Methane, dibromo-

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Gas phase ion energetics data

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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

Vibrational and/or electronic energy levels

Go To: Top, 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: Takehiko Shimanouchi

Symmetry:   C     Symmetry Number σ = 2


 Sym.   No   Approximate   Selected Freq.  Infrared   Raman   Comments 
 Species   type of mode   Value   Rating   Value  Phase  Value  Phase

a1 1 CH2 s-str 3009  C 3009 W gas 3008 gas
a1 2 CH2 scis 1382  C 1382 VW gas 1402 gas
a1 3 CBr2 s-str 588  C 588 M gas 584 gas
a1 4 CBr2 scis 169  C 169 gas
a2 5 CH2 twist 1095  D  ia 1095 liq.
b1 6 CH2 a-str 3073  B 3073 VW gas 3064 liq.
b1 7 CH2 rock 812  B 812 M gas 813 liq.
b2 8 CH2 wag 1195  B 1195 VS gas 1195 liq.
b2 9 CBr a-str 653  B 653 VS gas 640 gas

Source: Shimanouchi, 1972

Notes

VSVery strong
MMedium
WWeak
VWVery weak
iaInactive
B1~3 cm-1 uncertainty
C3~6 cm-1 uncertainty
D6~15 cm-1 uncertainty

References

Go To: Top, Gas phase ion energetics data, Vibrational and/or electronic energy levels, 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, https://doi.org/10.1016/S1387-3806(99)00125-6 . [all data]

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


Notes

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