Co (III)-containing mesoporous silica as an efficient catalyst in selective dihydroxylation of cyclohexene

Abstract

Cobalt-containing mesoporous silica have been synthesized hydrothermally using different Co content (Si/Co mole ratios 5-30) in the synthesis gel using the self-assembled molecular array of cationic surfactant cetyltrimethylammonium bromide as a supramolecular template under very mild acidic conditions. Powder XRD, N-2 adsorption, TEM, SEM/EDS, UV-visible and FT-IR tools have been employed to characterize these materials. Characterization data suggested that the Co(Ill) species have been anchored strongly in the 2D-hexagonal mesoporous silica framework. These Co(III)-containing mesoporous materials showed excellent catalytic activity and high trans-selectivity in the liquid phase dihydroxylation of cyclohexene under mild liquid phase reaction conditions using hydrogen peroxide, tert-butyl hydroperoxide (TBHP) or molecular O-2, as oxidants and acetonitrile solvent. (C) 2004 Elsevier B.V. All rights reserved.