Synthesis, structure and catalytic study of a new sandwiched-type vanadoselenite

A novel sandwiched-type vanadoselenite with the formula of K6H8[(SeV10O28(SeO3)(3))(2)(Ni(H2O)(4))]center dot 24H(2)O (1) has been synthesized in aqueous medium and well characterized. Single crystal X-ray diffraction indicates that the sandwiched polyanion [(SeV10O28(SeO3)(3))(2)(Ni(H2O)(4))](14)consisted of two trivicant Keggin building units [SeV10O28(SeO3)(3)](8) and one interconnected Ni2+ ion. Experimental results demonstrated that it could serve as a heterogeneous catalyst for sulfoxidation of thioethers and performed effectively catalytic activity. Under the optimized reaction condition, methyl phenyl sulfoxide could be oxidized to methyl phenyl sulfones within 1 h by using 1 mmol of the substrate, 3 mmol of TBHP and 2 mu mol of the catalyst 1 at 25 degrees C in methanol. Moreover, catalyst 1 can also be easily recycled and reused four times without obvious decrease of catalytic activity.