Synthesis, crystal structure, and property of one- and two-dimensional complexes based on paradodecatungstate-B cluster

摘要

Three polyoxotungstates, Na-8[Cu(H2O)(2)(H2W12O42)]center dot 30H(2)O (1), Na-8[Cd(H2O)(2)(H2W12O42)]center dot 20H(2)O (2), and Na-7.4[Cd-1.3(H2O)(2)(H2W12O42)]center dot 24H(2)O (3), were synthesized and characterized by elemental and thermogravimetric (TG)analysis, infrared spectroscopy and X-ray single-crystal analysis. Both complexes 1 and 2 exhibit one-dimensional structure with two neighboring paradodecatungstate-B clusters, [H2W12O42](10-), linked by [Cu(H2O)(2)](2+)or [Cd(H2O)(2)](2+) units, while complex 3 displays a two-dimensional network structure. The electrochemical behaviors of complexes 1 and 3 were investigated in the buffer solution of pH 4.8. The results of electrocatalysis reveal that the reduced species of complexes 1 and 3 are electrocatalytically active for the reduction of nitrite. Complex 1 exhibits the electrocatalytic activity for the reduction of nitrate as well. The surface photovoltage spectroscopy (SPS) and electric field-induced SPS (EFISPS) measurements show that the surface photovoltage behavior of complex 1 is complicated while complex 3 bears the property of n-type semiconductor.