Stable N-bridged diiron (IV) phthalocyanine cation radical complexes: synthesis and properties

P. Afanasiev (1) , D. Bouchu , E. V. Kudrik (1) , J. M. M. Millet , A. B. Sorokin (1)

1 IRCELYON - Institut de recherches sur la catalyse et l'environnement de Lyon

Oxidation of N-bridged diiron tetra-tert-butylphthalocyanine ((FePcBu)-Bu-t)(2)N with (BuOOH)-Bu-t in halogenated solvents afforded mu-nitrido diiron (IV) phthalocyanine cation radical complexes, (X)PcFeIV-N-(FePc+center dot)-Pc-IV(X) (X = Cl, Br), as evidenced by UV-vis, electron paramagnetic resonance (EPR), electrospray ionization mass spectrometry (ESI-MS), Mossbauer, X-ray absorption near edge structure (XANES) and extended X-ray absorption. ne structure (EXAFS) data. Continuous introduction ESI-MS showed the initial formation of the t-butylperoxo diiron complex (BuOO)-Bu-t-((FePcBu)-Bu-t)(2)N followed by intermediate formation of a monohalogenated adduct which gave the dihalogenated complex as final stable product. Fe K-edge EXAFS analysis of (X)PcFeIV-N-(FePc+center dot)-Pc-IV(X) showed bridging N atom at a distance of 1.69(1) angstrom. The distance between two equivalent hexacoordinated in-plane iron (IV) centers is 3.39(1) angstrom. Fe-X bond lengths are 2.33 and 2.54 angstrom for X = Cl and Br, respectively. The use of (Cl)PcFeIV-N-(FePc+center dot)-Pc-IV(Cl) for the catalytic oxidation of organic substrates has been shown for the first time.

Domaines: Catalyse

P. Afanasiev, D. Bouchu, E. V. Kudrik, J. M. M. Millet, A. B. Sorokin. Stable N-bridged diiron (IV) phthalocyanine cation radical complexes: synthesis and properties. Dalton Transactions, 2009, 44, pp.9828-9836. ⟨10.1039/b916047g⟩. ⟨hal-00445819⟩