Synthesis and characterization of square-planar palladium(II), platinum(II) and rhodium(I) complexes with a chiral pyridylphosphine hybrid ligand

Abstract

The complexes [PdLCl₂]1, [PtLCl₂]2, [PtL(SnCl₃)Cl]3 and [RhL(CO)Cl]4, where L is the chiral pyridylphosphine 4-(diphenylphosphinomethyl)-2,2-dimethyl-5-(2-pyridyl)-1,3-dioxolane, have been synthesized and characterized by IR, NMR and FAB mass spectra. The structure of compound 1 has been solved by X-ray diffraction: the ligand is co-ordinated through both the P and N atoms to form a seven-membered ring which adopts a chair conformation. One of the hydrogen atoms of the backbone is located 2.72(3)Å over the palladium atom in a pseudo-axial position. Spectroscopic evidence supports a chelating behaviour of the ligand also in compounds 2 and 3. The behaviour of the L ligand in the rhodium(I) species 4 is discussed.