Novel oxo–peroxo W(VI) Schiff base complex: synthesis, SC-XRD, spectral characterization, supporting on chloromethylated polystyrene, and catalytic oxidation of sulfides

Abstract

A novel oxo–peroxo tungsten(VI) Schiff base complex, [WO(O2)L(CH3OH)], as a homogeneous catalyst for sulfoxidation was synthesized by treating WO3 in H2O2 with an ONO–tridentate Schiff base ligand. The complex was characterized by FT-IR, UV–Vis, 1H NMR and 13C{1H} NMR spectroscopy. Moreover, the structure of the crystalline tungsten(VI) complex was further investigated by SC-XRD. The crystal structure analysis revealed that the coordination environment of the W complex is seven-coordinate, occupied by ONO sets of the coordinated ligand in a distorted pentagonal–bipyramidal. Also, the immobilized W(VI) Schiff base on chloromethylated polystyrene, showed high efficiency in the oxidation of the sulfide under heterogeneous conditions. The heterogeneous catalyst was systematically characterized by FT-IR, diffuse reflectance UV–Vis, XRD, FE-SEM, EDX, and ICP–AES techniques. Comparatively, the immobilized heterogeneous catalyst showed superior activity over its homogeneous counterpart and was reused several times. © 2022, Iranian Chemical Society.