Green, inexpensive, and fast conversion of sulfides to sulfoxides by multiusable Mo(VI) macrocyclic Schiff base complex supported on Fe3O4 nanoparticles in solvent-free conditions

In the present study, the macrocyclic-based Mo(VI) Schiff base complex was harbored on Fe3O4 nanoparticles and characterized by X-ray powder diffraction, scanning electron microscope, energy-dispersive X-ray spectroscopy, infrared spectroscopy, transmission electron microscopy, vibrating sample magnetometry, diffuse reflectance spectra, and atomic absorption spectroscopy. Separable nanocatalyst was tested under solvent-free conditions for the oxidation of methyl phenyl sulfide, diphenyl sulfide, benzyl phenyl sulfide, dipropyl sulfide, dibutyl sulfide, dimethyl sulfide, bis (4-hydroxyphenyl) sulfide, diallyl sulfide, and benzothiophene using H2O2 (30% in water) as green oxidant. This catalyst is very efficient for thioanisole oxidation with 100% conversion in 3 min. We were able to separate the nanocatalyst magnetically using external magnetic field and to apply the catalyst at least six consecutive times without a significant decrease in conversion. Remarkable and excellent turnover frequency of the catalyst was obtained to oxidize the thioanisole (526,000 h(-1)), dimethyl sulfide (526,000 h(-1)), diallyl sulfide (526,000 h(-1)), dibutyl sulfide (521,000 h(-1)), and dipropyl sulfide (500,000 h(-1)). The prepared nano catalyst has been beneficial in catalytic activity, selectivity, reaction time, and reusability with easy separation. (C) 2017 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.