A hybrid compound $(H_{2}bbi)[Cu_{2}(pzta)_{2}(H_{2}O)_{2}][β-$Mo_{8}O_{26}$] (1) (pztaH = 5-(2-pyrazinyl) tetrazolate,bbi = 1,1'-(1,4-butanediyl)bis(imidazole), has been hydrothermally synthesized and characterized byelemental analysis, IR spectroscopy and single-crystal X-ray diffraction. In 1, the β-$Mo_{8}$ clusters link dinuclearcopper (II) complexes as bidentate connectors to form inorganic-organic chains. These chains and the $[H_{2}bbi]^{2+}$ counter-cations are fused together forming layers via hydrogen bonding interactions. The electrochemicalproperties of 1 were studied. The results indicate that 1 has an electrocatalytic activity towards thereduction of iodate ascribed to the Mo-centers.

A new polyoxometalate-based 3D porous framework with inorganic molecular nanocage unit, (H₂dap)[K(H₂O)₂ (V₁₀O₂₈)₀.₅] (1) (dap = 1,2-diaminopropane), has been synthesized and characterized by routine methods. In 1, the decavanadate clusters, as twelve-dentate connectors, link eight potassium ions to form a 3D porous framework with inorganic molecular cage units. There are two dap ligand molecules occupying in each inorganic molecular cage. Furthermore, the electrochemical properties of 1 were studied, which indicate that 1 has a good electrocatalytic activity towards reduction of iodate (IO⁻ ₃ ) ascribed to the V-center.