Electronic Structure of Oxo-Bridged Iron(III) Dimers
Abstract
Magnetic susceptibility results and extensive electronic, infrared, and Mi:issbauer spectral data are presented for enH_2[(FeHEDT A)_2O]· 6H_2O_3, Na_4[(FeEDTA)_2O]· 12H_2O, FeHEDTA· H_2O, and NaFeEDT A· 3H_2O (HEDTA = N-hydroxoethylethylenediaminetriacetate, EDTA = ethylenediaminetetraacetate, and enH_2^(2+) = ethylenediammonium cation). The magnetic and spectral data establish an electronic structural model for the oxo-bridged dimers in which pairs of S = 5/2 Fe(III) ions interact antiferromagnetically, with J ≃ -95 cm^(-1). The oxo-bridged dimers show marked intensity enhancement of the one-center Fe(III) ligand-field bands. There are also several uv bands which are interpreted as arising from simultaneous electronic excitations of Fe(III) pairs. A simple high-spin ligand-field model modified by spin-spin interaction is judged to be considerably more appropriate than the Dunitz-Orgel molecular orbital approach as a vehicle for describing oxo-bridged Fe(IIl) dimers.
Additional Information
© 1972 American Chemical Society. Received June 24, 1971. Research at Rutgers University was supported by the Rutgers Research Council and a Petroleum Research Fund Starter Grant. Research at the California Institute of Technology was supported by the National Science Foundation. The authors wish to thank Professor R. Herber for obtaining the Mössbauer data and Professor J. Potenza for performing the X-ray diffraction studies related to the singlecrystal spectral measurements. We are also grateful to Professors R. L. Martin and S. J. Lippard for several stimulating discussions regarding the interpretation of various structural, spectral, and magnetic data for oxo-bridged dimeric complexes.Additional details
- Eprint ID
- 42744
- DOI
- 10.1021/ja00763a022
- Resolver ID
- CaltechAUTHORS:20131126-152704891
- Rutgers Research Council
- Petroleum Research Fund Starter Grant
- NSF
- Created
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2013-11-27Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field
- Caltech groups
- Division of Geological and Planetary Sciences