Adjusting photophysical properties of five daylight white-emitting copper (I) iodide hybrid complexes by modifying their ligands

Five new copper iodide complexes ( 1–5 ) were prepared by the solvent evaporation method of cuprous iodide with derivatives of 2-(1 H -imidazol-1-yl) pyrimidine ( L 1 -L 5 ). All of them are daylight white emissions among 5079–6483 K and have good thermal stabilities. Their internal quantum yields (IQYs) range from 17% to 66%. By modifying the ligand's pyrimidine ring with different groups, they successfully adjust distances of Cu…Cu in Cu 2 I 2 rhomboid dimers and further influences their optical properties, which is confirmed by electronic structure calculations employing density functional theory (DFT). This research will be very helpful for understanding the structure-activity relationship of copper (I) iodide hybrid materials. And all these complexes can be used in solid-state lighting and other optoelectronic devices.