Metal-substituted tungstosulfates with Keggin structure: synthesis and characterization.

Simple synthetic procedures for accessing novel metal-substituted tungstosulfates [SMW11O39](4-) with Keggin-type structures were developed based on the reaction of metal ions (M = Mn2+, Co2+, Ni2+, and Cu2+) with lacunary tungstosulfate, [SW11O39](6-), which was obtained by treating [SW12O40](2-) with a weak base in acetone. All metal-substituted tungstosulfates were characterized by elemental analysis, X-ray crystallography, ESI-MS, IR, Raman, UV-Vis and cyclic voltammetry analyses.