Selected ATcT [1, 2] enthalpy of formation based on version 1.124 of the Thermochemical Network [3]

This version of ATcT results was generated by additional expansion of version 1.122x [4] to include additional information relevant to the study of thermophysical and thermochemical properties of CH2 and CH3 using nonrigid rotor anharmonic oscillator (NRRAO) partition functions [5], the development and benchmarking of a state-of-the-art computational approach that aims to reproduce total atomization energies of small molecules within 10–15 cm^-1 [6], as well as the study of the reversible reaction C₂H₃ + H₂ ⇌ C₂H₄ + H ⇌ C₂H₅ [7]

Iodomethane cation

Formula: [CH3I]+ (g)

CAS RN: 12538-72-6

ATcT ID: 12538-72-6*0

SMILES: C[I+]

InChI: InChI=1S/CH3I/c1-2/h1H3/q+1

InChIKey: NPFPLWGVWWDMKQ-UHFFFAOYSA-N

Hills Formula: C1H3I1+

2D Image:

Aliases: [CH3I]+; Iodomethane cation; Iodomethane ion (1+); Methyl iodide cation; Methyl iodide ion (1+); Methyl monoiodide cation; Methyl monoiodride ion (1+); Monoiodomethane cation; Monoiodomethane ion (1+)

Relative Molecular Mass: 141.93844 ± 0.00083

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
944.68	935.28	± 0.18	kJ/mol

3D Image of [CH3I]+ (g)

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Top contributors to the provenance of Δ_fH° of [CH3I]+ (g)

The 12 contributors listed below account for 90.3% of the provenance of Δ_fH° 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
48.0	5542.2	CH3I (g) → [CH3]+ (g) + I (g)	Δ_rH°(0 K) = 12.251 ± 0.0024 eV	Lee 2007
17.5	5542.1	CH3I (g) → [CH3]+ (g) + I (g)	Δ_rH°(0 K) = 12.248 ± 0.003 (×1.325) eV	Bodi 2009
5.3	5544.4	CH3I (g) + HI (g) → I2 (g) + CH4 (g)	Δ_rG°(669 K) = -10.34 ± 0.09 (×1.834) kcal/mol	Goy 1965, 3rd Law
5.0	5544.2	CH3I (g) + HI (g) → I2 (g) + CH4 (g)	Δ_rG°(630.5 K) = -10.48 ± 0.08 (×2.134) kcal/mol	Golden 1965, 3rd Law, Cox 1970
3.6	5542.3	CH3I (g) → [CH3]+ (g) + I (g)	Δ_rH°(0 K) = 12.243 ± 0.008 (×1.091) eV	Lee 2007, Bodi 2009
3.5	2245.1	2 H2 (g) + C (graphite) → CH4 (g)	Δ_rG°(1165 K) = 37.521 ± 0.068 kJ/mol	Smith 1946, note COf, 3rd Law
1.9	5542.5	CH3I (g) → [CH3]+ (g) + I (g)	Δ_rH°(0 K) = 12.24 ± 0.01 (×1.189) eV	Mintz 1976
1.6	5555.1	2 CH3I (l) + 7/2 O2 (g) → 2 CO2 (g) + 3 H2O (l) + I2 (cr,l)	Δ_rH°(298.15 K) = -1617.2 ± 0.6 (×4.362) kJ/mol	Carson 1993
0.9	5542.4	CH3I (g) → [CH3]+ (g) + I (g)	Δ_rH°(0 K) = 12.269 ± 0.003 (×5.781) eV	Song 2001
0.9	5557.1	2 CH3I (l) + H2 (g) → 2 CH4 (g) + I2 (cr,l)	Δ_rH°(298.15 K) = -30.0 ± 0.8 kcal/mol	Carson 1961, note unc, Cox 1970
0.8	5544.5	CH3I (g) + HI (g) → I2 (g) + CH4 (g)	Δ_rH°(669 K) = -12.65 ± 0.39 (×1.067) kcal/mol	Goy 1965, 2nd Law
0.8	5475.7	CI4 (g) + 3 CH4 (g) → 4 CH3I (g)	Δ_rH°(0 K) = -6.16 ± 1.0 kcal/mol	xyx 2016

Top 10 species with enthalpies of formation correlated to the Δ_fH° 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	Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units	Relative Molecular Mass	ATcT ID
99.7	Iodomethane	CH3I (g)	24.39	14.86	± 0.18	kJ/mol	141.93899 ± 0.00083	74-88-4*0
89.6	Iodomethane	CH3I (l)		-12.29	± 0.20	kJ/mol	141.93899 ± 0.00083	74-88-4*590
27.2	Methylium	[CH3]+ (g)	1099.345	1095.402	± 0.049	kJ/mol	15.03397 ± 0.00083	14531-53-4*0
26.7	Methane	CH4 (g)	-66.551	-74.520	± 0.048	kJ/mol	16.04246 ± 0.00085	74-82-8*0
24.6	Methyl	CH3 (g)	149.872	146.471	± 0.053	kJ/mol	15.03452 ± 0.00083	2229-07-4*0
21.4	Methane cation	[CH4]+ (g)	1150.679	1144.296	± 0.061	kJ/mol	16.04191 ± 0.00085	20741-88-2*0
14.3	Tetraiodomethane	CI4 (g)	320.9	315.8	± 2.0	kJ/mol	519.62858 ± 0.00081	507-25-5*0
9.4	Carbon	C (g)	711.404	716.889	± 0.044	kJ/mol	12.01070 ± 0.00080	7440-44-0*0
9.4	Carbon	C (g, triplet)	711.404	716.889	± 0.044	kJ/mol	12.01070 ± 0.00080	7440-44-0*1
9.4	Carbon	C (g, singlet)	833.335	838.482	± 0.044	kJ/mol	12.01070 ± 0.00080	7440-44-0*2

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
0.904	5541.3	CH3I (g) → [CH3I]+ (g)	Δ_rH°(0 K) = 76930.0 ± 1.0 cm-1	Baig 1981
0.056	5541.1	CH3I (g) → [CH3I]+ (g)	Δ_rH°(0 K) = 76932 ± 4 cm-1	Urban 2002
0.036	5541.2	CH3I (g) → [CH3I]+ (g)	Δ_rH°(0 K) = 76934 ± 5 cm-1	Strobel 1994, Strobel 1993
0.002	5541.5	CH3I (g) → [CH3I]+ (g)	Δ_rH°(0 K) = 76930 ± 20 cm-1	Price 1936, est unc
0.000	5541.6	CH3I (g) → [CH3I]+ (g)	Δ_rH°(0 K) = 9.540 ± 0.004 eV	Karlsson 1977
0.000	5541.7	CH3I (g) → [CH3I]+ (g)	Δ_rH°(0 K) = 9.533 ± 0.01 eV	Tsai 1975
0.000	5541.8	CH3I (g) → [CH3I]+ (g)	Δ_rH°(0 K) = 9.550 ± 0.006 (×2) eV	Nicholson 1965

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 21^st 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. 1.124 of the Thermochemical Network, Argonne National Laboratory, Lemont, Illinois 2022; available at ATcT.anl.gov [DOI: 10.17038/CSE/1885923]
4		Y. Ren, L. Zhou, A. Mellouki, V. Daële, M. Idir, S. S. Brown, B. Ruscic, Robert S. Paton, M. R. McGillen, and A. R. Ravishankara, Reactions of NO3 with Aromatic Aldehydes: Gas-Phase Kinetics and Insights into the Mechanism of the Reaction. Atmos. Chem. Phys. 21, 13537-13551 (2021) [DOI: 10.5194/acp2021-228]
5		B. Ruscic and D. H. Bross, Active Thermochemical Tables: The Thermophysical and Thermochemical Properties of Methyl, CH3, and Methylene, CH2, Corrected for Nonrigid Rotor and Anharmonic Oscillator Effects. Mol. Phys. e1969046 (2021) [DOI: 10.1080/00268976.2021.1969046]
6		J. H. Thorpe, J. L. Kilburn, D. Feller, P. B. Changala, D. H. Bross, B. Ruscic, and J. F. Stanton, Elaborated Thermochemical Treatment of HF, CO, N2, and H2O: Insight into HEAT and Its Extensions J. Chem. Phys. 155, 184109 (2021) [DOI: 10.1063/5.0069322]
7		T. L. Nguyen, D. H. Bross, B. Ruscic, G. B. Ellison, and J. F. Stanton, Mechanism, Thermochemistry, and Kinetics of the Reversible Reactions: C2H3 + H2 ⇌ C2H4 + H ⇌ C2H5. Faraday Discuss. , (Advance Article) (2022) [DOI: 10.1039/D1FD00124H]
8		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]
9		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 [8,9]).
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.