sigma-Homoconjugation in Cyclically Preoriented N4-(Radical) Cations-N small middle dot small middle dot small middle dotN Bond Lengths >2 Å This project has been supported by the Deutsche Forschungsgemeinschaft, the Fonds der Chemischen Industrie and BASF AG. We thank Dipl.-Chem. V. Peron and B. Geiser for technical assistance |