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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:
MM - Michael M. Meot-Ner (Mautner)
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
B - John E. Bartmess

View reactions leading to C18H12+ (ion structure unspecified)

Quantity Value Units Method Reference Comment
IE (evaluated)7.60 ± 0.01eVN/AN/AL
Quantity Value Units Method Reference Comment
Proton affinity (review)201.0kcal/molN/AHunter and Lias, 1998HL
Quantity Value Units Method Reference Comment
Gas basicity193.6kcal/molN/AHunter and Lias, 1998HL

Electron affinity determinations

EA (eV) Method Reference Comment
0.320 ± 0.010LPESTschurl and Boesl, 2006B
0.3970 ± 0.0080ECDBecker and Chen, 1966B
0.33ECDWentworth and Becker, 1962B

Proton affinity at 298K

Proton affinity (kcal/mol) Reference Comment
198.1Aue, Guidoni, et al., 2000Experimental literature data re-evaluated by the authors using ab initio protonation entropies; MM

Gas basicity at 298K

Gas basicity (review) (kcal/mol) Reference Comment
192.3Aue, Guidoni, et al., 2000Experimental literature data re-evaluated by the authors using ab initio protonation entropies; MM

Ionization energy determinations

IE (eV) Method Reference Comment
7.60 ± 0.03PEShahbaz, Akiyama, et al., 1981LLK
8.0 ± 0.2EIShushan and Boyd, 1980LLK
7.59 ± 0.05EQMautner(Meot-Ner), 1980LLK
7.60 ± 0.01PEBoschi, Murrell, et al., 1972LLK
8.0 ± 0.3EIWacks, 1964RDSH
7.82CTSKuroda, 1964RDSH
7.83CTSBriegleb, 1964RDSH
7.68CTSKinoshita, 1962RDSH
7.75CTSBriegleb, Czekalla, et al., 1961RDSH
7.80CTSBirks and Stifkin, 1961RDSH
7.78CTSBriegleb and Czekalla, 1959RDSH
7.72CTSMatsen, 1956RDSH
7.59 ± 0.02PESchmidt, 1977Vertical value; LLK
7.59PEClar and Schmidt, 1976Vertical value; LLK
7.61PEBrogli and Heilbronner, 1972Vertical value; LLK

Appearance energy determinations

Ion AE (eV) Other Products MethodReferenceComment
C16H10+16.6 ± 0.3C2H2EIShushan and Boyd, 1980LLK
C18H11+15.1 ± 0.3HEIShushan and Boyd, 1980LLK


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]

Tschurl and Boesl, 2006
Tschurl, M.; Boesl, U., Photodetachment-photoelectron spectroscopy of jet-cooled chrysene, Int. J. Mass Spectrom., 2006, 249, 364-369, https://doi.org/10.1016/j.ijms.2005.11.024 . [all data]

Becker and Chen, 1966
Becker, R.S.; Chen, E., Extension of Electron Affinities and Ionization Potentials of Aromatic Hydrocarbons, J. Chem. Phys., 1966, 45, 7, 2403, https://doi.org/10.1063/1.1727954 . [all data]

Wentworth and Becker, 1962
Wentworth, W.E.; Becker, R.S., Potential Method for the Determination of Electron Affinities of Molecules: Application to Some Aromatic Hydrocarbons., J. Am. Chem. Soc., 1962, 84, 22, 4263, https://doi.org/10.1021/ja00881a014 . [all data]

Aue, Guidoni, et al., 2000
Aue, D.H.; Guidoni, M.; Betowski, L.D., Ab initio calculated gas-phase basicities of polynuclear aromatic hydrocarbons, Int. J. Mass Spectrom., 2000, 201, 283. [all data]

Shahbaz, Akiyama, et al., 1981
Shahbaz, M.; Akiyama, I.; LeBreton, P., Ultraviolet photoelectron studies of methyl substituted chrysenes, Biochem. Biophys. Res. Commun., 1981, 103, 25. [all data]

Shushan and Boyd, 1980
Shushan, B.; Boyd, R.K., Unimolecular and collision induced fragmentations of molecular ions of polycyclic aromatic hydrocarbons, Org. Mass Spectrom., 1980, 15, 445. [all data]

Mautner(Meot-Ner), 1980
Mautner(Meot-Ner), M., Ion thermochemistry of low volatility compounds in the gas phase. 3. Polycyclic aromatics: Ionization energies, proton, and hydrogen affinities. Extrapolations to graphite, J. Phys. Chem., 1980, 84, 2716. [all data]

Boschi, Murrell, et al., 1972
Boschi, R.; Murrell, J.N.; Schmidt, W., Photoelectron spectra of polycyclic aromatic hydrocarbons, Faraday Discuss. Chem. Soc., 1972, 54, 116. [all data]

Wacks, 1964
Wacks, M.E., Electron-impact studies of aromatic hydrocarbons. II. Naphthacene, naphthaphene, chrysene, triphenylene, and pyrene, J. Chem. Phys., 1964, 41, 1661. [all data]

Kuroda, 1964
Kuroda, H., Ionization potentials of polycyclic aromatic hydrocarbons, Nature, 1964, 201, 1214. [all data]

Briegleb, 1964
Briegleb, G., Electron affinity of organic molecules, Angew. Chem. Intern. Ed., 1964, 3, 617. [all data]

Kinoshita, 1962
Kinoshita, M., The absorption spectra of the molecular complexes of aromatic compounds with p-bromanil, Bull. Chem. Soc. Japan, 1962, 35, 1609. [all data]

Briegleb, Czekalla, et al., 1961
Briegleb, G.; Czekalla, J.; Reuss, G., Mesomeriemomente und Elektronenuberfuhrungsbanden von Elektronen-donator-akzeptor-komplexen des Chloranils und Tetracyanathylens mit aromatischen Kohlenwasserstoffen, Z. Phys. Chem. (Neue Folge), 1961, 30, 333. [all data]

Birks and Stifkin, 1961
Birks, J.B.; Stifkin, M.A., «pi»-Electronic excitation and ionization energies of condensed ring aromatic hydrocarbons, Nature, 1961, 191, 761. [all data]

Briegleb and Czekalla, 1959
Briegleb, G.; Czekalla, J., Die Bestimmung von lonisierungsenergien aus den Spektren von Elektronenubergangskomplexen, Z.Elektrochem., 1959, 63, 6. [all data]

Matsen, 1956
Matsen, F.A., Electron affinities, methyl affinities, and ionization energies of condensed ring aromatic hydrocarbons, J. Chem. Phys., 1956, 24, 602. [all data]

Schmidt, 1977
Schmidt, W., Photoelectron spectra of polynuclear aromatics. V. Correlations with ultraviolet absorption spectra in the catacondensed series, J. Chem. Phys., 1977, 66, 828. [all data]

Clar and Schmidt, 1976
Clar, E.; Schmidt, W., Correlations between photoelectron and phosphorescence spectra of polycyclic hydrocarbons, Tetrahedron, 1976, 32, 2563. [all data]

Brogli and Heilbronner, 1972
Brogli, F.; Heilbronner, E., The photoelectron spectra of benzenoid hydrocarbons C18H12, Angew. Chem. Int. Ed. Engl., 1972, 11, 538. [all data]


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