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

Metal phthalocyanine complexes (MPc; <F>M=V</F>, 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. [Copyright &y& Elsevier]