Synthesis, characterization, and luminescent properties of three-coordinate copper(I) halide complexes containing a carbazolyl monodentate phosphine ligand

A series of three-coordinate dinuclear copper halide complexes containing acarbazolyl monodentate phosphine ligand, [CuX(dppc)]2 (dppc =3,6-di-tert-butyl-9-[2-(diphenylphosphino)phenyl]carbazole, X = I (1), Br (2), and Cl (3)), were synthesized, and their molecular structures and photophysical properties were investigated. The structural analysis reveals that two copper(I) centers are bridged by two halogen ligands to form a dinuclear structure with a four-membered Cu2X2 ring. Crystal structures of 1-3 contain 1-D supramolecular arrays constructed by intermolecular C–H···π interactions. These complexes exhibit blue to green emission in the solid state at room temperature and have peak emission wavelengths at 492–495 nm with microsecond lifetimes and low emission quantum yields (< 0.01%). The emission of 1-3 mainly originates from MLCT, XLCT, and IL (intraligand) transitions. The three complexes displayed good thermal stability.