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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
MM - Michael M. Meot-Ner (Mautner)
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 C8H8O+ (ion structure unspecified)

Quantity Value Units Method Reference Comment
IE (evaluated)9.28 ± 0.03eVN/AN/AL
Quantity Value Units Method Reference Comment
Proton affinity (review)205.8kcal/molN/AHunter and Lias, 1998HL
Quantity Value Units Method Reference Comment
Gas basicity198.2kcal/molN/AHunter and Lias, 1998HL

Electron affinity determinations

EA (eV) Method Reference Comment
0.3339 ± 0.0043ECDWentworth, Kao, et al., 1975B
0.3340 ± 0.0040ECDWentworth and Chen, 1967B
2.550 ± 0.030LPESYagi, Maeyama, et al., 2007This vertical detachment energy value seems at least 2 eV too large. - JEB; B

Proton affinity at 298K

Proton affinity (kcal/mol) Reference Comment
206.4 ± 0.1Tabrizchi and Shooshtari, 2003T = 413-467K; Authors report only relative PAs. Absolute values are referenced here to PA(CH3COOC2H5) = 835.7 kJ/mol as listed in Hunter and Lias, 1998, although average PA(CH3COOC2H5) from the literature sources in Hunter and Lias, 1998 is 831.0 kJ/mol; MM

Ionization energy determinations

IE (eV) Method Reference Comment
9.1 ± 0.1EIDallinga, Nibbering, et al., 1981LLK
9.28PIMcLoughlin and Traeger, 1979LLK
9.45EIElder, Beynon, et al., 1976LLK
9.1 ± 0.1PEEgdell, Green, et al., 1975LLK
9.1EIMcLafferty, Bente, et al., 1973LLK
9.50EIBenoit, 1973LLK
9.3 ± 0.2PIIskakov and Potapov, 1971LLK
9.15 ± 0.03EIBock, Alt, et al., 1969RDSH
9.27 ± 0.03PIWatanabe, Nakayama, et al., 1962RDSH
9.6PITerenin, 1961RDSH
9.38PEDistefano, Granozzi, et al., 1987Vertical value; LBLHLM
9.51PEGal, Geribaldi, et al., 1985Vertical value; LBLHLM
9.51PEPfister-Guillouzo, Geribaldi, et al., 1982Vertical value; LBLHLM
9.45PECentineo, Fragala, et al., 1978Vertical value; LLK
9.45PEKoenig, Wielesek, et al., 1977Vertical value; LLK
9.35PEBenoit and Harrison, 1977Vertical value; LLK
8.9PERao, 1975Vertical value; LLK
9.37PEKobayashi and Nagakura, 1974Vertical value; LLK

Appearance energy determinations

Ion AE (eV) Other Products MethodReferenceComment
C2H3O+11.40 ± 0.28?EIFoffani, Pignataro, et al., 1963RDSH
C6H5+13.97CO+CH3EIBenoit, 1973LLK
C6H5+13.28CO+CH3EIJohnstone and Mellon, 1972LLK
C6H5+13.42 ± 0.07?EIFoffani, Pignataro, et al., 1963RDSH
C7H5O+9.67CH3PIMcLoughlin and Traeger, 1979LLK
C7H5O+10.50 ± 0.01CH3EIHelal and Zahran, 1978LLK
C7H5O+10.08CH3EIElder, Beynon, et al., 1976LLK
C7H5O+9.6CH3EIMcLafferty, Bente, et al., 1973LLK
C7H5O+10.38CH3EIBenoit, 1973LLK
C7H5O+9.91CH3EIBuchs, Rossetti, et al., 1964RDSH

De-protonation reactions

C8H7O- + Hydrogen cation = Acetophenone

By formula: C8H7O- + H+ = C8H8O

Quantity Value Units Method Reference Comment
Deltar361.3 ± 2.1kcal/molG+TSBartmess, Scott, et al., 1979gas phase; value altered from reference due to change in acidity scale; B
Deltar362.0 ± 2.7kcal/molD-EAZimmerman, Reed, et al., 1977gas phase; B
Deltar362.3 ± 2.6kcal/molG+TSCumming and Kebarle, 1978gas phase; B
Quantity Value Units Method Reference Comment
Deltar354.5 ± 2.0kcal/molIMREBartmess, Scott, et al., 1979gas phase; value altered from reference due to change in acidity scale; B
Deltar355.5 ± 2.0kcal/molIMRECumming and Kebarle, 1978gas 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, . [all data]

Wentworth, Kao, et al., 1975
Wentworth, W.E.; Kao, L.W.; Becker, R.S., Electron affinities of substituted aromatic compounds, J. Phys. Chem., 1975, 79, 1161. [all data]

Wentworth and Chen, 1967
Wentworth, W.E.; Chen, E., Experimental Determination of the Electron Affinity of Several Aromatic Aldehydes and Ketones, J. Phys. Chem., 1967, 71, 6, 1929, . [all data]

Yagi, Maeyama, et al., 2007
Yagi, I.; Maeyama, T.; Fujii, A.; Mikami, N., Stepwise solvatochromism of ketyl anions in the gas phase: Photodetachment excitation spectroscopy of benzophenone and acetophenone radical anions microsolvated with methanol, J. Phys. Chem. A, 2007, 111, 31, 7646-7652, . [all data]

Tabrizchi and Shooshtari, 2003
Tabrizchi, M.; Shooshtari, S., Proton affinity measurements using ion mobility spectrometry, J. Chem. Thermodynamics, 2003, 35, 863. [all data]

Dallinga, Nibbering, et al., 1981
Dallinga, J.W.; Nibbering, N.M.M.; Louter, G.J., Formation and structure of [C8H8O]+ ions, generated from gas phase ions of phenylcyclopropylcarbinol and 1-phenyl-1-(hydroxymethyl)cyclopropane, Org. Mass Spectrom., 1981, 16, 4. [all data]

McLoughlin and Traeger, 1979
McLoughlin, R.G.; Traeger, J.C., A photoionization study of some benzoyl compounds - thermochemistry of [C7H5O]+ formation, Org. Mass Spectrom., 1979, 14, 434. [all data]

Elder, Beynon, et al., 1976
Elder, J.F.; Beynon, J.H.; Cooks, R.G., The benzoyl ion. Thermochemistry and kinetic energy release, Org. Mass Spectrom., 1976, 11, 415. [all data]

Egdell, Green, et al., 1975
Egdell, R.; Green, J.C.; Rao, C.N.R., Photoelectron spectra of substituted benzenes, Chem. Phys. Lett., 1975, 33, 600. [all data]

McLafferty, Bente, et al., 1973
McLafferty, F.W.; Bente, P.F., III; Kornfeld, R.; Tsai, S.-C.; Howe, I., Collisional activation spectra of organic ions, J. Am. Chem. Soc., 1973, 95, 2120. [all data]

Benoit, 1973
Benoit, F., The benzoyl cation: The participation of isolated electronic excited states in the dissociation of molecular ions of the form [C6H5COX]+, Org. Mass Spectrom., 1973, 7, 1407. [all data]

Iskakov and Potapov, 1971
Iskakov, L.I.; Potapov, V.K., Photionization and decomposition of benzaldehyde, acetophenone, and benzophenone, High Energy Chem., 1971, 5, 238, In original 265. [all data]

Bock, Alt, et al., 1969
Bock, H.; Alt, H.; Seidl, H., d-Orbital effects in silicon-substituted «pi»-electron systems. XV. The color of silyl ketones, J. Am. Chem. Soc., 1969, 91, 355. [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]

Terenin, 1961
Terenin, A., Charge transfer in organic solids, induced by light, Proc. Chem. Soc., London, 1961, 321. [all data]

Distefano, Granozzi, et al., 1987
Distefano, G.; Granozzi, G.; Olivato, P.R.; Guerrero, S.A., Hyperconjugative interactions in halogen-substituted carbonyls: Ultraviolet photoelectron spectroscopy of w-halogenoacetophenones, J. Chem. Soc. Perkin Trans. 2, 1987, 1459. [all data]

Gal, Geribaldi, et al., 1985
Gal, J.-F.; Geribaldi, S.; Pfister-Guillouzo, G.; Morris, D.G., Basicity of the carbonyl group. Part 12. Correlations between ionization potentials and lewis basicities in aromatic carbonyl compounds, J. Chem. Soc. Perkin Trans. 2, 1985, 103. [all data]

Pfister-Guillouzo, Geribaldi, et al., 1982
Pfister-Guillouzo, G.; Geribaldi, S.; Gal, J.-F., Spectres photoelectroniques de cyclohexene-2-ones-1 diversement substituees en position 3. Correlations avec la reactivite, Can. J. Chem., 1982, 60, 1163. [all data]

Centineo, Fragala, et al., 1978
Centineo, G.; Fragala, I.; Bruno, G.; Spampinato, S., Photoelectron spectroscopy of benzophenone, acetophenone and their ortho-alkyl derivatives, J. Mol. Struct., 1978, 44, 203. [all data]

Koenig, Wielesek, et al., 1977
Koenig, T.; Wielesek, R.; Miller, L.L.; So, Y.-H., Correlation of electrochemical reactivity and photoelectron spectra of aromatic ketones, J. Am. Chem. Soc., 1977, 99, 7061. [all data]

Benoit and Harrison, 1977
Benoit, F.M.; Harrison, A.G., Predictive value of proton affinity. Ionization energy correlations involving oxygenated molecules, J. Am. Chem. Soc., 1977, 99, 3980. [all data]

Rao, 1975
Rao, C.N.R., Lone-pair ionization bands of chromophores in the photoelectron spectra of organic molecules, Indian J. Chem., 1975, 13, 950. [all data]

Kobayashi and Nagakura, 1974
Kobayashi, T.; Nagakura, S., Photoelectron spectra of substituted benzenes, Bull. Chem. Soc. Jpn., 1974, 47, 2563. [all data]

Foffani, Pignataro, et al., 1963
Foffani, A.; Pignataro, S.; Cantone, B.; Grasso, F., Mass spectra of diazocompounds. I. Diazocarbonyl compounds, Nuovo Cimento, 1963, 29, 918. [all data]

Johnstone and Mellon, 1972
Johnstone, R.A.W.; Mellon, F.A., Electron-impact ionization and appearance potentials, J. Chem. Soc. Faraday Trans. 2, 1972, 68, 1209. [all data]

Helal and Zahran, 1978
Helal, A.I.; Zahran, N.F., Kinetic shift in some para-substituted acetophenones, Org. Mass Spectrom., 1978, 13, 549. [all data]

Buchs, Rossetti, et al., 1964
Buchs, A.; Rossetti, G.P.; Susz, B.P., Etude, en fonction de la constante «sigma»p de Hammett, du spectre de masse d'acetophenones p-substituees, Helv. Chim. Acta, 1964, 47, 1563. [all data]

Bartmess, Scott, et al., 1979
Bartmess, J.E.; Scott, J.A.; McIver, R.T., Jr., The gas phase acidity scale from methanol to phenol, J. Am. Chem. Soc., 1979, 101, 6047. [all data]

Zimmerman, Reed, et al., 1977
Zimmerman, A.H.; Reed, K.J.; Brauman, J.I., Photodetachment of electrons from enolate anions. Gas phase electron affinities of enolate radicals, J. Am. Chem. Soc., 1977, 99, 7203. [all data]

Cumming and Kebarle, 1978
Cumming, J.B.; Kebarle, P., Summary of gas phase measurements involving acids AH. Entropy changes in proton transfer reactions involving negative ions. Bond dissociation energies D(A-H) and electron affinities EA(A), Can. J. Chem., 1978, 56, 1. [all data]


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