Study of synthesis of μ-oxo-bismanganese(III)porphyrin compounds and their catalysis of cyclohexane oxidation by PhIO

Ten substituted mu-oxo-bis[tetraphenylporphinatomanganese (III)] compounds ([TRPPMnIII](2)O) were synthesized by the reaction of chloro[tetraphenylporphinatomanganese(III)] ((TRPPMnCl)-Cl-III) with NaOH. Their catalysis of cyclohexane monooxygenation by PhIO under moderate conditions was studied. In contrast with other metalloporphyrins reported so far, mu-oxo-bis[tetraphenylporphinatomanganese(III)] compounds are shown to have better catalytic power for cyclohexane hydroxylation by PhIO. The kinetic research showed that the rate constants k of the cyclohexane reactions had a Hammett relationship to the characteristic constants a of substituents R on porphyrin rings. (C) 1999 Academic Press.