Aminolysis of the Si-Cl bond and ligand exchange reaction betwee silicon amido derivatives and SiCl4: synthetic applications and kinetic investigations

The aminolysis of the Si-Cl bond in SiCln(NR2)(4-n) (n = 1, 2, 3, 4) has been employed for the synthesis of binary amido, chloro-amido or mixed amido derivatives, depending on the nature of the silicon derivative and of the amine. The kinetics of the reaction have been investigated in some representative cases, i.e. SiCl4 + (NHPr2)-Pr-i, SiCl(NMe2)(3) + (NH2Pr)-Pr-i, SiCl2(NEt2)(2) + (NH2Pr)-Pr-i, showing that the rate law is first-order with respect to the silicon compound and does not depend on the concentration of the amine. Moreover, the activation parameters of the reaction of SiCl2(NEt2)(2) with (NH2Pr)-Pr-i have been determined. The ligand exchange reaction between SiCl4 and SiCln(NR2)(4-n) yields a number of chloro-amido derivatives, whose composition is strictly determined by the molar ratio of the reactants. The kinetics of the reaction between SiCl4 and SiCln(NR2)(4-n) were investigated for n = 3, R = Me, and n = 2, R = Et. Moreover in the latter case the equilibrium and activation parameters have been determined.