Lead heptaphosphide

Lead heptaphosphide is the only binary phosphide currently known to be formed by lead and phosphorus. The chemical formula is PbP7, which contains [P7]2− atom clusters. This compound is stable in the air.

Preparation
Lead heptaphosphide can be produced by the reaction of red phosphorus and lead:


 * 7 P4 + 4 Pb -> 4 PbP7

It decomposes again into the elements at 550 K (277 °C).

Properties
Lead heptaphosphide crystallises in the monoclinic crystal system, with space group P21/c, a=970.70(11), b=673.34(10), c=1243.89(18) pm and β=122.55(1)°. Each phosphorus atom in the phosphorus cluster is connected to the other six.