A La-containing poly(polyoxometalate) simultaneously comprising tungstoantimonate and tungstobismuthate segments: synthesis, structure and catalytic property

Abstract

A novel La-containing octameric polyoxotungstate [H2N(CH3)2]8Na12H16[{(WO2)2(WO3)2(B-β-BiW9O33)2}{Bi6O3(OH)3La3(H2O)6 (CO3)(B-α-SbW9O33)3}2]∙52H2O (1) has been synthesized under the weakly acidic aqueous solution conditions, and further structurally characterized by single-crystal X-ray diffraction, powder X-ray diffraction, IR spectrometry and thermogravimetric analysis. The polyoxoanion of 1 consists of a Krebs-type tungstobismuthate cluster (WO2)2(WO3)2(B-β-BiW9O33)2 connecting two identical trimeric tungstoantimonate units Bi6O3(OH)3La3(H2O)6(CO3)(B-α-SbW9O33)3. Furthermore, compound 1 as a heterogeneous catalyst, with H2O2 as the oxidant, can effectively accelerate the oxidative degradation of 2-chloroethyl ethyl sulfide (CESS) into 2-chloroethyl ethyl sulfoxide (CEESO), demonstrating high conversion and selectivity, as well as good recyclability and stability. This work expands the structural diversity by exploring the preparation of lanthanide incorporated polyoxometalates containing hybrid POM fragments and develops the application in the selective oxidation of CESS.