Assembly of Organic−Inorganic Hybrid Materials Based on Dawson-Type Polyoxometalate and Multinuclear Copper−Phen Complexes with Unique Magnetic Properties

Two novel hybrid compounds, [Cu2(Phen)4Cl][Cu2(Phen)3(H2O)Cl][P2W18O62]·H2O (1) and [Cu7(Phen)7(H2O)4Cl8] [P2W18O62]·6H2O (2) (Phen = 1,10-phenanthroline), containing multinuclear CuII complex cations, have been obtained in hydrothermal conditions and characterized by IR, elemental, thermogravimetric, magnetic, electrochemical and single-crystal X-ray diffraction analyses. The main structural feature to these two compounds is the presence of different copper−Phen complex moieties which compose new multinuclear copper−Phen complexes linked by a Cu−Cl bond. The binuclear cations [Cu2(Phen)4Cl]3+ and [Cu2(Phen)3(H2O)Cl]3+ of 1 indicate a special chiral arrangement. The 2 contains a heptanuclear copper chain [Cu7(phen)7(H2O)4Cl8]6+ formed by a one-Cl bridge and a two-Cl bridge. Magnetic studies prove that Cu−Cl−Cu angles result in different magnetic behaviors in 1 and 2. Furthermore, a compound 2-modiffied carbon paste electrode (2-CPE) displays good electrocatalytic activity toward the reduction of nitrite.