Selected ATcT [1, 2] enthalpy of formation based on version 1.122h of the Thermochemical Network [3] This version of ATcT results was generated from an expansion of version 1.122e [4] to include results centered on the determination of the appearance energy of CH3+ from CH4. [5].
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Species Name |
Formula |
Image |
ΔfH°(0 K) |
ΔfH°(298.15 K) |
Uncertainty |
Units |
Relative Molecular Mass |
ATcT ID |
Hydrogen isocyanide | HNC (g) | | 191.98 | 192.36 | ± 0.37 | kJ/mol | 27.02538 ± 0.00081 | 6914-07-4*0 |
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Representative Geometry of HNC (g) |
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spin ON spin OFF |
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Top contributors to the provenance of ΔfH° of HNC (g)The 20 contributors listed below account only for 88.5% of the provenance of ΔfH° of HNC (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.
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Contribution (%) | TN ID | Reaction | Measured Quantity | Reference | 32.6 | 2258.10 | HCN (g) → HNC (g)  | ΔrH°(0 K) = 5236 ± 50 cm-1 | Nguyen 2015a | 10.6 | 2259.3 | HCN (g) → HNC (g)  | ΔrH°(0 K) = 14.88 ± 0.25 kcal/mol | Karton 2011 | 8.1 | 2258.12 | HCN (g) → HNC (g)  | ΔrH°(0 K) = 5201 ± 100 cm-1 | Dawes 2009, est unc | 8.1 | 2258.11 | HCN (g) → HNC (g)  | ΔrH°(0 K) = 5185.64 ± 100 cm-1 | van Mourik 2001, Barber 2002, est unc, Sun 2015 | 8.0 | 2253.11 | HNC (g) → C (g) + N (g) + H (g)  | ΔrH°(0 K) = 288.27 ± 0.30 kcal/mol | Karton 2011 | 4.1 | 2259.2 | HCN (g) → HNC (g)  | ΔrH°(0 K) = 14.94 ± 0.4 kcal/mol | Karton 2011 | 3.2 | 2259.8 | HCN (g) → HNC (g)  | ΔrH°(0 K) = 62.7 ± 1.9 kJ/mol | Vogiatzis 2014, est unc | 2.6 | 2259.4 | HCN (g) → HNC (g)  | ΔrH°(0 K) = 14.69 ± 0.50 kcal/mol | Puzzarini 2010, est unc | 2.3 | 2253.10 | HNC (g) → C (g) + N (g) + H (g)  | ΔrH°(0 K) = 288.14 ± 0.56 kcal/mol | Karton 2011 | 2.2 | 2259.7 | HCN (g) → HNC (g)  | ΔrH°(0 K) = 62.7 ± 2.3 kJ/mol | Klopper 2010a, est unc | 1.2 | 2288.11 | CH3CN (g) → CH3NC (g)  | ΔrH°(0 K) = 103.6 ± 1.9 kJ/mol | Vogiatzis 2014, est unc | 0.8 | 2288.10 | CH3CN (g) → CH3NC (g)  | ΔrH°(0 K) = 103.3 ± 2.3 kJ/mol | Klopper 2010a, est unc | 0.7 | 2289.7 | CH3NC (g) + HCN (g) → CH3CN (g) + HNC (g)  | ΔrH°(0 K) = -40.9 ± 1.5 kJ/mol | Vogiatzis 2014, est unc | 0.5 | 2259.1 | HCN (g) → HNC (g)  | ΔrH°(0 K) = 14.85 ± 1.1 kcal/mol | Karton 2011 | 0.5 | 2289.6 | CH3NC (g) + HCN (g) → CH3CN (g) + HNC (g)  | ΔrH°(0 K) = -40.6 ± 1.8 kJ/mol | Klopper 2010a, est unc | 0.5 | 2263.1 | [HNC]+ (g) + Xe (g) → Xe+ (g) + HNC (g)  | ΔrH°(300 K) = 0.09 ± 0.02 eV | Hansel 1998 | 0.4 | 2258.8 | HCN (g) → HNC (g)  | ΔrH°(0 K) = 5090 ± 420 cm-1 | Ruscic W1RO | 0.4 | 2258.4 | HCN (g) → HNC (g)  | ΔrH°(0 K) = 5175 ± 450 cm-1 | Ruscic G4 | 0.3 | 2253.9 | HNC (g) → C (g) + N (g) + H (g)  | ΔrH°(0 K) = 288.10 ± 1.35 kcal/mol | Karton 2011 | 0.3 | 2258.7 | HCN (g) → HNC (g)  | ΔrH°(0 K) = 5014 ± 455 cm-1 | Ruscic CBS-n |
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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.
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Correlation Coefficent (%) | Species Name | Formula | Image | ΔfH°(0 K) | ΔfH°(298.15 K) | Uncertainty | Units | Relative Molecular Mass | ATcT ID | 99.8 | Hydrogen isocyanide anion | [HNC]- (g) | | 191.54 | 191.72 | ± 0.37 | kJ/mol | 27.02593 ± 0.00081 | 96913-22-3*0 | 25.9 | Isocyanomethane | CH3NC (g) | | 183.79 | 177.31 | ± 0.82 | kJ/mol | 41.0520 ± 0.0016 | 593-75-9*0 | 22.4 | Hydrogen cyanide | HCN (g) | | 129.661 | 129.276 | ± 0.090 | kJ/mol | 27.02538 ± 0.00081 | 74-90-8*0 | 22.3 | Hydrogen cyanide anion | [HCN]- (g) | | 129.509 | 129.031 | ± 0.090 | kJ/mol | 27.02593 ± 0.00081 | 12334-27-9*0 | 21.3 | Cyanide | [CN]- (g) | | 63.956 | 67.242 | ± 0.094 | kJ/mol | 26.01799 ± 0.00080 | 57-12-5*0 | 17.8 | Hydrogen isocyanide cation | [HNC]+ (g) | | 1352.9 | 1352.9 | ± 1.3 | kJ/mol | 27.02483 ± 0.00081 | 74158-11-5*0 | 11.9 | Acetylene | HCCH (g) | | 228.82 | 228.26 | ± 0.13 | kJ/mol | 26.0373 ± 0.0016 | 74-86-2*0 | 11.9 | Acetylene cation | [HCCH]+ (g) | | 1328.83 | 1328.17 | ± 0.13 | kJ/mol | 26.0367 ± 0.0016 | 25641-79-6*0 | 10.6 | Hydrogen cyanide cation | [HCN]+ (g) | | 1442.52 | 1442.05 | ± 0.20 | kJ/mol | 27.02483 ± 0.00081 | 12601-62-6*0 | 10.6 | Nitrilomethyl | CN (g) | | 436.73 | 440.01 | ± 0.15 | kJ/mol | 26.01744 ± 0.00080 | 2074-87-5*0 |
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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.
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Influence Coefficient | TN ID | Reaction | Measured Quantity | Reference | 0.780 | 2255.1 | [HNC]- (g) → HNC (g)  | ΔrH°(0 K) = 35.7 ± 2 cm-1 | Peterson 2002, est unc | 0.409 | 2263.1 | [HNC]+ (g) + Xe (g) → Xe+ (g) + HNC (g)  | ΔrH°(300 K) = 0.09 ± 0.02 eV | Hansel 1998 | 0.348 | 2258.10 | HCN (g) → HNC (g)  | ΔrH°(0 K) = 5236 ± 50 cm-1 | Nguyen 2015a | 0.255 | 2289.7 | CH3NC (g) + HCN (g) → CH3CN (g) + HNC (g)  | ΔrH°(0 K) = -40.9 ± 1.5 kJ/mol | Vogiatzis 2014, est unc | 0.177 | 2289.6 | CH3NC (g) + HCN (g) → CH3CN (g) + HNC (g)  | ΔrH°(0 K) = -40.6 ± 1.8 kJ/mol | Klopper 2010a, est unc | 0.113 | 2259.3 | HCN (g) → HNC (g)  | ΔrH°(0 K) = 14.88 ± 0.25 kcal/mol | Karton 2011 | 0.105 | 2255.4 | [HNC]- (g) → HNC (g)  | ΔrH°(0 K) = 42.41 ± 5 (×1.091) cm-1 | Sindelka 2004, est unc | 0.102 | 2254.8 | HNC (g) → [HNC]+ (g)  | ΔrH°(0 K) = 12.019 ± 0.040 eV | Ruscic W1RO | 0.100 | 2255.2 | [HNC]- (g) → HNC (g)  | ΔrH°(0 K) = 42.5 ± 5 (×1.114) cm-1 | Skurski 2001, est unc | 0.087 | 2258.11 | HCN (g) → HNC (g)  | ΔrH°(0 K) = 5185.64 ± 100 cm-1 | van Mourik 2001, Barber 2002, est unc, Sun 2015 | 0.087 | 2258.12 | HCN (g) → HNC (g)  | ΔrH°(0 K) = 5201 ± 100 cm-1 | Dawes 2009, est unc | 0.082 | 2253.11 | HNC (g) → C (g) + N (g) + H (g)  | ΔrH°(0 K) = 288.27 ± 0.30 kcal/mol | Karton 2011 | 0.045 | 2289.5 | CH3NC (g) + HCN (g) → CH3CN (g) + HNC (g)  | ΔrH°(0 K) = -9.93 ± 0.85 kcal/mol | Ruscic W1RO | 0.044 | 2259.2 | HCN (g) → HNC (g)  | ΔrH°(0 K) = 14.94 ± 0.4 kcal/mol | Karton 2011 | 0.040 | 2289.4 | CH3NC (g) + HCN (g) → CH3CN (g) + HNC (g)  | ΔrH°(0 K) = -9.57 ± 0.90 kcal/mol | Ruscic CBS-n | 0.040 | 2289.2 | CH3NC (g) + HCN (g) → CH3CN (g) + HNC (g)  | ΔrH°(0 K) = -9.08 ± 0.90 kcal/mol | Ruscic G4 | 0.040 | 2289.1 | CH3NC (g) + HCN (g) → CH3CN (g) + HNC (g)  | ΔrH°(0 K) = -9.70 ± 0.90 kcal/mol | Ruscic G3X | 0.034 | 2259.8 | HCN (g) → HNC (g)  | ΔrH°(0 K) = 62.7 ± 1.9 kJ/mol | Vogiatzis 2014, est unc | 0.032 | 2289.3 | CH3NC (g) + HCN (g) → CH3CN (g) + HNC (g)  | ΔrH°(0 K) = -9.56 ± 1.0 kcal/mol | Ruscic CBS-n | 0.030 | 2254.4 | HNC (g) → [HNC]+ (g)  | ΔrH°(0 K) = 12.051 ± 0.073 eV | Ruscic G4 |
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References
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1
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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]
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2
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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]
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3
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B. Ruscic and D. H. Bross, Active Thermochemical Tables (ATcT) values based on ver. 1.122h of the Thermochemical Network (2020); available at ATcT.anl.gov |
4
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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)
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5
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Y.-C. Chang, B. Xiong, D. H. Bross, B. Ruscic, and C. Y. Ng,
A Vacuum Ultraviolet laser Pulsed Field Ionization-Photoion Study of Methane (CH4): Determination of the Appearance Energy of Methylium From Methane with Unprecedented Precision and the Resulting Impact on the Bond Dissociation Energies of CH4 and CH4+.
Phys. Chem. Chem. Phys. 19, 9592-9605 (2017)
[DOI: 10.1039/c6cp08200a] (part of 2017 PCCP Hot Articles collection)
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6
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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]
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Formula
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The aggregate state is given in parentheses following the formula, such as: g - gas-phase, cr - crystal, l - liquid, etc.
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Uncertainties
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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.
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Website Functionality Credits
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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/.
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Acknowledgement
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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.
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