Zr (IV)-ninhydrin supported MCM-41 and MCM-48 as novel nanoreactor catalysts for the oxidation of sulfides to sulfoxides and thiols to disulfides

摘要

Modification of MCM-41 and MCM-48 mesoporous materials with bonded aminosilane species, Schiff base preparation by ninhydrin and finally complexation with zirconium, has attracted much attention in order to design catalyst with advanced applications in the oxidation of sulfides to sulfoxides and thiols to disulfides in the presence of hydrogen peroxide. In all oxidation of sulfides to sulfoxids 0.4 mL H2O2 used as oxidant in the presence of Zr(IV)-ninhydrin supported MCM-41 (0.01 g) or Zr(IV)ninhydrin supported MCM-48 (0.005 g) at room temperature and solvent-free condition. Also the best conditions for oxidation of thiols to disulfides with 0.4 mL H2O2 were 0.005 g Zr(IV)-ninhydrin supported MCM-41 or Zr(IV)ninhydrin supported MCM-48 at room temperature and in ethanol. These catalysts are characterized by SEM, XRD, TGA, FT-IR, EDS, ICP and BET analysis. Also the Turn over frequency (TOF) and Turn over number (TON) of catalysts are calculated. Obtained results by these heterogeneous catalysts revealed several advantages including short reaction times, simple workup, easy isolation and reusability.