Osmium Bisulphide, OsS₂

Osmium Bisulphide, OsS₂, results when a current of hydrogen sulphide is passed over dry osmium oxysulphide (vide infra), which is gently warmed. At higher temperatures the reaction is very vigorous, the whole mass glowing with heat:

Os₂O₃(SH)₂ + 2H₂S = 2OsS₂ + 3H₂O.

It is also produced on passing hydrogen sulphide through a neutral solution of an alkali osmate or chlorosmate.