MECHANISTIC ASPECTS OF TRANSITION-METAL CATALYZED DEHYDROGENATIVE POLYMERIZATION OF DISILANES AND HIGHER SILANES

The dehydrogenative polymerization of 1,2,3-trimethyltrisilane and a mixture of diastereomers of 1,2,3,4-tetramethyltetrasilane showed evidence that besides the sigma-bond metathesis'' mechanism a further mechanism is present. We therefore postulate a silylene mechanism. The silylenes are generated from the transition silyl complex intermediate by well-known alpha-elimination and a proposed new type of beta-elimination which involves Si-Si bond cleavage, and is designated ''beta(star)-bond elimination''.