Novel π-electron systems derived from siliconcontaining macrocyclic polyacetylenes

Abstract

Disilmethylene bridged cyclic triacetylene and tetraacetylene are prepared and subjected to the transition metal complex mediated reactions. In particular, the reaction with (cyclopentadienyl)tricarbonylmanganese gave a variety of cross-conjugated systems such as fulvene, dimethylenecyclobutene, trimethylenecyclopentene and radialene. Structures and reactions of these interesting π-electron systems are described. Dianions derived from these systems are also discussed briefly.