Several New Heteropoly Tungstate Synthesis And Crystal Structure

In this paper, nine new polyoxometalates were synthesized under the hydrothermal conditions by adjusting organic N-donor ligands, counter ions and transition-metal ions, all of which were characterized by elemental analysis, IR and single crystal X-ray diffraction. Some of these compounds were characterized by UV-vis diffuse reflectance spectrum, fluorescent spectrum, thermal anelysis or magnetic measurement.1. Two new inorganic-organic tungstoarsenates on the basis of trivacant Keggin ion [ASW9O34]9- have been hydrothermally synthesized by using organic ligands 2,2'-bpy or 1,2-diaminocyclohexane:H2[{Cu(2,2'-bpy)}8(H2O)2(AsW9O34)2]-12H2O(1)(NH4)3[Ni(C6H14N2)2]3[Ni(C6H15N2)Ni(H2O)Ni2(AsW9O34)2]·3H2O(2)In compound 1, two trivacant polyanions [a-AsW9O34]9- are connected via Cu-O to form a centrosymmetric dimer, on which eight-copper-complexed were connected. Compound 2 is a new sandwich tungstoarsenate constructed from two trivacant polyanions [ASW9O34]9-linked through an unique [Ni4(C6H15N2)(H2O)] unit.2. Five new inorganic-organic hybrids based saturated Keggin or monosubtituted Keggin polyoxometaltates have been hydrothermally synthesized by using different organic ligands:[Co(2,2'-bpy)3]2[AsWⅤWⅥ11O40]-3H20(3)[Co(2,2'-bpy)3][HAsW12O40]-8H2O(4)[Ni(C6H14N2)2]3[AsWⅤ3WⅥ9O40] (5)[4,4'-H2bpy]H[Co(imi)4(AsCo(imi)W11O39)](6)[Co(2,2'-bpy)3]1.5[Co(2,2'-bpy)2(H2O)SiWⅤWⅥ11O40]-0.5H2O(7)In compounds 3,4 and 5, the main interactions between metal complexes and saturated Keggin ions are hydrogen bond and electrostatic interaction; compound 6 is a Co(imi) gruop monosubtituted Keggin compound, and further covalently connected by [Co(imi)4] units to a one-dimensional chain; in compound 7, the saturated Keggin ion coordinates to Co(2,2'-bpy)2(H2O)2+ to form a monosupporting hybrid, furthmore linked by hydrogen bond to a 1D chain structure.3. A novel inorganic-organic Dawson-type tungstoarsenate has been synthesized by introducing mixed organic ligands 4,4'-bpy and imidazole under the hydrothermal conditions and structurally characterized:CuI8(imi)4(bpy)6(H2O)[AsⅤ2WⅤ2WⅥ16O62]-2H2O(8)The compound 8 exhibits a five-connected boron nitride topology with the Schlafli symbol (46·64), in which Dawson polyanoin as hepta-dentate inorganic ligands coordinates with seven metal ions, representing the highest connecting number of modifying Dawson POMs.4. A new copper-substituted sandwich tungstoarsenate has been hydrothermally synthesized by adjusting different counter ions:Na(H2O)6Cu(H2O)4(NH4)6[Cu3.5(NH4)2(H2O)4(AsW9O33)2]-5H2O(9)Compound 9 consists of two [ASW9O33]9- moieties linked by a new [Cu3.5(NH4)2(H2O)4] unit, and it is connected to four neighbors via four Cu-O-W bonds to form 2D network structure.