Expeditious Synthesis of [Au(NHC)(L)]⁺ (NHC = N-Heterocyclic Carbene; L = Phosphine or NHC) Complexes

The use of the versatile N-heterocyclic carbene (NHC) gold(I) hydroxide [Au(OH)(IPr)] (IPr = N,N′-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) as precursor permits the expedient synthesis of a series of cationic heteroleptic [Au(NHC)(NHC′)]+ and [Au(NHC)(PR3)]+ complexes by protonolysis with the appropriate acid salts. Complete characterization by 1H and 13C NMR spectroscopy and by single-crystal X-ray diffraction was performed in order to discern electronic and structural differences between cationic heteroleptic [Au(NHC)(NHC′)]+ and [Au(NHC)(PR3)]+ congeners.