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 ion energetics data
Go To: Top, 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) | 664.2 | kJ/mol | N/A | Hunter and Lias, 1998 | HL |
Quantity | Value | Units | Method | Reference | Comment |
Gas basicity | 638.0 | kJ/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° | 1660. ± 10. | kJ/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° | 1650. ± 19. | kJ/mol | EIAE | Rogers, Simpson, et al., 2010 | gas phase; B |
ΔrH° | 1643. ± 13. | kJ/mol | G+TS | Ingemann and Nibbering, 1985, 2 | gas phase; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 1631. ± 14. | kJ/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° | 1614. ± 13. | kJ/mol | IMRB | Ingemann and Nibbering, 1985, 2 | gas phase; B |
References
Go To: Top, Gas phase ion energetics data, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
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 ion energetics data, References
- Symbols used in this document:
AE Appearance energy IE (evaluated) Recommended ionization energy 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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