Development of New Synthetic Reactions for Silicon-Conpounds and Syntheses of Silicon-Based New Polymers

In order to develop new and effective homogeneous catalytic reactions relevant to the syntheses of silicon-containing polymers, several fundamental unit reactions between organosilicon compounds and metal complexes were investigatyed : 1) oxidative addition of halosilanes, disilanes and silacycles; 2) reductive elimination from bis(silyl) metal complexes; 3) insertion of unsaturated organic compounds into silyl-or bis(silyl) metal complexes. Based on these results, several new catalytic reactions were established; 1) dehydrogenative double silylation to give polycarbosilane ladder polymers; 2) ring-opening copolymerization to make transition-metal activation of cyclic polysilanes possible; 3) desilanative polycondensation leading to modifiable polymers with Sih2 units; 4) direct modification of polymer backbone via insertion of unsaturated molecules. Some new cataltst systems for dehydrogenative polycondensation, ring-opening polymerization, and hydrosilylation were also developed. By the use of these catalytic reactions, various structurally new polymers were prepared and characterized. Poly�m(m-phenylene) silylene�n which was synthesized by desilanative polycondensation showed a high thermal stability (T���T>1000��) after oxidative crosslinking.