Selected ATcT [1, 2] enthalpy of formation based on version 1.156 of the Thermochemical Network [3]

This version of ATcT results[3] was generated by additional expansion of version 1.148 to include species relevant to a recent study of the oxidation of ethylene [4] as well as new measurements that led to refining the thermochemistry of CF and SiF and their cations [5].

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:

CI
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)UncertaintyUnits
24.4214.88± 0.18kJ/mol

3D Image of CH3I (g)

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Top contributors to the provenance of ΔfH° of CH3I (g)

The 12 contributors listed below account for 90.7% 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.

Contribution
(%)
TN
ID
Reaction Measured Quantity Reference
48.76222.2 CH3I (g) → [CH3]+ (g) I (g) ΔrH°(0 K) = 12.251 ± 0.0024 eVLee 2007
18.56222.1 CH3I (g) → [CH3]+ (g) I (g) ΔrH°(0 K) = 12.248 ± 0.003 (×1.297) eVBodi 2009, Bodi 2023
5.26224.4 CH3I (g) HI (g) → I2 (g) CH4 (g) ΔrG°(669 K) = -10.34 ± 0.09 (×1.874) kcal/molGoy 1965, 3rd Law
4.86224.2 CH3I (g) HI (g) → I2 (g) CH4 (g) ΔrG°(630.5 K) = -10.48 ± 0.08 (×2.181) kcal/molGolden 1965, 3rd Law, Cox 1970
3.66222.3 CH3I (g) → [CH3]+ (g) I (g) ΔrH°(0 K) = 12.243 ± 0.008 (×1.091) eVLee 2007, Bodi 2009
2.42359.1 H2 (g) C (graphite) → CH4 (g) ΔrG°(1165 K) = 37.521 ± 0.068 kJ/molSmith 1946, note COf, 3rd Law
2.06222.5 CH3I (g) → [CH3]+ (g) I (g) ΔrH°(0 K) = 12.24 ± 0.01 (×1.164) eVMintz 1976
1.56235.1 CH3I (l) + 7/2 O2 (g) → 2 CO2 (g) + 3 H2O (l) I2 (cr,l) ΔrH°(298.15 K) = -1617.2 ± 0.6 (×4.458) kJ/molCarson 1993
0.96237.1 CH3I (l) H2 (g) → 2 CH4 (g) I2 (cr,l) ΔrH°(298.15 K) = -30.0 ± 0.8 kcal/molCarson 1961, note unc, Cox 1970
0.86222.4 CH3I (g) → [CH3]+ (g) I (g) ΔrH°(0 K) = 12.269 ± 0.003 (×5.907) eVSong 2001
0.86224.5 CH3I (g) HI (g) → I2 (g) CH4 (g) ΔrH°(669 K) = -12.65 ± 0.39 (×1.067) kcal/molGoy 1965, 2nd Law
0.86155.7 CI4 (g) + 3 CH4 (g) → 4 CH3I (g) ΔrH°(0 K) = -6.16 ± 1.0 kcal/molxyx 2016

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.


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)C[I+]944.71935.31± 0.18kJ/mol141.93844 ±
0.00083
12538-72-6*0
89.7 IodomethaneCH3I (l)CI-12.26± 0.20kJ/mol141.93899 ±
0.00083
74-88-4*590
25.2 Methylium[CH3]+ (g)[CH3+]1099.3541095.411± 0.045kJ/mol15.03397 ±
0.00083
14531-53-4*0
24.5 MethaneCH4 (g)C-66.541-74.511± 0.044kJ/mol16.04246 ±
0.00085
74-82-8*0
22.3 MethylCH3 (g)[CH3]149.882146.481± 0.050kJ/mol15.03452 ±
0.00083
2229-07-4*0
19.0 Methane cation[CH4]+ (g)[CH4+]1150.6881144.305± 0.057kJ/mol16.04191 ±
0.00085
20741-88-2*0
14.3 TetraiodomethaneCI4 (g)C(I)(I)(I)I320.8315.7± 2.0kJ/mol519.62858 ±
0.00081
507-25-5*0
11.5 Carbonic acidC(O)(OH)2 (aq, undissoc)OC(=O)O-698.670± 0.028kJ/mol62.0248 ±
0.0012
463-79-6*1000
11.4 WaterH2O (cr,l)O-286.274-285.802± 0.022kJ/mol18.01528 ±
0.00033
7732-18-5*500
11.4 WaterH2O (l)O-285.802± 0.022kJ/mol18.01528 ±
0.00033
7732-18-5*590

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.

Influence
Coefficient
TN
ID
Reaction Measured Quantity Reference
0.9046221.3 CH3I (g) → [CH3I]+ (g) ΔrH°(0 K) = 76930.0 ± 1.0 cm-1Baig 1981
0.5226222.2 CH3I (g) → [CH3]+ (g) I (g) ΔrH°(0 K) = 12.251 ± 0.0024 eVLee 2007
0.4586236.3 CH3I (l) → CH3I (g) ΔrG°(299.19 K) = 1.484 ± 0.125 kJ/molBoublik 1972, Fogg 1953, Zaalishvili 1962, Raetzsch 1965, ThermoData 2004
0.2796236.5 CH3I (l) → CH3I (g) ΔrG°(287.05 K) = 2.578 ± 0.160 kJ/molBoublik 1972, Fogg 1953, Zaalishvili 1962, Raetzsch 1965, ThermoData 2004
0.2476236.7 CH3I (l) → CH3I (g) ΔrG°(285.78 K) = 2.69 ± 0.17 kJ/molThompson 1936, Fogg 1953, Zaalishvili 1962, Raetzsch 1965, ThermoData 2004
0.2366234.4 CH3I (g) CBr4 (g) → 4 CH3Br (g) CI4 (g) ΔrH°(0 K) = -0.04 ± 1.0 kcal/molxyx 2016
0.2136155.7 CI4 (g) + 3 CH4 (g) → 4 CH3I (g) ΔrH°(0 K) = -6.16 ± 1.0 kcal/molxyx 2016
0.1986222.1 CH3I (g) → [CH3]+ (g) I (g) ΔrH°(0 K) = 12.248 ± 0.003 (×1.297) eVBodi 2009, Bodi 2023
0.1722923.2 ICN (g) CH3Br (g) → BrCN (g) CH3I (g) ΔrH°(0 K) = 2.43 ± 1.0 kcal/molRuscic unpub
0.1422923.3 ICN (g) CH3Br (g) → BrCN (g) CH3I (g) ΔrH°(0 K) = 2.43 ± 1.1 kcal/molRuscic unpub
0.1192923.1 ICN (g) CH3Br (g) → BrCN (g) CH3I (g) ΔrH°(0 K) = 2.40 ± 1.2 kcal/molRuscic unpub
0.0586224.4 CH3I (g) HI (g) → I2 (g) CH4 (g) ΔrG°(669 K) = -10.34 ± 0.09 (×1.874) kcal/molGoy 1965, 3rd Law
0.0566221.1 CH3I (g) → [CH3I]+ (g) ΔrH°(0 K) = 76932 ± 4 cm-1Urban 2002
0.0546224.2 CH3I (g) HI (g) → I2 (g) CH4 (g) ΔrG°(630.5 K) = -10.48 ± 0.08 (×2.181) kcal/molGolden 1965, 3rd Law, Cox 1970
0.0396222.3 CH3I (g) → [CH3]+ (g) I (g) ΔrH°(0 K) = 12.243 ± 0.008 (×1.091) eVLee 2007, Bodi 2009
0.0366221.2 CH3I (g) → [CH3I]+ (g) ΔrH°(0 K) = 76934 ± 5 cm-1Strobel 1994, Strobel 1993
0.0256155.1 CI4 (g) + 3 CH4 (g) → 4 CH3I (g) ΔrH°(298.15 K) = -39.9 ± 12 kJ/molMarshall 2005
0.0226222.5 CH3I (g) → [CH3]+ (g) I (g) ΔrH°(0 K) = 12.24 ± 0.01 (×1.164) eVMintz 1976
0.0152920.2 ICN (g) CH4 (g) → HCN (g) CH3I (g) ΔrH°(0 K) = -1.03 ± 3.1 kcal/molRuscic unpub
0.0142920.3 ICN (g) CH4 (g) → HCN (g) CH3I (g) ΔrH°(0 K) = -0.97 ± 3.2 kcal/molRuscic unpub


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. 1.156 of the Thermochemical Network (2024); available at ATcT.anl.gov
4   N. A. Seifert, B. Ruscic, R. Sivaramakrishnan, and K. Prozument,
The C2H4O Isomers in the Oxidation of Ethylene
J. Mol. Spectrosc. 398, 111847/1-8 (2023) [DOI: 10.1016/j.jms.2023.111847]
5   U. Jacovella, B. Ruscic, N. L. Chen, H.-L. Le, S. Boyé-Péronne, S. Hartweg, M. Roy-Chowdhury, G. A. Garcia, J.-C. Loison, and B. Gans,
Refining Thermochemical Properties of CF, SiF, and Their Cations by Combining Photoelectron Spectroscopy, Quantum Chemical Calculations, and the Active Thermochemical Tables Approach
Phys. Chem. Chem. Phys. 25, 30838-30847 (2023) [DOI: 10.1039/D3CP04244H]
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]
7   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]

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] and Ruscic and Bross[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.