Phosphorus heptabromide

Phosphorus heptabromide is an inorganic compound with the chemical formula PBr7. It is one of the phosphorus bromides. At normal conditions, it forms red prismatic crystals. PBr7 can be prepared by the sublimation of a mixture of phosphorus pentabromide and bromine.


 * PBr5 + Br2 → PBr7

The structure of PBr7 consists of a tetrabromophosphonium cation [PBr4]+, paired with a tribromide anion [Br3]–, and the tribromide anion is non-symmetric.