Selected ATcT [1, 2] enthalpy of formation based on version 1.122g 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].

Species Name Formula Image    ΔfH°(0 K)    ΔfH°(298.15 K) Uncertainty Units Relative
Molecular
Mass		 ATcT ID
Isocyanic acidHNCO (g)N=C=O-115.85-118.84± 0.31kJ/mol43.02478 ±
0.00086		75-13-8*0

Representative Geometry of HNCO (g)

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

The 20 contributors listed below account only for 75.6% of the provenance of ΔfH° of HNCO (g).
A total of 72 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
13.63701.7 HNCO (g) → NH (g) + CO (g) ΔrH°(0 K) = 30150 ± 60 cm-1Zyrianov 1996
7.53733.4 NCO (g) → N (g) + CO (g) ΔrH°(0 K) = 55.0 ± 0.2 kcal/molCyr 1992, est unc
6.63701.8 HNCO (g) → NH (g) + CO (g) ΔrH°(0 K) = 30075 ± 25 (×3.437) cm-1Sanov 1997
5.93703.8 HNCO (g) + H2O (g) → CO2 (g) + NH3 (g) ΔrH°(0 K) = -18.46 ± 0.3 kcal/molSchuurman 2004, est unc
5.83696.11 HNCO (g) → H (g) + N (g) + C (g) + O (g) ΔrH°(0 K) = 420.73 ± 0.30 kcal/molKarton 2011
4.93701.9 HNCO (g) → NH (g) + CO (g) ΔrH°(0 K) = 30060 ± 25 (×4) cm-1Zyrianov 1999
4.53704.6 HNCO (g) + O (g) → NH (g) + CO2 (g) ΔrH°(0 K) = -39.33 ± 0.3 kcal/molSchuurman 2004, est unc
4.33740.1 HNCO (g) → NCO (g) + H (g) ΔrH°(0 K) = 38370 ± 30 cm-1Zyrianov 1996
3.33738.1 NCO (g) + O (g) → CO2 (g) + N (g) ΔrH°(0 K) = -70.89 ± 0.3 kcal/molSchuurman 2004, est unc
2.73706.11 HOCN (g) → H (g) + N (g) + C (g) + O (g) ΔrH°(0 K) = 395.98 ± 0.30 kcal/molKarton 2011
2.73718.11 HONC (g) → H (g) + N (g) + C (g) + O (g) ΔrH°(0 K) = 336.83 ± 0.30 kcal/molKarton 2011
2.53712.11 HCNO (g) → H (g) + N (g) + C (g) + O (g) ΔrH°(0 K) = 352.25 ± 0.30 kcal/molKarton 2011
2.53701.6 HNCO (g) → NH (g) + CO (g) ΔrH°(0 K) = 30022 ± 100 (×1.384) cm-1Brown 1996, Brazier 1986
2.33739.1 NCO (g) + OH (g) → CO2 (g) + NH (g) ΔrH°(0 K) = -47.42 ± 0.3 kcal/molSchuurman 2004, est unc
1.63696.10 HNCO (g) → H (g) + N (g) + C (g) + O (g) ΔrH°(0 K) = 420.71 ± 0.56 kcal/molKarton 2011
0.93715.11 HCNO (g) → HNCO (g) ΔrH°(0 K) = -68.48 ± 0.25 kcal/molKarton 2011
0.83721.11 HONC (g) → HNCO (g) ΔrH°(0 K) = -83.90 ± 0.25 kcal/molKarton 2011
0.83711.11 HOCN (g) → HNCO (g) ΔrH°(0 K) = -24.75 ± 0.25 kcal/molKarton 2011
0.73706.10 HOCN (g) → H (g) + N (g) + C (g) + O (g) ΔrH°(0 K) = 395.89 ± 0.56 kcal/molKarton 2011
0.73718.10 HONC (g) → H (g) + N (g) + C (g) + O (g) ΔrH°(0 K) = 336.63 ± 0.56 kcal/molKarton 2011

Top 10 species with enthalpies of formation correlated to the ΔfH° of HNCO (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
67.1 CyanooxidanylNCO (g)N#C[O]127.02127.49± 0.35kJ/mol42.01684 ±
0.00086		22400-26-6*0
59.7 Isocyanic acid cation[HNCO]+ (g)[NH+]=C=O1003.101000.43± 0.51kJ/mol43.02423 ±
0.00086		444010-28-0*0
44.3 Cyanate[NCO]- (g)N#C[O-]-221.10-221.32± 0.54kJ/mol42.01739 ±
0.00086		661-20-1*0
44.0 Isofulminic acidHONC (g)O[N+]#[C-]235.38233.67± 0.48kJ/mol43.02478 ±
0.00086		506-85-4*0
43.7 Cyanic acidHOCN (g)OC#N-12.20-14.91± 0.49kJ/mol43.02478 ±
0.00086		420-05-3*0
42.4 Fulminic acidHCNO (g)C#[N+][O-]170.92169.46± 0.49kJ/mol43.02478 ±
0.00086		51060-05-0*0
38.4 Cyanato cation[NCO]+ (g)N#C[O+]1261.561262.06± 0.59kJ/mol42.01629 ±
0.00086		17247-99-3*0
25.0 ImidogenNH (g)[NH]358.75358.79± 0.17kJ/mol15.014680 ±
0.000099		13774-92-0*0
25.0 ImidogenNH (g, triplet)[NH]358.75358.79± 0.17kJ/mol15.014680 ±
0.000099		13774-92-0*1
25.0 Imidogen anion[NH]- (g)[NH-]322.63322.68± 0.17kJ/mol15.015229 ±
0.000099		23841-33-0*0

Most Influential reactions involving HNCO (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
0.6943697.1 HNCO (g) → [HNCO]+ (g) ΔrH°(0 K) = 11.595 ± 0.005 eVRuscic 1994b
0.5543740.1 HNCO (g) → NCO (g) + H (g) ΔrH°(0 K) = 38370 ± 30 cm-1Zyrianov 1996
0.3813698.5 [HNCO]- (g) → HNCO (g) ΔrH°(0 K) = -0.646 ± 0.050 eVRuscic W1RO
0.2563698.2 [HNCO]- (g) → HNCO (g) ΔrH°(0 K) = -0.605 ± 0.061 eVRuscic G4
0.1863715.11 HCNO (g) → HNCO (g) ΔrH°(0 K) = -68.48 ± 0.25 kcal/molKarton 2011
0.1853701.7 HNCO (g) → NH (g) + CO (g) ΔrH°(0 K) = 30150 ± 60 cm-1Zyrianov 1996
0.1813711.11 HOCN (g) → HNCO (g) ΔrH°(0 K) = -24.75 ± 0.25 kcal/molKarton 2011
0.1773721.11 HONC (g) → HNCO (g) ΔrH°(0 K) = -83.90 ± 0.25 kcal/molKarton 2011
0.1733697.3 HNCO (g) → [HNCO]+ (g) ΔrH°(0 K) = 11.60 ± 0.01 eVRowland 1968, est unc
0.1483742.8 HNCO (g) → [NCO]- (g) + H+ (g) ΔrH°(0 K) = 340.17 ± 0.3 kcal/molSchuurman 2004, est unc
0.1323698.1 [HNCO]- (g) → HNCO (g) ΔrH°(0 K) = -0.667 ± 0.085 eVRuscic G3X
0.1263711.13 HOCN (g) → HNCO (g) ΔrH°(0 K) = -24.58 ± 0.3 kcal/molSchuurman 2004, est unc
0.1233721.13 HONC (g) → HNCO (g) ΔrH°(0 K) = -83.97 ± 0.3 kcal/molSchuurman 2004, est unc
0.1173698.4 [HNCO]- (g) → HNCO (g) ΔrH°(0 K) = -0.667 ± 0.090 eVRuscic CBS-n
0.1123698.3 [HNCO]- (g) → HNCO (g) ΔrH°(0 K) = -0.634 ± 0.092 eVRuscic CBS-n
0.0903701.8 HNCO (g) → NH (g) + CO (g) ΔrH°(0 K) = 30075 ± 25 (×3.437) cm-1Sanov 1997
0.0723715.10 HCNO (g) → HNCO (g) ΔrH°(0 K) = -68.66 ± 0.40 kcal/molKarton 2011
0.0713711.10 HOCN (g) → HNCO (g) ΔrH°(0 K) = -24.82 ± 0.40 kcal/molKarton 2011
0.0693721.10 HONC (g) → HNCO (g) ΔrH°(0 K) = -84.08 ± 0.40 kcal/molKarton 2011
0.0663701.9 HNCO (g) → NH (g) + CO (g) ΔrH°(0 K) = 30060 ± 25 (×4) cm-1Zyrianov 1999
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 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. 1.122g of the Thermochemical Network (2019); available at ATcT.anl.gov
4   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)
5   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)
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.