Polysilanes by Ring-Opening Polymerization of Cyclic Monomers

摘要

Polysilanes are novel materials with exciting electronic, photochemical, and nonlinear optical properties and various potential applications. Some of them require polymers with controlled structure. Three synthetic routes to well defined polysilanes were undertaken and successfully accomplished: sonochemical reductive coupling of disubstituted dichlorosilanes with sodium at ambient temperatures, two-step modification of poly(phenylmethylsilylenes) with trifluoromethanesulfonic acid and various nucleophiles, and ring-opening polymerization. Sonochemistry leads to polymers with high molecular weight (Mn>50,000) and narrow polydispersity (Mw/Mn<1.3). Modification provides polysilanes with side functional groups which are not available by direct synthesis. Ring-opening polymerization allows control of polymer macro and microstructure. The latter is extremely important since most interesting properties of polysilanes are related to delocalization of electrons in the main chain. Polysilanes, Modifications, Sonochemical Synthesis, Ring opening, Polymerization, Silanes. (mjm)