Origin of the oxygen atom in C-H bond oxidations catalyzed by a water-soluble metalloporphyrin

Chemical research shows that 54% of all oxygen atoms found in 4-(1-hydroxy-1-methylethyl)benzoic acid originate from water when 4-isopropylbenzoic acid undergoes monopersulfate oxidation in H2(super 18)O and metalloporphyrin catalysis. Radioactive labelling techniques were used to study the redox tautomerism reaction in the active hydroxo-metal-oxo porphyrin complex.