ELECTROCHEMICAL REDUCTION OF TRIORGANOHALO-SILANES AND -GERMANES

Article abstract of DOI:10.1016/S0022-328X(00)83697-9

The electrochemical reduction of triorganohalo-silanes and -germanes in 1,2-dimethoxyethane has been investigated by polarography, cyclic voltammetry, controlled potential coulometry, and macroscale electrolysis.The reduction of the silicon compounds exhibits a single irreversible wave.The polarograms for the germanium compounds exhibit two irreversible waves.The second wave shifts to more anodic potentials with addition of phenol or acetic acid.Dimer (i.e. disilanes or digermanes) are the main product of macroscale electrolysis in aprotic solvent but the hydrides are the principal products in protic solution.The results are interpreted in terms of the coexistence of two separate processes.The first involves a one electron reduction followed by dimerization of the radical.At higher cathodic potential a two electron charge transfer step occurs to form an anion, which in aprotic solvents reacts with the starting halogeno compound to form dimer, and in protic solutions gives the hydride.