OXIDATIVE ADDITION OF PHOSPHOLES AND PHOSPHABENZENE INTO TRIOSMIUM AND TRIRUTHENIUM CLUSTERS - RING-OPENING VERSUSC-H BOND-CLEAVAGE

The five-membered heterocycles compounds 3,4-dimethyl-1-phenylphosphol e (PhPCH=CMeCMe=CH) and 1-phenylphosphole (PhPCH=CHCH=CH) react with t he clusters [Os3(CO)11(MeCN)] or [Os3-(CO)10(MeCN)2] to give the simpl e substitution products [Os3(CO)12-x (phosphole)x] (x=1 or 2), in whic h the phospholes are coordinated as tertiary phosphines through the ph osphorus atoms. The six membered heterocyclic compounds phosphabenzene and 2-terbutyl-phosphabenzene react with [Os3(CO)11(MeCN)] or [Os3(CO )10(MeCN)2] to give simple substitution products [Os3(CO)12-x(phosphab enzene)x] (x=1 or 2). [Ru3(CO)12] and [Os3H2(CO)10) react with 2-terbu tyl-phosphabenzene to give the nonacarbonyl species [HRu3(CO)9(P=CCH=C H-CH=C{(t)Bu})] and [H2Os3(CO)9(PCHCH=CHCH=C{(t)Bu})] respectively, wh ere a C-H bond cleavage has ocurred and the phosphorus atom is coordin ated to a metal center, even though the clusters show different geomet ries, which are discussed.