Al kyl and H yd r ido Derivatives of Tetrakis( t ri met hyl p hosph i ne)osm i um (11). X-Ray Crystal Structure of the Metallacycle Os( ( CH2)2SiMe2)( PMe& t

The interaction of the osmium acetato-complexes tran~-Os~~(O,CMe ),( PMe,), and OS'~~,CI~(~-O~CM ~), with alkylating agents in the presence of trimethylphosphine has led to the isolation of cis-OsMe,( PMe,),, Os[(CH2),SiMeZ] (PMe3)4, OsCI(CH2PMe2) (PMe3)3, and Os(CHZC6H4) ( PMe3),. The hydride cis-OsH,( PMe,), has been obtained from K,[OsO,(OMe),] by interaction with PMe, and methanol. The H, T-{l H), and 3lP-{l H} n.m.r. spectra of the compounds are discussed. The X-ray crystal 7.1