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]

Diazene anion

Formula: [HNNH]- (g, trans-cis equilib)

CAS RN: 100429-75-2

ATcT ID: 100429-75-2*1

SMILES: N=[NH-]

InChI: InChI=1S/H2N2/c1-2/h1-2H/q-1

InChIKey: YPQDUMCQFFJGOA-UHFFFAOYSA-N

Hills Formula: H2N2-

2D Image:

Aliases: [HNNH]-; Diazene anion; Diazene ion (1-); Diimide anion; Diimide ion (1-); Diimine anion; Diimine ion (1-); HNNH- g, trans-cis-iso equilib; HNNH- g,trans-cis-iso equilib; [HNNH]- g, trans-cis-iso equilib; [HNNH]- g,trans-cis-iso equilib; N2H2- g, trans-cis-iso equilib; N2H2- g,trans-cis-iso equilib; [N2H2]- g, trans-cis-iso equilib; [N2H2]- g,trans-cis-iso equilib; HNNH- g, trans-cis equilib; HNNH- g,trans-cis equilib; [HNNH]- g, trans-cis equilib; [HNNH]- g,trans-cis equilib; N2H2- g, trans-cis equilib; N2H2- g,trans-cis equilib; [N2H2]- g, trans-cis equilib; [N2H2]- g,trans-cis equilib

Relative Molecular Mass: 30.02991 ± 0.00020

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
265.5	258.7	± 2.0	kJ/mol

3D Image of [HNNH]- (g, trans-cis equilib)

spin ON spin OFF

Top contributors to the provenance of Δ_fH° of [HNNH]- (g, trans-cis equilib)

The 20 contributors listed below account only for 88.2% of the provenance of Δ_fH° of [HNNH]- (g, trans-cis equilib).
A total of 22 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
15.7	1764.8	[HNNH]- (g, trans) → HNNH (g, trans)	Δ_rH°(0 K) = -0.592 ± 0.050 eV	Ruscic W1RO
10.5	1764.4	[HNNH]- (g, trans) → HNNH (g, trans)	Δ_rH°(0 K) = -0.608 ± 0.061 eV	Ruscic G4
8.0	1770.8	[HNNH]- (g, cis) → HNNH (g, cis)	Δ_rH°(0 K) = -0.516 ± 0.050 eV	Ruscic W1RO
6.2	1779.8	[NNH2]- (g) → NNH2 (g)	Δ_rH°(0 K) = -0.732 ± 0.050 eV	Ruscic W1RO
5.4	1764.3	[HNNH]- (g, trans) → HNNH (g, trans)	Δ_rH°(0 K) = -0.644 ± 0.085 eV	Ruscic G3X
5.4	1770.4	[HNNH]- (g, cis) → HNNH (g, cis)	Δ_rH°(0 K) = -0.535 ± 0.061 eV	Ruscic G4
4.8	1764.7	[HNNH]- (g, trans) → HNNH (g, trans)	Δ_rH°(0 K) = -0.593 ± 0.090 eV	Ruscic CBS-n
4.6	1764.6	[HNNH]- (g, trans) → HNNH (g, trans)	Δ_rH°(0 K) = -0.598 ± 0.092 eV	Ruscic CBS-n
4.1	1779.4	[NNH2]- (g) → NNH2 (g)	Δ_rH°(0 K) = -0.752 ± 0.061 eV	Ruscic G4
2.7	1770.3	[HNNH]- (g, cis) → HNNH (g, cis)	Δ_rH°(0 K) = -0.569 ± 0.085 eV	Ruscic G3X
2.4	1770.7	[HNNH]- (g, cis) → HNNH (g, cis)	Δ_rH°(0 K) = -0.518 ± 0.090 eV	Ruscic CBS-n
2.3	1770.6	[HNNH]- (g, cis) → HNNH (g, cis)	Δ_rH°(0 K) = -0.526 ± 0.092 eV	Ruscic CBS-n
2.1	1779.3	[NNH2]- (g) → NNH2 (g)	Δ_rH°(0 K) = -0.810 ± 0.085 eV	Ruscic G3X
2.0	1800.8	[HNNH]- (g, trans) → [HNNH]- (g, cis)	Δ_rH°(0 K) = 1158 ± 300 cm-1	Ruscic W1RO
1.9	1800.7	[HNNH]- (g, trans) → [HNNH]- (g, cis)	Δ_rH°(0 K) = 1214 ± 310 cm-1	Ruscic CBS-n
1.9	1800.4	[HNNH]- (g, trans) → [HNNH]- (g, cis)	Δ_rH°(0 K) = 1210 ± 310 cm-1	Ruscic G4
1.9	1779.7	[NNH2]- (g) → NNH2 (g)	Δ_rH°(0 K) = -0.782 ± 0.090 eV	Ruscic CBS-n
1.8	1800.3	[HNNH]- (g, trans) → [HNNH]- (g, cis)	Δ_rH°(0 K) = 1268 ± 315 cm-1	Ruscic G3X
1.8	1801.8	[HNNH]- (g, trans) → [NNH2]- (g)	Δ_rH°(0 K) = 9424 ± 420 cm-1	Ruscic W1RO
1.8	1779.6	[NNH2]- (g) → NNH2 (g)	Δ_rH°(0 K) = -0.824 ± 0.092 eV	Ruscic CBS-n

Top 10 species with enthalpies of formation correlated to the Δ_fH° of [HNNH]- (g, trans-cis equilib)

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	Image	Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units	Relative Molecular Mass	ATcT ID
100.0	(E)-Diazene anion	[HNNH]- (g, trans)		265.5	258.7	± 2.0	kJ/mol	30.02991 ± 0.00020	59952-06-60
100.0	Diazene anion	[HNNH]- (g, trans-cis-iso equilib)		265.5	258.7	± 2.0	kJ/mol	30.02991 ± 0.00020	100429-75-2*0
73.7	(Z)-Diazene anion	[HNNH]- (g, cis)	$[H]/N=[N-]\[H]$	280.0	273.3	± 2.0	kJ/mol	30.02991 ± 0.00020	86631-37-00
62.6	Isodiazene anion	[NNH2]- (g)		380.9	374.1	± 2.1	kJ/mol	30.02991 ± 0.00020	63986-30-10
16.7	Diazene	HNNH (g, trans-cis equilib)		207.12	199.98	± 0.41	kJ/mol	30.02936 ± 0.00020	3618-05-1*1
16.7	Diazene	HNNH (g, trans-cis-iso equilib)		207.12	199.98	± 0.41	kJ/mol	30.02936 ± 0.00020	3618-05-1*0
16.7	(E)-Diazene	HNNH (g, trans)		207.12	199.98	± 0.41	kJ/mol	30.02936 ± 0.00020	15626-43-4*0
15.4	(Z)-Diazene	HNNH (g, cis)	$[H]/N=N\[H]$	228.83	221.69	± 0.63	kJ/mol	30.02936 ± 0.00020	15626-42-3*0
14.9	Isodiazene	NNH2 (g)		307.54	300.46	± 0.63	kJ/mol	30.02936 ± 0.00020	28647-38-3*0
10.1	(E)-Diazene cation	[HNNH]+ (g, trans)		1132.49	1125.55	± 0.64	kJ/mol	30.02881 ± 0.00020	59952-06-6*0

Most Influential reactions involving [HNNH]- (g, trans-cis equilib)

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	1799.1	[HNNH]- (g, trans-cis equilib) → [HNNH]- (g, trans)	Δ_rH°(0 K) = 0 ± 0 cm-1	triv, Ruscic G3B3

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.