Selected ATcT [1, 2] enthalpy of formation based on version 1.122b of the Thermochemical Network [3] This version of ATcT results was generated from an expansion of version 1.122 [4][5] to include the best possible isomerization of HCN and HNC [6].
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Species Name |
Formula |
Image |
ΔfH°(0 K) |
ΔfH°(298.15 K) |
Uncertainty |
Units |
Relative Molecular Mass |
ATcT ID |
Methylamine | CH3NH2 (g) | | -5.97 | -21.05 | ± 0.46 | kJ/mol | 31.05714 ± 0.00088 | 74-89-5*0 |
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Representative Geometry of CH3NH2 (g) |
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spin ON spin OFF |
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Top contributors to the provenance of ΔfH° of CH3NH2 (g)The 20 contributors listed below account only for 80.1% of the provenance of ΔfH° of CH3NH2 (g). A total of 34 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 | 14.4 | 3219.6 | (CH3)2NH (g) + NH3 (g) → 2 CH3NH2 (g)  | ΔrH°(298.15 K) = 4.68 ± 0.40 kcal/mol | Issoire 1960, as quoted by Cox 1970 | 13.0 | 1890.9 | CH3NH2 (g) → C (g) + N (g) + 5 H (g)  | ΔrH°(0 K) = 542.22 ± 0.30 kcal/mol | Karton 2008, Karton 2011 | 12.8 | 3223.6 | (CH3)3N (g) + NH3 (g) → (CH3)2NH (g) + CH3NH2 (g)  | ΔrH°(298.15 K) = 7.82 ± 0.40 kcal/mol | Issoire 1960, as quoted by Cox 1970 | 4.7 | 1904.3 | CH3NH2 (g) → CH2NH2 (g) + H (g)  | ΔrH°(0 K) = 91.19 ± 0.30 kcal/mol | Karton 2011 | 3.7 | 1890.8 | CH3NH2 (g) → C (g) + N (g) + 5 H (g)  | ΔrH°(0 K) = 542.32 ± 0.56 kcal/mol | Karton 2011 | 3.5 | 3226.1 | 2 (CH3)3N (l) + 21/2 O2 (g) → 6 CO2 (g) + 9 H2O (cr,l) + N2 (g)  | ΔrH°(298.15 K) = -1157.28 ± 0.30 kcal/mol | Jaffe 1970, Cox 1970, as quoted by Cox 1970 | 3.4 | 1896.1 | 2 CH3NH2 (l) + 9/2 O2 (g) → 2 CO2 (g) + 5 H2O (cr,l) + N2 (g)  | ΔrH°(298.15 K) = -507.08 ± 0.18 (×6.442) kcal/mol | Jaffe 1970, Cox 1970, as quoted by Cox 1970 | 3.3 | 1911.3 | CH3NH2 (g) → CH3NH (g) + H (g)  | ΔrH°(0 K) = 98.00 ± 0.30 kcal/mol | Karton 2011 | 3.2 | 1906.9 | CH3NH (g) → C (g) + N (g) + 4 H (g)  | ΔrH°(0 K) = 444.22 ± 0.30 kcal/mol | Karton 2008, Karton 2011 | 2.3 | 3219.5 | (CH3)2NH (g) + NH3 (g) → 2 CH3NH2 (g)  | ΔrH°(0 K) = 5.05 ± 1.0 kcal/mol | Ruscic CBS-n | 2.0 | 1899.9 | CH2NH2 (g) → C (g) + N (g) + 4 H (g)  | ΔrH°(0 K) = 451.03 ± 0.30 kcal/mol | Karton 2008, Karton 2011 | 2.0 | 3223.5 | (CH3)3N (g) + NH3 (g) → (CH3)2NH (g) + CH3NH2 (g)  | ΔrH°(0 K) = 8.53 ± 1.0 kcal/mol | Ruscic CBS-n | 1.6 | 3219.1 | (CH3)2NH (g) + NH3 (g) → 2 CH3NH2 (g)  | ΔrH°(0 K) = 4.95 ± 1.2 kcal/mol | Ruscic G3B3 | 1.6 | 3219.2 | (CH3)2NH (g) + NH3 (g) → 2 CH3NH2 (g)  | ΔrH°(0 K) = 4.96 ± 1.2 kcal/mol | Ruscic G3 | 1.4 | 3223.1 | (CH3)3N (g) + NH3 (g) → (CH3)2NH (g) + CH3NH2 (g)  | ΔrH°(0 K) = 8.31 ± 1.20 kcal/mol | Ruscic G3B3 | 1.4 | 3223.2 | (CH3)3N (g) + NH3 (g) → (CH3)2NH (g) + CH3NH2 (g)  | ΔrH°(0 K) = 8.40 ± 1.2 kcal/mol | Ruscic G3 | 1.3 | 3219.4 | (CH3)2NH (g) + NH3 (g) → 2 CH3NH2 (g)  | ΔrH°(0 K) = 5.03 ± 1.3 kcal/mol | Ruscic CBS-n | 1.3 | 1908.1 | [CH3NH]- (g) → CH3NH (g)  | ΔrH°(0 K) = 0.432 ± 0.015 eV | Radisic 2002 | 1.3 | 1904.2 | CH3NH2 (g) → CH2NH2 (g) + H (g)  | ΔrH°(0 K) = 91.21 ± 0.56 kcal/mol | Karton 2011 | 1.2 | 3223.4 | (CH3)3N (g) + NH3 (g) → (CH3)2NH (g) + CH3NH2 (g)  | ΔrH°(0 K) = 8.44 ± 1.3 kcal/mol | Ruscic CBS-n |
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Top 10 species with enthalpies of formation correlated to the ΔfH° of CH3NH2 (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 | 87.8 | Methylamine | CH3NH2 (l) | | | -44.83 | ± 0.52 | kJ/mol | 31.05714 ± 0.00088 | 74-89-5*500 | 52.6 | Methylamidogen anion | [CH3NH]- (g) | | 145.99 | 134.64 | ± 0.76 | kJ/mol | 30.04975 ± 0.00085 | 54448-39-4*0 | 41.8 | Dimethylamine | (CH3)2NH (g) | | 5.91 | -15.99 | ± 0.67 | kJ/mol | 45.0837 ± 0.0017 | 124-40-3*0 | 38.8 | Dimethylamine | (CH3)2NH (l) | | | -41.21 | ± 0.72 | kJ/mol | 45.0837 ± 0.0017 | 124-40-3*500 | 37.8 | Methylamidogen | CH3NH (g) | | 187.86 | 177.14 | ± 0.61 | kJ/mol | 30.04920 ± 0.00085 | 15622-51-2*0 | 32.1 | Aminomethyl | CH2NH2 (g) | | 159.40 | 148.51 | ± 0.58 | kJ/mol | 30.04920 ± 0.00085 | 10507-29-6*0 | 21.7 | Trimethylamine | (CH3)3N (g) | | 4.48 | -24.08 | ± 0.63 | kJ/mol | 59.1103 ± 0.0025 | 75-50-3*0 | 20.7 | Trimethylamine | (CH3)3N (l) | | | -45.80 | ± 0.61 | kJ/mol | 59.1103 ± 0.0025 | 75-50-3*500 | 9.5 | Methylenimine | H2CNH (g) | | 96.53 | 88.62 | ± 0.63 | kJ/mol | 29.04126 ± 0.00083 | 2053-29-4*0 | 9.3 | Methylammoniumyl | [CH3NH2]+ (g) | | 866.9 | 853.1 | ± 2.4 | kJ/mol | 31.05659 ± 0.00088 | 34516-31-9*0 |
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Most Influential reactions involving CH3NH2 (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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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. 1.122b of the Thermochemical Network (2016); available at ATcT.anl.gov |
4
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B. Ruscic,
Active Thermochemical Tables: Sequential Bond Dissociation Enthalpies of Methane, Ethane, and Methanol and the Related Thermochemistry.
J. Phys. Chem. A 119, 7810-7837 (2015)
[DOI: 10.1021/acs.jpca.5b01346]
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5
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S. J. Klippenstein, L. B. Harding, and B. Ruscic,
Ab initio Computations and Active Thermochemical Tables Hand in Hand: Heats of Formation of Core Combustion Species.
J. Phys. Chem. A 121, 6580-6602 (2017)
[DOI: 10.1021/acs.jpca.7b05945]
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6
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T. L. Nguyen, J. H. Baraban, B. Ruscic, and J. F. Stanton,
On the HCN – HNC Energy Difference.
J. Phys. Chem. A 119, 10929-10934 (2015)
[DOI: 10.1021/acs.jpca.5b08406]
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7
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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 [7]).
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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