Synthesis, structure, and properties of the multinuclear cobalt core POM Na-14[Co3O(H2O)(A-alpha-PW9O34)(2)]center dot similar to 29 center dot 5H(2)O

摘要

A new trimeric Co(II) containing Keggin trilacunary polyoxometalate (POM) sandwich complex, Na-14[Co3O(H2O)(A-alpha-PW9O34)(2)]center dot similar to 29 center dot 5H(2)O (Na14-1) was synthesized by the reaction of [Co-2 (mu- OH2)(O2CCMe3)(4) (HO2CCMe3)(4)] and Na-9 [A-alpha-PW9O34]center dot 7H(2)O. The compound has been characterized by elemental analysis, FTIR, TGA and single crystal XRD (Triclinic space group P- 1, a = 12.2204(8) angstrom, b = 16.7035(11) angstrom, c = 23.3466(16) angstrom, alpha = 78.448(2)degrees, beta = 80.551(2)degrees, gamma = 78.448(2)degrees and Z = 2). The POM was electrochemically active and its behavior was studied by cyclic voltammetry at different scan rates. Bond valence sum (BVS) calculation was used to determine the oxidation state of Co. The magnetic susceptibility study indicated antiferromagnetic interactions between Co(II) ions and at lower temperature ferromagnetic behavior dominant in the structure.