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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

View reactions leading to C7H8+ (ion structure unspecified)

Quantity Value Units Method Reference Comment
IE (evaluated)8.38 ± 0.04eVN/AN/AL
Quantity Value Units Method Reference Comment
Proton affinity (review)849.3kJ/molN/AHunter and Lias, 1998HL
Quantity Value Units Method Reference Comment
Gas basicity820.3kJ/molN/AHunter and Lias, 1998HL

Ionization energy determinations

IE (eV) Method Reference Comment
8.4PEOhno, Ishide, et al., 1985LBLHLM
8.35PITraeger and McLoughlin, 1978LLK
8.35PETraeger and McLoughlin, 1978LLK
8.42PEDemeo and Yencha, 1970RDSH
8.42 ± 0.02PIDemeo and El-Sayed, 1970RDSH
8.69PEHouk, Rondan, et al., 1983Vertical value; LBLHLM
8.7PEBieri, Asbrink, et al., 1982Vertical value; LBLHLM
8.73PEWorley and Webb, 1980Vertical value; LLK
8.73PEWorley, Webb, et al., 1979Vertical value; LLK
8.69PEKobayashi, 1978Vertical value; LLK
8.69PECowling, Johnstone, et al., 1973Vertical value; LLK
8.6PEPalmer and Findlay, 1972Vertical value; LLK
8.69PEHeilbronner and Martin, 1972Vertical value; LLK
8.70PEBischof, Heilbronner, et al., 1971Vertical value; LLK

Appearance energy determinations

Ion AE (eV) Other Products MethodReferenceComment
C7H7+9.25HPITraeger and McLoughlin, 1978LLK
C7H7+9.75HEIDolejsek, Hanus, et al., 1962RDSH
C7H7+9.6HEIMeyerson, McCollum, et al., 1961RDSH

De-protonation reactions

C7H7- + Hydrogen cation = 2,5-Norbornadiene

By formula: C7H7- + H+ = C7H8

Quantity Value Units Method Reference Comment
Δr1672. ± 7.5kJ/molG+TSLee and Squires, 1986gas phase; Between EtNH2, nPrNH2; B
Quantity Value Units Method Reference Comment
Δr1637. ± 6.3kJ/molIMRBLee and Squires, 1986gas phase; Between EtNH2, nPrNH2; B
Δr1628. ± 21.kJ/molIMRBWright and Beauchamp, 1981gas phase; 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]

Ohno, Ishide, et al., 1985
Ohno, K.; Ishide, T.; Naitoh, Y.; Izumi, Y., Study of stereochemical properties of molecular orbitals by penning ionization electron spectroscopy, J. Am. Chem. Soc., 1985, 107, 8082. [all data]

Traeger and McLoughlin, 1978
Traeger, J.C.; McLoughlin, R.G., A photoionization study of the energetics of C7H7+ ion formed from C7H8 precursors, Int. J. Mass Spectrom. Ion Phys., 1978, 27, 319. [all data]

Demeo and Yencha, 1970
Demeo, D.A.; Yencha, A.J., Photoelectron spectra of bicyclic and exocyclic olefins, J. Chem. Phys., 1970, 53, 4536. [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]

Houk, Rondan, et al., 1983
Houk, K.N.; Rondan, N.G.; Paddon-Row, M.N.; Jefford, C.W.; Huy, P.T.; Burrow, P.D.; Jordan, K.D., Ionization potentials, electron affinities, and molecular orbitals of 2-substituted norbornadienes. Theory of 1,2 and homo-1,4 carbene cycloaddition selectivities, J. Am. Chem. Soc., 1983, 105, 5563. [all data]

Bieri, Asbrink, et al., 1982
Bieri, G.; Asbrink, L.; Von Niessen, W., 30.4-nm He(II) photoelectron spectra of organic molecules, J. Electron Spectrosc. Relat. Phenom., 1982, 27, 129. [all data]

Worley and Webb, 1980
Worley, S.D.; Webb, T.R., The electronic structure of transition-metal carbonyl complexes of norbornadiene and mesitylene, J. Organomet. Chem., 1980, 192, 139. [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]

Kobayashi, 1978
Kobayashi, T., A new rule for photoelectron angular distributions of molecules, Phys. Lett. A, 1978, 69, 31. [all data]

Cowling, Johnstone, et al., 1973
Cowling, S.A.; Johnstone, R.A.W.; Gorman, A.A.; Smith, P.G., Photoelectron spectrum of 5-methylenenorborn-2-ene and through-space interactions (homobutadiene conjugation), J. Chem. Soc., Chem. Commun., 1973, 627. [all data]

Palmer and Findlay, 1972
Palmer, M.H.; Findlay, R.H., Ab initio molecular orbital calculations, the electronic structure and electron spectrum of norbornadiene, Chem. Phys. Lett., 1972, 15, 416. [all data]

Heilbronner and Martin, 1972
Heilbronner, E.; Martin, H.D., The π-orbital sequence in norbornadiene and related hydrocarbons, Helv. Chim. Acta, 1972, 55, 1490. [all data]

Bischof, Heilbronner, et al., 1971
Bischof, P.; Heilbronner, E.; Prinzbach, H.; Martin, H.D., A photoelectron-spectroscopic investigation of the homoconjugative interaction between π- and Walsh-orbitals in endo- and exo- cyclopropano-norbornene, Helv. Chim. Acta, 1971, 54, 1072. [all data]

Dolejsek, Hanus, et al., 1962
Dolejsek, Z.; Hanus, V.; Prinzbach, H., Das massenspektrometrische Verhalten von Quadricyclen, Angew. Chem., 1962, 74, 902. [all data]

Meyerson, McCollum, et al., 1961
Meyerson, S.; McCollum, J.D.; Rylander, P.N., Organic ions in the gas phase. VIII. Bicycloheptadiene, J. Am. Chem. Soc., 1961, 83, 1401. [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]

Wright and Beauchamp, 1981
Wright, C.A.; Beauchamp, J.L., Infrared spectra of gas phase ions and their use in elucidating reaction mechanisms. Identification of C7H7- structural isomers by multiphoton electron detachment using a low-powered laser, J. Am. Chem. Soc., 1981, 103, 6499. [all data]


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