Biphenyl Au(III) Complexes with Phosphine Ancillary Ligands: Synthesis, Optical Properties, and Electroluminescence in Light-Emitting Electrochemical Cells.

A series of ten cationic complexes of the general formula [(C^C)Au(P^P)]X, where C^C = 4,4'-di--butyl-1,1'-biphenyl, P^P is a diphosphine ligand, and X is a noncoordinating counteranion, have been synthesized and fully characterized by means of chemical and X-ray structural methods. All the complexes display a remarkable switch-on of the emission properties when going from a fluid solution to a solid state. In the latter, long-lived emission with lifetime τ = 1.