Cr(III), Fe(III) and Bi(III) complexes of N,N'-bis(salicylidene)diethylenetriamine (H(2)saldien) encapsulated in zeolite-Y have been isolated and characterised by spectroscopic (IR and UV-Vis) studies and thermal as well as X-ray diffraction (XRD) patterns. Catalytic activities of these complexes for the decomposition of H2O2 and for the oxidation of phenol to a mixture of catechol and hydroquinone using H2O2 as an oxidant have been studied. A best-suited condition has been optimised by considering the concentration of substrate, reaction time, amount of catalyst, oxidant and solvent for maximum transformation of phenol. Thus, for a fixed amount of phenol (4.7 g), 0.025 g of catalyst, 5.67 g of aqueous 30% H2O2) and 2 ml of CH3CN are required to carry out the reaction at 80 degreesC in order to have maximum phenol transformation. However, selectivity towards the formation of catechol and hydroquinone vary from catalyst to catalyst. Respective neat metal complexes have also been prepared and studied for their catalytic activities for comparing these results. (C) 2002 Elsevier Science B.V. All rights reserved.