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 (g)

CAS RN: 74-83-9

ATcT ID: 74-83-9*0

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
-20.48	-35.88	± 0.19	kJ/mol

3D Image of CH3Br (g)

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

The 20 contributors listed below account only for 54.1% of the provenance of Δ_fH° of CH3Br (g).
A total of 280 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
10.2	6283.6	4 CH3Cl (g) → CCl4 (g) + 3 CH4 (g)	Δ_rH°(0 K) = 2.52 ± 0.30 kcal/mol	Karton 2017
9.1	6290.1	CH3Br (g) → [CH3]+ (g) + Br (g)	Δ_rH°(0 K) = 12.834 ± 0.002 (×2.828) eV	Song 2001
5.1	1108.2	Br2 (cr,l) → Br2 (g)	Δ_rH°(298.15 K) = 7.386 ± 0.027 kcal/mol	Hildenbrand 1958
3.9	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
2.7	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
2.7	6304.13	4 CH3Br (g) → CBr4 (g) + 3 CH4 (g)	Δ_rH°(0 K) = 26.8 ± 2.5 kJ/mol	Bross 2023
2.5	1209.1	[HBr]+ (g) → H (g) + Br+ (g)	Δ_rH°(0 K) = 31394.5 ± 20 cm-1	Haugh 1971, Norling 1935
2.2	6323.5	4 CH3I (g) + CBr4 (g) → 4 CH3Br (g) + CI4 (g)	Δ_rH°(0 K) = -0.5 ± 2.5 kJ/mol	Bross 2023
2.2	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
1.6	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
1.5	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
1.4	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	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
1.1	6376.6	CHBr3 (g) + 2 CH4 (g) → 3 CH3Br (g)	Δ_rH°(0 K) = -8.6 ± 2.5 kJ/mol	Bross 2023
1.0	6277.10	CH3Cl (g) + H (g) → CH4 (g) + Cl (g)	Δ_rH°(0 K) = -7296 ± 100 cm-1	Czako 2012
0.9	6235.8	CBr4 (g) → C (g) + 4 Br (g)	Δ_rH°(0 K) = 1037.9 ± 2.5 kJ/mol	Bross 2023
0.9	6249.5	CI4 (g) + 4 Br (g) → CBr4 (g) + 4 I (g)	Δ_rH°(0 K) = -221.5 ± 2.5 kJ/mol	Bross 2023
0.9	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
0.9	6236.6	CBr4 (g) + 4 H (g) → CH4 (g) + 4 Br (g)	Δ_rH°(0 K) = -604.0 ± 2.5 kJ/mol	Bross 2023
0.8	6293.1	CH3Br (g) + H2 (g) → CH4 (g) + HBr (g)	Δ_rH°(523.15 K) = -18.062 ± 0.321 kcal/mol	Fowell 1965

Top 10 species with enthalpies of formation correlated to the Δ_fH° of CH3Br (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
97.1	Bromomethane cation	[CH3Br]+ (g)	996.63	981.72	± 0.20	kJ/mol	94.9380 ± 0.0013	12538-70-4*0
94.8	Bromomethane	CH3Br (l)	-56.20	-59.22	± 0.20	kJ/mol	94.9385 ± 0.0013	74-83-9*590
79.9	Chloromethane	CH3Cl (g)	-74.67	-82.60	± 0.17	kJ/mol	50.4872 ± 0.0012	74-87-3*0
79.1	Chloromethane cation	[CH3Cl]+ (g)	1014.61	1007.84	± 0.17	kJ/mol	50.4867 ± 0.0012	12538-71-5*0
78.4	Chloromethane	CH3Cl (l)	-106.46	-102.50	± 0.17	kJ/mol	50.4872 ± 0.0012	74-87-3*590
45.6	Hydrogen bromide	HBr (g)	-27.52	-35.36	± 0.12	kJ/mol	80.9119 ± 0.0010	10035-10-6*0
45.6	Bromoniumyl	[HBr]+ (g)	1098.16	1090.31	± 0.12	kJ/mol	80.9114 ± 0.0010	12258-64-9*0
41.7	Hydrogen bromide	HBr (aq, 2570 H2O)		-120.24	± 0.12	kJ/mol	80.9119 ± 0.0010	10035-10-6*952
41.6	Hydrogen bromide	HBr (aq, 3000 H2O)		-120.26	± 0.12	kJ/mol	80.9119 ± 0.0010	10035-10-6*842
41.6	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 (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
0.974	6307.2	CH3Br (l) → CH3Br (g)	Δ_rH°(276.71 K) = 5.769 ± 0.015 kcal/mol	Egan 1938
0.962	6294.3	CH3Br (g) + HCl (g) → CH3Cl (g) + HBr (g)	Δ_rG°(449.3 K) = 10.036 ± 0.019 kJ/mol	Bak 1948, 3rd Law
0.916	6288.1	CH3Br (g) → [CH3Br]+ (g)	Δ_rH°(0 K) = 85024.6 ± 4 cm-1	Urban 2002
0.280	6674.2	HCCH (g) + 2 CH3Br (g) → BrCCBr (g) + 2 CH4 (g)	Δ_rH°(0 K) = 2.34 ± 1.0 kcal/mol	Ruscic G4
0.238	6323.5	4 CH3I (g) + CBr4 (g) → 4 CH3Br (g) + CI4 (g)	Δ_rH°(0 K) = -0.5 ± 2.5 kJ/mol	Bross 2023
0.231	6674.1	HCCH (g) + 2 CH3Br (g) → BrCCBr (g) + 2 CH4 (g)	Δ_rH°(0 K) = 3.37 ± 1.1 kcal/mol	Ruscic G3X
0.172	2940.2	ICN (g) + CH3Br (g) → BrCN (g) + CH3I (g)	Δ_rH°(0 K) = 2.43 ± 1.0 kcal/mol	Ruscic unpub
0.143	6698.4	HCCBr (g) + CH3Br (g) → BrCCBr (g) + CH4 (g)	Δ_rH°(0 K) = 0.95 ± 1.0 kcal/mol	Ruscic G4
0.143	6697.4	HCCH (g) + CH3Br (g) → HCCBr (g) + CH4 (g)	Δ_rH°(0 K) = 1.39 ± 1.0 kcal/mol	Ruscic G4
0.142	2940.3	ICN (g) + CH3Br (g) → BrCN (g) + CH3I (g)	Δ_rH°(0 K) = 2.43 ± 1.1 kcal/mol	Ruscic unpub
0.124	6649.1	CH2CHI (g) + CH3Br (g) → CH2CHBr (g) + CH3I (g)	Δ_rH°(0 K) = -5.8 ± 2.5 kJ/mol	Bross 2023
0.119	2940.1	ICN (g) + CH3Br (g) → BrCN (g) + CH3I (g)	Δ_rH°(0 K) = 2.40 ± 1.2 kcal/mol	Ruscic unpub
0.118	6698.3	HCCBr (g) + CH3Br (g) → BrCCBr (g) + CH4 (g)	Δ_rH°(0 K) = 1.36 ± 1.1 kcal/mol	Ruscic G3X
0.118	6697.3	HCCH (g) + CH3Br (g) → HCCBr (g) + CH4 (g)	Δ_rH°(0 K) = 2.01 ± 1.1 kcal/mol	Ruscic G3X
0.107	6478.6	CH3Br (g) + CBr4 (g) → CH2Br2 (g) + CHBr3 (g)	Δ_rH°(0 K) = -17.1 ± 2.5 kJ/mol	Bross 2023
0.106	6290.1	CH3Br (g) → [CH3]+ (g) + Br (g)	Δ_rH°(0 K) = 12.834 ± 0.002 (×2.828) eV	Song 2001
0.100	6304.13	4 CH3Br (g) → CBr4 (g) + 3 CH4 (g)	Δ_rH°(0 K) = 26.8 ± 2.5 kJ/mol	Bross 2023
0.098	2919.4	BrCN (g) + CH4 (g) → HCN (g) + CH3Br (g)	Δ_rH°(0 K) = -1.87 ± 1.0 kcal/mol	Ruscic G4
0.086	6413.2	CH2Br2 (g) + 2 CH3Br (g) → CBr4 (g) + 2 CH4 (g)	Δ_rH°(0 K) = 25.7 ± 2.5 kJ/mol	Bross 2023
0.081	2919.3	BrCN (g) + CH4 (g) → HCN (g) + CH3Br (g)	Δ_rH°(0 K) = -2.27 ± 1.1 kcal/mol	Ruscic G3X

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.