Experimental evidence of phosphine oxide generation in solution and its trapping by ruthenium complexes

Phosphine oxide (H3PO), the first defined compound of phosphorus in the oxidation state -1, was obtained in solution by electrochemical methods starting from white phosphorus (see picture). H3PO was characterized by NMR solution spectroscopy as a free molecule and isolated as a ligand in ruthenium(II) complexes following tautomerization to phosphinous acid, H2P(OH).