phosphorus-rich phosphide

A phosphide is a chemical compound where phosphorus is bonded to a more electropositive element, typically a metal. The phosphide ion has a charge of P³⁻.12

Phosphides are formed by heating metals with red phosphorus or through other methods like electrolysis or reactions involving phosphine (PH₃). They can be classified by their stoichiometry: phosphorus-rich, metal-rich, or monophosphides. Phosphorus-rich phosphides, like RuP₂, tend to be less stable and have lower melting points compared to metal-rich phosphides, which exhibit metallic properties such as hardness and high conductivity. Phosphides of alkali and alkaline-earth metals behave more like ionic compounds and readily produce phosphine gas when reacting with water or acids.1