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

This version of ATcT results was generated from an expansion of version 1.122q [4, 5] to include a non-rigid rotor anharmonic oscillator (NRRAO) partition function for hydroxymethyl [6], as well as data on 42 additional species, some of which are related to soot formation mechanisms.

Species Name Formula Image    ΔfH°(0 K)    ΔfH°(298.15 K) Uncertainty Units Relative
Molecular
Mass
ATcT ID
CyanamideNH2CN (cr)NC#N58.89± 0.54kJ/mol42.04006 ±
0.00082
420-04-2*500

Top contributors to the provenance of ΔfH° of NH2CN (cr)

The 5 contributors listed below account for 99.1% of the provenance of ΔfH° of NH2CN (cr).

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
97.34360.1 NH2CN (cr) + 3/2 O2 (g) → CO2 (g) H2O (cr,l) N2 (g) ΔrH°(298.15 K) = -176.42 ± 0.13 kcal/molSalley 1948, as quoted by Cox 1970
0.44359.8 NH2CN (g) → 2 H (g) + 2 N (g) C (g) ΔrH°(0 K) = 464.38 ± 1.50 kcal/molRuscic W1RO
0.44361.1 NH2CN (cr) → NH2CN (g) ΔrH°(298.15 K) = 75.2 ± 1.5 kJ/molde Wit 1983a, est unc
0.44359.4 NH2CN (g) → 2 H (g) + 2 N (g) C (g) ΔrH°(0 K) = 464.45 ± 1.60 kcal/molRuscic G4
0.44359.7 NH2CN (g) → 2 H (g) + 2 N (g) C (g) ΔrH°(0 K) = 463.35 ± 1.60 kcal/molRuscic CBS-n

Top 10 species with enthalpies of formation correlated to the ΔfH° of NH2CN (cr)

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
30.8 CyanamideNH2CN (g)NC#N140.8134.5± 1.5kJ/mol42.04006 ±
0.00082
420-04-2*0
4.5 WaterH2O (g, ortho)O-238.644-241.832± 0.026kJ/mol18.01528 ±
0.00033
7732-18-5*1
4.5 WaterH2O (g, para)O-238.929-241.832± 0.026kJ/mol18.01528 ±
0.00033
7732-18-5*2
4.5 WaterH2O (g)O-238.929-241.832± 0.026kJ/mol18.01528 ±
0.00033
7732-18-5*0
4.5 WaterH2O (cr, l, eq.press.)O-286.300-285.828± 0.026kJ/mol18.01528 ±
0.00033
7732-18-5*499
4.5 WaterH2O (l, eq.press.)O-285.828± 0.026kJ/mol18.01528 ±
0.00033
7732-18-5*589
4.5 Oxonium[H3O]+ (aq)[OH3+]-285.826± 0.026kJ/mol19.02267 ±
0.00037
13968-08-6*800
4.5 WaterH2O (l)O-285.826± 0.026kJ/mol18.01528 ±
0.00033
7732-18-5*590
4.5 WaterH2O (cr,l)O-286.298-285.826± 0.026kJ/mol18.01528 ±
0.00033
7732-18-5*500
4.5 WaterH2O (cr)O-286.298-292.739± 0.026kJ/mol18.01528 ±
0.00033
7732-18-5*510

Most Influential reactions involving NH2CN (cr)

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
0.9764360.1 NH2CN (cr) + 3/2 O2 (g) → CO2 (g) H2O (cr,l) N2 (g) ΔrH°(298.15 K) = -176.42 ± 0.13 kcal/molSalley 1948, as quoted by Cox 1970
0.8184361.1 NH2CN (cr) → NH2CN (g) ΔrH°(298.15 K) = 75.2 ± 1.5 kJ/molde Wit 1983a, est unc


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. 1.122r of the Thermochemical Network, Argonne National Laboratory, Lemont, Illinois 2021 [DOI: 10.17038/CSE/1822363]; available at ATcT.anl.gov
4   D. Feller, D. H. Bross, and B. Ruscic,
Enthalpy of Formation of C2H2O4 (Oxalic Acid) from High-Level Calculations and the Active Thermochemical Tables Approach.
J. Phys. Chem. A 123, 3481-3496 (2019) [DOI: 10.1021/acs.jpca.8b12329]
5   B. K. Welch, R. Dawes, D. H. Bross, and B. Ruscic,
An Automated Thermochemistry Protocol Based on Explicitly Correlated Coupled-Cluster Theory: The Methyl and Ethyl Peroxy Families.
J. Phys. Chem. A 123, 5673-5682 (2019) [DOI: 10.1021/acs.jpca.8b12329]
6   D. H. Bross, H.-G. Yu, L. B. Harding, and B. Ruscic,
Active Thermochemical Tables: The Partition Function of Hydroxymethyl (CH2OH) Revisited.
J. Phys. Chem. A 123, 4212-4231 (2019) [DOI: 10.1021/acs.jpca.9b02295]
7   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 [7]).
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.