Methane, bromo-
- Formula: CH3Br
- Molecular weight: 94.939
- 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
The 3d structure may be viewed using Java or Javascript. - Isotopologues:
- 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
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Gas phase thermochemistry data
Go To: Top, Gas phase ion energetics data, Mass spectrum (electron ionization), References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled by: Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔfH°gas | -8.2 ± 0.2 | kcal/mol | Eqk | Ferguson, Okafo, et al., 1973 | |
ΔfH°gas | -9.0 ± 0.32 | kcal/mol | Chyd | Adams, Carson, et al., 1966 | |
ΔfH°gas | -8.97 ± 0.35 | kcal/mol | Chyd | Fowell, Lacher, et al., 1965 |
Gas phase ion energetics data
Go To: Top, Gas phase thermochemistry data, Mass spectrum (electron ionization), References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data evaluated as indicated in comments:
HL - Edward P. Hunter and Sharon G. Lias
L - Sharon G. Lias
Data compiled as indicated in comments:
B - John E. Bartmess
LBLHLM - Sharon G. Lias, John E. Bartmess, Joel F. Liebman, John L. Holmes, Rhoda D. Levin, and W. Gary Mallard
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
View reactions leading to CH3Br+ (ion structure unspecified)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
IE (evaluated) | 10.541 ± 0.003 | eV | N/A | N/A | L |
Quantity | Value | Units | Method | Reference | Comment |
Proton affinity (review) | 158.7 | kcal/mol | N/A | Hunter and Lias, 1998 | HL |
Quantity | Value | Units | Method | Reference | Comment |
Gas basicity | 152.5 | kcal/mol | N/A | Hunter and Lias, 1998 | HL |
Ionization energy determinations
IE (eV) | Method | Reference | Comment |
---|---|---|---|
10.54 | S | Baig, Connerade, et al., 1982 | LBLHLM |
10.53 | PE | Kimura, Katsumata, et al., 1981 | LLK |
10.53 | EI | Holmes, Fingas, et al., 1981 | LLK |
10.5 ± 0.2 | EI | Kaposi, Riedel, et al., 1976 | LLK |
10.54 ± 0.01 | PI | Tsai, Baer, et al., 1975 | LLK |
10.5 ± 0.2 | EI | Kaposi, Riedel, et al., 1975 | LLK |
10.541 | S | Hochmann, Templet, et al., 1975 | LLK |
10.53 | PE | Ragle, Stenhouse, et al., 1970 | RDSH |
10.54 | PE | Potts, Lempka, et al., 1970 | RDSH |
10.53 ± 0.015 | PE | Hashmall and Heilbronner, 1970 | RDSH |
10.53 | PI | Krauss, Walker, et al., 1968 | RDSH |
10.528 ± 0.005 | PI | Nicholson, 1965 | RDSH |
10.53 ± 0.01 | PI | Watanabe, 1957 | RDSH |
10.53 ± 0.02 | EI | Frost and McDowell, 1957 | RDSH |
10.541 ± 0.003 | S | Price, 1936 | RDSH |
10.54 | PE | Andrews, Dyke, et al., 1984 | Vertical value; LBLHLM |
10.53 | PE | Utsunomiya, Kobayashi, et al., 1980 | Vertical value; LLK |
10.53 | PE | Uehara, Saito, et al., 1973 | Vertical value; LLK |
10.70 | PE | Dixon, Murrell, et al., 1971 | Vertical value; LLK |
Appearance energy determinations
De-protonation reactions
CH2Br- + =
By formula: CH2Br- + H+ = CH3Br
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 396.7 ± 2.5 | kcal/mol | Endo | Hierl, Henchman, et al., 1992 | gas phase; HO- + MeBr:6.0±2.3 kcal/mol endo. "Better than Ingemann and Nibbering, 19852" 2.0 kcal would not show barrier; B |
ΔrH° | 394.3 ± 4.6 | kcal/mol | EIAE | Rogers, Simpson, et al., 2010 | gas phase; B |
ΔrH° | 392.7 ± 3.1 | kcal/mol | G+TS | Ingemann and Nibbering, 1985, 2 | gas phase; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 389.7 ± 3.4 | kcal/mol | H-TS | Hierl, Henchman, et al., 1992 | gas phase; HO- + MeBr:6.0±2.3 kcal/mol endo. "Better than Ingemann and Nibbering, 19852" 2.0 kcal would not show barrier; B |
ΔrG° | 385.8 ± 3.0 | kcal/mol | IMRB | Ingemann and Nibbering, 1985, 2 | gas phase; B |
Mass spectrum (electron ionization)
Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled by: NIST Mass Spectrometry Data Center, William E. Wallace, director
Spectrum
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Additional Data
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Due to licensing restrictions, this spectrum cannot be downloaded.
Owner | NIST Mass Spectrometry Data Center Collection (C) 2014 copyright by the U.S. Secretary of Commerce on behalf of the United States of America. All rights reserved. |
---|---|
NIST MS number | 19630 |
References
Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
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 ΔHf°(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]
Hunter and Lias, 1998
Hunter, E.P.; Lias, S.G.,
Evaluated Gas Phase Basicities and Proton Affinities of Molecules: An Update,
J. Phys. Chem. Ref. Data, 1998, 27, 3, 413-656, https://doi.org/10.1063/1.556018
. [all data]
Baig, Connerade, et al., 1982
Baig, M.A.; Connerade, J.P.; Hormes, J.,
Autoionisation resonances in the 4p(Π) spectrum of methyl bromide,
J. Phys. B:, 1982, 15, 5. [all data]
Kimura, Katsumata, et al., 1981
Kimura, K.; Katsumata, S.; Achiba, Y.; Yamazaki, T.; Iwata, S.,
Ionization energies, Ab initio assignments, and valence electronic structure for 200 molecules
in Handbook of HeI Photoelectron Spectra of Fundamental Organic Compounds, Japan Scientific Soc. Press, Tokyo, 1981. [all data]
Holmes, Fingas, et al., 1981
Holmes, J.L.; Fingas, M.; Lossing, F.P.,
Towards a general scheme for estimating the heats of formation of organic ions in the gas phase. Part I. Odd-electron cations,
Can. J. Chem., 1981, 59, 80. [all data]
Kaposi, Riedel, et al., 1976
Kaposi, O.; Riedel, M.; Vass-Balthazar, K.; Sanchez, G.R.; Lelik, L.,
Mass-spectrometric determination of thermochemical data of CHBr3 and CBr4 by study of their electron impact and heterogeneous pyrolytic decompositions,
Acta Chim. Acad. Sci. Hung., 1976, 89, 221. [all data]
Tsai, Baer, et al., 1975
Tsai, B.P.; Baer, T.; Werner, A.S.; Lin, S.F.,
A photoelectron-photoion coincidence study of the ionization and fragment appearance potentials of bromo- and iodomethanes,
J. Phys. Chem., 1975, 79, 570. [all data]
Kaposi, Riedel, et al., 1975
Kaposi, O.; Riedel, M.; Sanchez, G.R.,
Mass-spectrometric study of electron-impact and heterogeneous pyrolytic decomposition of methyl bromide,
Acta Chim. Acad. Sci. Hung., 1975, 85, 361. [all data]
Hochmann, Templet, et al., 1975
Hochmann, P.; Templet, P.H.; Wang, H.-t.; McGlynn, S.P.,
Molecular Rydberg transitions. I. Low-energy Rydberg transitions in methyl halides,
J. Chem. Phys., 1975, 62, 2588. [all data]
Ragle, Stenhouse, et al., 1970
Ragle, J.L.; Stenhouse, I.A.; Frost, D.C.; McDowell, C.A.,
Valence-shell ionization potentials of halomethanes by photoelectron spectroscopy. I. CH3Cl, CH3Br, CH3I. Vibrational frequencies and vibronic interaction in CH3Br+ and CH3Cl+,
J. Chem. Phys., 1970, 53, 178. [all data]
Potts, Lempka, et al., 1970
Potts, A.W.; Lempka, H.J.; Streets, D.G.; Price, W.C.,
Photoelectron spectra of the halides of elements in groups III, IV, V and VI,
Phil. Trans. Roy. Soc. (London), 1970, A268, 59. [all data]
Hashmall and Heilbronner, 1970
Hashmall, J.A.; Heilbronner, E.,
n-Ionization potentials of alkyl bromides,
Angew. Chem. Intern. Ed., 1970, 9, 305. [all data]
Krauss, Walker, et al., 1968
Krauss, M.; Walker, J.A.; Dibeler, V.H.,
Mass spectrometric study of photoionization. X. Hydrogen chloride and methyl halides,
J. Res. NBS, 1968, 72A, 281. [all data]
Nicholson, 1965
Nicholson, A.J.C.,
Photoionization-efficiency curves. II. False and genuine structure,
J. Chem. Phys., 1965, 43, 1171. [all data]
Watanabe, 1957
Watanabe, K.,
Ionization potentials of some molecules,
J. Chem. Phys., 1957, 26, 542. [all data]
Frost and McDowell, 1957
Frost, D.C.; McDowell, C.A.,
Studies of the ionization of molecules by electron impact. II. Excited states of the molecular ions of methane and the methyl halides,
Proc. Roy. Soc. (London), 1957, A241, 194. [all data]
Price, 1936
Price, W.C.,
The far ultraviolet absorption spectra and ionization potentials of the alkyl halides. Part I,
J. Chem. Phys., 1936, 4, 539. [all data]
Andrews, Dyke, et al., 1984
Andrews, L.; Dyke, J.M.; Jonathan, N.; Keddar, N.; orris, A.,
The first bands in the photoelectron spectra of the CH2Br, CD2Br, CHBr2, and CH2I free radicals,
J. Phys. Chem., 1984, 88, 1950. [all data]
Utsunomiya, Kobayashi, et al., 1980
Utsunomiya, C.; Kobayashi, T.; Nagakura, S.,
Photoelectron angular distribution measurements for some aliphatic alcohols, amines, halides,
Bull. Chem. Soc. Jpn., 1980, 53, 1216. [all data]
Uehara, Saito, et al., 1973
Uehara, Y.; Saito, N.; Yonezawa, T.,
Ionization potentials of trifluoromethyl and methyl halides by photoelectron spectroscopy and calculations by extended Hucket and CNDO/2 methods,
Chem. Lett., 1973, 495. [all data]
Dixon, Murrell, et al., 1971
Dixon, R.N.; Murrell, J.N.; Narayan, B.,
The photoelectron spectra of the halomethanes,
Mol. Phys., 1971, 20, 611. [all data]
Tsuda, Melton, et al., 1964
Tsuda, S.; Melton, C.E.; Hamill, W.H.,
Ionization- efficiency curves for molecular and fragment ions from methane and the methyl halides,
J. Chem. Phys., 1964, 41, 689. [all data]
Reed and Snedden, 1956
Reed, R.I.; Snedden, W.,
Studies in electron impact methods. Part 6.-The formation of the methine and carbon ions,
J. Chem. Soc. Faraday Trans., 1956, 55, 876. [all data]
Tsuda and Hamill, 1964
Tsuda, S.; Hamill, W.H.,
Structure in ionization efficiency curves near threshold from alkanes and alkyl halides,
J. Chem. Phys., 1964, 41, 2713. [all data]
Martin, Lampe, et al., 1966
Martin, R.H.; Lampe, F.W.; Taft, R.W.,
An electron-impact study of ionization and dissociation in methoxy- and halogen- substituted methanes,
J. Am. Chem. Soc., 1966, 88, 1353. [all data]
Traeger and McLoughlin, 1981
Traeger, J.C.; McLoughlin, R.G.,
Absolute heats of formation for gas phase cations,
J. Am. Chem. Soc., 1981, 103, 3647. [all data]
Williams and Hamill, 1968
Williams, J.M.; Hamill, W.H.,
Ionization potentials of molecules and free radicals and appearance potentials by electron impact in the mass spectrometer,
J. Chem. Phys., 1968, 49, 4467. [all data]
Hierl, Henchman, et al., 1992
Hierl, P.M.; Henchman, M.J.; Paulson, J.F.,
Threshold Energies for the Reactions HO- + MeX - MeOH + X- measured by Tandem Mass Spectrometry: Acidities of MeCl and MeBr,
Int. J. Mass Spectrom. Ion Proc., 1992, 117, 475, https://doi.org/10.1016/0168-1176(92)80109-E
. [all data]
Ingemann and Nibbering, 1985
Ingemann, S.; Nibbering, N.M.M.,
Gas phase chemistry of alpha-thio carbanions,
Can. J. Chem., 1985, 62, 2273. [all data]
Rogers, Simpson, et al., 2010
Rogers, N.J.; Simpson, M.J.; Tuckett, R.P.; Dunn, K.F.; Latimer, C.J.,
Vacuum-UV negative photoion spectroscopy of CH3F, CH3Cl and CH3Br,
Phys. Chem. Chem. Phys., 2010, 12, 36, 10971-10980, https://doi.org/10.1039/c0cp00234h
. [all data]
Ingemann and Nibbering, 1985, 2
Ingemann, S.; Nibbering, N.M.M.,
Gas-phase acidity of CH3X [X = P(CH3)2, SCH3, F, Cl, Br, I] compounds,
J. Chem. Soc. Perkin Trans. 2, 1985, 837. [all data]
Notes
Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), References
- Symbols used in this document:
AE Appearance energy IE (evaluated) Recommended ionization energy ΔfH°gas Enthalpy of formation of gas at standard conditions ΔrG° Free energy of reaction at standard conditions ΔrH° Enthalpy of reaction at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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