Selected ATcT [1, 2] enthalpy of formation based on version 1.176 of the Thermochemical Network [3]This version of ATcT results[3] was generated by additional expansion of version 1.172 to include species related to Criegee intermediates that are involved in several ongoing studies[4].
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Iodomethane |
Formula: CH3I (g) |
CAS RN: 74-88-4 |
ATcT ID: 74-88-4*0 |
SMILES: CI |
InChI: InChI=1S/CH3I/c1-2/h1H3 |
InChIKey: INQOMBQAUSQDDS-UHFFFAOYSA-N |
Hills Formula: C1H3I1 |
2D Image: |
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Aliases: CH3I; Iodomethane; Methyl iodide; Methyl monoiodide; Monoiodomethane; Carbon monoiodide; Monoiodocarbon; RCRA U138; UN 2644; Halon 10001 |
Relative Molecular Mass: 141.93899 ± 0.00083 |
ΔfH°(0 K) | ΔfH°(298.15 K) | Uncertainty | Units |
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24.47 | 14.94 | ± 0.17 | kJ/mol |
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3D Image of CH3I (g) |
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Top contributors to the provenance of ΔfH° of CH3I (g)The 16 contributors listed below account for 90.2% of the provenance of ΔfH° of CH3I (g).
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 | 42.7 | 6311.2 | CH3I (g) → [CH3]+ (g) + I (g)  | ΔrH°(0 K) = 12.251 ± 0.0024 eV | Lee 2007 | 21.0 | 6311.1 | CH3I (g) → [CH3]+ (g) + I (g)  | ΔrH°(0 K) = 12.248 ± 0.003 (×1.139) eV | Bodi 2009, Bodi 2023 | 3.8 | 6313.4 | CH3I (g) + HI (g) → I2 (g) + CH4 (g)  | ΔrG°(669 K) = -10.34 ± 0.09 (×2.044) kcal/mol | Goy 1965, 3rd Law | 3.8 | 6311.3 | CH3I (g) → [CH3]+ (g) + I (g)  | ΔrH°(0 K) = 12.243 ± 0.008 eV | Lee 2007, Bodi 2009 | 3.6 | 6313.2 | CH3I (g) + HI (g) → I2 (g) + CH4 (g)  | ΔrG°(630.5 K) = -10.48 ± 0.08 (×2.378) kcal/mol | Golden 1965, 3rd Law, Cox 1970 | 2.6 | 6245.8 | CI4 (g) + 3 CH4 (g) → 4 CH3I (g)  | ΔrH°(0 K) = -26.3 ± 2.5 kJ/mol | Bross 2023 | 2.6 | 2375.1 | 2 H2 (g) + C (graphite) → CH4 (g)  | ΔrG°(1165 K) = 37.521 ± 0.068 kJ/mol | Smith 1946, note COf, 3rd Law | 2.3 | 6323.5 | 4 CH3I (g) + CBr4 (g) → 4 CH3Br (g) + CI4 (g)  | ΔrH°(0 K) = -0.5 ± 2.5 kJ/mol | Bross 2023 | 1.9 | 6311.5 | CH3I (g) → [CH3]+ (g) + I (g)  | ΔrH°(0 K) = 12.24 ± 0.01 (×1.114) eV | Mintz 1976 | 1.2 | 6324.1 | 2 CH3I (l) + 7/2 O2 (g) → 2 CO2 (g) + 3 H2O (l) + I2 (cr,l)  | ΔrH°(298.15 K) = -1617.2 ± 0.6 (×4.655) kJ/mol | Carson 1993 | 0.8 | 6326.1 | 2 CH3I (l) + H2 (g) → 2 CH4 (g) + I2 (cr,l)  | ΔrH°(298.15 K) = -30.0 ± 0.8 kcal/mol | Carson 1961, note unc, Cox 1970 | 0.7 | 6311.4 | CH3I (g) → [CH3]+ (g) + I (g)  | ΔrH°(0 K) = 12.269 ± 0.003 (×6.037) eV | Song 2001 | 0.7 | 6244.6 | CI4 (g) → C (g) + 4 I (g)  | ΔrH°(0 K) = 816.4 ± 2.5 kJ/mol | Bross 2023 | 0.6 | 6313.5 | CH3I (g) + HI (g) → I2 (g) + CH4 (g)  | ΔrH°(669 K) = -12.65 ± 0.39 (×1.114) kcal/mol | Goy 1965, 2nd Law | 0.6 | 6250.5 | CI4 (g) + 4 H2 (g) → CH4 (g) + 4 HI (g)  | ΔrH°(0 K) = -275.1 ± 2.5 kJ/mol | Bross 2023 | 0.6 | 6253.4 | CI4 (g) + 4 HBr (g) → CBr4 (g) + 4 HI (g)  | ΔrH°(0 K) = 46.5 ± 2.5 kJ/mol | Bross 2023 |
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Top 10 species with enthalpies of formation correlated to the ΔfH° of CH3I (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 | 99.7 | Iodomethane cation | [CH3I]+ (g) | | 944.76 | 935.36 | ± 0.17 | kJ/mol | 141.93844 ± 0.00083 | 12538-72-6*0 | 88.6 | Iodomethane | CH3I (l) | | | -12.21 | ± 0.19 | kJ/mol | 141.93899 ± 0.00083 | 74-88-4*590 | 26.2 | Methylium | [CH3]+ (g) | | 1099.349 | 1095.405 | ± 0.045 | kJ/mol | 15.03397 ± 0.00083 | 14531-53-4*0 | 25.5 | Methane | CH4 (g) | | -66.547 | -74.516 | ± 0.043 | kJ/mol | 16.04246 ± 0.00085 | 74-82-8*0 | 23.2 | Methyl | CH3 (g) | | 149.876 | 146.476 | ± 0.049 | kJ/mol | 15.03452 ± 0.00083 | 2229-07-4*0 | 19.6 | Methane cation | [CH4]+ (g) | | 1150.683 | 1144.300 | ± 0.057 | kJ/mol | 16.04191 ± 0.00085 | 20741-88-2*0 | 19.6 | Tetraiodomethane | CI4 (g) | | 323.5 | 318.4 | ± 1.1 | kJ/mol | 519.62858 ± 0.00081 | 507-25-5*0 | 18.1 | Methane | CH4 (aq, undissoc) | | | -87.699 | ± 0.061 | kJ/mol | 16.04246 ± 0.00085 | 74-82-8*1000 | 11.9 | Carbonic acid | C(O)(OH)2 (aq, undissoc) | | | -698.673 | ± 0.028 | kJ/mol | 62.0248 ± 0.0012 | 463-79-6*1000 | 11.7 | Water | H2O (cr,l) | | -286.276 | -285.804 | ± 0.022 | kJ/mol | 18.01528 ± 0.00033 | 7732-18-5*500 |
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Most Influential reactions involving CH3I (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 | 0.904 | 6310.3 | CH3I (g) → [CH3I]+ (g)  | ΔrH°(0 K) = 76930.0 ± 1.0 cm-1 | Baig 1981 | 0.461 | 6311.2 | CH3I (g) → [CH3]+ (g) + I (g)  | ΔrH°(0 K) = 12.251 ± 0.0024 eV | Lee 2007 | 0.458 | 6325.3 | CH3I (l) → CH3I (g)  | ΔrG°(299.19 K) = 1.484 ± 0.125 kJ/mol | Boublik 1972, Fogg 1953, Zaalishvili 1962, Raetzsch 1965, ThermoData 2004 | 0.279 | 6325.5 | CH3I (l) → CH3I (g)  | ΔrG°(287.05 K) = 2.578 ± 0.160 kJ/mol | Boublik 1972, Fogg 1953, Zaalishvili 1962, Raetzsch 1965, ThermoData 2004 | 0.247 | 6325.7 | CH3I (l) → CH3I (g)  | ΔrG°(285.78 K) = 2.69 ± 0.17 kJ/mol | Thompson 1936, Fogg 1953, Zaalishvili 1962, Raetzsch 1965, ThermoData 2004 | 0.238 | 6323.5 | 4 CH3I (g) + CBr4 (g) → 4 CH3Br (g) + CI4 (g)  | ΔrH°(0 K) = -0.5 ± 2.5 kJ/mol | Bross 2023 | 0.227 | 6311.1 | CH3I (g) → [CH3]+ (g) + I (g)  | ΔrH°(0 K) = 12.248 ± 0.003 (×1.139) eV | Bodi 2009, Bodi 2023 | 0.210 | 6245.8 | CI4 (g) + 3 CH4 (g) → 4 CH3I (g)  | ΔrH°(0 K) = -26.3 ± 2.5 kJ/mol | Bross 2023 | 0.172 | 2940.2 | ICN (g) + CH3Br (g) → BrCN (g) + CH3I (g)  | ΔrH°(0 K) = 2.43 ± 1.0 kcal/mol | Ruscic unpub | 0.142 | 2940.3 | ICN (g) + CH3Br (g) → BrCN (g) + CH3I (g)  | ΔrH°(0 K) = 2.43 ± 1.1 kcal/mol | Ruscic unpub | 0.124 | 6649.1 | CH2CHI (g) + CH3Br (g) → CH2CHBr (g) + CH3I (g)  | ΔrH°(0 K) = -5.8 ± 2.5 kJ/mol | Bross 2023 | 0.119 | 2940.1 | ICN (g) + CH3Br (g) → BrCN (g) + CH3I (g)  | ΔrH°(0 K) = 2.40 ± 1.2 kcal/mol | Ruscic unpub | 0.056 | 6310.1 | CH3I (g) → [CH3I]+ (g)  | ΔrH°(0 K) = 76932 ± 4 cm-1 | Urban 2002 | 0.043 | 6313.4 | CH3I (g) + HI (g) → I2 (g) + CH4 (g)  | ΔrG°(669 K) = -10.34 ± 0.09 (×2.044) kcal/mol | Goy 1965, 3rd Law | 0.041 | 6311.3 | CH3I (g) → [CH3]+ (g) + I (g)  | ΔrH°(0 K) = 12.243 ± 0.008 eV | Lee 2007, Bodi 2009 | 0.041 | 6313.2 | CH3I (g) + HI (g) → I2 (g) + CH4 (g)  | ΔrG°(630.5 K) = -10.48 ± 0.08 (×2.378) kcal/mol | Golden 1965, 3rd Law, Cox 1970 | 0.036 | 6310.2 | CH3I (g) → [CH3I]+ (g)  | ΔrH°(0 K) = 76934 ± 5 cm-1 | Strobel 1994, Strobel 1993 | 0.021 | 6311.5 | CH3I (g) → [CH3]+ (g) + I (g)  | ΔrH°(0 K) = 12.24 ± 0.01 (×1.114) eV | Mintz 1976 | 0.015 | 2937.2 | ICN (g) + CH4 (g) → HCN (g) + CH3I (g)  | ΔrH°(0 K) = -1.03 ± 3.1 kcal/mol | Ruscic unpub | 0.014 | 2937.3 | ICN (g) + CH4 (g) → HCN (g) + CH3I (g)  | ΔrH°(0 K) = -0.97 ± 3.2 kcal/mol | Ruscic unpub |
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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. 1.176 of the Thermochemical Network (2024); available at ATcT.anl.gov |
4
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T. L. Nguyen et al, ongoing studies (2024)
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5
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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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6
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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]
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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 [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.
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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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