Synthesis and study of novel silicon-based unsaturated polymers

Abstract

Scheme 1. Synthesis of polysilacycloallenes. In compound 14," the allene unit was bent to 166.4° and the twisting dihedral angle defined by the Sii-Ci-Cj and Si2-C3-C2 planes is 64.6°. In compound 15,^^ the allene unit was bent to 161° and the twisting dihedral angle defined by the Sii-Ci-Cs and Si2-C3-Ci planes is 52.2°. The allene units in the two slighdy different six-membered ring systems, were bent 15-20° away from the normal linear geometry. Even though the twisting was defined differently in the two systems, the twisting was very removed from the normal vertical geometry.