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:

CBr
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

   ΔfH°(0 K)   ΔfH°(298.15 K)UncertaintyUnits
-20.48-35.88± 0.19kJ/mol

3D Image of CH3Br (g)

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

The 20 contributors listed below account only for 54.1% of the provenance of ΔfH° 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
10.26283.6 CH3Cl (g) → CCl4 (g) + 3 CH4 (g) ΔrH°(0 K) = 2.52 ± 0.30 kcal/molKarton 2017
9.16290.1 CH3Br (g) → [CH3]+ (g) Br (g) ΔrH°(0 K) = 12.834 ± 0.002 (×2.828) eVSong 2001
5.11108.2 Br2 (cr,l) → Br2 (g) ΔrH°(298.15 K) = 7.386 ± 0.027 kcal/molHildenbrand 1958
3.99678.1 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) ΔrH°(298.15 K) = -55.47 ± 0.11 kcal/molJohnson 1963
2.76468.7 CH4 (g) CH2Cl2 (g) → 2 CH3Cl (g) ΔrH°(0 K) = 1.03 ± 0.25 kcal/molKarton 2017, Karton 2011, Karton 2007, Karton 2006
2.76304.13 CH3Br (g) → CBr4 (g) + 3 CH4 (g) ΔrH°(0 K) = 26.8 ± 2.5 kJ/molBross 2023
2.51209.1 [HBr]+ (g) → H (g) Br+ (g) ΔrH°(0 K) = 31394.5 ± 20 cm-1Haugh 1971, Norling 1935
2.26323.5 CH3I (g) CBr4 (g) → 4 CH3Br (g) CI4 (g) ΔrH°(0 K) = -0.5 ± 2.5 kJ/molBross 2023
2.26274.1 CH3Cl (g) + 3/2 O2 (g) → CO2 (g) H2O (cr,l) HCl (aq, 600 H2O) ΔrH°(298.15 K) = -764.00 ± 0.50 (×1.756) kJ/molFletcher 1971
1.66292.3 CH3Br (g) HBr (g) → Br2 (g) CH4 (g) ΔrG°(712.2 K) = 35.8 ± 1.6 kJ/molFerguson 1973, 3rd Law
1.52375.1 H2 (g) C (graphite) → CH4 (g) ΔrG°(1165 K) = 37.521 ± 0.068 kJ/molSmith 1946, note COf, 3rd Law
1.46308.1 CH3Br (l) H2 (g) → 2 CH4 (g) Br2 (cr,l) ΔrH°(298.15 K) = -6.60 ± 0.60 (×1.189) kcal/molAdams 1966, as quoted by Cox 1970
1.46471.6 CH4 (g) CCl4 (g) → CH3Cl (g) CHCl3 (g) ΔrH°(0 K) = -3.24 ± 0.25 kcal/molKarton 2017, Karton 2011, Karton 2007, Karton 2006
1.16376.6 CHBr3 (g) + 2 CH4 (g) → 3 CH3Br (g) ΔrH°(0 K) = -8.6 ± 2.5 kJ/molBross 2023
1.06277.10 CH3Cl (g) H (g) → CH4 (g) Cl (g) ΔrH°(0 K) = -7296 ± 100 cm-1Czako 2012
0.96235.8 CBr4 (g) → C (g) + 4 Br (g) ΔrH°(0 K) = 1037.9 ± 2.5 kJ/molBross 2023
0.96249.5 CI4 (g) + 4 Br (g) → CBr4 (g) + 4 I (g) ΔrH°(0 K) = -221.5 ± 2.5 kJ/molBross 2023
0.96469.7 CH4 (g) CHCl3 (g) → CH2Cl2 (g) CH3Cl (g) ΔrH°(0 K) = -0.13 ± 0.25 kcal/molKarton 2017, Karton 2011, Karton 2007, Karton 2006
0.96236.6 CBr4 (g) + 4 H (g) → CH4 (g) + 4 Br (g) ΔrH°(0 K) = -604.0 ± 2.5 kJ/molBross 2023
0.86293.1 CH3Br (g) H2 (g) → CH4 (g) HBr (g) ΔrH°(523.15 K) = -18.062 ± 0.321 kcal/molFowell 1965

Top 10 species with enthalpies of formation correlated to the ΔfH° 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 Image    ΔfH°(0 K)    ΔfH°(298.15 K) Uncertainty Units Relative
Molecular
Mass
ATcT ID
97.1 Bromomethane cation[CH3Br]+ (g)C[Br+]996.63981.72± 0.20kJ/mol94.9380 ±
0.0013
12538-70-4*0
94.8 BromomethaneCH3Br (l)CBr-56.20-59.22± 0.20kJ/mol94.9385 ±
0.0013
74-83-9*590
79.9 ChloromethaneCH3Cl (g)CCl-74.67-82.60± 0.17kJ/mol50.4872 ±
0.0012
74-87-3*0
79.1 Chloromethane cation[CH3Cl]+ (g)C[Cl+]1014.611007.84± 0.17kJ/mol50.4867 ±
0.0012
12538-71-5*0
78.4 ChloromethaneCH3Cl (l)CCl-106.46-102.50± 0.17kJ/mol50.4872 ±
0.0012
74-87-3*590
45.6 Hydrogen bromideHBr (g)Br-27.52-35.36± 0.12kJ/mol80.9119 ±
0.0010
10035-10-6*0
45.6 Bromoniumyl[HBr]+ (g)[BrH+]1098.161090.31± 0.12kJ/mol80.9114 ±
0.0010
12258-64-9*0
41.7 Hydrogen bromideHBr (aq, 2570 H2O)Br-120.24± 0.12kJ/mol80.9119 ±
0.0010
10035-10-6*952
41.6 Hydrogen bromideHBr (aq, 3000 H2O)Br-120.26± 0.12kJ/mol80.9119 ±
0.0010
10035-10-6*842
41.6 Hydrogen bromideHBr (aq, 600 H2O)Br-120.01± 0.12kJ/mol80.9119 ±
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
0.9746307.2 CH3Br (l) → CH3Br (g) ΔrH°(276.71 K) = 5.769 ± 0.015 kcal/molEgan 1938
0.9626294.3 CH3Br (g) HCl (g) → CH3Cl (g) HBr (g) ΔrG°(449.3 K) = 10.036 ± 0.019 kJ/molBak 1948, 3rd Law
0.9166288.1 CH3Br (g) → [CH3Br]+ (g) ΔrH°(0 K) = 85024.6 ± 4 cm-1Urban 2002
0.2806674.2 HCCH (g) + 2 CH3Br (g) → BrCCBr (g) + 2 CH4 (g) ΔrH°(0 K) = 2.34 ± 1.0 kcal/molRuscic G4
0.2386323.5 CH3I (g) CBr4 (g) → 4 CH3Br (g) CI4 (g) ΔrH°(0 K) = -0.5 ± 2.5 kJ/molBross 2023
0.2316674.1 HCCH (g) + 2 CH3Br (g) → BrCCBr (g) + 2 CH4 (g) ΔrH°(0 K) = 3.37 ± 1.1 kcal/molRuscic G3X
0.1722940.2 ICN (g) CH3Br (g) → BrCN (g) CH3I (g) ΔrH°(0 K) = 2.43 ± 1.0 kcal/molRuscic unpub
0.1436698.4 HCCBr (g) CH3Br (g) → BrCCBr (g) CH4 (g) ΔrH°(0 K) = 0.95 ± 1.0 kcal/molRuscic G4
0.1436697.4 HCCH (g) CH3Br (g) → HCCBr (g) CH4 (g) ΔrH°(0 K) = 1.39 ± 1.0 kcal/molRuscic G4
0.1422940.3 ICN (g) CH3Br (g) → BrCN (g) CH3I (g) ΔrH°(0 K) = 2.43 ± 1.1 kcal/molRuscic unpub
0.1246649.1 CH2CHI (g) CH3Br (g) → CH2CHBr (g) CH3I (g) ΔrH°(0 K) = -5.8 ± 2.5 kJ/molBross 2023
0.1192940.1 ICN (g) CH3Br (g) → BrCN (g) CH3I (g) ΔrH°(0 K) = 2.40 ± 1.2 kcal/molRuscic unpub
0.1186698.3 HCCBr (g) CH3Br (g) → BrCCBr (g) CH4 (g) ΔrH°(0 K) = 1.36 ± 1.1 kcal/molRuscic G3X
0.1186697.3 HCCH (g) CH3Br (g) → HCCBr (g) CH4 (g) ΔrH°(0 K) = 2.01 ± 1.1 kcal/molRuscic G3X
0.1076478.6 CH3Br (g) CBr4 (g) → CH2Br2 (g) CHBr3 (g) ΔrH°(0 K) = -17.1 ± 2.5 kJ/molBross 2023
0.1066290.1 CH3Br (g) → [CH3]+ (g) Br (g) ΔrH°(0 K) = 12.834 ± 0.002 (×2.828) eVSong 2001
0.1006304.13 CH3Br (g) → CBr4 (g) + 3 CH4 (g) ΔrH°(0 K) = 26.8 ± 2.5 kJ/molBross 2023
0.0982919.4 BrCN (g) CH4 (g) → HCN (g) CH3Br (g) ΔrH°(0 K) = -1.87 ± 1.0 kcal/molRuscic G4
0.0866413.2 CH2Br2 (g) + 2 CH3Br (g) → CBr4 (g) + 2 CH4 (g) ΔrH°(0 K) = 25.7 ± 2.5 kJ/molBross 2023
0.0812919.3 BrCN (g) CH4 (g) → HCN (g) CH3Br (g) ΔrH°(0 K) = -2.27 ± 1.1 kcal/molRuscic 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 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. 1.176 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.