Polycondensation vs. cyclization of divinylsubstituted silicon compounds catalyzed by transition metal complexes

In the presence of ruthenium complexes divinyldiorganosilicon compounds und ergo de-ethenated coupling polycondensation yielding under optimum conditio ns trans-tactic polysilylene(siloxylene, silazanylene)vinylenes and poly(si lytene-arylene-vinylenes). Rhodium- ([RhX(cod)](2) X = Cl, OSiMe3) catalyze d ring closure of oligomeric (dimeric, trimeric) products of intermolecular condensation opens a new route to synthesizing organosilicon exo-cyclic me thylenes. In the presence of Ru-complexes the cross-coupling (poly)condensa tion of di- and trivinylsilicon monomers with organic dienes allows synthes es of a series of linear and dendrimeric poly(arylene-silylene-vinylene)s.