title: Metalloporphyrin mixed-valence π-cation radicals: [Fe(oxoOEC(•/2))(Cl)]2SbCl6, structure, magnetic properties, and near-IR spectra.
abstract: The preparation and characterization of a mixed-valence π-cation radical derivative of an iron(III) oxochlorinato complex is reported. The new complex has been synthesized by the one-electron oxidation of a pair of [Fe(oxoOEC)(Cl)] molecules to form the dimeric cation [Fe(oxoOEC)(Cl)]₂⁺. The cation has been characterized by X-ray analysis, Mössbauer spectroscopy, UV-vis and near-IR spectroscopy, and magnetic susceptibility measurements from 6-300 K. The crystal structure shows that the two rings have a smaller overlap area than those of the formally related nickel and copper octaethylporphinate derivatives, reflecting the larger steric congestion at the periphery in part of the oxochlorin rings. The Mössbauer data is consistent with two equivalent iron(III) centers. The unpaired electron is delocalized over the two oxochlorin rings and mediates a strong antiferromagnetic interaction between the high-spin iron(III) centers.
authors.affiliation: The Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA.
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.forename: Teresa J
authors.initials: TJ
authors.lastname: Neal
authors.forename: Graeme R A
authors.initials: GR
authors.lastname: Wyllie
authors.forename: Allen G
authors.initials: AG
authors.lastname: Oliver
authors.forename: Charles E
authors.initials: CE
authors.lastname: Schulz
authors.forename: W Robert
authors.initials: WR
authors.lastname: Scheidt
mesh_terms: D002412:Cations / Q000737:chemistry; D018360:Crystallography, X-Ray; D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals / Q000737:chemistry*; D060328:Magnetic Phenomena; D008665:Metalloporphyrins / Q000737:chemistry*; D008958:Models, Molecular; D015204:Spectroscopy, Mossbauer; D019265:Spectroscopy, Near-Infrared
chemical_list: D002412:Cations; D005609:Free Radicals; D008665:Metalloporphyrins