Incorporation of organotellurium(IV) in polyoxometalates

Abstract

We report on the synthesis and solid-state characterization of two sandwich-type heteropoloytungstates containing three cyclobutyltellurium(IV) units, [(C4H8TeIV)3(XIIIW9O33)2]12− (X = As, 1; Sb, 2). Polyanions 1 and 2 were prepared by reaction of cyclobutyltellurium(IV)diiodide (C4H8TeI2) and the trilacunary, lone-pair-containing POM precursors [XIIIW9O33]9- (X = As, Sb) in aqueous pH 7.5 medium, and isolated in good yield. The title polyanions crystallized as hydrated mixed cesium-ammonium-sodium salts, Cs8.5(NH4)2.75Na0.75[(C4H8Te)3As2W18O66]·30H2O (1a) and Cs1.5(NH4)10Na0.5[(C4H8Te)3Sb2W18O66]·23H2O (2a), which were characterized in the solid-state by single-crystal XRD, solid-state 125Te NMR, IR, thermogravimetric and elemental analyses. Both 1a and 2a are quasi–isomorphous, crystallizing in the chiral monoclinic space group C2, with unit cell parameters a = 18.211(5) Å, b = 17.647(4) Å, c = 16.872(4) Å, β = 107.482(13)° for 1a, and a = 18.1265(8) Å, b = 17.447(7) Å, c = 16.632(6) Å, β = 106.328(2)° for 2a.