Binuclear radical complexes of heavy-metal fragments containing ruthenium, osmium, rhodium and gold. Journal of the Chemical Society, Faraday Transactions 1: Physical Chemistry in Condensed Phases, (85)12:4047--4052, 1989. [PUMA: ESR;rhodium bipyridine complex;gold ESR ESR;osmium pyridyltetrazine radical complex metal phosphine norbornadiene transition]