Collection of Czechoslovak Chemical Communications - digital archive 

Abstract

The effect of solvent composition on reaction rates was studied by a kinetic method for reactions of Et₃SiH with Ph₂Si(OH)₂ in the presence of ZnCl₂ in a mixture of DMF and THF or Et₃SiH with PhCOOH and cadmium bromide CdBr₂ in DMF-1,4-dioxane and DMF-THF. A decrease in reaction rates with decreasing polarity of the medium (and its dielectric constant) has been observed. The kinetic order of dehydrocoupling reaction with respect to DMF was determined from kinetic studies. The constants of nucleophilic catalysis with DMF (λ) were found. The role of DMF in the mechanism of dehydrocoupling of hydrosilanes with hydroxylic reagents in the presence of ZnX₂ and CdX₂ halides (X = Cl, Br, I) is discussed.

Keywords: Hydrosilanes; Silanes; Silanols; Hydroxylic reagents; Dehydrocoupling; Solvent effects; Reaction mechanisms; Nucleophilic substitutions.

References: 66 live references.