Hydrothermal synthesis and characterization of one dimensional chain structures of monolacunary Keggin polyoxoanions substituted with copper

摘要

Two novel polymeric polyoxometallates constructed from transition metal substitutedheteropolytungstates, [(4,4’bpyH2)2(4,4’bpyH)][PCuW11O39]·H2O (1), and[(4,4’bpyH2)(pyH)3][PCuW11O39]·2H2O (2), (4,4’bpy = 4,4’bipyridine, py = pyridine) havebeen synthesized under hydrothermal conditions and characterized by IR, TGA, single crystalX-ray diffraction and magnetic measurements. The product formation showed a highsensitivity toward experimental factors including pH and stirring. Compounds 1 crystallizesin the monoclinic space group P2(1)/n with a = 13.503(3) Å, b = 26.726(5) Å, c = 15.168(3)Å, = 99.61(3)° and Z=4. The second compound also crystallizes in space group P2(1)/n, butwith a = 13.519(3) Å, b = 20.431(4) Å, c =18.655(4) Å, = 96.52(3)° and Z=4. Compound 1exhibits a zigzag chain structure, while compound 2 exhibits a straight chain structure.Compound 2 is the first example of a polyoxometallate containing 1D chains of transitionmetal-substituted heteropolytungstate designed with two significantly different organic unitsas the countercations. The Cu2+ ions in 1 exhibit paramagnetic behavior.