A Novel Family of Luminescent Pyrenyl‐(N‐Heterocyclic Carbene)‐ Halogenated Coinage Metal Complexes: Synthesis, Crystal Structures, and Optical Properties

Abstract

A family of luminescent pyrenyl‐(NHC)‐M‐Cl coinage metal complexes has been prepared and fully characterized (NHC = N‐heterocyclic carbene). Two classes of complexes are described: (M = Cu (1a), Ag (2a), Au (3a) where pyrenyl‐(NHC) = 1‐pyrenyl‐3‐methyl‐Imidazolin‐2‐ylidene and M = Cu (1b), Ag (2b), Au (3b) with pyrenyl‐(NHC) = 1‐pyrenyl‐3‐naphthyl‐Imidazolin‐2‐ylidene. The molecular structures of the six complexes were confirmed by single crystal X‐ray diffraction studies. All complexes were found to be emissive in solution and solid state. The use of the chromophoric‐(NHC) ligand endows to these complexes emissive properties in solution in the blue region (376‐397nm). The presence of the naphthyl‐substituent in the 1b‐3b series enhances the quantum yields relative to the methyl‐series 1a‐3a. In particular, the carbene gold complexes were the most emissive and displayed the highest quantum yields