic W1RO
7.8	4250.4	CH3OCH (g, anti singlet) → CH3OCH (g, syn singlet)	Δ_rH°(0 K) = 1372 ± 310 cm-1	Ruscic CBS-n
7.8	4250.2	CH3OCH (g, anti singlet) → CH3OCH (g, syn singlet)	Δ_rH°(0 K) = 1362 ± 310 cm-1	Ruscic G4
7.6	4250.1	CH3OCH (g, anti singlet) → CH3OCH (g, syn singlet)	Δ_rH°(0 K) = 1408 ± 315 cm-1	Ruscic G3X
6.4	4259.5	CH3OCH (g, syn singlet) → CH2CHOH (g, syn)	Δ_rH°(0 K) = -62.29 ± 1.2 kcal/mol	Ruscic W1RO
6.1	4250.3	CH3OCH (g, anti singlet) → CH3OCH (g, syn singlet)	Δ_rH°(0 K) = 1368 ± 350 cm-1	Ruscic CBS-n
5.4	4259.4	CH3OCH (g, syn singlet) → CH2CHOH (g, syn)	Δ_rH°(0 K) = -61.53 ± 1.3 kcal/mol	Ruscic CBS-n
5.4	4259.2	CH3OCH (g, syn singlet) → CH2CHOH (g, syn)	Δ_rH°(0 K) = -60.89 ± 1.3 kcal/mol	Ruscic G4
4.9	4262.5	CH3OCH (g, syn singlet) → CH3COH (g, syn singlet)	Δ_rH°(0 K) = -18.37 ± 1.2 kcal/mol	Ruscic W1RO
4.7	4259.1	CH3OCH (g, syn singlet) → CH2CHOH (g, syn)	Δ_rH°(0 K) = -61.10 ± 1.4 kcal/mol	Ruscic G3X
4.1	4262.2	CH3OCH (g, syn singlet) → CH3COH (g, syn singlet)	Δ_rH°(0 K) = -17.59 ± 1.3 kcal/mol	Ruscic G4
4.1	4262.4	CH3OCH (g, syn singlet) → CH3COH (g, syn singlet)	Δ_rH°(0 K) = -17.58 ± 1.3 kcal/mol	Ruscic CBS-n
3.6	4259.3	CH3OCH (g, syn singlet) → CH2CHOH (g, syn)	Δ_rH°(0 K) = -61.08 ± 1.6 kcal/mol	Ruscic CBS-n
3.6	4262.1	CH3OCH (g, syn singlet) → CH3COH (g, syn singlet)	Δ_rH°(0 K) = -17.45 ± 1.4 kcal/mol	Ruscic G3X
2.7	4262.3	CH3OCH (g, syn singlet) → CH3COH (g, syn singlet)	Δ_rH°(0 K) = -17.12 ± 1.6 kcal/mol	Ruscic CBS-n
1.7	4253.7	CH3OCH (g, anti singlet) → CH3CHO (g)	Δ_rH°(0 K) = -284.81 ± 2.0 kJ/mol	Klippenstein 2017
1.6	4263.6	CH3OCH (g, anti singlet) + CH4 (g) → CH3OCH3 (g) + CH2 (g, singlet)	Δ_rH°(0 K) = 199.60 ± 2.0 kJ/mol	Klippenstein 2017
1.5	4250.6	CH3OCH (g, anti singlet) → CH3OCH (g, syn singlet)	Δ_rH°(0 K) = 3.5 ± 2. kcal/mol	Dede 2012, est unc
0.9	4239.6	CH3COH (g, syn singlet) → CH3CHO (g)	Δ_rH°(0 K) = -224.37 ± 2.0 kJ/mol	Klippenstein 2017
0.8	4243.6	CH3COH (g, syn singlet) + CH2 (g, triplet) → CH3CH (g, triplet) + HCOH (g, trans)	Δ_rH°(0 K) = 12.95 ± 2.0 kJ/mol	Klippenstein 2017

Top 10 species with enthalpies of formation correlated to the Δ_fH° of CH3OCH (g, syn singlet)

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
36.1	Methoxymethylene	CH3OCH (g, anti singlet)	129.24	118.71	± 0.78	kJ/mol	44.0526 ± 0.0017	19527-10-7*21
36.1	Methoxymethylene	CH3OCH (g)	129.24	118.73	± 0.78	kJ/mol	44.0526 ± 0.0017	19527-10-7*0
36.1	Methoxymethylene	CH3OCH (g, singlet)	129.24	118.73	± 0.78	kJ/mol	44.0526 ± 0.0017	19527-10-7*2
24.1	1-Hydroxyethylidene	CH3COH (g, syn singlet)	70.07	59.56	± 0.86	kJ/mol	44.0526 ± 0.0017	30967-49-8*22
12.7	1-Hydroxyethylidene	CH3COH (g, singlet)	57.44	47.13	± 0.77	kJ/mol	44.0526 ± 0.0017	30967-49-8*2
12.7	1-Hydroxyethylidene	CH3COH (g)	57.44	47.13	± 0.77	kJ/mol	44.0526 ± 0.0017	30967-49-8*0
12.7	1-Hydroxyethylidene	CH3COH (g, anti singlet)	57.44	47.06	± 0.77	kJ/mol	44.0526 ± 0.0017	30967-49-8*21
12.6	Ethenol	CH2CHOH (g, syn)	-113.28	-124.41	± 0.37	kJ/mol	44.0526 ± 0.0017	557-75-5*1
12.6	Ethenol	CH2CHOH (g)	-113.28	-123.63	± 0.37	kJ/mol	44.0526 ± 0.0017	557-75-5*0
10.3	Ethenol	CH2CHOH (g, anti)	-108.86	-119.57	± 0.49	kJ/mol	44.0526 ± 0.0017	557-75-5*2

Most Influential reactions involving CH3OCH (g, syn singlet)

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
0.124	4250.5	CH3OCH (g, anti singlet) → CH3OCH (g, syn singlet)	Δ_rH°(0 K) = 1337 ± 300 cm-1	Ruscic W1RO
0.116	4250.4	CH3OCH (g, anti singlet) → CH3OCH (g, syn singlet)	Δ_rH°(0 K) = 1372 ± 310 cm-1	Ruscic CBS-n
0.116	4250.2	CH3OCH (g, anti singlet) → CH3OCH (g, syn singlet)	Δ_rH°(0 K) = 1362 ± 310 cm-1	Ruscic G4
0.112	4250.1	CH3OCH (g, anti singlet) → CH3OCH (g, syn singlet)	Δ_rH°(0 K) = 1408 ± 315 cm-1	Ruscic G3X
0.091	4250.3	CH3OCH (g, anti singlet) → CH3OCH (g, syn singlet)	Δ_rH°(0 K) = 1368 ± 350 cm-1	Ruscic CBS-n
0.076	4262.5	CH3OCH (g, syn singlet) → CH3COH (g, syn singlet)	Δ_rH°(0 K) = -18.37 ± 1.2 kcal/mol	Ruscic W1RO
0.069	4259.5	CH3OCH (g, syn singlet) → CH2CHOH (g, syn)	Δ_rH°(0 K) = -62.29 ± 1.2 kcal/mol	Ruscic W1RO
0.065	4262.2	CH3OCH (g, syn singlet) → CH3COH (g, syn singlet)	Δ_rH°(0 K) = -17.59 ± 1.3 kcal/mol	Ruscic G4
0.065	4262.4	CH3OCH (g, syn singlet) → CH3COH (g, syn singlet)	Δ_rH°(0 K) = -17.58 ± 1.3 kcal/mol	Ruscic CBS-n
0.059	4259.2	CH3OCH (g, syn singlet) → CH2CHOH (g, syn)	Δ_rH°(0 K) = -60.89 ± 1.3 kcal/mol	Ruscic G4
0.059	4259.4	CH3OCH (g, syn singlet) → CH2CHOH (g, syn)	Δ_rH°(0 K) = -61.53 ± 1.3 kcal/mol	Ruscic CBS-n
0.056	4262.1	CH3OCH (g, syn singlet) → CH3COH (g, syn singlet)	Δ_rH°(0 K) = -17.45 ± 1.4 kcal/mol	Ruscic G3X
0.051	4259.1	CH3OCH (g, syn singlet) → CH2CHOH (g, syn)	Δ_rH°(0 K) = -61.10 ± 1.4 kcal/mol	Ruscic G3X
0.043	4262.3	CH3OCH (g, syn singlet) → CH3COH (g, syn singlet)	Δ_rH°(0 K) = -17.12 ± 1.6 kcal/mol	Ruscic CBS-n
0.039	4259.3	CH3OCH (g, syn singlet) → CH2CHOH (g, syn)	Δ_rH°(0 K) = -61.08 ± 1.6 kcal/mol	Ruscic CBS-n
0.022	4250.6	CH3OCH (g, anti singlet) → CH3OCH (g, syn singlet)	Δ_rH°(0 K) = 3.5 ± 2. kcal/mol	Dede 2012, est unc

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. 1.176 of the Thermochemical Network (2024); available at ATcT.anl.gov
4		T. L. Nguyen et al, ongoing studies (2024)
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.