title: A Bispidine Iron(IV)-Oxo Complex in the Entatic State.
abstract: For a series of Fe(IV) =O complexes with tetra- and pentadentate bispidine ligands, the correlation of their redox potentials with reactivity, involving a variety of substrates for alkane hydroxylation (HAT), alkene epoxidation, and phosphine and thioether oxidation (OAT) are reported. The redox potentials span approximately 350 mV and the reaction rates over 8 orders of magnitude. From the experimental data and in comparison with published studies it emerges that electron transfer and the driving force are of major importance, and this is also supported by the DFT-based computational analysis. The striking difference of reactivity of two isomeric systems with pentadentate bispidines is found to be due to a destabilization of the S=1 ground state of one of the ferryl isomers, and this is supported by the experimentally determined redox potentials and published stability constants with a series of first-row transition metal ions with these two isomeric ligands.
authors.affiliation: Universität Heidelberg, Anorganisch-Chemisches Institut und Interdisziplinäres Zentrum für Wissenschaftliches Rechnen (IWR), INF 270, 69120, Heidelberg, Germany. peter.comba@aci.uni-heidelberg.de.
authors.forename: Peter
authors.identifier: 0000-0001-7796-3532
authors.initials: P
authors.lastname: Comba
authors.affiliation: Department of Chemistry and Nano Science, Ewha Womans University, Seoul, 120-750, Korea. fukuzumi@chem.eng.osaka-u.ac.jp.|Faculty of Science and Engineering, Meijo University, Nagoya, Aichi, 468-8502, Japan. fukuzumi@chem.eng.osaka-u.ac.jp.
authors.forename: Shunichi
authors.initials: S
authors.lastname: Fukuzumi
authors.affiliation: Universität Heidelberg, Anorganisch-Chemisches Institut und Interdisziplinäres Zentrum für Wissenschaftliches Rechnen (IWR), INF 270, 69120, Heidelberg, Germany.
authors.forename: Carsten
authors.initials: C
authors.lastname: Koke
authors.affiliation: Universität Heidelberg, Anorganisch-Chemisches Institut und Interdisziplinäres Zentrum für Wissenschaftliches Rechnen (IWR), INF 270, 69120, Heidelberg, Germany.
authors.forename: Bodo
authors.initials: B
authors.lastname: Martin
authors.affiliation: Universität Heidelberg, Anorganisch-Chemisches Institut und Interdisziplinäres Zentrum für Wissenschaftliches Rechnen (IWR), INF 270, 69120, Heidelberg, Germany.
authors.forename: Anna-Maria
authors.initials: AM
authors.lastname: Löhr
authors.affiliation: Universität Heidelberg, Anorganisch-Chemisches Institut und Interdisziplinäres Zentrum für Wissenschaftliches Rechnen (IWR), INF 270, 69120, Heidelberg, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Straub
keywords: coordination chemistry; density functional calculations; homogeneous catalysis; iron bispidine complexes; redox potentials