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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Reaction thermochemistry data
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 as indicated in comments:
B - John E. Bartmess
MS - José A. Martinho Simões
Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. A general reaction search form is also available. Future versions of this site may rely on reaction search pages in place of the enumerated reaction displays seen below.
Individual Reactions
CHBr2- + =
By formula: CHBr2- + H+ = CH2Br2
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 369.0 ± 3.1 | kcal/mol | G+TS | Born, Ingemann, et al., 2000 | gas phase; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 361.3 ± 3.0 | kcal/mol | IMRB | Born, Ingemann, et al., 2000 | gas phase; B |
C14H21MnO2 (solution) + (solution) = C8H7Br2MnO2 (solution) +
(solution)
By formula: C14H21MnO2 (solution) + CH2Br2 (solution) = C8H7Br2MnO2 (solution) + C7H16 (solution)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -12.2 ± 1.2 | kcal/mol | PAC | Yang and Yang, 1992 | solvent: Heptane; MS |
Gas phase ion energetics data
Go To: Top, Reaction thermochemistry data, 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° | 369.0 ± 3.1 | kcal/mol | G+TS | Born, Ingemann, et al., 2000 | gas phase; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 361.3 ± 3.0 | kcal/mol | IMRB | Born, Ingemann, et al., 2000 | gas phase; B |
References
Go To: Top, Reaction thermochemistry data, 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.
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]
Yang and Yang, 1992
Yang, P.-F.; Yang, K.G.,
J. Am. Chem. Soc., 1992, 114, 6937. [all data]
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]
Notes
Go To: Top, Reaction thermochemistry data, 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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