Synthesis and Electrochemical Properties of a New 1D Organic-Inorganic Hybrid Compound Based on Keggin-Type Heteropolyanions and Isopolyanions Decorated by Transition Metal Fragments

A new chain-like organic-inorganic hybrid compound composed of the heteropolyanions and isopolyanions, [{Cu-II(2,2'-bpy)}(6)((MoMoVI)-Mo-V O-5(22))] [(PMo12O40)-O-VI] center dot H2O 1 (bpy = 2,2'-bipyridine) has been hydrothermally synthesized and characterized by elemental analysis, IR spectroscopy, TG analysis, XPS spectrum and single-crystal X-ray diffraction. Crystal data for compound 1: monoclinic, space group P (2(1)/c), a = 13.9382(14) angstrom, b = 20.0300(19) angstrom, c = 17.1757(17) angstrom, beta = 94.054(2)degrees, V = 4783.2(8) angstrom(3), Z = 2. The Keggin-heteropolyanion [PMo12O40](3-) and the Cu-supporting isopolyanion [{Cu(2,2'-bpy)}(6)(Mo6O22)](3+) building units are bridged through the O-Cu-O bridges into 1D infinite chain. Note that, the [{Cu(2,2'-bpy)}(6)(Mo6O22)](3+) unit, which contains a rarely reported isopolyanion [Mo6O22](9-) decorated by six [Cu(2,2'-bpy)] fragments. Furthermore, the electrochemical behavior of a 1-modified carbon paste electrode (1-CPE) and its electrocatalytic reduction of nitrite were investigated.