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]

Methyl nitrite

Formula: CH3ONO (cr,l)

CAS RN: 624-91-9

ATcT ID: 624-91-9*500

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
	-88.77	± 0.56	kJ/mol

Top contributors to the provenance of Δ_fH° of CH3ONO (cr,l)

The 20 contributors listed below account only for 88.2% of the provenance of Δ_fH° of CH3ONO (cr,l).
A total of 26 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
36.2	6605.2	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
35.1	6610.1	CH3ONO (cr,l) → CH3ONO (g)	Δ_rH°(298.15 K) = 5.40 ± 0.08 kcal/mol	Baldrey 1958, Gray 1958, note unc2
2.8	6605.1	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
2.1	6611.1	C (graphite) + 3/2 H2 (g) + O2 (g) + 1/2 N2 (g) → CH3ONO (cr,l)	Δ_rH°(298.15 K) = -20.329 ± 0.5 (×1.795) kcal/mol	Baldrey 1958, Gray 1958, note unc2
1.9	1973.1	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
1.2	1662.3	(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
0.9	2823.2	CH3OH (g) + 3/2 O2 (g) → CO2 (g) + 2 H2O (cr,l)	Δ_rH°(298.15 K) = -182.72 ± 0.05 (×1.719) kcal/mol	Rossini 1932a, Domalski 1972, Weltner 1951, Rossini 1934a, note old units, mw conversion
0.7	1972.1	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
0.7	6609.5	CH3ONO (g, cis) + H2O (g) → CH3OH (g) + HONO (g, trans)	Δ_rH°(0 K) = 7.30 ± 0.85 kcal/mol	Ruscic W1RO
0.7	6604.1	2 CH3ONO (g) + 3/2 O2 (g) → 2 CO2 (g) + 3 H2O (l) + N2 (g)	Δ_rH°(298.15 K) = -359.4 ± 1.6 (×1.242) kcal/mol	Geiseler 1961
0.6	6609.1	CH3ONO (g, cis) + H2O (g) → CH3OH (g) + HONO (g, trans)	Δ_rH°(0 K) = 7.52 ± 0.90 kcal/mol	Ruscic G3X
0.6	6609.2	CH3ONO (g, cis) + H2O (g) → CH3OH (g) + HONO (g, trans)	Δ_rH°(0 K) = 7.02 ± 0.90 kcal/mol	Ruscic G4
0.6	6609.4	CH3ONO (g, cis) + H2O (g) → CH3OH (g) + HONO (g, trans)	Δ_rH°(0 K) = 7.48 ± 0.90 kcal/mol	Ruscic CBS-n
0.5	6609.3	CH3ONO (g, cis) + H2O (g) → CH3OH (g) + HONO (g, trans)	Δ_rH°(0 K) = 7.52 ± 1.0 kcal/mol	Ruscic CBS-n
0.5	1972.4	3 ONO (g) + H2O (g) → NO (g) + 2 HON(O)O (g)	Δ_rG°(298.15 K) = 10.33 ± 1.08 (×1.114) kJ/mol	Chambers 1937, 3rd Law
0.5	1425.2	NO (g) → N (g) + O (g)	Δ_rH°(0 K) = 52400 ± 10 cm-1	Dingle 1975
0.5	1425.1	NO (g) → N (g) + O (g)	Δ_rH°(0 K) = 52400 ± 10 cm-1	Callear 1970
0.4	2873.1	[CH2OH]+ (g) → CH2O (g) + H+ (g)	Δ_rH°(0 K) = 704.98 ± 0.39 kJ/mol	Czako 2009
0.4	6607.5	CH3ONO (g, cis) → CH3N(O)O (g)	Δ_rH°(0 K) = -1.91 ± 1.2 kcal/mol	Ruscic W1RO
0.3	6607.4	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 (cr,l)

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
79.7	Methyl nitrite	CH3ONO (g)	-55.54	-66.21	± 0.45	kJ/mol	61.0401 ± 0.0010	624-91-9*0
79.7	Methyl nitrite	CH3ONO (g, cis)	-55.54	-67.32	± 0.45	kJ/mol	61.0401 ± 0.0010	624-91-9*2
39.7	Methyl nitrite	CH3ONO (g, trans)	-52.43	-64.38	± 0.89	kJ/mol	61.0401 ± 0.0010	624-91-9*1
35.0	Ethyl nitrite	CH3CH2ONO (g, trans-cis)	-81.29	-100.02	± 0.87	kJ/mol	75.0666 ± 0.0017	109-95-5*1
35.0	Ethyl nitrite	CH3CH2ONO (g)	-81.29	-98.69	± 0.87	kJ/mol	75.0666 ± 0.0017	109-95-5*0
23.6	Methanol	CH3OH (g)	-190.04	-200.92	± 0.15	kJ/mol	32.04186 ± 0.00090	67-56-1*0
23.1	Methanol	CH3OH (cr,l)	-235.28	-238.62	± 0.16	kJ/mol	32.04186 ± 0.00090	67-56-1*500
16.9	Hydroxymethylium	[CH2OH]+ (g)	717.67	709.73	± 0.19	kJ/mol	31.03337 ± 0.00088	18682-95-6*0
-16.7	Nitric acid	HON(O)O (cr,l)	-178.99	-173.27	± 0.18	kJ/mol	63.01288 ± 0.00091	7697-37-2*500
-20.0	Nitric acid	HON(O)O (g)	-124.47	-134.18	± 0.18	kJ/mol	63.01288 ± 0.00091	7697-37-2*0

Most Influential reactions involving CH3ONO (cr,l)

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
0.992	6610.1	CH3ONO (cr,l) → CH3ONO (g)	Δ_rH°(298.15 K) = 5.40 ± 0.08 kcal/mol	Baldrey 1958, Gray 1958, note unc2
0.021	6611.1	C (graphite) + 3/2 H2 (g) + O2 (g) + 1/2 N2 (g) → CH3ONO (cr,l)	Δ_rH°(298.15 K) = -20.329 ± 0.5 (×1.795) kcal/mol	Baldrey 1958, Gray 1958, note unc2

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.