Immobilization of MoO2Cl2 on polystyrene via different linkers and oxidation of sulfides in the presence of hydrogen peroxide

Abstract

Chloromethylated polystyrene was oxidized to aldehydic polystyrene and by reaction of this aldehydic polystyrene resin with furfuryl amine and 2-(amino methyl) pyridine, imine-bounded polystyrene resins 1a and 1b were obtained. Amine-bounded polystyrene resins 1c–1f were also prepared by direct reaction of chloromethylated polystyrene and amines. These functionalized polystyrene resins were used to immobilize MoO2Cl2 on polystyrene. These functionalized polystyrene resins were characterized with elemental analysis (CHN) and FT-IR spectrum. Polymer-supported catalysts were characterized with FT-IR and neutron activation analysis (NAA). These catalysts were used in oxidation of methyl phenyl sulfide in the presence of H2O2 as oxidant and the results showed that these catalysts were highly active and selective. The reusability of these heterogeneous catalysts was also investigated and the results showed that the supported MoO2Cl2 catalyst on polystyrene via imidazole liker was highly reusable as it was used 15 times in oxidation of methyl phenyl sulfide in the presence of environmental benign oxidant (H2O2) and solvent (H2O) without any decrease in its activity. Then the catalytic activity of these supported catalysts was investigated in oxidation of some aliphatic and aromatic sulfides. Almost all of these supported molybdenum-based catalysts were highly active and selective in the conversion of these sulfides to their corresponding sulfoxides.