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Z. Naturforsch. 2013,
68b, 458 – 466
doi:10.5560/ZNB.2013-3091
Nickel(II) and Iron(II) Complexes with Tetradentate NHC/Amide Hybrid Ligands
Institut für Anorganische Chemie, Georg-August-Universität, Tammannstraße 4, 37077 Göttingen, Germany
Reprint requests to Prof. Dr. Franc Meyer. Fax: (++49) 551 393063. E-mail:
franc.meyer@chemie.uni-goettingen.de
Received March 20, 2013 / published online Juli 2, 2013
Dedicated to Professor Heinrich Nöth on the occasion of his 85th birthday
Two methylene-bridged bis(imidazolium) salts [H4L1](PF6)2 and [H4L2](PF6)2 with appended amide groups have been synthesized which, after deprotonation, may serve as potentially tetradentate ligands providing two bis(imidazole-2-ylidene) and two amide donors. Using [H4L1](PF6)2, a square-planar nickel(II) complex [NiL1] and a six-coordinate bis(ligand) iron(II) complex [Fe(HL1)2] have been isolated and structurally characterized. Their low-spin states have been confirmed spectroscopically, and their redox properties have been studied by cyclic voltammetry. Oxidations are metal-centered to give NiIII and FeIII species, respectively.
Key words: Nickel, Iron, N-Heterocyclic Carbene, Chelate Ligand, X-Ray Crystallography, Mößbauer Spectroscopy, Redox Properties