| Abstract
| - A formally FeIII7FeII complex, containing an inner Fe4O4-cubane and four peripheral Fe centers, is derived from the one-electron reduction of its FeIII8 precursor. Spectroscopic analysis of the former reveals that the redox activity of this Fe8 system is confined within its cubane core. The resulting (Fe4O4)3+-cubane, which is valence-delocalized in the NMR, Mössbauer, and IR spectroscopy time scales but valence-trapped in the X-ray photoelectron spectroscopy (XPS) time scale, is better described as a Robin−Day class-II system by the analysis of its near-infrared (NIR) intervalence charge transfer (IVCT) band profile.
- One-electron reduction of an octanuclear all-ferric complex generates a product containing a mixed-valent Fe4O4-cubane, as determined by its X-ray photoelectron and Mössbauer spectra. Analysis of the NIR intervalence charge transfer band identifies this complex as a Robin−Day type-II system.
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