Ruthenium Tri-iodide, RuI₃

Ruthenium Tri-iodide, RuI₃, was prepared by Claus by double decomposition of potassium iodide and ruthenium trichloride in aqueous solution. The salt separates out as a black amorphous precipitate which, on heating, evolves the whole of its iodine content. It absorbs ammonia, yielding 2RuI₃.7NH₃, but does not appear to yield double salts with alkali iodides.