Cobalt phosphate is the inorganic compound with the formula Co3(PO4)2. It is a violet solid that is insoluble in water.

Structure

According to X-ray crystallography, the anhydrous Co3(PO4)2 consists of discrete phosphate (PO3− 4) anions that link Co2+ centres. The cobalt ions occupy both octahedral (six-coordinate) and pentacoordinate sites in a 1:2 ratio.

Preparation

The tetrahydrate Co3(PO4)2•4H2O precipitates as a solid upon mixing aqueous solutions of cobalt(II) and phosphate salts. Upon heating, the tetrahydrate converts to the anhydrous material.

Uses

Thin films of this material are water oxidation catalysts.

It is also a commercial inorganic pigment known as cobalt violet (PV14).

See also