Methane, tribromo-

Formula: CHBr₃
Molecular weight: 252.731
IUPAC Standard InChI: InChI=1S/CHBr3/c2-1(3)4/h1H
IUPAC Standard InChIKey: DIKBFYAXUHHXCS-UHFFFAOYSA-N
CAS Registry Number: 75-25-2
Chemical structure:
This structure is also available as a 2d Mol file or as a computed 3d SD file
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Isotopologues:
- Methane-d tribromo-
Other names: Bromoform; Methenyl tribromide; Tribromomethane; CHBr3; Bromoforme; Bromoformio; NCI-C55130; Tribrommethaan; Tribrommethan; Tribromometan; Rcra waste number U225; UN 2515; NSC 8019
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- Gas Phase Kinetics Database
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Gas phase ion energetics data

Go To: Top, Vibrational and/or electronic energy levels, References, Notes

Data evaluated as indicated in comments:
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
LL - Sharon G. Lias and Joel F. Liebman

Quantity	Value	Units	Method	Reference	Comment
IE (evaluated)	10.50 ± 0.02	eV	N/A	N/A	L

Ionization energy determinations

IE (eV)	Method	Reference	Comment
10.5	PE	Von Niessen, Asbrink, et al., 1982	LBLHLM
10.7 ± 0.3	EI	Kaposi, Riedel, et al., 1976	LLK
10.48 ± 0.02	PI	Tsai, Baer, et al., 1975	LLK
10.51 ± 0.02	PI	Watanabe, Nakayama, et al., 1962	RDSH
10.47	PE	Nicholson and Rademacher, 1974	Vertical value; LLK
10.47	PE	Dixon, Murrell, et al., 1971	Vertical value; LLK
10.47	PE	Potts, Lempka, et al., 1970	Vertical value; RDSH

Appearance energy determinations

Ion	AE (eV)	Other Products	Method	Reference	Comment
Br⁺	15.4 ± 0.4	CHBr₂	EI	Kaposi, Riedel, et al., 1976	LLK
HBr⁺	14.7 ± 0.3	CBr₂	EI	Kaposi, Riedel, et al., 1976	LLK
Br₂⁺	15.1 ± 0.3	CHBr	EI	Kaposi, Riedel, et al., 1976	LLK
C⁺	23.6 ± 0.5	H⁺³Br	EI	Kaposi, Riedel, et al., 1976	LLK
C⁺	23.55 ± 0.05	?	EI	Reed and Snedden, 1956	RDSH
CBr⁺	16.2 ± 0.4	HBr+Br	EI	Kaposi, Riedel, et al., 1976	LLK
CBr₂⁺	13.7 ± 0.2	HBr	EI	Kaposi, Riedel, et al., 1976	LLK
CBr₃⁺	13.0 ± 0.3	H	EI	Kaposi, Riedel, et al., 1976	LLK
CH⁺	20.5 ± 0.5	3Br	EI	Kaposi, Riedel, et al., 1976	LLK
CH⁺	21.70 ± 0.05	?	EI	Reed and Snedden, 1956	RDSH
CHBr⁺	17.4 ± 0.4	2Br	EI	Kaposi, Riedel, et al., 1976	LLK
CHBr₂⁺	10.53	Br	EI	Holmes, Lossing, et al., 1988	LL
CHBr₂⁺	10.70 ± 0.02	Br	PI	Tsai, Baer, et al., 1975	LLK
CHBr₂⁺	10.80 ± 0.01	Br	EI	Reed and Snedden, 1956	RDSH

De-protonation reactions

CBr₃^- + = Methane, tribromo-

By formula: CBr₃^- + H⁺ = CHBr₃

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	349.7 ± 2.2	kcal/mol	G+TS	Born, Ingemann, et al., 2000	gas phase; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	342.0 ± 2.0	kcal/mol	IMRE	Born, Ingemann, et al., 2000	gas phase; B

Vibrational and/or electronic energy levels

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

Data compiled by: Takehiko Shimanouchi

Symmetry: C_3ν Symmetry Number σ = 3

Sym.	No	Approximate	Selected Freq.		Infrared		Raman

Species		type of mode	Value	Rating	Value	Phase	Value	Phase

a₁	1	CH str	3042	B	3042 M	gas	3017 p	liq.
a₁	2	CBr3 s-str	541	B	541 M	gas	540 p	liq.
a₁	3	CBr3 s-deform	222	C			222 p	liq.
e	4	CH bend	1149	B	1149 VS	gas	1143 dp	liq.
e	5	CBr3 d-str	669	B	669 VS	gas	655 dp	liq.
e	6	CBr d-deform	155	C			155 dp	liq.

Source: Shimanouchi, 1972

Notes

Very strong

Medium

Polarized

Depolarized

1~3 cm^-1 uncertainty

3~6 cm^-1 uncertainty

References

Go To: Top, Gas phase ion energetics data, Vibrational and/or electronic energy levels, Notes

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]

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]

Nicholson and Rademacher, 1974
Nicholson, D.G.; Rademacher, P., Photoelectron spectra and electronic structures of antimony(III) halides, Acta Chem. Scand. Ser. A:, 1974, 28, 1136. [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]

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

Go To: Top, Gas phase ion energetics data, Vibrational and/or electronic energy levels, References

Symbols used in this document:

AE Appearance energy

IE (evaluated) Recommended ionization energy

Δ_rG° Free energy of reaction at standard conditions

Δ_rH° Enthalpy of reaction at standard conditions
Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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AE	Appearance energy
IE (evaluated)	Recommended ionization energy
Δ_rG°	Free energy of reaction at standard conditions
Δ_rH°	Enthalpy of reaction at standard conditions

Methane, tribromo-

Data at NIST subscription sites:

Gas phase ion energetics data

Ionization energy determinations

Appearance energy determinations

De-protonation reactions

Vibrational and/or electronic energy levels

Symmetry: C3ν Symmetry Number σ = 3

Notes

References

Notes

Symmetry: C_3ν Symmetry Number σ = 3