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].

Methyl nitrite

Formula: CH3ONO (g)

CAS RN: 624-91-9

ATcT ID: 624-91-9*0

SMILES: CON=O

InChI: InChI=1S/CH3NO2/c1-4-2-3/h1H3

InChIKey: BLLFVUPNHCTMSV-UHFFFAOYSA-N

Hills Formula: C1H3N1O2

2D Image:

Aliases: CH3ONO; Methyl nitrite; Nitrous acid, methyl ester; Methyl ester of nitrous acid; Nitrosyl methoxide

Relative Molecular Mass: 61.0401 ± 0.0010

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
-55.43	-66.10	± 0.43	kJ/mol

3D Image of CH3ONO (g)

spin ON spin OFF

Top contributors to the provenance of Δ_fH° of CH3ONO (g)

The 20 contributors listed below account only for 84.3% of the provenance of Δ_fH° of CH3ONO (g).
A total of 36 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
56.5	7545.2	CH3OH (g) + 2 ONO (g) → HON(O)O (g) + CH3ONO (g)	Δ_rG°(393.95 K) = -0.865 ± 0.105 kcal/mol	Silverwood 1967, 3rd Law
4.4	7545.1	CH3OH (g) + 2 ONO (g) → HON(O)O (g) + CH3ONO (g)	Δ_rH°(393.95 K) = -15.808 ± 0.376 kcal/mol	Silverwood 1967, 2nd Law
3.8	7547.6	CH3ONO (g, cis) → CH3N(O)O (g)	Δ_rH°(0 K) = -6.02 ± 2.0 kJ/mol	Klippenstein 2017
2.9	2034.1	2 ONO (g) + 1/2 O2 (g) + H2O (g) → 2 HON(O)O (g)	Δ_rG°(371 K) = -6.04 ± 0.63 kJ/mol	Jones 1943, 3rd Law
2.2	2956.2	CH3OH (g) + 3/2 O2 (g) → CO2 (g) + 2 H2O (cr,l)	Δ_rH°(298.15 K) = -182.72 ± 0.05 (×1.022) kcal/mol	Rossini 1932a, Domalski 1972, Weltner 1951, Rossini 1934a, note old units, mw conversion
1.9	1725.3	(NH4)NO3 (cr,l) → N2 (g) + 1/2 O2 (g) + 2 H2O (cr,l)	Δ_rH°(293.65 K) = -49.44 ± 0.06 kcal/mol	Becker 1934
1.3	7551.1	C (graphite) + 3/2 H2 (g) + O2 (g) + 1/2 N2 (g) → CH3ONO (cr,l)	Δ_rH°(298.15 K) = -20.329 ± 0.5 (×1.756) kcal/mol	Baldrey 1958, Gray 1958, note unc2
1.1	7549.5	CH3ONO (g, cis) + H2O (g) → CH3OH (g) + HONO (g, trans)	Δ_rH°(0 K) = 7.30 ± 0.85 kcal/mol	Ruscic W1RO
1.1	2033.1	3 ONO (g) + H2O (g) → NO (g) + 2 HON(O)O (g)	Δ_rH°(293.1 K) = -8.95 ± 0.24 kcal/mol	Forsythe 1942, Chambers 1937, Wilson 1940, apud Gurvich TPIS
1.0	7549.4	CH3ONO (g, cis) + H2O (g) → CH3OH (g) + HONO (g, trans)	Δ_rH°(0 K) = 7.48 ± 0.90 kcal/mol	Ruscic CBS-n
1.0	7549.1	CH3ONO (g, cis) + H2O (g) → CH3OH (g) + HONO (g, trans)	Δ_rH°(0 K) = 7.52 ± 0.90 kcal/mol	Ruscic G3X
1.0	7549.2	CH3ONO (g, cis) + H2O (g) → CH3OH (g) + HONO (g, trans)	Δ_rH°(0 K) = 7.02 ± 0.90 kcal/mol	Ruscic G4
1.0	7544.1	2 CH3ONO (g) + 3/2 O2 (g) → 2 CO2 (g) + 3 H2O (l) + N2 (g)	Δ_rH°(298.15 K) = -359.4 ± 1.6 (×1.269) kcal/mol	Geiseler 1961
0.8	7549.3	CH3ONO (g, cis) + H2O (g) → CH3OH (g) + HONO (g, trans)	Δ_rH°(0 K) = 7.52 ± 1.0 kcal/mol	Ruscic CBS-n
0.7	2033.4	3 ONO (g) + H2O (g) → NO (g) + 2 HON(O)O (g)	Δ_rG°(298.15 K) = 10.33 ± 1.08 (×1.164) kJ/mol	Chambers 1937, 3rd Law
0.7	1483.2	NO (g) → N (g) + O (g)	Δ_rH°(0 K) = 52400 ± 10 cm-1	Dingle 1975
0.7	1483.1	NO (g) → N (g) + O (g)	Δ_rH°(0 K) = 52400 ± 10 cm-1	Callear 1970
0.6	7547.5	CH3ONO (g, cis) → CH3N(O)O (g)	Δ_rH°(0 K) = -1.91 ± 1.2 kcal/mol	Ruscic W1RO
0.5	1483.4	NO (g) → N (g) + O (g)	Δ_rH°(0 K) = 52408 ± 10 (×1.164) cm-1	Kley 1973, Miescher 1974, est unc
0.5	7547.4	CH3ONO (g, cis) → CH3N(O)O (g)	Δ_rH°(0 K) = -1.86 ± 1.3 kcal/mol	Ruscic CBS-n

Top 10 species with enthalpies of formation correlated to the Δ_fH° of CH3ONO (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	Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units	Relative Molecular Mass	ATcT ID
100.0	Methyl nitrite	CH3ONO (g, cis)	-55.43	-67.21	± 0.43	kJ/mol	61.0401 ± 0.0010	624-91-9*2
78.6	Methyl nitrite	CH3ONO (cr,l)		-88.66	± 0.54	kJ/mol	61.0401 ± 0.0010	624-91-9*500
48.5	Methyl nitrite	CH3ONO (g, trans)	-52.31	-64.27	± 0.89	kJ/mol	61.0401 ± 0.0010	624-91-9*1
43.1	Ethyl nitrite	CH3CH2ONO (g, trans-cis)	-81.16	-99.90	± 0.87	kJ/mol	75.0666 ± 0.0017	109-95-5*1
43.1	Ethyl nitrite	CH3CH2ONO (g)	-81.16	-98.56	± 0.87	kJ/mol	75.0666 ± 0.0017	109-95-5*0
25.7	Methanol	CH3OH (g)	-189.91	-200.80	± 0.14	kJ/mol	32.04186 ± 0.00090	67-56-1*0
25.1	Methanol	CH3OH (cr,l)	-235.16	-238.50	± 0.14	kJ/mol	32.04186 ± 0.00090	67-56-1*500
-20.4	Nitric acid	HON(O)O (aq, 1000 H2O)		-206.23	± 0.18	kJ/mol	63.01288 ± 0.00091	7697-37-2*839
-20.6	Nitric acid	HON(O)O (cr,l)	-178.99	-173.26	± 0.18	kJ/mol	63.01288 ± 0.00091	7697-37-2*500
-24.8	Nitric acid	HON(O)O (g)	-124.46	-134.17	± 0.17	kJ/mol	63.01288 ± 0.00091	7697-37-2*0

Most Influential reactions involving CH3ONO (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
1.000	7543.1	CH3ONO (g) → CH3ONO (g, cis)	Δ_rH°(0 K) = 0 ± 0 cm-1	Ruscic G3X, Ruscic CBS-n, Ruscic W1RO, Ruscic G4
0.991	7550.1	CH3ONO (cr,l) → CH3ONO (g)	Δ_rH°(298.15 K) = 5.40 ± 0.08 kcal/mol	Baldrey 1958, Gray 1958, note unc2
0.770	7545.2	CH3OH (g) + 2 ONO (g) → HON(O)O (g) + CH3ONO (g)	Δ_rG°(393.95 K) = -0.865 ± 0.105 kcal/mol	Silverwood 1967, 3rd Law
0.060	7545.1	CH3OH (g) + 2 ONO (g) → HON(O)O (g) + CH3ONO (g)	Δ_rH°(393.95 K) = -15.808 ± 0.376 kcal/mol	Silverwood 1967, 2nd Law
0.010	7544.1	2 CH3ONO (g) + 3/2 O2 (g) → 2 CO2 (g) + 3 H2O (l) + N2 (g)	Δ_rH°(298.15 K) = -359.4 ± 1.6 (×1.269) kcal/mol	Geiseler 1961
0.004	7559.1	CH3CH2ONO (g) + CH3O (g) → CH3CH2O (g) + CH3ONO (g)	Δ_rH°(500 K) = 1.3 ± 3 kcal/mol	Steacie 1937, Rebbert 1952, 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.