s-Indacene: A Delocalized, Formally Antiaromatic 12 π Electron System

Authors

  • Dipl.-Chem. Roland H. Hertwig,

    1. Institut für Organische Chemie der Technischen Universität, Strasse des 17. Juni 135, D-10623 Berlin (FRG)
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  • Dipl.-Chem. Max C. Holthausen,

    1. Institut für Organische Chemie der Technischen Universität, Strasse des 17. Juni 135, D-10623 Berlin (FRG)
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  • Prof. Dr. Wolfram Koch,

    Corresponding author
    1. Institut für Organische Chemie der Technischen Universität, Strasse des 17. Juni 135, D-10623 Berlin (FRG)
    • Institut für Organische Chemie der Technischen Universität, Strasse des 17. Juni 135, D-10623 Berlin (FRG)
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  • Prof. Dr. Zvonimir B. Maksić

    1. Ruder Bošković Institute, Bijenička 54, HR-41001 Zagreb (Croatia)
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  • This research was supported by the Gesellschaft von Freunden der TU Berlin and the Fonds der Chemischen Industrie. Excellent service, in particular by Dr. T. Steinke, and a generous amount of computing time was provided by the Konrad-Zuse Zentrum für Informationstechnik Berlin.

Abstract

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A D2h-symmetric structure with a delocalized π electron system describes the ground state of s-indacene (1), although it is a formally antiaromatic system. These results, obtained by both high-level ab initio MO methods and calculations based on density functional theory, are in agreement with the known structure of 1,3,5,7-tetra-tert-butyl-s-indacene.

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