A New Look at Molecular and Electronic Structure of Homoleptic Diiron(II,II) Complexes with N,N-Bidentate Ligands: Combined Experimental and Theoretical Study |
| |
Authors: | Krzesimir Korona Michał Terlecki Dr. Iwona Justyniak Michał Magott Dr. Jan Żukrowski Dr. Arkadiusz Kornowicz Prof. Dawid Pinkowicz Prof. Adam Kubas Prof. Janusz Lewiński |
| |
Affiliation: | 1. Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland;2. Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland;3. Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Cracow, Poland;4. Academic Centre for Materials and Nanotechnology, AGH University of Science and Technology, Av. A. Mickiewicza 30, 30-059 Cracow, Poland |
| |
Abstract: | Paddlewheel-type binuclear complexes featuring metal−metal bonding have been the subject of widespread interest due to fundamental concern in their electronic structures and potential applications. Here, we explore the molecular and electronic structures of diiron(II,II) complexes with N,N’-diarylformamidinate ligands. While a paddlewheel-type diiron(II,II) complex with N,N’-diphenylformamidinate ligands (DPhF) exhibits the centrosymmetric [Fe2(μ-DPhF)4] structure, a minor alteration in the ligand system, i. e., switching from phenyl to p-tolyl N-substituted formamidinate ligand (DTolF), resulted in the isolation of an unprecedented non-centrosymmetric [Fe(μ-DTolF)3Fe(κ2-DTolF)] complex. Both complexes were characterized using single-crystal X-ray diffraction, magnetic measurements, 57Fe Mössbauer spectroscopy, and cyclic voltammetry along with high-level ab-initio calculations. The results provide a new view on a range of factors controlling the ground-state electronic configuration and structural diversity of homoleptic diiron(II,II) complexes. Model calculations determined that the Mayer bond orders for Fe−Fe interactions are significantly lower than 1 and equal to 0.15 and 0.28 for [Fe2(μ-DPhF)4] and [Fe(μ-DTolF)3Fe(κ2-DTolF)], respectively. |
| |
Keywords: | ab initio calculations electronic structure iron magnetic properties metal-metal interactions |
|
|