Copper Platinocyanide, CuPt(CN)₄

Copper Platinocyanide, CuPt(CN)₄, is obtained as a gelatinous greenish blue precipitate on adding a solution of a copper salt to potassium platinocyanide. The precipitate is voluminous, shrinking on drying to an anhydrous greenish blue mass. When heated strongly it becomes dark green in colour, then evolves cyanogen vapours, and finally yields a black mass containing platinum and copper oxide. The salt is not attacked by acids, but alkalies readily effect its decomposition. On account of this latter property it is a useful starting-point for the preparation of the platinocyanides of other metals.