Ruthenium Trisulphide, RuS₃

Ruthenium Trisulphide, RuS₃, is obtained by passing hydrogen sulphide through an aqueous solution of potassium chlor-ruthenate at 0° C. It is formed as a yellowish brown precipitate. When dry it readily oxidises in air, becoming heated to incandescence; for this reason the sulphide is dried in an atmosphere of an inert gas.