Methane, bromo-

Formula: CH₃Br
Molecular weight: 94.939
IUPAC Standard InChI: InChI=1S/CH3Br/c1-2/h1H3
IUPAC Standard InChIKey: GZUXJHMPEANEGY-UHFFFAOYSA-N
CAS Registry Number: 74-83-9
Chemical structure:
This structure is also available as a 2d Mol file or as a computed 3d SD file
View 3d structure (requires JavaScript / HTML 5)
Isotopologues:
- bromo(2H3)methane
Other names: Bromomethane; Curafume; Embafume; Halon 1001; Haltox; Iscobrome; Methyl bromide; Monobromomethane; Terabol; CH3Br; Bercema; Brom-methan; Brom-O-gas; Brom-O-gaz; Bromometano; Bromure de methyle; Bromuro di metile; Broommethaan; Celfume; Dawson 100; Detia gas ex-M; Dowfume mc-2; Dowfume mc-33; Dowfume mc-2 soil fumigant; Edco; Fumigant-1; Kayafume; MBX; MeBr; Metafume; Methogas; Methylbromid; Metylu bromek; Pestmaster; Profume; R 40B1; Rcra waste number U029; Terr-O-gas 67; Terr-O-gas 100; UN 1062; Zytox; Brom-O-sol; Methybrom
Permanent link for this species. Use this link for bookmarking this species for future reference.
Information on this page:
Other data available:
Data at other public NIST sites:
- Gas Phase Kinetics Database
- X-ray Photoelectron Spectroscopy Database, version 5.0
Options:
- Switch to calorie-based units

Data at NIST subscription sites:

NIST subscription sites provide data under the NIST Standard Reference Data Program, but require an annual fee to access. The purpose of the fee is to recover costs associated with the development of data collections included in such sites. Your institution may already be a subscriber. Follow the links above to find out more about the data in these sites and their terms of usage.

Gas phase thermochemistry data

Go To: Top, Condensed phase thermochemistry data, Ion clustering data, Vibrational and/or electronic energy levels, References, Notes

Data compiled by: Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

Quantity	Value	Units	Method	Reference
Δ_fH°_gas	-34.3 ± 0.8	kJ/mol	Eqk	Ferguson, Okafo, et al., 1973
Δ_fH°_gas	-38. ± 1.3	kJ/mol	Chyd	Adams, Carson, et al., 1966
Δ_fH°_gas	-37.5 ± 1.5	kJ/mol	Chyd	Fowell, Lacher, et al., 1965

Condensed phase thermochemistry data

Go To: Top, Gas phase thermochemistry data, Ion clustering data, Vibrational and/or electronic energy levels, References, Notes

Data compiled as indicated in comments:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DH - Eugene S. Domalski and Elizabeth D. Hearing

Quantity	Value	Units	Method	Reference	Comment
Δ_fH°_liquid	-60.6 ± 1.3	kJ/mol	Chyd	Adams, Carson, et al., 1966	Reanalyzed by Cox and Pilcher, 1970, Original value = -61.1 ± 1.3 kJ/mol; ALS
Quantity	Value	Units	Method	Reference	Comment
S°_liquid	155.14	J/mol*K	N/A	Egan and Kemp, 1938	DH

Constant pressure heat capacity of liquid

C_p,liquid (J/mol*K)	Temperature (K)	Reference	Comment
114.6	283.	Kurbatov, 1948	T = -67 to 9°C. Mean Cp, three temperatures.; DH
78.83	280.	Egan and Kemp, 1938	T = 15 to 280 K.; DH

Ion clustering data

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Vibrational and/or electronic energy levels, References, Notes

Data compiled as indicated in comments:
B - John E. Bartmess
M - Michael M. Meot-Ner (Mautner) and Sharon G. Lias

Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. Searches may be limited to ion clustering reactions. A general reaction search form is also available.

Clustering reactions

+ Methane, bromo- = ( • )

By formula: Br^- + CH₃Br = (Br^- • CH₃Br)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	46.9 ± 4.2	kJ/mol	TDAs	Li, Ross, et al., 1996	gas phase; B
Δ_rH°	38.5 ± 2.1	kJ/mol	TDAs	Dougherty and Roberts, 1974	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	58.6	J/mol*K	HPMS	Dougherty and Roberts, 1974	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	19.2 ± 0.84	kJ/mol	TDAs	Li, Ross, et al., 1996	gas phase; B
Δ_rG°	20.9 ± 3.3	kJ/mol	TDAs	Dougherty and Roberts, 1974	gas phase; B

+ Methane, bromo- = ( • )

By formula: CH₃⁺ + CH₃Br = (CH₃⁺ • CH₃Br)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	265.	kJ/mol	PHPMS	McMahon, Heinis, et al., 1988	gas phase; switching reaction(CH3+)N2, Entropy change calculated or estimated, uses MCA(N2) = 202. kJ/mol; Foster, Williamson, et al., 1974; M

CH₆N⁺ + Methane, bromo- = (CH₆N⁺ • )

By formula: CH₆N⁺ + CH₃Br = (CH₆N⁺ • CH₃Br)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	46.9	kJ/mol	PHPMS	Meot-Ner, 1984	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	87.9	J/mol*K	PHPMS	Meot-Ner, 1984	gas phase; M

+ Methane, bromo- = ( • )

By formula: Cl^- + CH₃Br = (Cl^- • CH₃Br)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	52.3 ± 4.2	kJ/mol	TDAs	Li, Ross, et al., 1996	gas phase; B
Δ_rH°	45.6 ± 2.1	kJ/mol	TDAs	Dougherty and Roberts, 1974	gas phase; B,M
Δ_rH°	51. ± 13.	kJ/mol	IMRB	Riveros, Breda, et al., 1973	gas phase; Anchored: Larson and McMahon, 1984; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	53.6	J/mol*K	HPMS	Dougherty and Roberts, 1974	gas phase; Entropy change is questionable; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	28.5 ± 0.84	kJ/mol	TDAs	Li, Ross, et al., 1996	gas phase; B
Δ_rG°	30. ± 5.0	kJ/mol	TDAs	Dougherty and Roberts, 1974	gas phase; B

+ Methane, bromo- = ( • )

By formula: I^- + CH₃Br = (I^- • CH₃Br)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	34.7 ± 0.84	kJ/mol	N/A	Van Duzor, Wei, et al., 2010	gas phase; B
Δ_rH°	34.7 ± 2.1	kJ/mol	PDis	Cyr, Bishea, et al., 1992	gas phase; B

Vibrational and/or electronic energy levels

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Ion clustering data, References, Notes

Data compiled by: Takehiko Shimanouchi

Symmetry: C_3ν Symmetry Number σ = 3

Sym.	No	Approximate	Selected Freq.		Infrared		Raman		Comments

Species		type of mode	Value	Rating	Value	Phase	Value	Phase

a₁	1	CH3 s-str	2935	E	2972 M	gas	2972 VS	liq.	FR(2ν₅)
a₁	1	CH3 s-str	2935	E	2862.1 M	gas	2862 W	liq.	FR(2ν₅)
a₁	2	CH3 s-deform	1306	A	1305.9 S	gas	1309 W	liq.
a₁	3	CBr str	611	A	611.1 S	gas	609 S	liq.
e	4	CH3 d-str	3056	A	3056.35 S	gas	3068 VS	liq.
e	5	CH3 d-deform	1443	A	1442.7 M	gas	1456 M	liq.
e	6	CH3 rock	955	A	954.7 M	gas	956 VW	liq.

Source: Shimanouchi, 1972

Notes

Very strong

Strong

Medium

Weak

Very weak

Fermi resonance with an overtone or a combination tone indicated in the parentheses.

0~1 cm^-1 uncertainty

15~30 cm^-1 uncertainty

References

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Ion clustering data, Vibrational and/or electronic energy levels, Notes

Ferguson, Okafo, et al., 1973
Ferguson, K.C.; Okafo, E.N.; Whittle, E., Bond dissociation energies from equilibrium studies Part 4.-The equilibrium Br₂ + CH₄ = HBr + CH₃Br. Determination of D(CH₃-Br) and ΔH_f°(CH₃Br,g), J. Chem. Soc. Faraday Trans. 1, 1973, 69, 295-301. [all data]

Adams, Carson, et al., 1966
Adams, G.P.; Carson, A.S.; Laye, P.G., Thermochemistry of reductions caused by lithium aluminium hydride. Part 4.-Heat of formation of methyl bromide, Trans. Faraday Soc., 1966, 62, 1447-1449. [all data]

Fowell, Lacher, et al., 1965
Fowell, P.; Lacher, J.R.; Park, J.D., Reaction heats of organic compounds. Part 3.-Heats of hydrogenation of methyl bromide and ethyl bromide, Trans. Faraday Soc., 1965, 61, 1324-1327. [all data]

Cox and Pilcher, 1970
Cox, J.D.; Pilcher, G., Thermochemistry of Organic and Organometallic Compounds, Academic Press, New York, 1970, 1-636. [all data]

Egan and Kemp, 1938
Egan, C.J.; Kemp, J.D., Methyl bromide. The heat capacity, vapor pressure, heats of transition, fusion and vaporization. Entropy and density of the gas, J. Am. Chem. Soc., 1938, 60, 2097-2101. [all data]

Kurbatov, 1948
Kurbatov, V.Ya., Heat capacity of liquids. 2. Heat capacity and the temperature dependence of heat capacity from halogen derivatives of acylic hydrocarbons, Zh. Obshch. Kim., 1948, 18, 372-389. [all data]

Li, Ross, et al., 1996
Li, C.; Ross, P.; Szulejko, J.; McMahon, T.B., High-Pressure Mass Spectrometric Investigations of the Potential Energy Surfaces of Gas-Phase Sn2 Reactions., J. Am. Chem. Soc., 1996, 118, 39, 9360, https://doi.org/10.1021/ja960565o . [all data]

Dougherty and Roberts, 1974
Dougherty, R.C.; Roberts, J.D., SN₂ reactions in the gas phase. Nucleophilicity effects, Org. Mass Spectrom., 1974, 8, 81. [all data]

McMahon, Heinis, et al., 1988
McMahon, T.; Heinis, T.; Nicol, G.; Hovey, J.K.; Kebarle, P., Methyl Cation Affinities, J. Am. Chem. Soc., 1988, 110, 23, 7591, https://doi.org/10.1021/ja00231a002 . [all data]

Foster, Williamson, et al., 1974
Foster, M.S.; Williamson, A.D.; Beauchamp, J.L., Photoionization mass spectrometry of trans-azomethane, Int. J. Mass Spectrom. Ion Phys., 1974, 15, 429. [all data]

Meot-Ner, 1984
Meot-Ner, (Mautner)M., The Ionic Hydrogen Bond and Ion Solvation. 1. -NH+ O-, -NH+ N- and -OH+ O- Bonds. Correlations with Proton Affinity. Deviations Due to Structural Effects, J. Am. Chem. Soc., 1984, 106, 5, 1257, https://doi.org/10.1021/ja00317a015 . [all data]

Riveros, Breda, et al., 1973
Riveros, J.M.; Breda, A.C.; Blair, L.K., Formation and relative stability of chloride ion clusters in the gas phase by ICR spectroscopy, J. Am. Chem. Soc., 1973, 95, 4066. [all data]

Larson and McMahon, 1984
Larson, J.W.; McMahon, T.B., Fluoride and chloride affinities of main group oxides, fluorides, oxofluorides, and alkyls. Quantitative scales of lewis acidities from ion cyclotron resonance halide-exchange equilibria, J. Phys. Chem., 1984, 88, 1083. [all data]

Van Duzor, Wei, et al., 2010
Van Duzor, M.; Wei, J.; Mbaiwa, F.; Mabbs, R., I-center dot CH3X (X=Cl, Br, I) photodetachment: The effect of electron-molecule interactions in cluster anion photodetachment spectra and angular distributions, J. Chem. Phys., 2010, 133, 14, 144303, https://doi.org/10.1063/1.3487739 . [all data]

Cyr, Bishea, et al., 1992
Cyr, D.M.; Bishea, G.A.; Scarton, M.G.; Johnson, M.A., Observation of Charge-Transfer Excited States in the I-.CH3I, I-.CH3Br, and I-.CH2Br2 S(N)2 Reaction Intermediates Using Photofragmentation, J. Chem. Phys., 1992, 97, 8, 5911, https://doi.org/10.1063/1.463752 . [all data]

Shimanouchi, 1972
Shimanouchi, T., Tables of Molecular Vibrational Frequencies Consolidated Volume I, National Bureau of Standards, 1972, 1-160. [all data]

Notes

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Ion clustering data, Vibrational and/or electronic energy levels, References

Symbols used in this document:

C_p,liquid	Constant pressure heat capacity of liquid
S°_liquid	Entropy of liquid at standard conditions
Δ_fH°_gas	Enthalpy of formation of gas at standard conditions
Δ_fH°_liquid	Enthalpy of formation of liquid at standard conditions
Δ_rG°	Free energy of reaction at standard conditions
Δ_rH°	Enthalpy of reaction at standard conditions
Δ_rS°	Entropy of reaction at standard conditions

Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound scientific judgment. However, NIST makes no warranties to that effect, and NIST shall not be liable for any damage that may result from errors or omissions in the Database.
Customer support for NIST Standard Reference Data products.

Methane, bromo-

Data at NIST subscription sites:

Gas phase thermochemistry data

Condensed phase thermochemistry data

Constant pressure heat capacity of liquid

Ion clustering data

Clustering reactions

Vibrational and/or electronic energy levels

Symmetry: C3ν Symmetry Number σ = 3

Notes

References

Notes

Symmetry: C_3ν Symmetry Number σ = 3