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

Two novel hybrid compounds, [Cu-2(Phen)(4)Cl][Cu-2(Phen)(3)(H2O)Cl][P2W18O62]center dot[H2O] (1) and [Cu-7(Phen)(7)(H2O)(4)Cl-8][P2W18O62]center dot 6[H2O] (2) (Phen = 1,10-phenanthroline), containing multinuclear Cu-II 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 [Cu-2(Phen)(4)Cl](3+) and [Cu-2(Phen)(3)(H2O)Cl](3+) of 1 indicate a special chiral arrangement. The 2 contains it heptanuclear copper chain [Cu-7(phen)(7)(H2O)(4)Cl-8](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.