FORMATION AND REACTIVITY TOWARD HYDROCARBONS OF OXOMANGANESE PORPHYRINS IN THE PRESENCE OF ANIONIC BASES

In dichloroethane oxygen transfer from Ph(4)PHSO(5) to manganese(III) porphyrins forming the corresponding ore-species, which then oxidize o rganic substrates, occurs only in the presence of basic species acting as axial ligands. Together with neutral nitrogen bases such as pyridi nes and imidazole, anionic bases, i.e., ClO, SO, and CH3CO, promote th e formation of oxomanganese porphyrin species. However, on the basis o f a comparison of the spectral properties and of the oxidative behavio rs towards cis-stilbene and diphenylmethane, we suggest that the ore-s pecies formed in the presence of anionic oxygen bases is different fro m that formed in the presence of neutral bases. In particular, the for mer is suggested to be a manganese (IV) derivative behaving as a radic al oxidant.