Osmium tetrasulfide

Osmium tetrasulfide is an inorganic compound, a salt of osmium metal and hydrogen sulfide acid with the chemical formula OsS4.

Synthesis
Osmium tetrasulfide can be made by passing hydrogen sulfide through acidified solutions of osmium tetroxide:


 * OsO4 + 4H2S -> OsS4 + 4H2O

Physical properties
Osmium tetrasulfide forms dark brown crystals, does not dissolve in cold water. It is soluble in dilute HNO3. It forms hydrates.

Osmium tetrasulfide decomposes upon melting.