Coordination nature of europium(III) with tBuPNP (2,6-bis(di-tert-butylphosphinomethyl) pyridine) ligand

The reaction of 2,6-bis(di-tert-butylphosphinomethyl)pyridine (PNP) with hydrated europium(III) chloride yields a novel complex, dichlorotriaqua-(2,6-bis(di-tert-butylphosphinoxidomethyl)pyridine)europium(III)chloride. The complex crystallizes as a dihydrate. IR, 1H and 31P NMR spectroscopic studies were undertaken along with X-ray diffraction studies for structural elucidation. The solid state structure of the compound reveals the insertion of oxygen atoms in the inner coordination sphere bridging phosphorus and europium atoms. The metal center is a seven coordinate system ligated by two chloride ligands, three water ligands and two oxygen atoms from the oxidized phosphine moiety of the PNP ligand. The nitrogen atom of the pyridine unit of the ligand is not coordinated to the metal center.