Silylene Reactions with Ethylene and Butadiene: Mechanism and Kinetics

摘要

The reactions of SiH2 (generated from the disilane pyrolysis with ethylene and with butadiene have been studied by the comparative rate technique. Ethylene trapping of silylene is a consecutive step process involving the formation of a silacyclopropane intermediate which can react back to reactants or forward to either ethylsilylene or vinylsilane. Reaction products of ethylene trapping vary with reaction conditions. At high reactant concentrations and low temperatures the main product is ethylsilane, but numerous other products including diethylsilane and ethyldisilane are also formed. At low reactant concentrations and moderate temperatures the main products are ethylsilane and vinylsilane, while at high temperatures vinylsilane is the only significant product. A number of rate constants and rate-constant parameters for the relevant reactions of the proposed rather complex mechanism have been estimated by using a variety of data sources.