Selected ATcT [1, 2] enthalpy of formation based on version 1.122e of the Thermochemical Network [3]

This version of ATcT results was generated from an expansion of version 1.122d [4] to include chemical species related to methyl acetate and methyl formate [5].

Species Name	Formula	Image	Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units	Relative Molecular Mass	ATcT ID
Cyanoamidogen anion	[NCN]- (g)		210.92	210.93	± 0.77	kJ/mol	40.02473 ± 0.00081	189879-95-6*0

Representative Geometry of [NCN]- (g)

spin ON spin OFF

Top contributors to the provenance of Δ_fH° of [NCN]- (g)

The 20 contributors listed below account only for 87.4% of the provenance of Δ_fH° of [NCN]- (g).
A total of 25 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
18.9	3984.1	[NCN]- (g) → NCN (g)	Δ_rH°(0 K) = 2.484 ± 0.006 eV	Clifford 1997
10.6	3984.2	[NCN]- (g) → NCN (g)	Δ_rH°(0 K) = 2.481 ± 0.008 eV	Taylor 1999
9.3	3982.8	NCN (g) → 2 N (g) + C (g)	Δ_rH°(0 K) = 287.49 ± 0.4 kcal/mol	Klippenstein 2014, Klippenstein 2014
5.9	3992.8	NCN (g) + H (g) → CH (g) + N2 (g)	Δ_rH°(0 K) = -17.52 ± 0.5 kcal/mol	Klippenstein 2014, Klippenstein 2014
5.9	3994.2	NCN (g) + H (g) → HCN (g) + N (g)	Δ_rH°(0 K) = -15.86 ± 0.5 kcal/mol	Klippenstein 2014, Klippenstein 2014
5.8	3995.2	NCN (g) + H (g) → NH (g) + CN (g)	Δ_rH°(0 K) = 30.78 ± 0.5 kcal/mol	Klippenstein 2014, Klippenstein 2014
5.5	3987.6	NCN (g) + 2 HCCH (g) → HCCCH (g) + 2 HCN (g)	Δ_rH°(0 K) = -25.40 ± 0.4 kcal/mol	Klippenstein 2014, Klippenstein 2014
5.0	3993.2	NCN (g) + H (g) → CH (g, quartet) + N2 (g)	Δ_rH°(0 K) = -0.25 ± 0.5 kcal/mol	Klippenstein 2014, Klippenstein 2014
4.5	3988.9	NCN (g) → N2 (g) + C (g, triplet)	Δ_rH°(0 K) = 2.712 ± 0.025 eV	Klippenstein 2014, Klippenstein 2014
4.4	3990.9	NCN (g) → CN (g) + N (g)	Δ_rH°(0 K) = 4.732 ± 0.025 eV	Klippenstein 2014, Klippenstein 2014
1.7	3984.9	[NCN]- (g) → NCN (g)	Δ_rH°(0 K) = 2.475 ± 0.020 eV	Klippenstein 2014
1.6	3992.2	NCN (g) + H (g) → CH (g) + N2 (g)	Δ_rH°(1700 K) = -86.4 ± 4 kJ/mol	Fassheber 2014, 2nd Law
1.6	3992.1	NCN (g) + H (g) → CH (g) + N2 (g)	Δ_rG°(1700 K) = -112.2 ± 4 kJ/mol	Fassheber 2014, 3rd Law
1.4	3986.6	[NCN]- (g) → 2 N (g) + C (g)	Δ_rH°(0 K) = 343.79 ± 1.50 kcal/mol	Ruscic W1RO
0.8	3987.4	NCN (g) + 2 HCCH (g) → HCCCH (g) + 2 HCN (g)	Δ_rH°(0 K) = -25.42 ± 1.0 kcal/mol	Ruscic CBS-n
0.8	3987.2	NCN (g) + 2 HCCH (g) → HCCCH (g) + 2 HCN (g)	Δ_rH°(0 K) = -25.10 ± 1.0 kcal/mol	Ruscic G4
0.7	3987.1	NCN (g) + 2 HCCH (g) → HCCCH (g) + 2 HCN (g)	Δ_rH°(0 K) = -24.51 ± 1.1 kcal/mol	Ruscic G3X
0.7	3986.4	[NCN]- (g) → 2 N (g) + C (g)	Δ_rH°(0 K) = 344.80 ± 2.16 kcal/mol	Ruscic CBS-n
0.7	3987.5	NCN (g) + 2 HCCH (g) → HCCCH (g) + 2 HCN (g)	Δ_rH°(0 K) = -26.28 ± 0.9 (×1.242) kcal/mol	Ruscic W1RO
0.6	3988.8	NCN (g) → N2 (g) + C (g, triplet)	Δ_rH°(0 K) = 2.693 ± 0.065 eV	Ruscic W1RO

Top 10 species with enthalpies of formation correlated to the Δ_fH° of [NCN]- (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
81.6	Methanetetraylbisamidogen	NCN (g)	450.42	450.83	± 0.64	kJ/mol	40.02418 ± 0.00081	2669-76-3*0
18.2	Propynylidene	HCCCH (g)	543.41	546.41	± 0.64	kJ/mol	38.0480 ± 0.0024	67152-18-5*0
18.2	Propynylidene	HCCCH (g, triplet)	543.41	546.41	± 0.64	kJ/mol	38.0480 ± 0.0024	67152-18-5*1
16.6	Cyanoaminyliumyl	[NCN]+ (g)	1671.6	1672.9	± 2.6	kJ/mol	40.02363 ± 0.00081	316122-03-9*0
8.3	Propynylidene	HCCCH (g, trans singlet)	597.4	599.2	± 1.1	kJ/mol	38.0480 ± 0.0024	67152-18-5*4
8.0	Methylidyne	CH (g, quartet)	664.55	667.89	± 0.59	kJ/mol	13.01864 ± 0.00080	3315-37-5*2
7.1	Propynylidene	HCCCH (g, cis singlet)	597.6	599.4	± 1.3	kJ/mol	38.0480 ± 0.0024	67152-18-5*3
7.1	Propynylidene	HCCCH (g, singlet)	597.6	599.4	± 1.3	kJ/mol	38.0480 ± 0.0024	67152-18-5*2
6.8	Propynylidene cation	[HCCCH]+ (g)	1410.8	1413.4	± 1.3	kJ/mol	38.0474 ± 0.0024	75123-91-0*0
6.7	Hydrogen cyanide	HCN (g)	129.661	129.277	± 0.090	kJ/mol	27.02538 ± 0.00081	74-90-8*0

Most Influential reactions involving [NCN]- (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
0.587	3984.1	[NCN]- (g) → NCN (g)	Δ_rH°(0 K) = 2.484 ± 0.006 eV	Clifford 1997
0.330	3984.2	[NCN]- (g) → NCN (g)	Δ_rH°(0 K) = 2.481 ± 0.008 eV	Taylor 1999
0.052	3984.9	[NCN]- (g) → NCN (g)	Δ_rH°(0 K) = 2.475 ± 0.020 eV	Klippenstein 2014
0.015	3986.6	[NCN]- (g) → 2 N (g) + C (g)	Δ_rH°(0 K) = 343.79 ± 1.50 kcal/mol	Ruscic W1RO
0.008	3984.8	[NCN]- (g) → NCN (g)	Δ_rH°(0 K) = 2.478 ± 0.050 eV	Ruscic W1RO
0.007	3986.4	[NCN]- (g) → 2 N (g) + C (g)	Δ_rH°(0 K) = 344.80 ± 2.16 kcal/mol	Ruscic CBS-n
0.005	3984.5	[NCN]- (g) → NCN (g)	Δ_rH°(0 K) = 2.514 ± 0.061 eV	Ruscic G4
0.002	3984.4	[NCN]- (g) → NCN (g)	Δ_rH°(0 K) = 2.464 ± 0.085 eV	Ruscic G3X
0.002	3984.7	[NCN]- (g) → NCN (g)	Δ_rH°(0 K) = 2.474 ± 0.090 eV	Ruscic CBS-n, Clifford 1997
0.002	3984.6	[NCN]- (g) → NCN (g)	Δ_rH°(0 K) = 2.438 ± 0.092 eV	Ruscic CBS-n

References (for your convenience, also available in RIS and BibTex format)

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. 1.122e of the Thermochemical Network, Argonne National Laboratory (2019); available at ATcT.anl.gov
4		L. Cheng, J. Gauss, B. Ruscic, P. Armentrout, and J. Stanton, Bond Dissociation Energies for Diatomic Molecules Containing 3d Transition Metals: Benchmark Scalar-Relativistic Coupled-Cluster Calculations for Twenty Molecules. J. Chem. Theory Comput. 13, 1044-1056 (2017) [DOI: 10.1021/acs.jctc.6b00970]
5		J. P. Porterfield, D. H. Bross, B. Ruscic, J. H. Thorpe, T. L. Nguyen, J. H. Baraban, J. F. Stanton, J. W. Daily, and G. B. Ellison, Thermal Decomposition of Potential Ester Biofuels, Part I: Methyl Acetate and Methyl Butanoate. J. Chem. Phys. A 121, 4658-4677 (2017) [DOI: 10.1021/acs.jpca.7b02639] (Veronica Vaida Festschrift)
6		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]

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 [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.

Selected ATcT [1, 2] enthalpy of formation based on version 1.122e of the Thermochemical Network [3]

Representative Geometry of [NCN]- (g)

Top contributors to the provenance of ΔfH° of [NCN]- (g)

Top 10 species with enthalpies of formation correlated to the ΔfH° of [NCN]- (g)

Most Influential reactions involving [NCN]- (g)

Top contributors to the provenance of Δ_fH° of [NCN]- (g)

Top 10 species with enthalpies of formation correlated to the Δ_fH° of [NCN]- (g)