Novel palladium complexes employing mixed phosphine phosphonates and phosphine phosphinates as anionic chelating [P,O] ligands

Abstract

A route to various substituted phosphine phosphonic acid compounds of the general form Ar₂PC₆H₄PO(OH)₂ (Ar = Ph, o-MeC₆H₄, o-MeOC₆H₄) has been investigated. These compounds were employed as bidentate anionic [P,O] ligands in neutral palladium complexes. The [P,O] chelating coordination was determined by X-ray crystallography of a representative palladium complex. Furthermore, the bifunctional ligand Ph₂PC₆H₄PO(OH)Ph represents the first example of a chelating anionic [P,O] ligand resulting from the combination of a phosphine and a phosphinate moiety.