Synthesis of Na22[((RE)4(H2O)6Sb6O4)(SbW10O37)2(SbW8O31)2] [(RE)III = Y, Gd, Tb, Dy, Ho, Er, Tm, Yb]: Synthesis, characterization and catalytic application

Abstract

A series of eight rare-earth substituted antimony tungstates with the formulae [((RE)4(H2O)6Sb6O4)(SbW10O37)2(SbW8O31)2]22– [(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 Na9[B-α-SbW9O33]•19.5 H2O as precursors along with sodium dihydrogen phosphate in 1 M NaCl solution. The addition of dihydrogen 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.