Molecular imprinting with ruthenium porphyrin catalysts

A ruthenium meso-tetra[4-(vinylbenzoxy)benzyl]porphyrin catalyst with four polymerizable side chains was synthesized in three steps from commercially available starting materials. The polymerizable side chains allowed the incorporation of this complex in highly cross-linked mesoporous co-polymers. A block polymer and a molecularly imprinted polymer were prepared by co-polymerization with ethyleneglycol dimethacrylate using chloroform as the porogen. The imprinted polymer was prepared in the presence of aminodiphenylmethane as a template. Subsequent removal of the template created a substrate pocket next to the catalytically active center. Both polymers displayed a high catalytic activity for the oxidation of alcohols and alkanes with 2,6-dichloropyridine-N-oxide as the oxidant while the homogeneous catalyst was completely inactive. Furthermore, the imprinted polymer displayed a significant increase in activity compared to the block co-polymer.