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.