Structure and Reactivity of Distanna[2]metallocenophanes of Ruthenium and Osmium

We report the molecular structures of 1,1′-dilithiometallocenes of ruthenium and osmium. These compounds served as precursors for the synthesis and subsequent structural characterization of the first [2]­osmocenophanes with disilane and distannane bridges, as well as of a distanna[2]­ruthenocenophane. In addition, the insertion of sulfur and selenium into the Sn–Sn bridges was studied and it was observed that the presence of the Lewis base pmdta (N,N,N′,N″,N″-pentamethyldiethylenetriamine) dramatically accelerates the reaction.