Synthesis and characterization of two new transition-metal complex salts of the wells-dawson polyanion

Two new transition-metal (TM) complex salts of the Wells-Dawson polyanion: [Cu(2,2 '-bpy)(3)](2)[Cu(2,2 '-bPY)(2)](2)[P2W18O62] (1) and [2,2 '-bpy](8)[Fe(2,2 '-bPY)(3)](8)[P2W18O62](4) center dot 9H(2)O (2) (2,2 '-bpy = 2,2 '-bipyridine), have been synthesized under hydrothermal conditions by using pre-prepared alpha-K6P2W18O62 center dot 15H(2)O as a precursor. Crystal data for compound 1: monoclinic, space group C2/c, a = 20.722(4) angstrom, 6 = 21.988(4) angstrom, c = 29.614(6) angstrom, ss = 104.32(3)degrees, V = 13074(5) angstrom(3), Z = 4; for compound 2: triclinic, space group P (1) over bar, a = 15.804(3) A angstrom, b = 27.519(6) angstrom, c = 27.566(6) angstrom, alpha = 72.71(3), ss = 89.94(3)degrees, gamma = 89.90(3)degrees, V = 11447(5) angstrom(3); Z = 1. Compounds I and 2 have been characterized by single-crystal X-ray diffraction, IR spectra, thermogravimetric analysis, XPS spectra and cyclic voltammetry. The two compounds were used as solid bulk modifiers to fabricate bulk-modified carbon paste electrodes (1-, 2-CPE). The electrochemical behaviors of 1-, 2-CPE have been studied in detail. The redox behavior of the parent Wells-Dawson type cluster was maintained completely in compounds 1 and 2.