Tetrameric Lanthanide-Substituted Silicotungstate {Ln8Si4W40} Nanoclusters: Synthesis, Structural Characterization, Electrochemistry, and Catalytic Application for Oxidation of Thioethers

Abstract

All the title nanoclusters 1–10 with the molecular formula [(Ln2SiW10O38)4(W3O8)(OH)4(H2O)2]26− [LnIII =Sm (1), Eu (2), Gd (3), Tb (4), Dy (5), Ho (6), Er (7), Tm (8), Yb (9), and Y (10)] have been synthesized and isolated as mixed sodium and potassium salts. These nanoclusters are characterized by various analytical techniques such as FT-IR, UV/Vis, Photoluminescence, Single crystal X-ray diffraction, Electrochemistry, ICP-AES and Thermogravimetric analysis, and Powder X-ray diffraction. The {Ln8Si4W40} complexes show high efficiency and selectivity for the oxidation of thioethers using H2O2 as green oxidant. It is worth mentioning that the catalyst can be recovered even after five cycles of reaction with only a slight loss in its activity.