The Radical Ions of Indolizino [6,5,4,3-aij]quinoline and Some of its Derivatives

Authors

  • Fabian Gerson,

    Corresponding author
    1. Physikalisch-Chemisches Institut der Universität Basel, Klingelbergstrasse 80, CH–4056 Basel
    • Physikalisch-Chemisches Institut der Universität Basel, Klingelbergstrasse 80, CH–4056 Basel
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  • André Metzger

    1. Physikalisch-Chemisches Institut der Universität Basel, Klingelbergstrasse 80, CH–4056 Basel
    Current affiliation:
    1. Ciba-GeigySA, CH-4133 Schweizerhalle
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Abstract

Indolizino [6,5,4,3-aij]quinoline (1) and its 3,9-dimethyl- (2), di-tert-butyl- (3) and diphenyl-(4) derivatives yield persistent radical cations which have been studied by ESR and ENDOR spectroscopy. The corresponding radical anions have also been prepared, but only that of 3 was amenable to a complete characterization by hyperfine data. The π-spin populations in the radical anions are essentially localized on the 13-membered C-perimeter, and thus both the HOMO and LUMO of 1 exhibit an ‘annulenyl character’. The radical anions of 1 and 2 have gradually been converted into those of the corresponding 3,4-dihydro derivatives (1-H2 and 2-H2) which have been unambiguously identified by a combination of preparative and spectroscopic methods.

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