A molybdenum(VI) Schiff base complex as an efficient and highly heterogeneous catalyst was developed by immobilization of a molybdenum complex on the surface of modified Fe3O4 magnetite nanoparticles, The complete characterization of catalysts was carried out by means of thermogravimetric analysis (TGA), Energy-dispersive X-ray spectroscopy (EDX) analysis, FT-IR. The obtained nanoparticles were employed as catalysts for the selective oxidation of sulfides to corresponding sulfoxides using urea hydrogen peroxide as the oxidant. Furthermore, the obtained catalysts showed not only high catalytic activity in oxidation reactions but also high degree of chemical stability in various organic solvents. The immobilized molybdenum complex on silica coated magnetic nanoparticles can easily be recovered from the reaction system using an external magnet and reused several times with high yields. The thermogravimetric analysis (TGA) curve of the nanocatalyst shows the multistep mass loss of the organic materials between 50 and 600 ◦C (Fig. 1). EDX analysis of the nanocatalyst showed expected elements such as oxygen, silicon, carbon, nitrogen, chlorine and molybdenum (Fig. 2).
