immobilized vanadium compounds within nanoreactors of al-mcm-41 as catalyst for epoxidation of alkenes

vo2+ and its complexes with ethylenediamine (en), acetylacetonate (acac), 2, 2’-bipyridine(bpy) ligands, immobilized within nanoreactors of al-mcm-41 designated as vo2+/al-mcm-41 or vol2/al-mcm-41, were prepared and characterized by x-ray powder diffraction (xrd), ft-ir, bet nitrogen adsorption-desorption and chemical analysis techniques. vo2+/al-mcm-41 and vol2/al-mcm-41 were found to catalyze the epoxidation of trans-stilbene, norbornene, and geraniol with aqueous hydrogen peroxide (h2o2) in refluxing acetonitrile with 30-80% conversion and up to 98% selectivity toward the formation of the corresponding epoxides. on the other hand, under similar conditions, these alkenes underwent epoxidation with 50 to 99% conversion and up to 100 % selectivitiy in the presence of vo(acac)2/al-mcm-41with tert-butylhydroperoxide (tbhp) as oxidant.