Synthesis, structure, and nonrigidity of Os,(CO),,, Os,(CO), ,(PMe,)tP(OMe),l, and OS,(CO), ,(cNB~*)

The binary carbonyl OS,(CO)~,, 1, has been prepared by the addition of Os(CO), to Os,(CO),,- (cyclooctene), at - lS°C. The related clusters 0s4(CO),,(PMe,)(P(OMe),), 2, and OS,(CO)~,(CNBU'),