title: Binding of molecular oxygen by an artificial heme analogue: investigation on the formation of an Fe-tetracarbene superoxo complex.
abstract: The dioxygen reactivity of a cyclic iron(ii) tetra-NHC-complex (NHC: N-heterocyclic carbene) is investigated. Divergent oxidation behavior is observed depending on the choice of the solvent (acetonitrile or acetone). In the first case, exposure to molecular oxygen leads to an oxygen free Fe(iii) whereas in the latter case an oxide bridged Fe(iii) dimer is formed. In acetone, an Fe(iii)-superoxide can be trapped, isolated and characterized as intermediate at low temperatures. An Fe(iii)-O-Fe(iii) dimer is formed from the Fe(iii) superoxide in acetone upon warming and the molecular structure has been revealed by single crystal X-ray diffraction. It is shown that the oxidation of the Fe(ii) complex in both solvents is a reversible process. For the regeneration of the initial Fe(ii) complex both organic and inorganic reducing agents can be used.
authors.affiliation: Chair of Inorganic Chemistry/Molecular Catalysis, Catalysis Research Center, Ernst-Otto-Fischer-Strasse 1 and Faculty of Chemistry, Lichtenbergstrasse 4, Technische Universität München, D-85747 Garching bei München, Germany. fritz.kuehn@ch.tum.de.
authors.forename: Markus R
authors.initials: MR
authors.lastname: Anneser
authors.affiliation: Chair of Inorganic Chemistry/Molecular Catalysis, Catalysis Research Center, Ernst-Otto-Fischer-Strasse 1 and Faculty of Chemistry, Lichtenbergstrasse 4, Technische Universität München, D-85747 Garching bei München, Germany. fritz.kuehn@ch.tum.de.
authors.forename: Stefan
authors.initials: S
authors.lastname: Haslinger
authors.affiliation: Chair of Inorganic Chemistry/Molecular Catalysis, Catalysis Research Center, Ernst-Otto-Fischer-Strasse 1 and Faculty of Chemistry, Lichtenbergstrasse 4, Technische Universität München, D-85747 Garching bei München, Germany. fritz.kuehn@ch.tum.de.
authors.forename: Alexander
authors.initials: A
authors.lastname: Pöthig
authors.affiliation: Chair of Inorganic Chemistry/Molecular Catalysis, Catalysis Research Center, Ernst-Otto-Fischer-Strasse 1 and Faculty of Chemistry, Lichtenbergstrasse 4, Technische Universität München, D-85747 Garching bei München, Germany. fritz.kuehn@ch.tum.de.
authors.forename: Mirza
authors.initials: M
authors.lastname: Cokoja
authors.affiliation: KAUST Catalysis Center, King Abdullah University of Science and Technology, 23955-6900, Thuwal, Kingdom of Saudi Arabia and Department of Materials Science and Engineering, School of Molecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology, 21210, Wang Chan, Rayong, Thailand.
authors.forename: Valerio
authors.initials: V
authors.lastname: D'Elia
authors.affiliation: KAUST Catalysis Center, King Abdullah University of Science and Technology, 23955-6900, Thuwal, Kingdom of Saudi Arabia.
authors.forename: Manuel P
authors.initials: MP
authors.lastname: Högerl
authors.affiliation: KAUST Catalysis Center, King Abdullah University of Science and Technology, 23955-6900, Thuwal, Kingdom of Saudi Arabia.
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Basset
authors.affiliation: Chair of Inorganic Chemistry/Molecular Catalysis, Catalysis Research Center, Ernst-Otto-Fischer-Strasse 1 and Faculty of Chemistry, Lichtenbergstrasse 4, Technische Universität München, D-85747 Garching bei München, Germany. fritz.kuehn@ch.tum.de.
authors.forename: Fritz E
authors.initials: FE
authors.lastname: Kühn
mesh_terms: D040761:Biomimetic Materials / Q000737:chemistry*; D006418:Heme / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D008697:Methane / Q000031:analogs & derivatives* / Q000737:chemistry; D008958:Models, Molecular; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry*
chemical_list: D009942:Organometallic Compounds; C030011:carbene; D006418:Heme; D007501:Iron; D008697:Methane; D010100:Oxygen