Ammonolysis and aminolysis reactions of dichlorodimethylsilane

Abstract

The final composition of the products of ammonolysis of aminolysis of dichlorodimethylsilane depends on the reaction temperature, the concentration of the starting materials the nature of the solvent and of the organic groups bonded to silicon and to nitrogen. When dichlorodimethylsilane in excess reacts with methylamine, the condensation of the Si-Cl and Si-NH2 groups to give the silazane bond is the basic reaction. The rate of the reaction is decreased by an increase of the length of the organic radicals on silicon or nitrogen. In the ammonolysis or aminolysis of organochlorosilanes with small organic groups the ratio of the rates of halogen displacement by amine and of condensation is the factor which determines whether aminosilanes or silazanes are formed. The yield of silazane falls as the difference in rates increases.