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

Three-coordinate copper halide complexes with a bidentate phosphine ligand have received much attention. Here, a series of three-coordinate dinuclear copper halide complexes containing a diphenylamino monodentate phosphine ligand, [CuX(dpnp)](2) (dpnp=N-[2-(diphenylphosphino)-4,5-dimethylphenyl]-N-phenylaniline, 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 interactions. These complexes exhibit blue emission in the solid state at room temperature and have peak emission wavelengths at 483-487nm with microsecond lifetimes (=13.9-38.1s) and low emission quantum yields (<0.01%). The emission of complex 1 mainly originates from intraligand (IL) transition, whereas the emissions of complexes 2 and 3 are from a combination of MLCT, XLCT and IL transitions. The three complexes displayed good thermal stability.