Silane-silanol dehydrocondensation. The microscopic reverse of hydrogen activation by an organometallic oxide complex

Article abstract of DOI:10.1016/0022-328X(88)83022-5

Hydrogen evolution from the dehydrocondensation reaction of triphenylsilane with triphenylsilanol is catalyzed by sodium trimethylsiloxide at 90 deg C in dioxane solvent.This system is the first example of a silane hydrolysis reaction that exhibits simple first order kinetics when investigated under second order conditions, equal concentrations of silane to proton source.Further analysis of the kinetics by the method of initial rates indicates that the reaction is first order in silane and zero order in silanol, demonstrating a multistep mechanistic process and that the proton source is not involved in the rate limiting step.The microscopic reverse process, hydrogen activation, has been investigated at 200-250 deg C and 330 atm of hydrogen using hexamethyldisiloxane and sodium trimethylsiloxide to yield significant, 12percent, quantities of trimethylsilyl hydride; however, the reaction has limited application since the methyl groups are concurrently cleaved to the organic product methane under these conditions.