Selected ATcT [1, 2] enthalpy of formation based on version 1.156 of the Thermochemical Network [3]

This version of ATcT results[3] was generated by additional expansion of version 1.148 to include species relevant to a recent study of the oxidation of ethylene [4] as well as new measurements that led to refining the thermochemistry of CF and SiF and their cations [5].

Methyl nitrite

Formula: CH3ONO (g, trans)

CAS RN: 624-91-9

ATcT ID: 624-91-9*1

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
-52.30	-64.26	± 0.89	kJ/mol

3D Image of CH3ONO (g, trans)

spin ON spin OFF

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

The 8 contributors listed below account for 90.8% of the provenance of Δ_fH° of CH3ONO (g, trans).

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
49.6	7376.1	CH3ONO (g, cis) → CH3ONO (g, trans)	Δ_rH°(0 K) = 280 ± 80 cm-1	Rogowski 1942, Gray 1958, est unc
14.1	7376.2	CH3ONO (g, cis) → CH3ONO (g, trans)	Δ_rH°(0 K) = 190 ± 150 cm-1	Tarte 1952, Tarte 1951, Tarte 1951a, Elder 1962, Gray 1958, est unc
13.3	7375.2	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
3.5	7376.8	CH3ONO (g, cis) → CH3ONO (g, trans)	Δ_rH°(0 K) = 333 ± 300 cm-1	Ruscic W1RO
3.3	7376.5	CH3ONO (g, cis) → CH3ONO (g, trans)	Δ_rH°(0 K) = 158 ± 310 cm-1	Ruscic G4
3.2	7376.4	CH3ONO (g, cis) → CH3ONO (g, trans)	Δ_rH°(0 K) = 260 ± 315 cm-1	Ruscic G3X
2.5	7376.6	CH3ONO (g, cis) → CH3ONO (g, trans)	Δ_rH°(0 K) = 301 ± 350 cm-1	Ruscic CBS-n
1.0	7375.1	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

Top 10 species with enthalpies of formation correlated to the Δ_fH° of CH3ONO (g, trans)

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
48.5	Methyl nitrite	CH3ONO (g, cis)	-55.42	-67.20	± 0.43	kJ/mol	61.0401 ± 0.0010	624-91-9*2
48.5	Methyl nitrite	CH3ONO (g)	-55.42	-66.09	± 0.43	kJ/mol	61.0401 ± 0.0010	624-91-9*0
38.1	Methyl nitrite	CH3ONO (cr,l)		-88.65	± 0.54	kJ/mol	61.0401 ± 0.0010	624-91-9*500
20.9	Ethyl nitrite	CH3CH2ONO (g, trans-cis)	-81.14	-99.88	± 0.87	kJ/mol	75.0666 ± 0.0017	109-95-5*1
20.9	Ethyl nitrite	CH3CH2ONO (g)	-81.14	-98.54	± 0.87	kJ/mol	75.0666 ± 0.0017	109-95-5*0
12.4	Methanol	CH3OH (g)	-189.90	-200.79	± 0.13	kJ/mol	32.04186 ± 0.00090	67-56-1*0
12.1	Methanol	CH3OH (cr,l)	-235.15	-238.48	± 0.14	kJ/mol	32.04186 ± 0.00090	67-56-1*500
-9.8	Nitric acid	HON(O)O (aq, 1000 H2O)		-206.23	± 0.18	kJ/mol	63.01288 ± 0.00091	7697-37-2*839
-10.0	Nitric acid	HON(O)O (cr,l)	-178.98	-173.26	± 0.18	kJ/mol	63.01288 ± 0.00091	7697-37-2*500
-12.0	Nitric acid	HON(O)O (g)	-124.45	-134.17	± 0.17	kJ/mol	63.01288 ± 0.00091	7697-37-2*0

Most Influential reactions involving CH3ONO (g, trans)

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
0.649	7376.1	CH3ONO (g, cis) → CH3ONO (g, trans)	Δ_rH°(0 K) = 280 ± 80 cm-1	Rogowski 1942, Gray 1958, est unc
0.184	7376.2	CH3ONO (g, cis) → CH3ONO (g, trans)	Δ_rH°(0 K) = 190 ± 150 cm-1	Tarte 1952, Tarte 1951, Tarte 1951a, Elder 1962, Gray 1958, est unc
0.046	7376.8	CH3ONO (g, cis) → CH3ONO (g, trans)	Δ_rH°(0 K) = 333 ± 300 cm-1	Ruscic W1RO
0.043	7376.5	CH3ONO (g, cis) → CH3ONO (g, trans)	Δ_rH°(0 K) = 158 ± 310 cm-1	Ruscic G4
0.041	7376.4	CH3ONO (g, cis) → CH3ONO (g, trans)	Δ_rH°(0 K) = 260 ± 315 cm-1	Ruscic G3X
0.033	7376.6	CH3ONO (g, cis) → CH3ONO (g, trans)	Δ_rH°(0 K) = 301 ± 350 cm-1	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. 1.156 of the Thermochemical Network (2024); available at ATcT.anl.gov
4		N. A. Seifert, B. Ruscic, R. Sivaramakrishnan, and K. Prozument, The C2H4O Isomers in the Oxidation of Ethylene J. Mol. Spectrosc. 398, 111847/1-8 (2023) [DOI: 10.1016/j.jms.2023.111847]
5		U. Jacovella, B. Ruscic, N. L. Chen, H.-L. Le, S. Boyé-Péronne, S. Hartweg, M. Roy-Chowdhury, G. A. Garcia, J.-C. Loison, and B. Gans, Refining Thermochemical Properties of CF, SiF, and Their Cations by Combining Photoelectron Spectroscopy, Quantum Chemical Calculations, and the Active Thermochemical Tables Approach Phys. Chem. Chem. Phys. 25, 30838-30847 (2023) [DOI: 10.1039/D3CP04244H]
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]
7		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 [6] and Ruscic and Bross[7]).
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.