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]

Nitrilomethyl

Formula: CN (g)

CAS RN: 2074-87-5

ATcT ID: 2074-87-5*0

SMILES: [C]#N

InChI: InChI=1S/CN/c1-2

InChIKey: JEVCWSUVFOYBFI-UHFFFAOYSA-N

Hills Formula: C1N1

2D Image:

Aliases: CN; Nitrilomethyl; Cyano radical; Cyano; Cyanide radical; Monocyanogen; Cyanogen radical; Cyanogen; Carbon mononitride; Carbon nitride; Carbon nitride radical; Nitrile; Carbonitrile; 15808-32-9; 211750-61-7

Relative Molecular Mass: 26.01744 ± 0.00080

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
436.73	440.02	± 0.14	kJ/mol

3D Image of CN (g)

spin ON spin OFF

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

The 20 contributors listed below account only for 43.6% of the provenance of Δ_fH° of CN (g).
A total of 189 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
5.2	2660.1	[CN]- (g) → CN (g)	Δ_rH°(0 K) = 3.862 ± 0.004 eV	Bradforth 1993
4.5	2735.12	HCN (g) → CN (g) + H (g)	Δ_rH°(0 K) = 43729 ± 35 cm-1	Makhnev 2018
4.5	2657.4	CN (g) → C (g) + N (g)	Δ_rH°(0 K) = 744.81 ± 0.56 kJ/mol	Harding 2008
3.6	2656.8	CN (g) → C (g) + N (g)	Δ_rH°(0 K) = 178.18 ± 0.15 kcal/mol	Karton 2008
2.8	2657.2	CN (g) → C (g) + N (g)	Δ_rH°(0 K) = 745.90 ± 0.70 kJ/mol	Harding 2008
2.3	2661.6	[CN]- (g) → CN (g)	Δ_rH°(0 K) = 3.867 ± 0.006 eV	Feller 2016, note unc2
2.0	2655.11	CN (g) → C (g) + N (g)	Δ_rH°(0 K) = 178.20 ± 0.20 kcal/mol	Feller 2014
2.0	2657.5	CN (g) → C (g) + N (g)	Δ_rH°(0 K) = 745.40 ± 0.84 kJ/mol	Harding 2008
1.6	2736.11	HCN (g) → CN (g) + H (g)	Δ_rH°(0 K) = 523.78 ± 0.56 (×1.242) kJ/mol	Harding 2008
1.6	2736.9	HCN (g) → CN (g) + H (g)	Δ_rH°(0 K) = 522.84 ± 0.70 kJ/mol	Harding 2008
1.6	2657.3	CN (g) → C (g) + N (g)	Δ_rH°(0 K) = 744.33 ± 0.74 (×1.269) kJ/mol	Harding 2008
1.5	2657.7	CN (g) → C (g) + N (g)	Δ_rH°(0 K) = 744.30 ± 0.84 (×1.139) kJ/mol	Harding 2008
1.4	2666.7	CN (g) + HCCH (g) → CCH (g) + HCN (g)	Δ_rH°(0 K) = 6.74 ± 0.15 kcal/mol	Martin 2006, Karton 2006
1.3	2736.10	HCN (g) → CN (g) + H (g)	Δ_rH°(0 K) = 523.84 ± 0.74 (×1.022) kJ/mol	Harding 2008
1.3	2667.1	2 CN (g) → N2 (g) + C2 (g)	Δ_rH°(0 K) = -12.78 ± 0.50 kcal/mol	Feller 2014
1.2	2656.7	CN (g) → C (g) + N (g)	Δ_rH°(0 K) = 178.22 ± 0.25 kcal/mol	Martin 2006
1.1	2666.9	CN (g) + HCCH (g) → CCH (g) + HCN (g)	Δ_rH°(0 K) = 28.10 ± 0.70 kJ/mol	Harding 2008
1.1	2735.2	HCN (g) → CN (g) + H (g)	Δ_rH°(0 K) = 43710 ± 70 cm-1	Cook 2000
1.1	2736.12	HCN (g) → CN (g) + H (g)	Δ_rH°(0 K) = 522.69 ± 0.84 kJ/mol	Harding 2008
1.1	2736.14	HCN (g) → CN (g) + H (g)	Δ_rH°(0 K) = 523.62 ± 0.84 kJ/mol	Harding 2008

Top 10 species with enthalpies of formation correlated to the Δ_fH° of CN (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
49.1	Hydrogen cyanide	HCN (g)	129.678	129.294	± 0.089	kJ/mol	27.02538 ± 0.00081	74-90-8*0
49.1	Hydrogen cyanide anion	[HCN]- (g)	129.527	129.048	± 0.089	kJ/mol	27.02593 ± 0.00081	12334-27-9*0
47.8	Cyanide	[CN]- (g)	63.974	67.260	± 0.093	kJ/mol	26.01799 ± 0.00080	57-12-5*0
29.6	Ethynyl	CCH (g)	563.76	567.88	± 0.15	kJ/mol	25.0293 ± 0.0016	2122-48-7*0
28.1	Cyanogen	NCCN (g)	308.17	310.12	± 0.41	kJ/mol	52.0349 ± 0.0016	460-19-5*0
27.8	Cyanogen	NCCN (cr,l)	273.93	289.18	± 0.42	kJ/mol	52.0349 ± 0.0016	460-19-5*500
27.4	Cyanogen cation	[NCCN]+ (g)	1598.24	1600.45	± 0.42	kJ/mol	52.0343 ± 0.0016	37354-81-7*0
27.0	Nitrilomethylium	[CN]+ (g)	1783.13	1786.61	± 0.48	kJ/mol	26.01689 ± 0.00080	12539-57-0*0
26.9	Carbon	C (g)	711.404	716.889	± 0.044	kJ/mol	12.01070 ± 0.00080	7440-44-0*0
26.9	Carbon	C (g, triplet)	711.404	716.889	± 0.044	kJ/mol	12.01070 ± 0.00080	7440-44-0*1

Most Influential reactions involving CN (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
0.692	2812.1	[ICN]- (g) → I (g, 2P3/2) + CN (g)	Δ_rH°(0 K) = 4.69 ± 0.10 eV	Miller 2012, est unc
0.495	2659.10	CN (g) → [CN]+ (g)	Δ_rH°(0 K) = 321.757 ± 0.157 kcal/mol	Feller 2017a
0.469	2659.1	CN (g) → [CN]+ (g)	Δ_rH°(0 K) = 13.956 ± 0.007 eV	Gans 2017a
0.452	2808.2	ICN (g) → I (g) + CN (g)	Δ_rH°(0 K) = 26980 ± 200 cm-1	Costen 1999, note unc2
0.222	7442.1	CN (g) + SiH4 (g) → HCN (g) + SiH3 (g)	Δ_rH°(0 K) = -34.60 ± 0.30 kcal/mol	Burke 2021
0.137	2767.12	ClCN (g) → Cl (g) + CN (g)	Δ_rH°(0 K) = 100.55 ± 0.30 kcal/mol	Martin 2006, Karton 2006
0.096	2660.1	[CN]- (g) → CN (g)	Δ_rH°(0 K) = 3.862 ± 0.004 eV	Bradforth 1993
0.082	7323.6	NCNNN (g) → CN (g) + NNN (g)	Δ_rH°(0 K) = 4.011 ± 0.065 eV	Ruscic W1RO
0.079	2735.12	HCN (g) → CN (g) + H (g)	Δ_rH°(0 K) = 43729 ± 35 cm-1	Makhnev 2018
0.077	2767.11	ClCN (g) → Cl (g) + CN (g)	Δ_rH°(0 K) = 100.37 ± 0.40 kcal/mol	Martin 2006, Karton 2006
0.074	2789.1	BrCN (g) → Br (g) + CN (g)	Δ_rH°(0 K) = 3.77 ± 0.05 eV	Davis 1968
0.072	7323.3	NCNNN (g) → CN (g) + NNN (g)	Δ_rH°(0 K) = 4.015 ± 0.069 eV	Ruscic G4
0.072	7323.5	NCNNN (g) → CN (g) + NNN (g)	Δ_rH°(0 K) = 3.992 ± 0.069 eV	Ruscic CBS-n
0.072	2808.1	ICN (g) → I (g) + CN (g)	Δ_rH°(0 K) = 26580 ± 500 cm-1	Nadler 1985
0.063	2727.4	NCCN (g) → 2 CN (g)	Δ_rH°(0 K) = 134.96 ± 0.40 kcal/mol	Martin 2006
0.063	2727.3	NCCN (g) → 2 CN (g)	Δ_rH°(0 K) = 134.76 ± 0.40 kcal/mol	Martin 2006
0.061	7323.2	NCNNN (g) → CN (g) + NNN (g)	Δ_rH°(0 K) = 3.998 ± 0.075 eV	Ruscic G3X
0.056	2726.1	NCCN (g) → 2 CN (g)	Δ_rH°(0 K) = 47108 ± 50 (×2.954) cm-1	Huang 1992
0.054	5175.3	NCN (g) + H (g) → NH (g) + CN (g)	Δ_rH°(0 K) = 128.49 ± 2.0 kJ/mol	Klippenstein 2017
0.052	2657.4	CN (g) → C (g) + N (g)	Δ_rH°(0 K) = 744.81 ± 0.56 kJ/mol	Harding 2008

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.