Hexacoordinate silicon-azomethine complexes: Synthesis, characterization, and properties

N,N'-Ethylene-bis(2-hydroxyacetophenoneimine) = salen*H-2 and N,N'-ethylene -bis(3,5-di-tert-butyl-salicylideneimine) = salen double dagger H-2 react b oth with SiCl4 under formation of hexacoordinate silicon compounds ((salen' )SiCl2, salen'=salen* or salen double dagger). The analogous fluoro derivat ives (salen')SiF2 have been prepared by reaction of (salen')SiCl2 with ZnF2 . X-ray structure analysis of (salen*)SiF2 clearly demonstrates the octahed ral coordination of silicon. Salen* acts as a tetradentate chelating ligand , two halogen atoms remaining at the silicon atom. The reduction of (salen* )SiCl2 by alkaline metal affords polysilanes containing main chain hexacoor dinate silicon. Coupling with acetylides results in polycarbosilanes with a Si-C=C-Si backbone.