Synthesis and characterization of platinum group metal complexes of diphenylphosphinoacetic acid

Abstract

Complexes of diphenylphosphinoacetic acid (POH) with platinum group metal ions are reported. Reaction of an excess of POH with the rhodium(I) complex RhCl(PPh₃)₃ resulted in the formation of the octahedral Rh(III) complex fac-Rh(PO)₃ by the oxidative addition of protons to the Rh(I) species. Reaction of RhCl(PPh₃)₃ with POH in a 1:2 molar ratio however, gave the square planar Rh(I) complex Rh(PO)(POH)(PPh₃). Interaction of POH with the Rh(I) and Ir(I) square planar complex MCI(CO)(PPh₃)₂ in a 2:1 molar ratio gave complexes of the type trans-M(PO)(POH)(CO). The reaction of PdCl₂(C₆H₅CN)₂ and K₂PtCl₄ with POH in a 1:2 molar ratio gave complexes of the composition cis-M(PO)(POH)Cl. Interaction of RhCl₃ and IrCl₃ with POH in a 1:3 molar ratio resulted in the formation of complexes of the type M(PO)₂(POH)Cl (M = Rh(III) and Ir(III)). The complexes were characterized by ¹H, ¹³C, ³¹p, NMR and IR spectroscopy.