The role of silylenes in the direct synthesis of methylchlorosilanes

Article abstract of DOI:10.1016/0022-328X(91)86378-4

From butadiene trapping experiments in a batch flow reactor, the silylene intermediates SiMeCl and SiCl2 are shown to be formed during the Direct Synthesis.Two types of silylene intermediate are believed to be involved.Silylenoids are formed on the surface where they react with methyl chloride yielding methylchlorosilanes (SiMeCl gives Me2SiCl2, SiCl2 gives MeSiCl3) in accordance with the van den Berg mechanism.Free silylenes are released into the gas phase, where they may be trapped by butadiene, but are not directly involved in methylchlorosilane production.The addition of Me3SiH to the methyl chloride promotes radical reactions; the major product is Me3SiCl.Me3SiCl is believed to result from an efficient chain sequence proceeding mainly on the surface involving Me3Si^. radicals which scavenge surface-bound chlorine.