SYNTHESIS AND REACTIVITY OF PLATINUM-CONTAINING HETERODINUCLEAR COMPLEXES WITH METHYL AND 1,2-BIS(DIPHENYLPHOSPHINO)ETHANE LIGANDS - X-RAY CRYSTAL-STRUCTURE OF (DPE)MEPT-FECP(CO)2-CENTER-DOT-THF

New Platinum-containing heterodinuclear complexes with methyl and 1,2- bis(diphenylphosphino)ethane (dpe) ligands have been prepared by metat hetical reactions of PtMe(NO3)(dpe) with Na[ML(n)]: ML(n) = MoCp(CO)3 (1); WCp(CO)3 (2); Mn(CO)5 (3); FeCp(CO)2 (4); Co(CO)4 (5). The molecu lar structure of (dpe)MePt-FeCP(CO)2 . THF (4 . THF) has been determin ed by X-ray crystallography: the geometry at Pt is square planar and t he FeCP(CO)2 moiety has a piano-stool type structure. Thermolysis of 4 in C6D6 at 70-degrees-C for 2 h gives MeFeCp(CO)2 (8) in 30% yield, b ut other dinuclear complexes are thermally stable under these conditio ns. Methyl migration to produce 8 was accelerated by the addition of e lectron-deficient olefins such as acrylonitrile and fumaronitrile. Fro m the kinetic study, a mechanism involving two pathways is proposed: o ne is direct thermolysis from 4 to 8, while the other is the associati ve reductive elimination of 8 from the olefin-coordinated intermediate 9.