In this work, we investigated the catalytic activity of representatives of the three generations of ironporphyrins, namely [5,10,15,20-tetraphenylporphyrin]iron(III) chloride (Fe(TPP)Cl), [5,10,15,20-tetrakis(2,6-dichlorophenyl)porphyrin]iron(III) chloride (Fe(TDCPP)Cl), and [5-mono(pentafluorophenyl) 10, 15,20-tris(2,6-dichlorophenyl)2,3,7,8,12,13,17,18-octachloroporphyrin] iron(Ill) (Fe(PCl8)Cl), occluded in a polymeric film based on poly(dimethylsiloxane) (PDMS), in the oxidation of cyclohexane by iodosylbenzene. The catalytic results show the influence of the polymeric support on the reactivity of the three generations of metalloporphyrins, its importance in concentrating the substrate close to the catalytic site, and the protection it renders the catalyst against auto-oxidative destruction. (C) 2004 Elsevier B.V. All rights reserved.