Helping copper glow: Copper's abundance makes the metal an appealing candidate for luminescence applications. However, many copper complexes tend to decay nonradiatively after photoexcitation. A recently described exception involves a two-coordinate complex that sandwiches the metal between an amide ligand and a carbene ligand. Hamze et al. thoroughly explored this motif and measured a nearly perfect luminescence efficiency. They used this property to produce a prototype blue organic light-emitting diode. The photodynamics appeared largely ligand-centered, with the excited state attributed to copper-facilitated charge transfer from amide to carbene. Science , this issue p. 601

A series of three phosphorescent mononuclear (NHC)–Cu(i) complexes were prepared and characterized.