η⁶‑Tetramethylfulvene and μ‑η³:η³‑Benzene Complexes of Iridium

The reaction of Cp*Ir­(NHC)­Me2 (Ir-Me2) with [CPh3]+[B­(C6F5)4] in dichloromethane resulted in conversion of the Cp* ligand to an η6-tetramethylfulvene ligand via apparent hydride abstraction (Cp* = η5-C5Me5; NHC = 1,3-N,N-dimethylimidazol-2-ylidene). The products of this reaction are triphenylmethane and the η6-tetramethylfulvene complex [(η6-C5Me4CH2)­Ir­(NHC)­(Me2)]+[B­(C6F5)4] (fulv-Ir+). When dichloromethane solutions of the related complex [Cp*Ir­(NHC)­(Ph)­(solv)]+[MeB­(C6F5)3]− were allowed to stand at room temperature, crystals of the unusual sandwich complex [{Cp*Ir­(NHC)}2(μ-η3:η3-C6H6)]2+ (Ir-C6H6-Ir2+) were obtained. Complexes fulv-Ir+ and Ir-C6H6-Ir2+ represent unique architectures in the Cp*Ir­(NHC) family. Both compounds were characterized by spectroscopic methods as well as by single-crystal X-ray diffraction.