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].

2-Methanidylidynehydrazin-2-ium-1-ide

Formula: [HNNC]- (g, t-triplet)

CAS RN: *947408-74-4

ATcT ID: *947408-74-4*11

SMILES: [NH-][N+]#[C-]

InChI: InChI=1S/CHN2/c1-3-2/h2H/q-1

InChIKey: TUNCMFQJRYLNEA-UHFFFAOYSA-N

2D Image:

Aliases: [HNNC]-; 2-Methanidylidynehydrazin-2-ium-1-ide; Isocyanoamidogen anion; Isocyanoamidogen ion (1-); (Diazan-1-ium-2-id-1-ylidyne)methyl anion; (Diazan-1-ium-2-id-1-ylidyne)methyl ion (1-); HNNC-

Relative Molecular Mass: 41.03267 ± 0.00082

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
531.6	530.3	± 2.3	kJ/mol

3D Image of [HNNC]- (g, t-triplet)

spin ON spin OFF

Top contributors to the provenance of Δ_fH° of [HNNC]- (g, t-triplet)

The 20 contributors listed below account only for 73.8% of the provenance of Δ_fH° of [HNNC]- (g, t-triplet).
A total of 60 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
11.9	5593.5	[HNNC]- (g, c-triplet) → [HNNC]- (g, t-triplet)	Δ_rH°(0 K) = 1063 ± 300 cm-1	Ruscic W1RO
11.2	5593.4	[HNNC]- (g, c-triplet) → [HNNC]- (g, t-triplet)	Δ_rH°(0 K) = 1120 ± 310 cm-1	Ruscic CBS-n
11.2	5593.2	[HNNC]- (g, c-triplet) → [HNNC]- (g, t-triplet)	Δ_rH°(0 K) = 1057 ± 310 cm-1	Ruscic G4
10.8	5593.1	[HNNC]- (g, c-triplet) → [HNNC]- (g, t-triplet)	Δ_rH°(0 K) = 1101 ± 315 cm-1	Ruscic G3X
8.7	5593.3	[HNNC]- (g, c-triplet) → [HNNC]- (g, t-triplet)	Δ_rH°(0 K) = 1107 ± 350 cm-1	Ruscic CBS-n
2.2	5564.5	[HNNC]- (g, c-triplet) → HNNC (g, c-quartet)	Δ_rH°(0 K) = 3.262 ± 0.050 (×1.067) eV	Ruscic W1RO
1.7	5591.5	[HNNC]- (g, singlet) → [HNNC]- (g, c-triplet)	Δ_rH°(0 K) = 19569 ± 420 cm-1	Ruscic W1RO
1.6	5564.2	[HNNC]- (g, c-triplet) → HNNC (g, c-quartet)	Δ_rH°(0 K) = 3.228 ± 0.061 eV	Ruscic G4
1.5	5591.2	[HNNC]- (g, singlet) → [HNNC]- (g, c-triplet)	Δ_rH°(0 K) = 20076 ± 450 cm-1	Ruscic G4
1.5	5591.4	[HNNC]- (g, singlet) → [HNNC]- (g, c-triplet)	Δ_rH°(0 K) = 20004 ± 455 cm-1	Ruscic CBS-n
1.3	5596.5	[HNNC]- (g, c-triplet) → [HCNN]- (g, triplet)	Δ_rH°(0 K) = -9.16 ± 1.2 kcal/mol	Ruscic W1RO
1.3	5591.1	[HNNC]- (g, singlet) → [HNNC]- (g, c-triplet)	Δ_rH°(0 K) = 19880 ± 490 cm-1	Ruscic G3X
1.2	5597.5	[HNNC]- (g, c-triplet) → [HNCN]- (g, c-triplet)	Δ_rH°(0 K) = -30.15 ± 1.2 kcal/mol	Ruscic W1RO
1.1	5596.4	[HNNC]- (g, c-triplet) → [HCNN]- (g, triplet)	Δ_rH°(0 K) = -10.12 ± 1.3 kcal/mol	Ruscic CBS-n
1.1	5596.2	[HNNC]- (g, c-triplet) → [HCNN]- (g, triplet)	Δ_rH°(0 K) = -9.40 ± 1.3 kcal/mol	Ruscic G4
1.0	5597.4	[HNNC]- (g, c-triplet) → [HNCN]- (g, c-triplet)	Δ_rH°(0 K) = -31.27 ± 1.3 kcal/mol	Ruscic CBS-n
1.0	5597.2	[HNNC]- (g, c-triplet) → [HNCN]- (g, c-triplet)	Δ_rH°(0 K) = -29.85 ± 1.3 kcal/mol	Ruscic G4
0.9	5591.3	[HNNC]- (g, singlet) → [HNNC]- (g, c-triplet)	Δ_rH°(0 K) = 19471 ± 560 cm-1	Ruscic CBS-n
0.9	5596.1	[HNNC]- (g, c-triplet) → [HCNN]- (g, triplet)	Δ_rH°(0 K) = -9.16 ± 1.4 kcal/mol	Ruscic G3X
0.9	5597.1	[HNNC]- (g, c-triplet) → [HNCN]- (g, c-triplet)	Δ_rH°(0 K) = -29.93 ± 1.4 kcal/mol	Ruscic G3X

Top 10 species with enthalpies of formation correlated to the Δ_fH° of [HNNC]- (g, t-triplet)

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
67.8	2-Methanidylidynehydrazin-2-ium-1-ide	[HNNC]- (g, c-triplet)	518.6	516.1	± 1.6	kJ/mol	41.03267 ± 0.00082	947408-74-412
67.8	2-Methanidylidynehydrazin-2-ium-1-ide	[HNNC]- (g, triplet)	518.6	516.2	± 1.6	kJ/mol	41.03267 ± 0.00082	947408-74-41
31.9	1H-diazirin-3-ide	[HN(NC)]- (g, triplet)	655.2	652.1	± 2.1	kJ/mol	41.03267 ± 0.00082	735234-64-71
28.4	2-Methanidylidynehydrazin-2-ium-1-ide	[HNNC]- (g, singlet)	281.9	279.1	± 1.4	kJ/mol	41.03267 ± 0.00082	947408-74-42
28.4	2-Methanidylidynehydrazin-2-ium-1-ide	[HNNC]- (g)	281.9	279.1	± 1.4	kJ/mol	41.03267 ± 0.00082	947408-74-40
27.7	Cyanoamidogen anion	[HNCN]- (g, triplet)	391.7	389.9	± 1.8	kJ/mol	41.03267 ± 0.00082	67131-47-9*1
27.7	Cyanoamidogen anion	[HNCN]- (g, c-triplet)	391.7	389.5	± 1.8	kJ/mol	41.03267 ± 0.00082	67131-47-9*12
27.5	Diazomethanide	[HCNN]- (g, triplet)	479.7	478.3	± 1.8	kJ/mol	41.03267 ± 0.00082	100840-43-5*1
23.9	Isocyanoamidogen	HNNC (g, c-quartet)	828.2	825.4	± 1.3	kJ/mol	41.03212 ± 0.00082	947408-73-3*22
23.9	Isocyanoamidogen	HNNC (g, quartet)	828.2	825.6	± 1.3	kJ/mol	41.03212 ± 0.00082	947408-73-3*2

Most Influential reactions involving [HNNC]- (g, t-triplet)

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
0.221	5593.5	[HNNC]- (g, c-triplet) → [HNNC]- (g, t-triplet)	Δ_rH°(0 K) = 1063 ± 300 cm-1	Ruscic W1RO
0.207	5593.4	[HNNC]- (g, c-triplet) → [HNNC]- (g, t-triplet)	Δ_rH°(0 K) = 1120 ± 310 cm-1	Ruscic CBS-n
0.207	5593.2	[HNNC]- (g, c-triplet) → [HNNC]- (g, t-triplet)	Δ_rH°(0 K) = 1057 ± 310 cm-1	Ruscic G4
0.200	5593.1	[HNNC]- (g, c-triplet) → [HNNC]- (g, t-triplet)	Δ_rH°(0 K) = 1101 ± 315 cm-1	Ruscic G3X
0.162	5593.3	[HNNC]- (g, c-triplet) → [HNNC]- (g, t-triplet)	Δ_rH°(0 K) = 1107 ± 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. 1.148 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.