Cadmium permanganate

Cadmium permanganate is an inorganic compound with the chemical formula Cd(MnO4)2. It can form the hexahydrate Cd(MnO4)2·6H2O.

Preparation
Cadmium permanganate can be obtained by reacting cadmium sulfate and barium permanganate. After removing the barium sulfate precipitate, the solution is crystallized in the dark:


 * Ba(MnO4)2 + CdSO4 → Cd(MnO4)2 + BaSO4↓

Cadmium permanganate can also be produced by reacting manganese heptoxide with cadmium oxide or cadmium hydroxide.

Properties
Cadmium permanganate hexahydrate loses water of crystallisation at 61~62 °C, and anhydrate can be obtained at a constant temperature of 90 °C. The anhydrous form begins to decompose at 108 °C:


 * Cd(MnO4)2 → CdMnO3 + MnO2 + 3/2 O2↑