Vanadyl Dithionate, VOS₂O₆

Vanadyl Dithionate, VOS₂O₆, is prepared by treating a solution of vanadyl sulphate with barium dithionate. It decomposes on standing, with evolution of sulphur dioxide.

A series of crystalline salts is known which resemble the ortho- and pyro-vanadates in composition, except that the oxygen is either wholly or partially replaced by sulphur. Copper orthothiovanadate, Cu₃(VS₄)₂, occurs naturally as sulvanite. The following thio- and oxythio-compounds have been prepared.