IRON(III)-TETRAPHENYLPORPHYRINS IN REVERSED MICELLES OF SURFACTANTS AS PEROXIDASE MODELS

The kinetics of o-dianisidine oxidation by hydrogen peroxide catalyzed by meso-tetrakis-phenylferrichloroporphyrin (TPP-1)(4), aminoethyl)am inoethoxy]phenyl}ferrichloroporphyrin (TPP-2), l-meso[4(2-bromoethoxy) phenyl]ferrichloroporphyrin (TPP-3), rakis-[4(2-bromoethoxy)phenyl]fer richloroporphyrin (TPP-4), and their complexes with additional ligands (aniline, imidazole, and pyridine) were studied in reversed micelles of Aerosol OT (AOT) in octane. The TPP complexes incorporated in rever sed micelles of AOT in octane mimicked characteristic features of the active site of horseradish peroxidase, i.e., the high-spin state of he me iron and its ability to bind hydrogen peroxide and generate the act ive forms of hydrogen peroxide, thus initiating o-dianisidine oxidatio n by a mechanism involving free radicals. The imidazole and pyridine c omplexes of TPP-4 exhibited the maximum catalytic activity. Means for regulating the activity of the peroxidase models in reversed micelles of surfactants, such as selection and modification of surfactant, atta chment of porphyrins to micelles by ''anchor'' groups, and an addition al ligation of Fe ion, are discussed.