The reaction of water-soluble manganese porphyrin complex, Mn^I^I^I (TMPyP), with two oxidants (NaOCl and KHSO~5) in 1:1 (V/V) CH~3CN/H~2O at pH 7.4 was investigated using the stopped-flow technique. In this reaction system, high-valent oxo-manganese(V) porphyrin (1) and oxo manganese (IV) porphyrin (2) were produced. Epoxidation of trans, trans-1, 4-diphenyl-1, 3-butadiene (DPBD) by Mn^I^I^I(TMPyP) with NaOCl and KHSO~5 showed that reactivity of the Mn^I^I^I(TMPyP)-KHSO~5 model system was higher than that of the Mn^I^I^I(TMPyP)-NaOCl system. In the Mn^I^I^I(TMPyP)-KHSO~5 model system, intermediate 2 was also active. The mechanism of oxygen atom transfer from the high-valent manganese prophyrine to olefine is discussed.

Key words: MANGANESE COMPLEX, PORPHYRIN, CATALYTIC OXIDATION, STOPPED-FLOW TECHNIQUE, CATALYTIC ACTIVITY