Hydrazine Platinocyanide, N₂H₄.H₂Pt(CN)₄

Hydrazine Platinocyanide, N₂H₄.H₂Pt(CN)₄.xH₂O, may be obtained by mixing aqueous solutions of hydrazine sulphate and barium platinocyanide. On evaporation, the filtered solution deposits red crystals, which show blue and purple colours by reflected light. Owing to their instability when dried, analysis is difficult, but probably the red crystals are the tetrahydrate, N₂H₄.H₂Pt(CN)₄.4H₂O.

When air dried the crystals become light yellow and opaque, and correspond in composition to the trihydrate, N₂H₄.H₂Pt(CN)₄.3H₂O. When gently warmed they become white, the transformation occurring at about 28° C. Maintained at 100° C. for some time a dull, olive-green, anhydrous salt is obtained.