A Cyclometalated NHC Iridium Complex Bearing a Cationic (η(5)‐Cyclopentadienyl)(η(6)‐phenyl)iron Backbone

Nucleophilic substitution of [(η(5)‐cyclopentadienyl)(η(6)‐chlorobenzene)iron(II)] hexafluorophosphate with sodium imidazolate resulted in the formation of [(η(5)‐cyclopentadienyl)(η(6)‐phenyl)iron(II)]imidazole hexafluorophosphate. The corresponding dicationic imidazolium salt, which was obtained by treating this imidazole precursor with methyl iodide, underwent cyclometallation with bis[dichlorido(η(5)‐1,2,3,4,5‐pentamethylcyclopentadienyl]iridium(III) in the presence of triethyl amine. The resulting bimetallic iridium(III) complex is the first example of an NHC complex bearing a cationic and cyclometallated [(η(5)‐cyclopentadienyl)(η(6)‐phenyl)iron(II)](+) substituent. As its iron(II) precursors, the bimetallic iridium(III) complex was fully characterized by means of spectroscopy, elemental analysis and single crystal X‐ray diffraction. In addition, it was investigated in a catalytic study, wherein it showed high activity in transfer hydrogenation compared to its neutral analogue having a simple phenyl instead of a cationic [(η(5)‐cyclopentadienyl)(η(6)‐phenyl)iron(II)](+) unit at the NHC ligand.