sigma-Bishomoconjugation (sigma-Bishomoaromaticity) in 4C/3(2)e Cations-Scope and Limitations This project has been supported by the Deutsche Forschungsgemeinschaft, the Fonds der Chemischen Industrie, and BASF AG. We thank A. Kurscheidt and M. Lutterbeck for technical assistance, Dr. D. Hunkler and Dr. J. Wörth for NMR and MS measurements, and Prof. Dr. T. Bally for access to his (60)Co-gamma-irradiation equipment. - Prinzbach H; Reinbold J; Bertau M; Voss T; Martin HD; Mayer B; Heinze J; Neschchadin D; Gescheidt G; Prakash GK; Olah GA (Angewandte Chemie (International ed. in English), 2001)