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A Ferrocene-Based Dicationic Iron(IV) Carbonyl Complex
Moritz Malischewski1, Konrad Seppelt1, Jörg Sutter2
1Freie Universität Berlin, Institut für Chemie und Biochemie, Anorganische Chemie, Fabeckstrasse 34-36, 14195, Berlin, Germany.
Abstract:
The 16-valence electron species [Cp*2 Fe]2+ (Cp*=η-C5 Me5 ), formally featuring a tetravalent iron ion, quantitatively binds CO in HF solution to form the stable, diamagnetic carbonyl species [Cp*2 Fe(CO)]2+ . This dication forms salts in the presence of AsF6 - and SbF6 - that were crystallographically characterized. The molecular structure in crystals of [Cp*2 Fe(CO)](AsF6 )2 displays cyclopentadienyl rings that are clearly not parallel and an equatorially bound η1 -CO ligand. The formal oxidation state +IV of iron was investigated by 57 Fe Mössbauer spectroscopy and is supported by DFT computational analysis. A detailed spectroscopic characterization of the hitherto unprecedented high-valent iron carbonyl compounds is reported.
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