Selected ATcT [1, 2] enthalpy of formation based on version 1.172 of the Thermochemical Network [3]

This version of ATcT results[3] was generated by additional expansion of version 1.156 to include species relevant to a study of photodissociation of formamide[4].

Hydrogen isocyanide

Formula: HNC (g)
CAS RN: 6914-07-4
ATcT ID: 6914-07-4*0
SMILES: [C]=N
SMILES: [C]=[NH]
InChI: InChI=1S/CHN/c1-2/h2H
InChIKey: QIUBLANJVAOHHY-UHFFFAOYSA-N
Hills Formula: C1H1N1

2D Image:

[C]=N
Aliases: HNC; Hydrogen isocyanide; Iminomethylidene; Isohydrocyanic acid; Hydroisocyanic acid; Nitriliomethanide; CNH; 18660-97-4
Relative Molecular Mass: 27.02538 ± 0.00081

   ΔfH°(0 K)   ΔfH°(298.15 K)UncertaintyUnits
192.06192.44± 0.32kJ/mol

3D Image of HNC (g)

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Top contributors to the provenance of ΔfH° of HNC (g)

The 20 contributors listed below account only for 81.8% of the provenance of ΔfH° of HNC (g).
A total of 53 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
23.82782.10 HCN (g) → HNC (g) ΔrH°(0 K) = 5236 ± 50 cm-1Nguyen 2015c
7.82783.3 HCN (g) → HNC (g) ΔrH°(0 K) = 14.88 ± 0.25 kcal/molKarton 2011
6.12782.13 HCN (g) → HNC (g) ΔrH°(0 K) = 5312.8 ± 60 (×1.646) cm-1Makhnev 2018
6.02776.11 HNC (g) → C (g) N (g) H (g) ΔrH°(0 K) = 288.27 ± 0.30 kcal/molKarton 2011
5.92782.11 HCN (g) → HNC (g) ΔrH°(0 K) = 5185.64 ± 100 cm-1van Mourik 2001, Barber 2002, est unc, Sun 2015
5.92782.12 HCN (g) → HNC (g) ΔrH°(0 K) = 5201 ± 100 cm-1Dawes 2009, est unc
5.42783.14 HCN (g) → HNC (g) ΔrH°(0 K) = 14.93 ± 0.30 kcal/molBurke 2021
3.72783.13 HCN (g) → HNC (g) ΔrH°(0 K) = 62.55 ± 1.5 kJ/molKlippenstein 2017
3.02783.2 HCN (g) → HNC (g) ΔrH°(0 K) = 14.94 ± 0.4 kcal/molKarton 2011
2.12823.8 CH3NC (g) HCN (g) → CH3CN (g) HNC (g) ΔrH°(0 K) = -40.97 ± 1.5 kJ/molKlippenstein 2017
1.92783.4 HCN (g) → HNC (g) ΔrH°(0 K) = 14.69 ± 0.50 kcal/molPuzzarini 2010, est unc
1.72776.10 HNC (g) → C (g) N (g) H (g) ΔrH°(0 K) = 288.14 ± 0.56 kcal/molKarton 2011
1.32783.8 HCN (g) → HNC (g) ΔrH°(0 K) = 62.7 ± 2.5 kJ/molVogiatzis 2014, est unc
1.32783.7 HCN (g) → HNC (g) ΔrH°(0 K) = 62.7 ± 2.5 kJ/molKlopper 2010a, est unc
1.12823.7 CH3NC (g) HCN (g) → CH3CN (g) HNC (g) ΔrH°(0 K) = -40.9 ± 2.0 kJ/molVogiatzis 2014, est unc
1.12823.6 CH3NC (g) HCN (g) → CH3CN (g) HNC (g) ΔrH°(0 K) = -40.6 ± 2.0 kJ/molKlopper 2010a, est unc
1.02822.12 CH3CN (g) → CH3NC (g) ΔrH°(0 K) = 103.26 ± 0.7 kJ/molNguyen 2018
0.92781.4 HCN (g) → HNC (g) ΔrH°(0 K) = 5162 ± 250 cm-1Baraban 2015, note unc
0.42783.1 HCN (g) → HNC (g) ΔrH°(0 K) = 14.85 ± 1.1 kcal/molKarton 2011
0.32823.5 CH3NC (g) HCN (g) → CH3CN (g) HNC (g) ΔrH°(0 K) = -9.93 ± 0.85 kcal/molRuscic W1RO

Top 10 species with enthalpies of formation correlated to the ΔfH° of HNC (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 Image    ΔfH°(0 K)    ΔfH°(298.15 K) Uncertainty Units Relative
Molecular
Mass
ATcT ID
99.7 Hydrogen isocyanide anion[HNC]- (g)[C-]=N191.61191.80± 0.32kJ/mol27.02593 ±
0.00081
96913-22-3*0
31.8 Hydrogen isocyanide cation[HNC]+ (g)[C+]=N1351.521351.48± 0.83kJ/mol27.02483 ±
0.00081
74158-11-5*0
25.1 Hydrogen cyanideHCN (g)C#N129.677129.293± 0.087kJ/mol27.02538 ±
0.00081
74-90-8*0
25.1 Hydrogen cyanide anion[HCN]- (g)[CH-]#N129.526129.047± 0.087kJ/mol27.02593 ±
0.00081
12334-27-9*0
23.9 Cyanide[CN]- (g)[C-]#N63.97367.259± 0.091kJ/mol26.01799 ±
0.00080
57-12-5*0
16.0 IsocyanomethaneCH3NC (g)C[N+]#[C-]183.80177.25± 0.47kJ/mol41.0520 ±
0.0016
593-75-9*0
12.2 AcetyleneHCCH (g)C#C228.86228.30± 0.12kJ/mol26.0373 ±
0.0016
74-86-2*0
12.2 Acetylene cation[HCCH]+ (g)C#[CH+]1328.881328.21± 0.12kJ/mol26.0367 ±
0.0016
25641-79-6*0
12.1 NitrilomethylCN (g)[C]#N436.72440.01± 0.14kJ/mol26.01744 ±
0.00080
2074-87-5*0
11.6 Hydrogen cyanide cation[HCN]+ (g)[CH+]#N1442.531442.06± 0.20kJ/mol27.02483 ±
0.00081
12601-62-6*0

Most Influential reactions involving HNC (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
0.7802778.1 [HNC]- (g) → HNC (g) ΔrH°(0 K) = 35.7 ± 2 cm-1Peterson 2002, est unc
0.6682777.1 HNC (g) → [HNC]+ (g) ΔrH°(0 K) = 12.011 ± 0.010 eVGans 2019
0.2582782.10 HCN (g) → HNC (g) ΔrH°(0 K) = 5236 ± 50 cm-1Nguyen 2015c
0.1052778.4 [HNC]- (g) → HNC (g) ΔrH°(0 K) = 42.41 ± 5 (×1.091) cm-1Sindelka 2004, est unc
0.1002778.2 [HNC]- (g) → HNC (g) ΔrH°(0 K) = 42.5 ± 5 (×1.114) cm-1Skurski 2001, est unc
0.0992823.8 CH3NC (g) HCN (g) → CH3CN (g) HNC (g) ΔrH°(0 K) = -40.97 ± 1.5 kJ/molKlippenstein 2017
0.0872787.1 [HNC]+ (g) Xe (g) → Xe+ (g) HNC (g) ΔrH°(300 K) = 0.09 ± 0.02 (×1.384) eVHansel 1998
0.0842783.3 HCN (g) → HNC (g) ΔrH°(0 K) = 14.88 ± 0.25 kcal/molKarton 2011
0.0662782.13 HCN (g) → HNC (g) ΔrH°(0 K) = 5312.8 ± 60 (×1.646) cm-1Makhnev 2018
0.0642782.12 HCN (g) → HNC (g) ΔrH°(0 K) = 5201 ± 100 cm-1Dawes 2009, est unc
0.0642782.11 HCN (g) → HNC (g) ΔrH°(0 K) = 5185.64 ± 100 cm-1van Mourik 2001, Barber 2002, est unc, Sun 2015
0.0622776.11 HNC (g) → C (g) N (g) H (g) ΔrH°(0 K) = 288.27 ± 0.30 kcal/molKarton 2011
0.0582783.14 HCN (g) → HNC (g) ΔrH°(0 K) = 14.93 ± 0.30 kcal/molBurke 2021
0.0562823.7 CH3NC (g) HCN (g) → CH3CN (g) HNC (g) ΔrH°(0 K) = -40.9 ± 2.0 kJ/molVogiatzis 2014, est unc
0.0562823.6 CH3NC (g) HCN (g) → CH3CN (g) HNC (g) ΔrH°(0 K) = -40.6 ± 2.0 kJ/molKlopper 2010a, est unc
0.0537943.5 HCCNC (g) HCN (g) → HCCCN (g) HNC (g) ΔrH°(0 K) = -12.50 ± 0.9 kcal/molRuscic W1RO
0.0497978.5 CH2CHNC (g) HCN (g) → CH2CHCN (g) HNC (g) ΔrH°(0 K) = -7.30 ± 0.9 kcal/molRuscic W1RO
0.0437943.4 HCCNC (g) HCN (g) → HCCCN (g) HNC (g) ΔrH°(0 K) = -11.50 ± 1.0 kcal/molRuscic CBS-n
0.0437943.2 HCCNC (g) HCN (g) → HCCCN (g) HNC (g) ΔrH°(0 K) = -12.14 ± 1.0 kcal/molRuscic G4
0.0412777.9 HNC (g) → [HNC]+ (g) ΔrH°(0 K) = 12.019 ± 0.040 eVRuscic 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 21st 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. 1.172 of the Thermochemical Network (2024); available at ATcT.anl.gov
4   K. L. Caster, N. A. Seifert, B. Ruscic, A. W. Jasper, and K. Prozument,
Dynamics of HCN, NHC, and HNCO Formation in the 193 nm Photodissociation of Formamide
J. Phys. Chem. A (in press) (2024) [DOI: 10.1021/acs.jpca.4c02232]
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.