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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

Data compiled as indicated in comments:
B - John E. Bartmess
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
LBLHLM - Sharon G. Lias, John E. Bartmess, Joel F. Liebman, John L. Holmes, Rhoda D. Levin, and W. Gary Mallard

View reactions leading to C6H8+ (ion structure unspecified)

Quantity Value Units Method Reference Comment
Proton affinity (review)837.kJ/molN/AHunter and Lias, 1998HL
Quantity Value Units Method Reference Comment
Gas basicity804.5kJ/molN/AHunter and Lias, 1998HL

Ionization energy determinations

IE (eV) Method Reference Comment
8.25PEKimura, Katsumata, et al., 1981LLK
8.25 ± 0.02PEBieri, Burger, et al., 1977LLK
8.25 ± 0.03PIDemeo and El-Sayed, 1970RDSH
8.25PEBischof and Heilbronner, 1970RDSH
8.28 ± 0.05EIFranklin and Carroll, 1969RDSH
8.32PEWorley, Webb, et al., 1979Vertical value; LLK
8.25 ± 0.03PEHeilbronner, Hoshi, et al., 1976Vertical value; LLK

Appearance energy determinations

Ion AE (eV) Other Products MethodReferenceComment
C3H2+23.51 ± 0.50?EIFranklin and Carroll, 1969RDSH
C3H3+14.87 ± 0.10?EIFranklin and Carroll, 1969RDSH
C3H4+14.52 ± 0.10?EIFranklin and Carroll, 1969RDSH
C4H2+19.81 ± 0.10C2H2+2H2EIFranklin and Carroll, 1969RDSH
C4H3+17.62 ± 0.10C2H2+H2+H?EIFranklin and Carroll, 1969RDSH
C4H4+13.91 ± 0.20C2H2+H2EIFranklin and Carroll, 1969RDSH
C4H5+14.69 ± 0.10C2H2+HEIFranklin and Carroll, 1969RDSH
C4H6+12.60 ± 0.10C2H2EIFranklin and Carroll, 1969RDSH
C5H3+15.44 ± 0.10CH3+H2?EIFranklin and Carroll, 1969RDSH
C5H5+13.02 ± 0.10CH3EIFranklin and Carroll, 1969RDSH
C6H5+13.92 ± 0.10H2+HEIFranklin and Carroll, 1969RDSH
C6H6+10.12 ± 0.10H2EIFranklin and Carroll, 1969RDSH
C6H6+9.88 ± 0.10H2EIFranklin and Carroll, 1969RDSH
C6H7+10.45HPIPECOLias and Ausloos, 1985LBLHLM
C6H7+10.82 ± 0.10HEIFranklin and Carroll, 1969RDSH

De-protonation reactions

C6H7- + Hydrogen cation = 1,3-Cyclohexadiene

By formula: C6H7- + H+ = C6H8

Quantity Value Units Method Reference Comment
Δr1561. ± 17.kJ/molG+TSLee and Squires, 1986gas phase; Between SiH4, tBuOH; value altered from reference due to change in acidity scale; B
Quantity Value Units Method Reference Comment
Δr1531. ± 17.kJ/molIMRBLee and Squires, 1986gas phase; Between SiH4, tBuOH; value altered from reference due to change in acidity scale; 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]

Kimura, Katsumata, et al., 1981
Kimura, K.; Katsumata, S.; Achiba, Y.; Yamazaki, T.; Iwata, S., Ionization energies, Ab initio assignments, and valence electronic structure for 200 molecules in Handbook of HeI Photoelectron Spectra of Fundamental Organic Compounds, Japan Scientific Soc. Press, Tokyo, 1981. [all data]

Bieri, Burger, et al., 1977
Bieri, G.; Burger, F.; Heilbronner, E.; Maier, J.P., Valence ionization enrgies of hydrocarbons, Helv. Chim. Acta, 1977, 60, 2213. [all data]

Demeo and El-Sayed, 1970
Demeo, D.A.; El-Sayed, M.A., Ionization potential and structure of olefins, J. Chem. Phys., 1970, 52, 2622. [all data]

Bischof and Heilbronner, 1970
Bischof, P.; Heilbronner, E., Photoelektron-Spektren von Cycloalkenen und Cycloalkadienen, Helv. Chim. Acta, 1970, 53, 1677. [all data]

Franklin and Carroll, 1969
Franklin, J.L.; Carroll, S.R., Effect of molecular structure on ionic decomposition. II. An electron-impact study of 1,3-and 1,4-cyclohexadiene and 1,3,5-hexatriene, J. Am. Chem. Soc., 1969, 91, 6564. [all data]

Worley, Webb, et al., 1979
Worley, S.D.; Webb, T.R.; Gibson, D.H.; Ong, T.-S., On the electronic structures of cyclobutadiene trimethylenemethane, J. Organomet. Chem., 1979, 168, 16. [all data]

Heilbronner, Hoshi, et al., 1976
Heilbronner, E.; Hoshi, T.; von Rosenberg, J.L.; Hafner, K., Alkyl-induced, natural hypsochromic shifts of the 2A←2X and 2B←2X transitions of azulene and naphthalene radical cations, Nouv. J. Chim., 1976, 1, 105. [all data]

Lias and Ausloos, 1985
Lias, S.G.; Ausloos, P., Structures of C6H7+ ions formed in unimolecular and bimolecular reactions, J. Chem. Phys., 1985, 82, 3613. [all data]

Lee and Squires, 1986
Lee, R.E.; Squires, R.R., Anionic homoaromaticity: A gas phase experimental study, J. Am. Chem. Soc., 1986, 105, 5078. [all data]


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