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
Angew Chem Int Ed Engl. 2000 Apr;39(8):1455-1458.
doi: 10.1002/(sici)1521-3773(20000417)39:8<1455::aid-anie1455>3.0.co;2-w.