A novel sandwich polyoxotungstogermanate: Synthesis, crystal structure and magnetic property of [Pr(GeW11O39)2]13−

A novel sandwich-type polyoxometalate built on the lancunary Keggin-type polyanion [GeW11O39]8− and trivalent rare earth ion, K11.5H1.5[Pr(GeW11O39)2] · 29H2O (1) has been synthesized and characterized by IR spectroscopy, UV electronic spectroscopy, luminescence spectroscopy, cyclic voltammetry and single crystal X-ray diffraction. This is the first report of crystal structure for the sandwich Keggin-type polyoxotungstogermanate containing lanthanide. In compound 1, PrIII cation sandwiched between two [GeW11O39]8− anions is of eight coordination and occupies square anti-prismatic geometry. The magnetic investigation of compound 1 demonstrate the presence of an antiferromagnetic interaction in 1.