{SeO 2 (OH)} Bridging Lanthanide-Containing Antimono-Seleno-Tungstates.

A series of new trigonal pyramidal {SeO 2 (OH)} bridging lanthanide-containing antimono-seleno-tungstates [H 2 N(CH 3 ) 2 ] 8 Na 8 Cs 4 H 9 [Ln 2 SeW 4 O 11 (OH)(H 2 O) 4 (SbW 9 O 33 )(SeW 9 O 33 )(Se 1/2 Sb 1/2 W 9 O 33 )] 2 ·32H 2 O [Ln = Tb ( 1 ), Dy ( 2 ), Ho ( 3 ), Er ( 4 )] have been prepared by the synthetic strategy of simultaneously using the antimonotungstate precursor and simple material in an acidic aqueous solution and structurally characterized by single-crystal X-ray diffraction, powder X-ray diffraction, IR spectrometry, and thermogravimetric analysis. Their molecular structures contain an unprecedented hexameric polyoxoanion [Ln 2 SeW 4 O 11 (OH)(H 2 O) 4 (SbW 9 O 33 )(SeW 9 O 33 )(Se 1/2 Sb 1/2 W 9 O 33 )] 2 29- constituted by two equivalent trimeric subunits Ln 2 W 4 O 9 (H 2 O) 4 (SbW 9 O 33 )(SeW 9 O 33 )(Se 1/2 Sb 1/2 W 9 O 33 ) bridged via two μ 2 -{SeO 2 (OH)} linkers. Furthermore, the catalytic oxidation of various aromatic sulfides and sulfur mustard simulant 2-chloroethyl ethyl sulfide (CEES) by compound 3 as the heterogeneous catalyst has been investigated, exhibiting high conversion and selectivity as well as good stability and recyclability.