Mn-Schiff base complex supported on magnetic nanoparticles: Synthesis, crystal structure, electrochemical properties and catalytic activities for oxidation of olefins and sulfides

A novel, magnetically recoverable Mn-Schiff base catalyst has been prepared by the adsorption on silica-coated magnetic nanoparticles. X-ray crystallography studies reveal that the Mn-complex adopt a distorted octahedral six-coordinate configuration formed by the tetradentate Schiff base ligand and two oxygen atoms of acetate anion. The heterogeneous catalyst was characterized by powder X-ray diffraction, transmission electron microscopy, scanning electron microscopy, vibrating sample magnetometer, thermo-gravimetric analysis, the energy-dispersive X-ray spectroscopy and FTIR spectroscopy. The catalyst loading on the magnetic support was determined by atomic absorption spectroscopy. Highly chemoselective oxidation of sulfides with excellent yield to the corresponding sulfoxides, and epoxidation of olefins in ethanol at room temperature were efficiently enhanced under the influence of the magnetically separable catalyst. The separation and recycling of the catalyst is simple, effective, and economic in this clean oxidation method. The electrochemical properties of the Mn-complex were investigated.