title: A Low-Valent Iron Imido Heterocubane Cluster: Reversible Electron Transfer and Catalysis of Selective C-C Couplings.
abstract: Enzymes and cofactors with iron-sulfur heterocubane core structures, [Fe4 S4 ], are often found in nature as electron transfer reagents in fundamental catalytic transformations. An artificial heterocubane with a [Fe4 N4 ] core is reported that can reversibly store up to four electrons at very negative potentials. The neutral [Fe4 N4 ] and the singly reduced low-valent [Fe4 N4 ](-) heterocubanes were isolated and fully characterized. The low-valent species bears one unpaired electron, which is localized predominantly at one iron center in the electronic ground state but fluctuates with increasing temperatures. The electrons stored or released by the [Fe4 N4 ]/[Fe4 N4 ](-) redox couple can be used in reductive or oxidative CC couplings and even allow catalytic one-pot reactions, which show a remarkably enhanced selectivity in the presence of the [Fe4 N4 ] heterocubanes.
authors.affiliation: Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1, 8093 Zürich (Switzerland).
authors.forename: Crispin
authors.initials: C
authors.lastname: Lichtenberg
authors.affiliation: Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1, 8093 Zürich (Switzerland).|Current address: Centro Universitario de la Defensa, Academia General Militar, Crta. de Huesca s/n, Zaragoza, 50090 (Spain).
authors.forename: Inés
authors.initials: I
authors.lastname: Garcia Rubio
authors.affiliation: Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1, 8093 Zürich (Switzerland).
authors.forename: Liliana
authors.initials: L
authors.lastname: Viciu
authors.affiliation: Department of Chemistry & Pharmacy, Friedrich-Alexander University, Erlangen-Nürnberg (FAU), Egerlandstrasse 1, 91058 Erlangen (Germany).
authors.forename: Mario
authors.initials: M
authors.lastname: Adelhardt
authors.affiliation: Department of Chemistry & Pharmacy, Friedrich-Alexander University, Erlangen-Nürnberg (FAU), Egerlandstrasse 1, 91058 Erlangen (Germany).
authors.forename: Karsten
authors.initials: K
authors.lastname: Meyer
authors.affiliation: Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1, 8093 Zürich (Switzerland).
authors.forename: Gunnar
authors.initials: G
authors.lastname: Jeschke
authors.affiliation: Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1, 8093 Zürich (Switzerland). hgruetzmacher@ethz.ch.
authors.forename: Hansjörg
authors.initials: H
authors.lastname: Grützmacher
mesh_terms: D002384:Catalysis; D004579:Electron Transport; D007094:Imides / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D015394:Molecular Structure; D010084:Oxidation-Reduction
chemical_list: D007094:Imides; D007501:Iron
keywords: CC coupling; cluster compounds; heterocubanes; homogeneous catalysis; low-valent iron