Hydrogen-rich metal cluster complexes. Hexahydrido platinum-osmium carbonyl cluster complexes from the reaction of Pt2Os4(CO)18 with hydrogen

Abstract

As part of a study of heteronuclear cluster complexes containing platinum, the reaction of Pt{sub 2}Os{sub 4}(CO){sub 18} with hydrogen was investigated. Two new compounds, Pt{sub 2}Os{sub 5}(CO){sub 17}(mu-H){sub 6} (I) and PtOs{sub 5}(CO){sub 16}(mu-H){sub 6} (II), have been isolated and characterized by ir, {sup 1}H NMR and single-crystal x-ray diffraction analysis. Compound II was found to be electron deficient, and it is proposed that the electron deficiency is associated with the short doubly hydride-bridged bond Pt-Os. It is also reported that I can be converted into II by reaction with Os{sub 3}(CO){sub 11}(NCMe). The concomitant formation of Os{sub 3}(CO){sub 12} suggests that Os{sub 3}(CO){sub 11}(NCMe) is acting simply as a decarbonylation reagent, but the fate of the Pt atom expelled from I in this transformation has not been explained. 14 refs., 2 figs.