Methane, dibromo-

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 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:
L - Sharon G. Lias

Data compiled as indicated in comments:
B - John E. Bartmess
LL - Sharon G. Lias and Joel F. Liebman
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

Quantity Value Units Method Reference Comment
IE (evaluated)10.41 ± 0.13eVN/AN/AL

Ionization energy determinations

IE (eV) Method Reference Comment
10.24 ± 0.02PIMa, Liao, et al., 1993LL
10.5 ± 0.1EIKaposi, Riedel, et al., 1976LLK
10.52 ± 0.05PITsai, Baer, et al., 1975LLK
10.49 ± 0.02PIWatanabe, Nakayama, et al., 1962RDSH
10.6PEVon Niessen, Asbrink, et al., 1982Vertical value; LBLHLM
9.78PEWittel and Bock, 1974Vertical value; LLK
10.61PEDixon, Murrell, et al., 1971Vertical value; LLK
10.61PEPotts, Lempka, et al., 1970Vertical value; RDSH

Appearance energy determinations

Ion AE (eV) Other Products MethodReferenceComment
Br+15.5 ± 0.1CH2BrEIDeCorpo, Bafus, et al., 1971LLK
Br+16.0CH2BrEIFranklin and Haney, 1970RDSH
HBr+18.2 ± 0.2?EIKaposi, Riedel, et al., 1976LLK
Br2+20.7 ± 0.5?EIKaposi, Riedel, et al., 1976LLK
C+22.7 ± 0.5?EIKaposi, Riedel, et al., 1976LLK
C+24.52 ± 0.05?EIReed and Snedden, 1956RDSH
CBr+19.6 ± 0.3?EIKaposi, Riedel, et al., 1976LLK
CBr2+15.6 ± 0.5?EIKaposi, Riedel, et al., 1976LLK
CH+22.0 ± 0.5?EIKaposi, Riedel, et al., 1976LLK
CH+21.55 ± 0.05?EIReed and Snedden, 1956RDSH
CHBr+16.0 ± 0.5?EIKaposi, Riedel, et al., 1976LLK
CH2+17.1 ± 0.3?EIKaposi, Riedel, et al., 1976LLK
CH2Br+11.27BrPIMa, Liao, et al., 1993LL
CH2Br+11.29BrEIHolmes, Lossing, et al., 1988LL
CH2Br+11.1 ± 0.2BrEIKaposi, Riedel, et al., 1976LLK
CH2Br+11.35 ± 0.02BrPITsai, Baer, et al., 1975LLK
CH2Br+10.93 ± 0.04BrEIReed and Snedden, 1956RDSH

De-protonation reactions

CHBr2- + Hydrogen cation = Methane, dibromo-

By formula: CHBr2- + H+ = CH2Br2

Quantity Value Units Method Reference Comment
Δr1544. ± 13.kJ/molG+TSBorn, Ingemann, et al., 2000gas phase; B
Quantity Value Units Method Reference Comment
Δr1512. ± 13.kJ/molIMRBBorn, Ingemann, et al., 2000gas phase; B


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.

Ma, Liao, et al., 1993
Ma, Z.-X.; Liao, C.-L.; Ng, C.Y.; Ma, N.G.; Li, W.-K., Adiabatic ionization energy and electron affinity of CH2Br, J. Chem. Phys., 1993, 99, 6470. [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]

Watanabe, Nakayama, et al., 1962
Watanabe, K.; Nakayama, T.; Mottl, J., Ionization potentials of some molecules, J. Quant. Spectry. Radiative Transfer, 1962, 2, 369. [all data]

Von Niessen, Asbrink, et al., 1982
Von Niessen, W.; Asbrink, L.; Bieri, G., 30.4 nm He(II) Photoelectron spectra of organic molecules. Part VI. Halogeno-compounds (C,H,X: X = Cl, Br, I), J. Electron Spectrosc. Relat. Phenom., 1982, 26, 173. [all data]

Wittel and Bock, 1974
Wittel, K.; Bock, H., Photoelektronenspekten und molekuleigenschaften. XXVII. Chlor- und bromathylene- beispiele fur anderungen in π- und σ-Systemen, Chem. Ber., 1974, 107, 317. [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]

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]

DeCorpo, Bafus, et al., 1971
DeCorpo, J.J.; Bafus, D.A.; Franklin, J.L., Enthalpies of formation of the monohalomethyl radicals from mass spectrometric studies of the dihalomethanes, J. Chem. Thermodyn., 1971, 3, 125. [all data]

Franklin and Haney, 1970
Franklin, J.L.; Haney, M.A., Energy distribution in ionic decomposition processes, Recent Developments in Mass Spectroscopy, ed. K. Ogata and T. Hayakawa Baltimore Univ. Park Press, Baltimore, MD, 1970, 909. [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]

Holmes, Lossing, et al., 1988
Holmes, J.L.; Lossing, F.P.; McFarlane, R.A., Stabilization energy and positional effects in halogen-substituted alkyl ions., Int. J. Mass Spectrom. Ion Phys., 1988, 86, 209. [all data]

Born, Ingemann, et al., 2000
Born, M.; Ingemann, S.; Nibbering, N.M.M., Thermochemical properties of halogen-substituted methanes, methyl radicals, and carbenes in the gas phase, Int. J. Mass Spectrom., 2000, 194, 2-3, 103-113, . [all data]


Go To: Top, Gas phase ion energetics data, References