Mechanism of Catalytic Oxygenation of Alkanes by Halogenated Iron Porphyrins
Abstract
Halogenation of an iron porphyrin causes severe saddling of the macrocyclic structure and a large positive shift in the iron(III)/(II) redox couple. Although perhalogenated iron(II) porphyrins such as Fe(TFPPBr_8) [H_2TFPPBr_8, β-octabromo-tetrakis(pentafluorophenyl)-porphyrin] are relatively resistant to autoxidation, they rapidly reduce alkyl hydroperoxides. These and related reactivity studies suggest that catalysis of alkane oxygenation by Fe(TFPPBr_8)CI occurs through a radical-chain mechanism in which the radicals are generated by oxidation and reduction of alkyl hydroperoxides.
- Publication:
-
Science
- Pub Date:
- May 1994
- DOI:
- 10.1126/science.8191283
- Bibcode:
- 1994Sci...264.1311G