Amine catalysts for the disproportionation reaction of trichlorosilane

Abstract

The relative activities of tertiary amine and quaternary ammonium chloride catalysts for the disproportionation of trichlorosilane were investigated using triethylamine and tetraethyl ammonium chloride. The results showed that triethylamine was more effective than tetraethyl ammonium chloride. Ten tertiaryamine catalysts having different alkyl groups on the nitrogen atom were studied for the disproportionation reaction to investigate the correlation between the molecular structure and catalytic activity. The activity of the catalyst was decreased as the steric hinderance of the substituents on nitrogen increased. N-methyl pyrrolidine showed the highest activity among the amines. In order to prepare the new heterogeneous catalyst of amines immobilized on silica support trimethoxysilyl propyl pyrrolidine and trimethoxysilyl propyl dimethylamine were synthesized and used for the reaction. The exchange of methoxy group with chlorine was observed when the trimethoxysilylamine catalysts were used. The activities of silylamines were as good as those of the corresponding organic amines. The immobilized catalysts were prepared by hydrolyzing the silylamines and used for the reaction. The immobilized catalysts gave about same or slightly less activities compared with the corresponding organic amine catalysts. A novel group of chlorosilane disproportionation catalysts consisting of tertiary amines immobilized by bonding through 3-(trimethoxysilyl)propyl chain to inorganic supports was suggested as new possible candidates of commercial catalysts.