Hexacoordinate Silicon-Azomethine Complexes: Synthesis, Characterization, and Properties

Abstract

N,N H -Ethylene-bis(2-hydroxyacetophenoneimine) salen*H 2 and N,N H -ethylenebis(3,5-di-tert-butyl-salicylideneimine) salen z H 2 react both with SiCl 4 under formation of hexacoordinate silicon compounds ((salen H )SiCl 2 , salen H salen* or salen z ). The analogous¯uoro derivatives (salen H )SiF 2 have been prepared by reaction of (salen H )SiCl 2 with ZnF 2 . X-ray structure analysis of (salen*)SiF 2 clearly demonstrates the octahedral coordination of silicon. Salen* acts as a tetradentate chelating ligand, two halogen atoms remaining at the silicon atom. The reduction of (salen*)SiCl 2 by alkaline metal affords polysilanes containing main chain hexacoordinate silicon. Coupling with acetylides results in polycarbosilanes with a Si±C:C±Si backbone.