Selected ATcT [1, 2] enthalpy of formation based on version 1.148 of the Thermochemical Network [3]

This version of ATcT results[3] was generated by additional expansion of version 1.140 to include species relevant to a recent study of the role of atmospheric methanediol[4].

Cyanoamidogen

Formula: HNCN (g, doublet)

CAS RN: 12347-01-2

ATcT ID: 12347-01-2*1

SMILES: [NH]C#N

SMILES: N=C=[N]

InChI: InChI=1S/CHN2/c2-1-3/h2H

InChIKey: RCDKZYGELCBJTH-UHFFFAOYSA-N

Hills Formula: C1H1N2

2D Image:

Aliases: HNCN; Cyanoamidogen; (Iminomethylidene)amino; Cyanoamino radical; Cyanomidyl; HN-C~N; 38150-66-2; Carbonimidoylamidogen; HN=C=N

Relative Molecular Mass: 41.03212 ± 0.00082

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
322.72	320.23	± 0.63	kJ/mol

Top contributors to the provenance of Δ_fH° of HNCN (g, doublet)

The 20 contributors listed below account only for 61.4% of the provenance of Δ_fH° of HNCN (g, doublet).
A total of 135 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
9.7	5511.2	HNCN (g, doublet) → HCN (g) + N (g, quartet)	Δ_rH°(0 K) = 277.37 ± 2.0 kJ/mol	Klippenstein 2017
9.7	5509.9	HNCN (g, doublet) → CH (g) + N2 (g)	Δ_rH°(0 K) = 271.15 ± 2.0 kJ/mol	Klippenstein 2017
7.9	5512.8	HNCN (g, doublet) → NCN (g) + H (g)	Δ_rH°(0 K) = 344.75 ± 2.0 kJ/mol	Klippenstein 2017
4.6	5509.1	HNCN (g, doublet) → CH (g) + N2 (g)	Δ_rH°(0 K) = 2.80 ± 0.03 eV	Bise 2001
4.4	5681.1	NH2CN (cr) → NH2CN (g)	Δ_rH°(298.15 K) = 75.2 ± 1.5 kJ/mol	de Wit 1983a, est unc
3.6	5539.8	HCNN (g, doublet) → HNCN (g, doublet)	Δ_rH°(0 K) = -144.27 ± 2.0 kJ/mol	Klippenstein 2017
3.3	5512.7	HNCN (g, doublet) → NCN (g) + H (g)	Δ_rH°(0 K) = 82.32 ± 0.74 kcal/mol	Puzzarini 2005, note unc2
2.4	5611.8	HC(NN) (g, 2A2) → HNCN (g, doublet)	Δ_rH°(0 K) = -168.15 ± 2.0 kJ/mol	Klippenstein 2017
1.8	5494.1	[HNCN]- (g, singlet) → HNCN (g, doublet)	Δ_rH°(0 K) = 2.622 ± 0.005 eV	Clifford 1997
1.5	5511.1	HNCN (g, doublet) → HCN (g) + N (g, quartet)	Δ_rH°(0 K) = 65.73 ± 1.2 kcal/mol	Harding 2008a, est unc
1.5	5509.7	HNCN (g, doublet) → CH (g) + N2 (g)	Δ_rH°(0 K) = 63.56 ± 1.2 kcal/mol	Harding 2008a, est unc
1.4	5544.2	HCNN (g, doublet) → HCN (g) + N (g, quartet)	Δ_rH°(0 K) = 133.10 ± 2.0 kJ/mol	Klippenstein 2017
1.4	5541.9	HCNN (g, doublet) → CH (g, doublet) + N2 (g)	Δ_rH°(0 K) = 126.88 ± 2.0 kJ/mol	Klippenstein 2017
1.3	5510.1	HNCN (g, doublet) → CH (g, quartet) + N2 (g)	Δ_rH°(0 K) = 81.01 ± 1.2 kcal/mol	Harding 2008a, est unc
1.2	5512.6	HNCN (g, doublet) → NCN (g) + H (g)	Δ_rH°(0 K) = 83.10 ± 1.2 kcal/mol	Harding 2008a, est unc
1.1	5491.6	HNCN (g, doublet) → [HNCN]+ (g, triplet)	Δ_rH°(0 K) = 10.799 ± 0.020 eV	Puzzarini 2005, note unc2
0.9	5488.6	HNCN (g, doublet) → H (g) + 2 N (g) + C (g)	Δ_rH°(0 K) = 370.0 ± 1.5 kcal/mol	Berman 2007, est unc
0.9	5488.5	HNCN (g, doublet) → H (g) + 2 N (g) + C (g)	Δ_rH°(0 K) = 369.01 ± 1.50 kcal/mol	Ruscic W1RO
0.9	5509.6	HNCN (g, doublet) → CH (g) + N2 (g)	Δ_rH°(0 K) = 64.44 ± 1.50 kcal/mol	Ruscic W1RO
0.9	5509.8	HNCN (g, doublet) → CH (g) + N2 (g)	Δ_rH°(0 K) = 65.0 ± 1.5 kcal/mol	Berman 2007, est unc

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

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	Cyanoamidogen	HNCN (g)	322.72	320.23	± 0.63	kJ/mol	41.03212 ± 0.00082	12347-01-2*0
79.1	Cyanoamidogen anion	[HNCN]- (g, singlet)	69.74	66.73	± 0.72	kJ/mol	41.03267 ± 0.00082	67131-47-9*2
79.1	Cyanoamidogen anion	[HNCN]- (g)	69.74	66.73	± 0.72	kJ/mol	41.03267 ± 0.00082	67131-47-9*0
46.4	Cyanamide	NH2CN (g)	141.61	135.60	± 0.78	kJ/mol	42.04006 ± 0.00082	420-04-2*0
36.6	Diazomethyl	HCNN (g)	467.86	465.30	± 0.68	kJ/mol	41.03212 ± 0.00082	20813-32-5*0
36.6	Diazomethyl	HCNN (g, doublet)	467.86	465.30	± 0.68	kJ/mol	41.03212 ± 0.00082	20813-32-5*1
33.6	Diazomethanide	[HCNN]- (g, singlet)	305.19	302.10	± 0.76	kJ/mol	41.03267 ± 0.00082	100840-43-5*2
33.6	Diazomethanide	[HCNN]- (g)	305.19	302.10	± 0.76	kJ/mol	41.03267 ± 0.00082	100840-43-5*0
33.3	Cyanoaminylium	[HNCN]+ (g, triplet)	1363.1	1360.8	± 1.3	kJ/mol	41.03157 ± 0.00082	205443-18-1*1
33.3	Cyanoaminylium	[HNCN]+ (g)	1363.1	1360.8	± 1.3	kJ/mol	41.03157 ± 0.00082	205443-18-1*0

Most Influential reactions involving HNCN (g, doublet)

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	5505.1	HNCN (g) → HNCN (g, doublet)	Δ_rH°(0 K) = 0 ± 0 cm-1	Ruscic W1RO, Ruscic G4, Ruscic CBS-n
0.832	5494.1	[HNCN]- (g, singlet) → HNCN (g, doublet)	Δ_rH°(0 K) = 2.622 ± 0.005 eV	Clifford 1997
0.388	5491.6	HNCN (g, doublet) → [HNCN]+ (g, triplet)	Δ_rH°(0 K) = 10.799 ± 0.020 eV	Puzzarini 2005, note unc2
0.227	5611.8	HC(NN) (g, 2A2) → HNCN (g, doublet)	Δ_rH°(0 K) = -168.15 ± 2.0 kJ/mol	Klippenstein 2017
0.134	5539.8	HCNN (g, doublet) → HNCN (g, doublet)	Δ_rH°(0 K) = -144.27 ± 2.0 kJ/mol	Klippenstein 2017
0.118	5512.8	HNCN (g, doublet) → NCN (g) + H (g)	Δ_rH°(0 K) = 344.75 ± 2.0 kJ/mol	Klippenstein 2017
0.099	5511.2	HNCN (g, doublet) → HCN (g) + N (g, quartet)	Δ_rH°(0 K) = 277.37 ± 2.0 kJ/mol	Klippenstein 2017
0.098	5509.9	HNCN (g, doublet) → CH (g) + N2 (g)	Δ_rH°(0 K) = 271.15 ± 2.0 kJ/mol	Klippenstein 2017
0.097	5491.5	HNCN (g, doublet) → [HNCN]+ (g, triplet)	Δ_rH°(0 K) = 10.789 ± 0.040 eV	Ruscic W1RO
0.064	5711.5	CH2NN (g) + HNCN (g, doublet) → HCNN (g, doublet) + NH2CN (g)	Δ_rH°(0 K) = 2.78 ± 0.9 kcal/mol	Ruscic W1RO
0.060	5507.5	HNCN (g, doublet) → HNCN (g, t-quartet)	Δ_rH°(0 K) = 27547 ± 420 cm-1	Ruscic W1RO
0.055	5572.6	HNNC (g, doublet) → HNCN (g, doublet)	Δ_rH°(0 K) = -39.88 ± 1.2 kcal/mol	Harding 2008a, est unc
0.055	5572.5	HNNC (g, doublet) → HNCN (g, doublet)	Δ_rH°(0 K) = -39.74 ± 1.2 kcal/mol	Ruscic W1RO
0.051	5684.5	NH2CN (g) + CH3NH (g) → HNCN (g, doublet) + CH3NH2 (g)	Δ_rH°(0 K) = -3.16 ± 0.85 kcal/mol	Ruscic W1RO
0.049	5512.7	HNCN (g, doublet) → NCN (g) + H (g)	Δ_rH°(0 K) = 82.32 ± 0.74 kcal/mol	Puzzarini 2005, note unc2
0.047	5509.1	HNCN (g, doublet) → CH (g) + N2 (g)	Δ_rH°(0 K) = 2.80 ± 0.03 eV	Bise 2001
0.043	5683.5	NH2CN (g) + NH2 (g) → HNCN (g, doublet) + NH3 (g)	Δ_rH°(0 K) = -10.79 ± 0.85 kcal/mol	Ruscic W1RO
0.037	5684.3	NH2CN (g) + CH3NH (g) → HNCN (g, doublet) + CH3NH2 (g)	Δ_rH°(0 K) = -4.11 ± 1.0 kcal/mol	Ruscic CBS-n
0.036	5611.6	HC(NN) (g, 2A2) → HNCN (g, doublet)	Δ_rH°(0 K) = -39.92 ± 1.2 kcal/mol	Harding 2008a, est unc
0.036	5611.5	HC(NN) (g, 2A2) → HNCN (g, doublet)	Δ_rH°(0 K) = -40.04 ± 1.2 kcal/mol	Ruscic W1RO

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. 1.148 of the Thermochemical Network (2023); available at ATcT.anl.gov
4		T. L. Nguyen, J. Peeters, J.-F. Müller, A. Perera, D. H. Bross, B. Ruscic, and J. F. Stanton, Methanediol from Cloud-Processed Formaldehyde is Only a Minor Source of Atmospheric Formic Acid Natl. Acad. Sci. 120, e2304650120/1-8 (2023) [DOI: 10.1073/pnas.2304650120]
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.