Rate enhancement of oxidation reactions by the encapsulation of metal phthalocyanine complexes

Iron phthalocyanine (FePc) and cobalt phthalocyanine (CoPc) as free complex es as well as encapsulated in zeolite-Y (FePc-ZeY and CoPc-ZeY) have been s tudied as catalysts in mild, aerobic oxidation of hydroquinone. A remarkabl e rate enhancement was observed with the encapsulated catalysts, especially in the case of the encapsulated cobalt phthalocyanine, where the encapsula ted complex was a good, active oxidation catalyst, while its homogeneous an alogue was completely inactive. The site isolation effect is responsible fo r the observed rate enhancement. The solvent effect was also studied in the case of free complexes and encapsulated catalysts.