A Manganese(IV)-Hydroperoxo Intermediate Generated by Protonation of the Corresponding Manganese(III)-Superoxo Complex
| Autor: | Yen Hao Lin, Maurice van Gastel, Yury Kutin, Way Zen Lee, Shengfa Ye, Eckhard Bill, Alexander Schnegg |
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| Rok vydání: | 2020 |
| Předmět: |
Chemistry
chemistry.chemical_element Protonation General Chemistry Manganese 010402 general chemistry 01 natural sciences Biochemistry Medicinal chemistry Catalysis 0104 chemical sciences law.invention chemistry.chemical_compound Colloid and Surface Chemistry Deprotonation law Electrophile Pyridine Scandium Electron paramagnetic resonance Trifluoromethanesulfonate |
| Zdroj: | Journal of the American Chemical Society. 142(23) |
| ISSN: | 1520-5126 |
| Popis: | Earlier work revealed that metal-superoxo species primarily function as radicals and/or electrophiles. Herein, we present ambiphilicity of a MnIII-superoxo complex revealed by its proton- and metal-coupled electron-transfer processes. Specifically, a MnIV-hydroperoxo intermediate, [Mn(BDPBrP)(OOH)]+ (1, H2BDPBrP = 2,6-bis((2-(S)-di(4-bromo)phenylhydroxylmethyl-1-pyrrolidinyl)methyl)pyridine) was generated by treatment of a MnIII-superoxo complex, Mn(BDPBrP)(O2•) (2) with trifluoroacetic acid at -120 °C. Detailed insights into the electronic structure of 1 are obtained using resonance Raman and multi-frequency electron paramagnetic resonance spectroscopies coupled with density functional theory calculations. Similarly, the reaction of 2 with scandium(III) triflate was shown to give a Mn(IV)/Sc(III) bridging peroxo species, [Mn(BDPBrP)(OO)Sc(OTf)n](3-n)+ (4). Furthermore, it is found that deprotonation of 1 quantitatively regenerates 2, and that one-electron oxidation of the corresponding MnIII-hydroperoxo species, Mn(BDPBrP)(OOH) (3), also yields 1. |
| Databáze: | OpenAIRE |
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