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 ( 1 a ), Ag ( 2 a ), Au ( 3 a ) where pyrenyl‐(NHC)=1‐pyrenyl‐3‐methyl‐Imidazolin‐2‐ylidene and M=Cu ( 1 b ), Ag ( 2 b ), Au ( 3 b ) 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 both in solution and solid state. The use of the chromophoric‐(NHC) ligand endows to these complexes emissive properties in solution in the blue region (376–397 nm). The presence of the naphthyl‐substituent in the 1 b – 3 b series enhances the quantum yields relative to the methyl‐series 1 a – 3 a . In particular, the carbene gold complexes were the most emissive and displayed the highest quantum yields.