Generation of a π-Bonded Isomer of [P ] by Aluminyl Reduction of White Phosphorus and its Ammonolysis to PH.

By employing the highly reducing aluminyl complex [K{(NON)Al}] (NON=4,5-bis(2,6-diisopropylanilido)-2,7-di-tert-butyl-9,9-dimethylxanthene), we demonstrate the controlled formation of P and P complexes from white phosphorus, and chemically reversible inter-conversion between them. The tetra-anion features a unique planar π-bonded structure, with the incorporation of the K cations implicit in the use of the anionic nucleophile offering additional stabilization of the unsaturated isomer of the P fragment. This complex is extremely reactive, acting as a source of P : exposure to ammonia leads to the release of phosphine (PH ) under mild conditions (room temperature and pressure), which contrast with those necessitated for the direct combination of P and NH (>5 kbar and >250 °C).