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Methane, bromo-

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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 ± 0.003eVN/AN/AL
Quantity Value Units Method Reference Comment
Proton affinity (review)664.2kJ/molN/AHunter and Lias, 1998HL
Quantity Value Units Method Reference Comment
Gas basicity638.0kJ/molN/AHunter and Lias, 1998HL

Ionization energy determinations

IE (eV) Method Reference Comment
10.54SBaig, Connerade, et al., 1982LBLHLM
10.53PEKimura, Katsumata, et al., 1981LLK
10.53EIHolmes, Fingas, et al., 1981LLK
10.5 ± 0.2EIKaposi, Riedel, et al., 1976LLK
10.54 ± 0.01PITsai, Baer, et al., 1975LLK
10.5 ± 0.2EIKaposi, Riedel, et al., 1975LLK
10.541SHochmann, Templet, et al., 1975LLK
10.53PERagle, Stenhouse, et al., 1970RDSH
10.54PEPotts, Lempka, et al., 1970RDSH
10.53 ± 0.015PEHashmall and Heilbronner, 1970RDSH
10.53PIKrauss, Walker, et al., 1968RDSH
10.528 ± 0.005PINicholson, 1965RDSH
10.53 ± 0.01PIWatanabe, 1957RDSH
10.53 ± 0.02EIFrost and McDowell, 1957RDSH
10.541 ± 0.003SPrice, 1936RDSH
10.54PEAndrews, Dyke, et al., 1984Vertical value; LBLHLM
10.53PEUtsunomiya, Kobayashi, et al., 1980Vertical value; LLK
10.53PEUehara, Saito, et al., 1973Vertical value; LLK
10.70PEDixon, Murrell, et al., 1971Vertical value; LLK

Appearance energy determinations

Ion AE (eV) Other Products MethodReferenceComment
Br+15.8 ± 0.5CH3EIKaposi, Riedel, et al., 1976LLK
Br+15.8 ± 0.5CH3EIKaposi, Riedel, et al., 1975LLK
Br+14.7 ± 0.05CH3EITsuda, Melton, et al., 1964RDSH
HBr+15.9 ± 0.3CH2EIKaposi, Riedel, et al., 1976LLK
HBr+15.9 ± 0.3CH2EIKaposi, Riedel, et al., 1975LLK
C+22.9 ± 0.5H+H2+BrEIKaposi, Riedel, et al., 1976LLK
C+22.9 ± 0.5H+H2+BrEIKaposi, Riedel, et al., 1975LLK
CBr+18.8 ± 0.3H+H2EIKaposi, Riedel, et al., 1976LLK
CBr+18.8 ± 0.3H+H2EIKaposi, Riedel, et al., 1975LLK
CH+21.7 ± 0.3H2+BrEIKaposi, Riedel, et al., 1976LLK
CH+21.7 ± 0.3H2+BrEIKaposi, Riedel, et al., 1975LLK
CH+21.41?EIReed and Snedden, 1956RDSH
CHBr+16.3 ± 0.5H2EIKaposi, Riedel, et al., 1976LLK
CHBr+16.3 ± 0.5H2EIKaposi, Riedel, et al., 1975LLK
CH2+14.7 ± 0.5HBrEIKaposi, Riedel, et al., 1976LLK
CH2+14.7 ± 0.5HBrEIKaposi, Riedel, et al., 1975LLK
CH2+14.9 ± 0.2HBrEITsuda and Hamill, 1964RDSH
CH2Br+13.4 ± 0.3HEIKaposi, Riedel, et al., 1976LLK
CH2Br+13.4 ± 0.3HEIKaposi, Riedel, et al., 1975LLK
CH2Br+12.12 ± 0.09HEIMartin, Lampe, et al., 1966RDSH
CH3+12.77BrPITraeger and McLoughlin, 1981LLK
CH3+12.8 ± 0.3BrEIKaposi, Riedel, et al., 1976LLK
CH3+12.80 ± 0.03BrPITsai, Baer, et al., 1975LLK
CH3+12.8 ± 0.3BrEIKaposi, Riedel, et al., 1975LLK
CH3+9.60 ± 0.05Br-EIWilliams and Hamill, 1968RDSH
CH3+12.77BrPIKrauss, Walker, et al., 1968RDSH

De-protonation reactions

CH2Br- + Hydrogen cation = Methane, bromo-

By formula: CH2Br- + H+ = CH3Br

Quantity Value Units Method Reference Comment
Deltar1660. ± 10.kJ/molEndoHierl, Henchman, et al., 1992gas phase; HO- + MeBr:6.0±2.3 kcal/mol endo. "Better than Ingemann and Nibbering, 19852" 2.0 kcal would not show barrier; B
Deltar1650. ± 19.kJ/molEIAERogers, Simpson, et al., 2010gas phase; B
Deltar1643. ± 13.kJ/molG+TSIngemann and Nibbering, 1985, 2gas phase; B
Quantity Value Units Method Reference Comment
Deltar1631. ± 14.kJ/molH-TSHierl, Henchman, et al., 1992gas phase; HO- + MeBr:6.0±2.3 kcal/mol endo. "Better than Ingemann and Nibbering, 19852" 2.0 kcal would not show barrier; B
Deltar1614. ± 13.kJ/molIMRBIngemann and Nibbering, 1985, 2gas 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(«PI») 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