Sodium Osmium Hexachloride, Na₆OsCl₁₂

Sodium Osmium Hexachloride, Na₆OsCl₁₂ or OsCl₆.6NaCl, has been prepared by Rosenheim and Sasserath by passing dry hydrogen chloride over sodium osmisulphite, gently warming the while. A black reaction product is obtained, which is dissolved in a small quantity of water and recrystallised over sulphuric acid. Bright, coppery leaflets are obtained consisting of sodium osmium hexachloride, contaminated with a small quantity of sulphite. Addition of potassium chloride to the solution of the salt does not yield the corresponding potassium salt, but potassium chlorosmate; neither could the potassium or ammonium salt be obtained by the direct method.