Green oxidation of sulfides by dioxide Molybdenum(VI) Schiff base anchored on Fe3O4 nanoparticles in solvent-free condition

Abstract

In this research work, magnetite nanoparticles were prepared, functionalized with molybdenum(VI) salophen complex and characterized using physico-chemical technique. The prepared nanocatalyst was tested for catalytic oxidation of sulfides. The catalytic reaction optimized by changing of solvent, temperature of reaction, time of reaction, [oxidant]/[sulfides] ratio and amount of catalyst. Phenyl methyl sulfide , diphenyl sulfide, dimethyl sulfide, dipropyl sulfide, dibutyl sulfide, Benzyl phenyl sulfide , bis(4-hydroxyphenyl) sulfide, diallyl sulfide and benzothiophene. We obtained the best results in solvent-free condition. The amount of catalyst was optimized by 35% aqueous H2O2 as environmental friendly oxidant. The nanocatalyst is so effective for selective oxidation of thioanisole, dimethyl sulfide, with a >99% conversion, and excellent turnover frequency (131000 h-1<) in shortest time (5 min). The catalyst was easily separated from reaction mixture by using an external magnetic field and reused for several time without significant decreasing in activity.

Keywords

• molybdenum (vi)
• sulfides
• schiff base
• green oxidation
• nanocatalyst
• solvent-free