Catalytic oxidation of alkanes including methane using µ-nitrido diiron macrocyclic complexes
Résumé
Phthalocyanine complexes with FeIIIN=FeIV structural unit activate H2O2 to give strong non-radical oxidizing species. Spectroscopic, 18O labelling data and reactivity studies indicate the formation of the high-valent diiron oxo species. N-Bridged diiron phthalocyanines show remarkable catalytic properties in the oxidation of CH4 in water at near-ambient temperatures via oxo-transfer chemistry as evidenced by low temperature UV-vis, EPR, ESI-MS, Mössbauer, XANES and EXAFS data. High turnover numbers (TON>220) were attained. The system keeps the same catalytic activity upon successive additions of H2O2 indicating a high stability of catalyst and even a possibility of recycling. Readily accessible solid catalyst, H2O2 as the clean oxidant, water as the clean reaction medium are important practical and green features of this novel approach for transformation of hydrocarbons.