Phosphanide

Phosphanides are chemicals containing the [PH₂]⁻ anion. This is also known as the phosphino anion or phosphido ligand. The IUPAC name can also be dihydridophosphate(1−).

It can occur as a group phosphanyl -PH₂ in organic compounds or ligand called phosphanido, or dihydridophosphato(1−). A related substance has PH²⁻. Phosphinidene (PH) has phosphorus in a −1 oxidation state.

As a ligand PH₂ can either bond to one atom or be in a μ₂-bridged ligand across two metal atoms. With transition metals and actinides, bridging is likely unless the metal atom is mostly enclosed in a ligand.

In phosphanides, phosphorus is in the −3 oxidation state. When phosphanide is oxidised, the first step is phosphinite ([H₂PO]⁻). Further oxidation yields phosphonite ([HPO₂]²⁻) and phosphite ([PO₃]³⁻).

The study of phosphine derivatives is unpopular, because they are unstable, poisonous and malodorous.