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].

Bromomethane

Formula: CH3Br (l)

CAS RN: 74-83-9

ATcT ID: 74-83-9*590

SMILES: CBr

InChI: InChI=1S/CH3Br/c1-2/h1H3

InChIKey: GZUXJHMPEANEGY-UHFFFAOYSA-N

Hills Formula: C1H3Br1

2D Image:

Aliases: CH3Br; Bromomethane; Methyl bromide; Methyl monobromide; Monobromomethane; Carbon monobromide; Monobromocarbon; RCRA U029; UN 1062; Halon 1001; R 40B1; Bercema; Brom-O-gas; Celfume; Curafume; Dawson 100; Detia gas ex-M; Dowfume; Dowfume mc-2; Dowfume mc-33; Edco; Embafume; Fumigant-1; Haltox; Iscobrome; Kayafume; MB; MBX; Mebr; Metafume; Methogas; Pestmaster; Profume; Rotox; Terabol; Terr-O-gas 100; Terr-O-gas 67; Zytox

Relative Molecular Mass: 94.9385 ± 0.0013

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
-56.20	-59.22	± 0.20	kJ/mol

Top contributors to the provenance of Δ_fH° of CH3Br (l)

The 20 contributors listed below account only for 57.6% of the provenance of Δ_fH° of CH3Br (l).
A total of 254 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.

Contribution (%)	TN ID	Reaction	Measured Quantity	Reference
9.4	6307.2	CH3Br (l) → CH3Br (g)	Δ_rH°(276.71 K) = 5.769 ± 0.015 kcal/mol	Egan 1938
9.2	6283.6	4 CH3Cl (g) → CCl4 (g) + 3 CH4 (g)	Δ_rH°(0 K) = 2.52 ± 0.30 kcal/mol	Karton 2017
8.1	6290.1	CH3Br (g) → [CH3]+ (g) + Br (g)	Δ_rH°(0 K) = 12.834 ± 0.002 (×2.828) eV	Song 2001
4.6	1108.2	Br2 (cr,l) → Br2 (g)	Δ_rH°(298.15 K) = 7.386 ± 0.027 kcal/mol	Hildenbrand 1958
3.5	9678.1	S(O)(OH)2 (aq, 2500 H2O) + Br2 (cr,l) + H2O (cr,l) → OS(O)(OH)2 (aq, 2500 H2O) + 2 HBr (aq, 1250 H2O)	Δ_rH°(298.15 K) = -55.47 ± 0.11 kcal/mol	Johnson 1963
2.5	6468.7	CH4 (g) + CH2Cl2 (g) → 2 CH3Cl (g)	Δ_rH°(0 K) = 1.03 ± 0.25 kcal/mol	Karton 2017, Karton 2011, Karton 2007, Karton 2006
2.4	6304.13	4 CH3Br (g) → CBr4 (g) + 3 CH4 (g)	Δ_rH°(0 K) = 26.8 ± 2.5 kJ/mol	Bross 2023
2.3	1209.1	[HBr]+ (g) → H (g) + Br+ (g)	Δ_rH°(0 K) = 31394.5 ± 20 cm-1	Haugh 1971, Norling 1935
2.0	6323.5	4 CH3I (g) + CBr4 (g) → 4 CH3Br (g) + CI4 (g)	Δ_rH°(0 K) = -0.5 ± 2.5 kJ/mol	Bross 2023
1.9	6274.1	CH3Cl (g) + 3/2 O2 (g) → CO2 (g) + H2O (cr,l) + HCl (aq, 600 H2O)	Δ_rH°(298.15 K) = -764.00 ± 0.50 (×1.756) kJ/mol	Fletcher 1971
1.5	6308.1	2 CH3Br (l) + H2 (g) → 2 CH4 (g) + Br2 (cr,l)	Δ_rH°(298.15 K) = -6.60 ± 0.60 (×1.189) kcal/mol	Adams 1966, as quoted by Cox 1970
1.4	6292.3	CH3Br (g) + HBr (g) → Br2 (g) + CH4 (g)	Δ_rG°(712.2 K) = 35.8 ± 1.6 kJ/mol	Ferguson 1973, 3rd Law
1.4	2375.1	2 H2 (g) + C (graphite) → CH4 (g)	Δ_rG°(1165 K) = 37.521 ± 0.068 kJ/mol	Smith 1946, note COf, 3rd Law
1.2	6471.6	CH4 (g) + CCl4 (g) → CH3Cl (g) + CHCl3 (g)	Δ_rH°(0 K) = -3.24 ± 0.25 kcal/mol	Karton 2017, Karton 2011, Karton 2007, Karton 2006
1.0	6376.6	CHBr3 (g) + 2 CH4 (g) → 3 CH3Br (g)	Δ_rH°(0 K) = -8.6 ± 2.5 kJ/mol	Bross 2023
0.9	6277.10	CH3Cl (g) + H (g) → CH4 (g) + Cl (g)	Δ_rH°(0 K) = -7296 ± 100 cm-1	Czako 2012
0.8	6235.8	CBr4 (g) → C (g) + 4 Br (g)	Δ_rH°(0 K) = 1037.9 ± 2.5 kJ/mol	Bross 2023
0.8	6249.5	CI4 (g) + 4 Br (g) → CBr4 (g) + 4 I (g)	Δ_rH°(0 K) = -221.5 ± 2.5 kJ/mol	Bross 2023
0.8	6469.7	CH4 (g) + CHCl3 (g) → CH2Cl2 (g) + CH3Cl (g)	Δ_rH°(0 K) = -0.13 ± 0.25 kcal/mol	Karton 2017, Karton 2011, Karton 2007, Karton 2006
0.8	6236.6	CBr4 (g) + 4 H (g) → CH4 (g) + 4 Br (g)	Δ_rH°(0 K) = -604.0 ± 2.5 kJ/mol	Bross 2023

Top 10 species with enthalpies of formation correlated to the Δ_fH° of CH3Br (l)

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
94.8	Bromomethane	CH3Br (g)	-20.48	-35.88	± 0.19	kJ/mol	94.9385 ± 0.0013	74-83-9*0
92.1	Bromomethane cation	[CH3Br]+ (g)	996.63	981.72	± 0.20	kJ/mol	94.9380 ± 0.0013	12538-70-4*0
75.8	Chloromethane	CH3Cl (g)	-74.67	-82.60	± 0.17	kJ/mol	50.4872 ± 0.0012	74-87-3*0
75.0	Chloromethane cation	[CH3Cl]+ (g)	1014.61	1007.84	± 0.17	kJ/mol	50.4867 ± 0.0012	12538-71-5*0
74.4	Chloromethane	CH3Cl (l)	-106.46	-102.50	± 0.17	kJ/mol	50.4872 ± 0.0012	74-87-3*590
43.3	Hydrogen bromide	HBr (g)	-27.52	-35.36	± 0.12	kJ/mol	80.9119 ± 0.0010	10035-10-6*0
43.2	Bromoniumyl	[HBr]+ (g)	1098.16	1090.31	± 0.12	kJ/mol	80.9114 ± 0.0010	12258-64-9*0
39.5	Hydrogen bromide	HBr (aq, 2570 H2O)		-120.24	± 0.12	kJ/mol	80.9119 ± 0.0010	10035-10-6*952
39.5	Hydrogen bromide	HBr (aq, 3000 H2O)		-120.26	± 0.12	kJ/mol	80.9119 ± 0.0010	10035-10-6*842
39.4	Hydrogen bromide	HBr (aq, 600 H2O)		-120.01	± 0.12	kJ/mol	80.9119 ± 0.0010	10035-10-6*834

Most Influential reactions involving CH3Br (l)

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
0.974	6307.2	CH3Br (l) → CH3Br (g)	Δ_rH°(276.71 K) = 5.769 ± 0.015 kcal/mol	Egan 1938
0.018	6307.1	CH3Br (l) → CH3Br (g)	Δ_rH°(298.15 K) = 23.24 ± 0.46 kJ/mol	Majer 1985
0.016	6308.1	2 CH3Br (l) + H2 (g) → 2 CH4 (g) + Br2 (cr,l)	Δ_rH°(298.15 K) = -6.60 ± 0.60 (×1.189) kcal/mol	Adams 1966, as quoted by Cox 1970
0.002	6307.5	CH3Br (l) → CH3Br (g)	Δ_rH°(271.82 K) = 24.497 ± 1.319 kJ/mol	Egan 1938, 2nd Law, ThermoData 2004
0.002	6307.9	CH3Br (l) → CH3Br (g)	Δ_rH°(266.40 K) = 24.689 ± 1.331 kJ/mol	Hsia 1931, 2nd Law, ThermoData 2004
0.001	6307.7	CH3Br (l) → CH3Br (g)	Δ_rH°(245.60 K) = 25.529 ± 1.809 kJ/mol	Egan 1938, 2nd Law, ThermoData 2004

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. 1.176 of the Thermochemical Network (2024); available at ATcT.anl.gov
4		T. L. Nguyen et al, ongoing studies (2024)
5		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]
6		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 [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.

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.