Kinetics of the Reaction of Organosilyl Hydrides with Carbenium Ions in an Inert Solvent. Silicocation Intermediacy. Single Electron Transfer versus Synchronous Hydride Transfer

Article abstract of DOI:10.1021/ja00259a028

The rate of reduction of carbenium center with various organosilyl hydrides and one organogermyl hydride in methylene chloride solution was studied.Triphenylmethylium and cycloheptatrienylium salts having metal-halogen complex anions were used as the carbenium substrates.Although the net result of the process at silicon and germanium centers is the formal substitution of H^- by halide ion originating from the decomposition of halometallate ion, this substitution proceeds stepwise and one or more silicocation (germanium cation) intermediates are formed.It is possible that one of them has a structure of silylenium (germylenium) ion *Si⁺ (*Ge⁺), which may be modified by interaction with solvent.The process which occurs at the carbon center is the hydride-transfer reduction.The kinetic data indicate that the single electron transfer pathway involving the radical silicocation intermediate is followed rather than a synchronous H^- transfer from silicon to the carbenium center.