Phenol hydroxylation activity of metal phthalocyanine complexes encapsulated in zeolite-Y

Metal phthalocyanine complexes (MPc; M = V, Co and Cu) were encapsulated in zeolite-Y by "in situ ligand synthesis" method and were characterized by chemical and thermal analyses, FT-IR, diffuse reflectance UV-VIS and EPR spectroscopic techniques. The Pc moiety undergoes distortion from square planarity on encapsulation. The studies have provided evidence for the encapsulation of MPc inside the supercages of zeolite-Y. The encapsulated complexes exhibited enhanced phenol hydroxylation activity with H2O2 compared to the "neat" complexes in homogeneous medium. A comparative study has revealed that the activity and product selectivity of the encapsulated complexes can be correlated with the redox potential of the M((n+1))/Mn+ couple of the central metal atom of the encapsulated phthalocyanine. (C) 2002 Elsevier Science B.V. All rights reserved.