Synthesis, Crystal Structure and Magnetic Property of Sanwich-Type Heteropolyoxometalate Na9[{Na(H2O)2}3{Cu(H2O)}3(BiW9O33)2]·42H2O

The heteropolytungstate Na9[{Na(H2O)2}3{Cu(H2O)}3(BiW9O33)2]·42H2O is obtained by the reaction of Na2WO4·2H2O, Bi(NO3)3·5H2O with CuCl2·2H2O at pH≈6. The structure and chemical composition are determined by X-ray diffraction analysis and elemental analysis. The crystal data and main structure refinement are: a＝1.410(3) nm, b＝2.338(5) nm, c＝3.173(6) nm, β＝98.06(4)°, V＝10.354(35) nm3, monoclinic crystal system, space group: C2/c, Z＝4, R1＝0.0471, wR2＝0.0642 [I＞2σ(I)], R1＝0.1371, wR2＝0.0868 (all data). [{Na(H2O)2}3{Cu(H2O)}3W9O33)2]9- has D3h symmetry. IR, UV-vis spectra, TG curve and magnetic property of the complex were also discussed. The compound exhibits an antiferromagnetic coupling with J＝-8.08 cm-1 and g＝2.21.