Journal of Applied Polymer Science, Vol.118, No.1, 52-62, 2010
Catalytic Oxidation of Organic Substrates Using a Reusable Polystyrene-Anchored Orthometallated Palladium(II) Complex
A new heterogeneous secondary amine Pd(II) complex anchored to macroporous polystyrene beads, P-Pd-2(seam)(2)(OAc)(2)] (seam = secondary amine), was synthesized by reacting polymer-anchored secondary amine with palladium acetate in acetic acid medium. The structure of this immobilized complex has been established on the basis of scanning electron microscope, thermogravimetric analysis, elemental analysis, atomic absorption spectroscopy, and spectrometric methods like diffuse reflectance spectra of solid and Fourier transform infrared spectroscopy. The catalytic activity of the Pd-complex was investigated toward the oxidation of various olefins and alcohols in presence of tert-butylhydroperoxide as an oxidant. The effects of various parameters such as sol-vent, oxidant, reaction time, reaction temperature, amount of catalyst, and substrates-to-oxidant ratio have been studied. The catalytic results reveal that the present polymer-anchored Pd(II) complex can be recycled more than seven times without much loss in the catalytic activity. Comparative studies have been done with the corresponding unsupported metal complex. The polymer-anchored catalyst was found to be superior to its homogeneous counterpart in activity, product selectivity, stability, and reusability (c) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 118: 52-62, 2010