Modified crosslinked polyacrylamide anchored Schiff base-cobalt complex: A novel nano-sized heterogeneous catalyst for selective oxidation of olefins and alkyl halides with hydrogen peroxide in aqueous media

A new nano-sized polymer-supported Schiff base-cobalt complex catalyst based on crosslinked polyacrylamide was synthesized and characterized. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) of the catalyst show nanosize fiber-like image of the polymeric catalyst. The catalyst activity was studied in the oxidation of various olefins including non-activated terminal olefin in water with hydrogen peroxide as an oxygen source. The catalyst showed high degree of selectivity. The effects of reaction parameters such as solvent, oxidant, temperature, molar ratio of catalyst and catalyst structure on the oxidation of styrene were investigated. The oxidation of benzyl halides to their corresponding carbonyl compounds in the presence of this heterogeneous catalyst was studied as well. The catalyst can be recycled several times without significant loss in its activity. (C) 2010 Elsevier B.V. All rights reserved.