Selected ATcT [1, 2] enthalpy of formation based on version 1.140 of the Thermochemical Network [3]

This version of ATcT results[3] was generated by additional expansion of version 1.130 to fully include the highest-level electronic structure computations described in reference [4].

Acetonitrile

Formula: CH3CN (g)

CAS RN: 75-05-8

ATcT ID: 75-05-8*0

SMILES: CC#N

InChI: InChI=1S/C2H3N/c1-2-3/h1H3

InChIKey: WEVYAHXRMPXWCK-UHFFFAOYSA-N

Hills Formula: C2H3N1

2D Image:

Aliases: CH3CN; Acetonitrile; Methyl cyanide; Cyanomethane; Ethanenitrile; Ethyl nitrile; Methanecarbonitrile; H3CCN; H3C-C~N; MeCN; NSC 7593; UN 1648; RCRA U003

Relative Molecular Mass: 41.0520 ± 0.0016

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
81.15	74.09	± 0.24	kJ/mol

3D Image of CH3CN (g)

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Top contributors to the provenance of Δ_fH° of CH3CN (g)

The 20 contributors listed below account only for 85.3% of the provenance of Δ_fH° of CH3CN (g).
A total of 41 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
34.6	2725.1	2 CH3CN (cr,l) + 11/2 O2 (g) → 4 CO2 (g) + 3 H2O (l) + N2 (g)	Δ_rH°(298.15 K) = -2512.56 ± 0.60 kJ/mol	An 1983
22.7	2725.2	2 CH3CN (cr,l) + 11/2 O2 (g) → 4 CO2 (g) + 3 H2O (l) + N2 (g)	Δ_rH°(298.15 K) = -2512.76 ± 0.74 kJ/mol	Barnes 1976, An 1983
5.9	2724.3	CH3CN (cr,l) → CH3CN (g)	Δ_rH°(298.15 K) = 33.50 ± 0.20 kJ/mol	An 1983
5.4	2724.4	CH3CN (cr,l) → CH3CN (g)	Δ_rH°(298.15 K) = 33.45 ± 0.21 kJ/mol	Howard 1970, An 1983
4.9	2722.9	CH3CN (g) → 2 C (g) + 3 H (g) + N (g)	Δ_rH°(0 K) = 2460.19 ± 1.00 kJ/mol	Nguyen 2018
3.5	2724.2	CH3CN (cr,l) → CH3CN (g)	Δ_rH°(298.15 K) = 33.42 ± 0.26 kJ/mol	ThermoData 2004
1.6	2731.1	2 CH4 (g) + NH3 (g) → CH3NC (g) + 4 H2 (g)	Δ_rH°(0 K) = 355.35 ± 1.5 kJ/mol	Klippenstein 2017
0.9	2724.1	CH3CN (cr,l) → CH3CN (g)	Δ_rH°(298.15 K) = 33.40 ± 0.50 kJ/mol	Majer 1985
0.8	2735.6	CH2CN (g) → 2 C (g) + 2 H (g) + N (g)	Δ_rH°(0 K) = 492.78 ± 0.35 kcal/mol	Karton 2017
0.7	2740.1	2 CH4 (g) + NH3 (g) → CH2CN (g) + 9/2 H2 (g)	Δ_rH°(0 K) = 435.33 ± 1.5 kJ/mol	Klippenstein 2017
0.5	125.2	1/2 O2 (g) + H2 (g) → H2O (cr,l)	Δ_rH°(298.15 K) = -285.8261 ± 0.040 kJ/mol	Rossini 1939, Rossini 1931, Rossini 1931b, note H2Oa, Rossini 1930
0.4	2287.1	2 H2 (g) + C (graphite) → CH4 (g)	Δ_rG°(1165 K) = 37.521 ± 0.068 kJ/mol	Smith 1946, note COf, 3rd Law
0.4	2729.1	CH3CN (g) + F- (g) → CH3F (g) + [CN]- (g)	Δ_rH°(0 K) = 1.37 ± 0.8 kcal/mol	Gonzales 2003, est unc
0.3	2142.7	C (graphite) + O2 (g) → CO2 (g)	Δ_rH°(298.15 K) = -393.464 ± 0.024 kJ/mol	Hawtin 1966, note CO2e
0.3	2726.5	CH3CN (g) + HCCH (g) → HCN (g) + CH3CCH (g)	Δ_rH°(0 K) = 2.92 ± 0.85 kcal/mol	Ruscic W1RO
0.3	2727.5	CH3CN (g) + CH3CCH (g) → HCN (g) + CH3CCCH3 (g)	Δ_rH°(0 K) = 3.82 ± 0.85 kcal/mol	Ruscic W1RO
0.3	2726.4	CH3CN (g) + HCCH (g) → HCN (g) + CH3CCH (g)	Δ_rH°(0 K) = 2.66 ± 0.90 kcal/mol	Ruscic CBS-n
0.3	2726.2	CH3CN (g) + HCCH (g) → HCN (g) + CH3CCH (g)	Δ_rH°(0 K) = 2.93 ± 0.90 kcal/mol	Ruscic G4
0.3	2726.1	CH3CN (g) + HCCH (g) → HCN (g) + CH3CCH (g)	Δ_rH°(0 K) = 3.16 ± 0.90 kcal/mol	Ruscic G3X
0.3	2727.4	CH3CN (g) + CH3CCH (g) → HCN (g) + CH3CCCH3 (g)	Δ_rH°(0 K) = 4.16 ± 0.90 kcal/mol	Ruscic CBS-n

Top 10 species with enthalpies of formation correlated to the Δ_fH° of CH3CN (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
86.0	Acetonitrile	CH3CN (cr,l)		40.64	± 0.22	kJ/mol	41.0520 ± 0.0016	75-05-8*500
44.5	Isocyanomethane	CH3NC (g)	183.85	177.31	± 0.46	kJ/mol	41.0520 ± 0.0016	593-75-9*0
26.8	Cyanomethanide	[CH2CN]- (g)	113.69	110.87	± 0.53	kJ/mol	40.0446 ± 0.0016	21438-99-3*0
26.8	Cyanomethyl	CH2CN (g)	262.84	259.96	± 0.53	kJ/mol	40.0440 ± 0.0016	2932-82-3*0
23.6	Cyanomethylium	[CH2CN]+ (g)	1256.23	1253.59	± 0.61	kJ/mol	40.0435 ± 0.0016	34430-18-7*0
17.7	Isocyanomethanide	[CH2NC]- (g)	254.05	251.01	± 0.89	kJ/mol	40.0446 ± 0.0016	81704-80-5*0
15.9	Carbonic acid	C(O)(OH)2 (aq, undissoc)		-698.665	± 0.028	kJ/mol	62.0248 ± 0.0012	463-79-6*1000
13.8	Benzonitrile	C6H5CN (g)	230.03	215.84	± 0.92	kJ/mol	103.1213 ± 0.0056	100-47-0*0
13.0	Water	H2O (l)		-285.798	± 0.022	kJ/mol	18.01528 ± 0.00033	7732-18-5*590
13.0	Water	H2O (l, eq.press.)		-285.799	± 0.022	kJ/mol	18.01528 ± 0.00033	7732-18-5*589

Most Influential reactions involving CH3CN (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
0.848	5673.1	CH2NN (g) + [CH2CN]- (g) → [HCNN]- (g) + CH3CN (g)	Δ_rH°(298.15 K) = -0.40 ± 0.12 kcal/mol	Clifford 1998a
0.356	2724.3	CH3CN (cr,l) → CH3CN (g)	Δ_rH°(298.15 K) = 33.50 ± 0.20 kJ/mol	An 1983
0.342	2733.12	CH3CN (g) → CH3NC (g)	Δ_rH°(0 K) = 103.26 ± 0.7 kJ/mol	Nguyen 2018
0.323	2724.4	CH3CN (cr,l) → CH3CN (g)	Δ_rH°(298.15 K) = 33.45 ± 0.21 kJ/mol	Howard 1970, An 1983
0.210	2724.2	CH3CN (cr,l) → CH3CN (g)	Δ_rH°(298.15 K) = 33.42 ± 0.26 kJ/mol	ThermoData 2004
0.157	6806.5	C6H5NC (g) + CH3CN (g) → C6H5CN (g) + CH3NC (g)	Δ_rH°(0 K) = 2.77 ± 0.85 kcal/mol	Ruscic W1RO
0.140	6806.1	C6H5NC (g) + CH3CN (g) → C6H5CN (g) + CH3NC (g)	Δ_rH°(0 K) = 2.42 ± 0.90 kcal/mol	Ruscic G3X
0.140	6806.4	C6H5NC (g) + CH3CN (g) → C6H5CN (g) + CH3NC (g)	Δ_rH°(0 K) = 3.10 ± 0.90 kcal/mol	Ruscic CBS-n
0.140	6806.2	C6H5NC (g) + CH3CN (g) → C6H5CN (g) + CH3NC (g)	Δ_rH°(0 K) = 2.35 ± 0.90 kcal/mol	Ruscic G4
0.113	7723.5	[CH2CCN]- (g) + CH3CN (g) → CH2CHCN (g, singlet) + [CH2CN]- (g)	Δ_rH°(0 K) = 0.38 ± 0.8 kcal/mol	Ruscic W1RO
0.113	6806.3	C6H5NC (g) + CH3CN (g) → C6H5CN (g) + CH3NC (g)	Δ_rH°(0 K) = 2.64 ± 1.00 kcal/mol	Ruscic CBS-n
0.092	2734.7	CH3NC (g) + HCN (g) → CH3CN (g) + HNC (g)	Δ_rH°(0 K) = -40.9 ± 1.5 kJ/mol	Vogiatzis 2014, est unc
0.092	2734.8	CH3NC (g) + HCN (g) → CH3CN (g) + HNC (g)	Δ_rH°(0 K) = -40.97 ± 1.5 kJ/mol	Klippenstein 2017
0.092	7664.5	CH3CCN (g, singlet) + CH4 (g) → CH3CH (g, singlet) + CH3CN (g)	Δ_rH°(0 K) = 10.35 ± 0.85 kcal/mol	Ruscic W1RO
0.082	7664.4	CH3CCN (g, singlet) + CH4 (g) → CH3CH (g, singlet) + CH3CN (g)	Δ_rH°(0 K) = 11.29 ± 0.90 kcal/mol	Ruscic CBS-n
0.082	7664.2	CH3CCN (g, singlet) + CH4 (g) → CH3CH (g, singlet) + CH3CN (g)	Δ_rH°(0 K) = 10.94 ± 0.90 kcal/mol	Ruscic G4
0.082	7664.1	CH3CCN (g, singlet) + CH4 (g) → CH3CH (g, singlet) + CH3CN (g)	Δ_rH°(0 K) = 11.20 ± 0.90 kcal/mol	Ruscic G3X
0.081	7765.5	HCCN (g, triplet) + CH4 (g) → CH2 (g, triplet) + CH3CN (g)	Δ_rH°(0 K) = 13.72 ± 0.9 kcal/mol	Ruscic W1RO
0.075	2757.5	CH3NC (g) + CH2CN (g) → CH2NC (g) + CH3CN (g)	Δ_rH°(0 K) = -0.56 ± 0.85 kcal/mol	Ruscic W1RO
0.074	2733.13	CH3CN (g) → CH3NC (g)	Δ_rH°(0 K) = 103.52 ± 1.5 kJ/mol	Klippenstein 2017

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. 1.140 of the Thermochemical Network (2024); available at ATcT.anl.gov
4		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]
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.