| It has been seen under silicon thiochloride that silicon chlorohydrosulphide is an intermediate product of the interaction of silicon tetrachloride and hydrogen sulphide. This compound is therefore formed by passing a mixture of silicon tetrachloride vapour and hydrogen sulphide through a tube at a lower temperature than that required for preparing silicon thiochloride. It is separated from unchanged silicon tetrachloride by fractional distillation and condensation in a freezing mixture. It is a colourless, fuming liquid, of density 1.43 at 15° C., which boils at 96° C. Friedel and Ladenburg found its vapour density between 155° C. and 161° C. to be 5.74 and 5.24-5.32, theory requiring 5.83 (air = 1). It is decomposed by water with separation of silicic acid and evolution of hydrogen chloride and sulphide; bromine forms hydrogen bromide and SiCl3Br, and alcohol the compound Si(OC2H5)3SH. |