Silicon Thiobromide, SiSBr₂

Silicon Thiobromide, SiSBr₂, is formed with evolution of hydrogen bromide by the interaction of silicon tetrabromide and hydrogen sulphide at 150° C. in presence of aluminium bromide as a eatalyser. It is separated from unchanged silicon tetrabromide by fractionation in vacuo, and forms colourless plates melting at 93° C. to a liquid which boils at 150° C. under 18.3 mm. pressure. The crystals fume in moist air, and react vigorously with water, with separation of silicic acid and evolution of hydrogen bromide and sulphide.