Methane, dibromo-
- Formula: CH2Br2
- Molecular weight: 173.835
- IUPAC Standard InChIKey: FJBFPHVGVWTDIP-UHFFFAOYSA-N
- CAS Registry Number: 74-95-3
- 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. - Other names: Dibromomethane; Methylene bromide; Methylene dibromide; CH2Br2; Rcra waste number U068; UN 2664
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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:
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 ± 0.13 | eV | N/A | N/A | L |
Ionization energy determinations
IE (eV) | Method | Reference | Comment |
---|---|---|---|
10.24 ± 0.02 | PI | Ma, Liao, et al., 1993 | LL |
10.5 ± 0.1 | EI | Kaposi, Riedel, et al., 1976 | LLK |
10.52 ± 0.05 | PI | Tsai, Baer, et al., 1975 | LLK |
10.49 ± 0.02 | PI | Watanabe, Nakayama, et al., 1962 | RDSH |
10.6 | PE | Von Niessen, Asbrink, et al., 1982 | Vertical value; LBLHLM |
9.78 | PE | Wittel and Bock, 1974 | Vertical value; LLK |
10.61 | PE | Dixon, Murrell, et al., 1971 | Vertical value; LLK |
10.61 | PE | Potts, Lempka, et al., 1970 | Vertical value; RDSH |
Appearance energy determinations
Ion | AE (eV) | Other Products | Method | Reference | Comment |
---|---|---|---|---|---|
Br+ | 15.5 ± 0.1 | CH2Br | EI | DeCorpo, Bafus, et al., 1971 | LLK |
Br+ | 16.0 | CH2Br | EI | Franklin and Haney, 1970 | RDSH |
HBr+ | 18.2 ± 0.2 | ? | EI | Kaposi, Riedel, et al., 1976 | LLK |
Br2+ | 20.7 ± 0.5 | ? | EI | Kaposi, Riedel, et al., 1976 | LLK |
C+ | 22.7 ± 0.5 | ? | EI | Kaposi, Riedel, et al., 1976 | LLK |
C+ | 24.52 ± 0.05 | ? | EI | Reed and Snedden, 1956 | RDSH |
CBr+ | 19.6 ± 0.3 | ? | EI | Kaposi, Riedel, et al., 1976 | LLK |
CBr2+ | 15.6 ± 0.5 | ? | EI | Kaposi, Riedel, et al., 1976 | LLK |
CH+ | 22.0 ± 0.5 | ? | EI | Kaposi, Riedel, et al., 1976 | LLK |
CH+ | 21.55 ± 0.05 | ? | EI | Reed and Snedden, 1956 | RDSH |
CHBr+ | 16.0 ± 0.5 | ? | EI | Kaposi, Riedel, et al., 1976 | LLK |
CH2+ | 17.1 ± 0.3 | ? | EI | Kaposi, Riedel, et al., 1976 | LLK |
CH2Br+ | 11.27 | Br | PI | Ma, Liao, et al., 1993 | LL |
CH2Br+ | 11.29 | Br | EI | Holmes, Lossing, et al., 1988 | LL |
CH2Br+ | 11.1 ± 0.2 | Br | EI | Kaposi, Riedel, et al., 1976 | LLK |
CH2Br+ | 11.35 ± 0.02 | Br | PI | Tsai, Baer, et al., 1975 | LLK |
CH2Br+ | 10.93 ± 0.04 | Br | EI | Reed and Snedden, 1956 | RDSH |
De-protonation reactions
CHBr2- + =
By formula: CHBr2- + H+ = CH2Br2
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 1544. ± 13. | kJ/mol | G+TS | Born, Ingemann, et al., 2000 | gas phase; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 1512. ± 13. | kJ/mol | IMRB | Born, Ingemann, et al., 2000 | 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.
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]
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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