Using hydrosilylation to assemble organometallic polymers containing combinations of silicon-based functional groups

A set of silicon-based monomers has been prepared by a series of hydrosilylation reactions. These compounds serve as a molecular set of organosilicon compounds from which well-defined oligomers can be assembled. The organic functional groups contained in the monomers include alkynes, diynes, and arylsilanes for use as ligands for transition metals, and also disiloxanes. Depending upon the catalyst and temperature used, it was possible to prepare symmetric or asymmetric molecules from Ph2SiH2, 2. The direct polymerization of these small molecules was limited by the degree to which the concentration of functional groups could be matched; decamers were the highest molecular weight materials prepared. These fragments were also oligomerized with a HSi-terminated silicone to give a functional organosilicone polymer of molecular weight (M) over bar(w) = 140 000.