Zirconium diphosphide

Zirconium diphosphide is a binary inorganic compound of zirconium metal and phosphorus with the chemical formula ZrP2.

Preparation
Zirconium diphosphide can be obtained from arc-melting of zirconium with red phosphorus:
 * 2 Zr + P4 -> 2 ZrP2

Physical properties
Zirconium diphosphide forms grey crystals that is insoluble in water. Zirconium diphosphide is very toxic. Has a lead(II) chloride crystal structure. It dissolves in warm concentrated sulfuric acid. It decomposes into phosphorus and ZrP when heated in vacuum:
 * ZrP2 -> ZrP + P