Reactions between silicon hydrides and aryl halides.

The chemical reactivity of silicon hydrides in the gas phase is reviewed and the published work on the reactions of silicon hydrides with olefins and aryl halides outlined. The gas phase reaction between trichlorosilane and chlorobenzene has been investigated in a static system between 379 and 592°C, and the products determined to be phenyltrichlorosilane, hydrogen chloride, benzene, and silicon tetrachloride; kinetic measurements being made by means of a gas chromatographic analysis system. This reaction was shown to proceed by a heterogeneous process at lower temperatures and by a homogeneous process at higher temperatures. The Arrhenius equation for both the homogeneous and heterogeneous reaction was determined. The products of the reactions between trimethylsilane and chlorobenzene, and trichlorosilane and p-chlorotri-fluoromethylbenzene have been determined, and the activation energies of these reactions measured. A free-radical chain mechanism is proposed for the homogeneous reactions, and surface initiation and termination of a chain mechanism for the heterogeneous reaction. Reactions between other silicon hydrides and aryl halides have also been studied and their rates of reaction correlated with the effects of substituents on the silicon atom and the aromatic ring. A brief study of the reaction between silicon hydrides and arylsilanes has been made and the replacement of one silicon group attached to a aromatic ring by another silicon group shown to occur