Surface decorated magnetic nanoparticles with Mn-porphyrin as an effective catalyst for oxidation of sulfides

Abstract

Mn-porphyrin complex was anchored coordinatively to silica-coated surface of magnetic nanoparticles (SMNP). Afterward, a heterogeneous nanocatalyst (Fe3O4@SiO2-MnTCPP) has been characterized by Fourier transform infrared (FT-IR), ultraviolet-visible (UV-vis) spectroscopy, powder X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating sample magnetometry (VSM), thermogravimetric analysis (TGA), and transmission electron microscope (TEM). A thermal stability up to around 350[Formula: see text]C was verified for prepared nanocatalyst based on thermogravimetric analysis. Finally, the catalytic performance of magnetically recoverable Mn-catalyst was exploited in the green oxidation of different sulfides with urea hydrogen peroxide (UHP) in the presence of imidazole as co-catalyst in ethanol under heterogeneous conditions. The eco-friendly property of ethanol strongly induced us to employ it as the reaction solvent in this oxidation system. Complete conversion ([Formula: see text]99) of sulfides to the corresponding sulfoxide or sulfones was obtained for ethyl phenyl sulfide, phenyl vinyl sulfide, diallyl sulfide, thiocyanatoethane, 2-ethyl mercaptoethanol and tetrahydrothiophene. Moreover, the recovered catalysts keep constant conversion yield up to at least three cycles.