Synthesis and Reactivity of New Bis(N-heterocyclic carbene) Iridium(I) Complexes

New complexes of the type <i>trans</i>-[IrCl­(η²-COE)­(NHC)₂] (COE = <i>cis</i>-cyclooctene; NHC = N-heterocyclic carbene) have been prepared in one step from the reaction of ca. 4 equiv of NHC or [AgCl­(NHC)] with [IrCl­(η²-COE)₂]₂ in benzene. These new complexes have been characterized by techniques including NMR and IR spectroscopy, X-ray crystallography, and elemental analysis. Exposing <i>trans</i>-[IrCl­(COE)­(I^<i>i</i>Pr^Me)₂] to CO yielded <i>trans</i>-[IrCl­(CO)­(I^<i>i</i>Pr^Me)₂], which is the only bis­(NHC) analogue of Vaska’s complex <i>trans</i>-[IrCl­(CO)­(PPh₃)₂] known to date. The synthesis of <i>trans</i>-[Ir­(CO)­(I^<i>i</i>Pr^Me)₂(R)] (R = MeO, PhCC, OSiPh₃, O₂CPh) complexes has been achieved via deprotonation reactions involving the new hydroxide species <i>trans</i>-[Ir­(OH)­(CO)­(I<i>ⁱ</i>Pr^Me)₂]