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Benzene, 1-bromo-4-methyl-

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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:
HL - Edward P. Hunter and Sharon G. Lias
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

Quantity Value Units Method Reference Comment
IE (evaluated)8.68 ± 0.02eVN/AN/AL
Quantity Value Units Method Reference Comment
Proton affinity (review)185.3kcal/molN/AHunter and Lias, 1998HL
Quantity Value Units Method Reference Comment
Gas basicity178.3kcal/molN/AHunter and Lias, 1998HL

Ionization energy determinations

IE (eV) Method Reference Comment
8.42PEBaidin, Misharev, et al., 1985LBLHLM
8.68 ± 0.01EQLias and Ausloos, 1978LLK
8.67PEJohnstone and Mellon, 1973LLK
8.7 ± 0.1EITajima and Tsuchiya, 1972LLK
8.71PEBaker, May, et al., 1968RDSH
8.67 ± 0.02PIWatanabe, 1957RDSH
8.76PEBaidin, Misharev, et al., 1985Vertical value; LBLHLM

Appearance energy determinations

Ion AE (eV) Other Products MethodReferenceComment
C5H5+15.2 ± 0.2C2H2+BrEITajima and Tsuchiya, 1973LLK
C5H5+15.23 ± 0.15C2H2+BrEITajima and Tsuchiya, 1972LLK
C7H6Br+12.48HEIHowe and Williams, 1969RDSH
C7H7+11.1 ± 0.3?EIMcLafferty and Winkler, 1974LLK
C7H7+11.2 ± 0.1?EITajima and Tsuchiya, 1972LLK
C7H7+11.30BrEIHowe and Williams, 1969RDSH

De-protonation reactions

C7H6Br- + Hydrogen cation = Benzene, 1-bromo-4-methyl-

By formula: C7H6Br- + H+ = C7H7Br

Quantity Value Units Method Reference Comment
Deltar373.8 ± 3.1kcal/molG+TSWenthold, Wierschke, et al., 1994gas phase; Between MeOCH2CH2OH and tBuCH2OH, near CH2Cl2; B
Quantity Value Units Method Reference Comment
Deltar366.5 ± 3.0kcal/molIMRBWenthold, Wierschke, et al., 1994gas phase; Between MeOCH2CH2OH and tBuCH2OH, near CH2Cl2; 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.

Hunter and Lias, 1998
Hunter, E.P.; Lias, S.G., Evaluated Gas Phase Basicities and Proton Affinities of Molecules: An Update, J. Phys. Chem. Ref. Data, 1998, 27, 3, 413-656, https://doi.org/10.1063/1.556018 . [all data]

Baidin, Misharev, et al., 1985
Baidin, V.N.; Misharev, A.D.; Takhistov, V.V., Effect of alkyl substituents on the ionization potentials of halogenobenzenes, Zh. Org. Khim., 1985, 21, 817. [all data]

Lias and Ausloos, 1978
Lias, S.G.; Ausloos, P.J., eIonization energies of organic compounds by equilibrium measurements, J. Am. Chem. Soc., 1978, 100, 6027. [all data]

Johnstone and Mellon, 1973
Johnstone, R.A.W.; Mellon, F.A., Effects of induction and resonance in the calculation of ionization potentials of substituted benzenes by perturbation molecular orbital theory, J. Chem. Soc. Faraday Trans. 2, 1973, 69, 36. [all data]

Tajima and Tsuchiya, 1972
Tajima, S.; Tsuchiya, T., The effects of the repeller voltage and the shield voltage on appearance potential measurements by electron impact, Shitsuryo Bunseki, 1972, 20, 117. [all data]

Baker, May, et al., 1968
Baker, A.D.; May, D.P.; Turner, D.W., Molecular photoelectron spectroscopy. Part VII. The vertical ionisation potentials of benzene and some of its monosubstituted and 1,4-disubstituted derivatives, J. Chem. Soc. B, 1968, 22. [all data]

Watanabe, 1957
Watanabe, K., Ionization potentials of some molecules, J. Chem. Phys., 1957, 26, 542. [all data]

Tajima and Tsuchiya, 1973
Tajima, S.; Tsuchiya, T., Energetics consideration of C5H5+ ions produced from various precursors by electron impact, Bull. Chem. Soc. Jpn., 1973, 46, 3291. [all data]

Howe and Williams, 1969
Howe, I.; Williams, D.H., Calculation and qualitative predictions of mass spectra. Mono- and paradisubstituted benzenes, J. Am. Chem. Soc., 1969, 91, 7137. [all data]

McLafferty and Winkler, 1974
McLafferty, F.W.; Winkler, J., Gaseous tropylium, benzyl, tolyl, and norbornadienyl cations, J. Am. Chem. Soc., 1974, 96, 5182. [all data]

Wenthold, Wierschke, et al., 1994
Wenthold, P.G.; Wierschke, S.G.; Nash, J.J.; Squires, R.R., Biradical thermochemistry from collision-induced dissociation threshold energy measurements .2. Experimental and theoretical studies of the Mechanism and Thermochemistry of Formation of alph, J. Am. Chem. Soc., 1994, 116, 16, 7378, https://doi.org/10.1021/ja00095a048 . [all data]


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