Syntheses and Crystal Structure Determination of hexacoordinated Silicon-Complexes with Dimethylpyridines

Halogensilane, HSiCl3, forms with 3,4-dimethylpyridine in aprotic solvents a crystalline 1:2-compound which is stable at room temperature and readily soluble in CHCl3. Colourless crystals of the dicationic complex, [H2Si(3,4-dimethylpyridine)4]2+ 2Cl-×6 CHCl3 (verified by X-ray structure analysis) are obtained by dismutation of HSiCl3(3,4-di-methylpyridine)2 in CHCl3, within one week at room temperature. 29Si-NMR indicates that SiCl4 is generated as a second product. H2SiCl2 with 2,4-dimethylpyridine as well as MeHSiBr2 with 3,5-dimethylpyridine in aprotic solvents form 1:2-compounds stable at room temperature. X-ray structure analysis in both cases establish neutral-complexes with a hexacoordinated silicon atom.