Indene

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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)
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 C9H8+ (ion structure unspecified)

Quantity Value Units Method Reference Comment
IE (evaluated)8.14 ± 0.01eVN/AN/AL
Quantity Value Units Method Reference Comment
Proton affinity (review)202.9kcal/molN/AHunter and Lias, 1998HL
Quantity Value Units Method Reference Comment
Gas basicity195.9kcal/molN/AHunter and Lias, 1998HL

Electron affinity determinations

EA (eV) Method Reference Comment
<0.173 ± 0.026ECDWojnarovits and Foldiak, 1981EA is an upper limit: Chen and Wentworth, 1989; G3MP2B3 calculations indicate an EA of ca. -0.6 eV, unbound anion.; B

Proton affinity at 298K

Proton affinity (kcal/mol) Reference Comment
202.8Aue, 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
195.8Aue, 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
8.33 ± 0.01EIRakita, Hoffman, et al., 1973LLK
8.14 ± 0.01PEDewar, Haselbach, et al., 1970RDSH
8.62EIOccolowitz and White, 1968RDSH
8.13 ± 0.05PEEland and Danby, 1968RDSH
8.15 ± 0.015PEGusten, Klasinc, et al., 1976Vertical value; LLK

Appearance energy determinations

Ion AE (eV) Other Products MethodReferenceComment
C9H7+12.62 ± 0.05HEISchwarz and Bohlmann, 1973LLK
C9H7+12.53HEIOccolowitz and White, 1968RDSH

De-protonation reactions

indenide anion + Hydrogen cation = Indene

By formula: C9H7- + H+ = C9H8

Quantity Value Units Method Reference Comment
Δr354.3 ± 2.5kcal/molTDEqMeot-ner, Liebman, et al., 1988gas phase; anchored to 88MEO scale, not the "87 acidity scale". The Kiefer, Zhang, et al., 1997 BDE is for ortho.; B
Δr351.9 ± 2.1kcal/molG+TSTaft and Bordwell, 1988gas phase; B
Quantity Value Units Method Reference Comment
Δr346.7 ± 2.0kcal/molTDEqMeot-ner, Liebman, et al., 1988gas phase; anchored to 88MEO scale, not the "87 acidity scale". The Kiefer, Zhang, et al., 1997 BDE is for ortho.; B
Δr344.6 ± 2.0kcal/molIMRETaft and Bordwell, 1988gas 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]

Wojnarovits and Foldiak, 1981
Wojnarovits, L.; Foldiak, G., Electron capture detection of aromatic hydrocarbons, J. Chromatogr. Sci., 1981, 206, 511. [all data]

Chen and Wentworth, 1989
Chen, E.C.M.; Wentworth, W.E., Experimental Determination of Electron Affinities of Organic Molecules, Mol. Cryst. Liq. Cryst., 1989, 171, 271. [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]

Rakita, Hoffman, et al., 1973
Rakita, P.E.; Hoffman, M.K.; Andrews, M.N.; Bursey, M.M., σ-π Conjugation in group IVA compounds of indene and indane, J. Organomet. Chem., 1973, 49, 213. [all data]

Dewar, Haselbach, et al., 1970
Dewar, M.J.S.; Haselbach, E.; Worley, S.D., Calculated and observed ionization potentials of unsaturated polycyclic hydrocarbons; calculated heats of formation by several semiempirical s.c.f. m.o. methods, Proc. Roy. Soc. (London), 1970, A315, 431. [all data]

Occolowitz and White, 1968
Occolowitz, J.L.; White, G.L., Energetic considerations in the assignment of some fragment ion structures, Australian J. Chem., 1968, 21, 997. [all data]

Eland and Danby, 1968
Eland, J.H.D.; Danby, C.J., Inner ionization potentials of aromatic compounds, Z. Naturforsch., 1968, 23a, 355. [all data]

Gusten, Klasinc, et al., 1976
Gusten, H.; Klasinc, L.; Ruscic, B., Photoelectron spectroscopy of J. Heterocycl. Chem.. Indene analogs, Z. Naturforsch. A:, 1976, 31, 1051. [all data]

Schwarz and Bohlmann, 1973
Schwarz, H.; Bohlmann, F., Elektronenstossinduzierte fragmentierung von acetylenverbindungen. VI. Struktur und bildungsenthalpie der ionen [C11H9]+ und [C9H7]+, Org. Mass Spectrom., 1973, 7, 395. [all data]

Meot-ner, Liebman, et al., 1988
Meot-ner, M.; Liebman, J.F.; Kafafi, S.A., Ionic Probes of Aromaticity in Annelated Rings, J. Am. Chem. Soc., 1988, 110, 18, 5937, https://doi.org/10.1021/ja00226a001 . [all data]

Kiefer, Zhang, et al., 1997
Kiefer, J.H.; Zhang, Q.; Kern, R.D.; Yao, J.; Jursic, B., Pyrolysis of Aromatic Azines: Pyrazine, Pyrimidine, and Pyridine, J. Phys. Chem. A, 1997, 101, 38, 7061, https://doi.org/10.1021/jp970211z . [all data]

Taft and Bordwell, 1988
Taft, R.W.; Bordwell, F.G., Structural and Solvent Effects Evaluated from Acidities Measured in Dimethyl Sulfoxide and in the Gas Phase, Acc. Chem. Res., 1988, 21, 12, 463, https://doi.org/10.1021/ar00156a005 . [all data]


Notes

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