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Benzyne


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

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

View reactions leading to C6H4+ (ion structure unspecified)

Quantity Value Units Method Reference Comment
Proton affinity (review)841.kJ/molN/AHunter and Lias, 1998HL
Quantity Value Units Method Reference Comment
Gas basicity808.5kJ/molN/AHunter and Lias, 1998HL

Electron affinity determinations

EA (eV) Method Reference Comment
1.2650 ± 0.0080LPESWenthold, Squires, et al., 1998Triplet state 3.8±0.5 kcal/mol up.; B
0.5640 ± 0.0070LPESWenthold, Squires, et al., 1998Triplet state 37.5±0.3 kcal/mol up.; B
1.249 ± 0.022CIDTWenthold, Hu, et al., 1996B
0.5594 ± 0.0087CIDTWenthold, Hu, et al., 1996B
0.560 ± 0.010LPESLeopold, Miller, et al., 1986B

Ionization energy determinations

IE (eV) Method Reference Comment
9.03 ± 0.05PEZhang and Chen, 1992LL
9.24PEDewar and Tien, 1985LBLHLM
8.95ESTRosenstock, Stockbauer, et al., 1980LLK
9.8 ± 0.2EIGrutzmacher and Hubner, 1969RDSH
9.5 ± 0.2EIGrutzmacher and Lohmann, 1967RDSH

De-protonation reactions

benzynide anion + Hydrogen cation = Benzyne

By formula: C6H3- + H+ = C6H4

Quantity Value Units Method Reference Comment
Deltar1584. ± 13.kJ/molG+TSGuo and Grabowski, 1991gas phase; Acidity between MeOH and tBuOH, comparable to EtOH; B
Quantity Value Units Method Reference Comment
Deltar1552. ± 13.kJ/molIMRBGuo and Grabowski, 1991gas phase; Acidity between MeOH and tBuOH, comparable to EtOH; B
Deltar1556. ± 21.kJ/molIMRBGronert and DePuy, 1989gas 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.

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]

Wenthold, Squires, et al., 1998
Wenthold, P.G.; Squires, R.R.; Lineberger, W.C., Ultraviolet photoelectron spectroscopy of the o-, m-, and p-benzyne negative ions. Electron affinities and singlet-triplet splittings for o-, m-, and p-benzyne, J. Am. Chem. Soc., 1998, 120, 21, 5279-5290, https://doi.org/10.1021/ja9803355 . [all data]

Wenthold, Hu, et al., 1996
Wenthold, P.G.; Hu, J.; Squires, R.R., o-, m-, and p-Benzyne Negative Ions in the Gas Phase: Synthesis, Authentication, and Thermochemistry, J. Am. Chem. Soc., 1996, 118, 47, 11865, https://doi.org/10.1021/ja960663+ . [all data]

Leopold, Miller, et al., 1986
Leopold, D.G.; Miller, A.G.; Lineberger, W.C., Determination of the singlet-triplet splitting and electron affinity of, o-benzyne by negative ion photoelectron spectroscopy, J. Am. Chem. Soc., 1986, 108, 1379. [all data]

Zhang and Chen, 1992
Zhang, X.; Chen, P., Photoelectron spectrum of o-benzyne. Ionization potentials as a measure of singlet-triplet gaps, J. Am. Chem. Soc., 1992, 114, 3147. [all data]

Dewar and Tien, 1985
Dewar, M.J.S.; Tien, T.-P., Photoelectron spectrum of benzyne, J. Chem. Soc., Chem. Commun., 1985, 1243. [all data]

Rosenstock, Stockbauer, et al., 1980
Rosenstock, H.M.; Stockbauer, R.; Parr, A.C., Photoelectron-photoion coincidence study of benzonitrile, J. Chim. Phys., 1980, 77, 745. [all data]

Grutzmacher and Hubner, 1969
Grutzmacher, H.-F.; Hubner, J., Massenspektrometrie instabiler molekule. III: Nachweis und untersuchungen zur stabilitat chlorsubstituierter dehydrobenzole in der gasphase, Org. Mass Spectrom., 1969, 2, 649. [all data]

Grutzmacher and Lohmann, 1967
Grutzmacher, H.-F.; Lohmann, J., Massenspektrometrie instabiler organischer Molekule. I. Ionisations-potential und Bildungsenthalpie von Dehydrobenzol, Ann. Chem., 1967, 705, 81. [all data]

Guo and Grabowski, 1991
Guo, Y.L.; Grabowski, J.J., Reactions of the Benzyne Radical Anion in the Gas Phase, the Acidity of the Phenyl Radical, and the Heat of Formation of ortho-Benzyne, J. Am. Chem. Soc., 1991, 113, 16, 5923, https://doi.org/10.1021/ja00016a001 . [all data]

Gronert and DePuy, 1989
Gronert, S.; DePuy, C.H., The Dehydrophenyl Anion and the Gas Phase Ion Chemistry of Benzyne, J. Am. Chem. Soc., 1989, 111, 26, 9253, https://doi.org/10.1021/ja00208a032 . [all data]


Notes

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