SYNTHESIS AND APPLICATION OF IMMOBILIZED CATALYSTS FOR THE HETEROGENEOUSLY CATALYZED CLEAVAGE OF THE SI-SI BOND OF CHLOROMETHYLDISILANES

Lewis bases like bis(dimethylamide)phosphoryl compounds (2, 5-7), N-he terocycles (8 and 9) and N,N-dialkylamina-3-propylsilanes bearing alko xy groups are grafted via siloxane bonds onto silica carriers. The pre paration and characterisation of 5-9 are reported. The grafted bis(dim ethylamide)phosphoryl compounds (2, 5-7) and N-heterocycles (8, 9) are efficient catalysts for the disproportionation of chloromethyldisilan es into chloromethyloligosilanes and chloromethylsilanes. Grafted N,N- dialkylamino-3-propylsilyl compounds heterogeneously catalyze the Si-S i bond cleavage of the disilanes with hydrogen chloride at 170 degrees C in excellent yields. A mixture of chloromethylmonosilanes is obtain ed. This reaction is also performed under pressure.