Abstract
A series of eight rare-earth substituted antimony tungstates with the formulae [((RE)(4)(H2O)(6)Sb6O4) (SbW10O37)(2)(SbW8O31)(2)](2)(2-) [(RE)(III) = Y(1), Gd(2), Tb(3), Dy(4), Ho(5), Er(6), Tm(7), Yb(8)] has been synthesized under ambient conditions. The compounds were isolated using rare-earth salts and Na-9[B-alpha-SbW9O33] center dot 19.5 H2O as precursors along with sodium dihydrogen phosphate in 1 M NaCl solution. The addition of di hydrogen phosphate was found to be a crucial step for the isolation of these polyanions. The polyanions were characterized by various analytical techniques such as single crystal X-ray diffraction (1a - 6a) (SC-XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA). The compounds were found to show efficient heterogeneous catalytic activity for oxidation of thioethers.