Mixed-Valence, Tetranuclear Iron Chelate Complexes as Endoreceptors: Charge Compensation Through Inclusion of Cations


  • “Adamantanoid” Chelate Complexes, Part 4. This work was supported by the Deutsche Forschungsgemeinschaft and by the Fonds der Chemischen Industrie. We thank Prof. Dr. F. Vögtle and Dr. S. Schuth, Universität Bonn, and Prof. Dr. K.-P. Zeller, Universität Tübingen for the measurement of the FAB mass spectra. Part 3: ref. [1].

  • Dedicated to Professor Helmut Ringsdorf on the occasion of his 65th birthday


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In a simple one-pot reaction the host-guest compounds 1 (white spheres FeIII; black = FeII; gray = NHmath image; angled rods = 2: R = Me, Et) are accessible in gram quantities by self-assembly. They are the only fully characterized redox isomers whose cyclic voltammograms display four quasi-reversible waves and whose mixed-valent character has been established by Mössbauer spectra. The endohedral complexation of one NHmath image ion in 1 has been confirmed by X-ray crystallography.