Synthesis and Characterization of Square-planar Palladium(II), Platinum(II) and Rhodium(I) Complexes with a Chiral Pyridylphosphine Hybrid Ligand

The complexes [PdLCl,] 1, [PtLCl,] 2, [PtL(SnCI,)Cl] 3 and [RhL(CO)CI] 4, where L is the chiral
pyridylphosphine 4-(diphenylphosphinomet hyl)-2,2-dimethyl-5-(2-pyridyl)1-, 3-dioxolane7 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) A 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(1) species 4 is discussed.