Organo Chalcogenone-Triggered Luminescent Copper(I) Clusters for Light Emitting Applications.

A novel organo sulfur and selenium-controlled emission behavior in discrete copper(I) clusters has been demonstrated for the first time. The pentanuclear [CuBr()] (), trinuclear [CuBr()] (), dinuclear [CuI()] (), and tetranuclear [CuI()CHCN] () copper(I) discrete clusters have been synthesized from the reaction between [ = 1-isopropyl-3-(pyridin-2-yl)-imidazol-2-thione] or [ = 1-isopropyl-3-(pyridin-2-yl)-imidazol-2-selone] chelating ligands and corresponding copper(I) halide salts. These new clusters have been characterized by FT-IR, UV-visible, thermogravimetric analysis, and fluorescence spectroscopy techniques. Single-crystal X-ray diffraction studies reveal that consists of abundant interactions. The structural and bonding features of clusters have been investigated using density functional theory calculations. Notably, the -ligated and are poorly emissive, while -ligated and showed strong emission in the orange and green regions, respectively. The time-dependent density functional theory natural transition orbital calculations of and reveal the nature of the transitions contributed by MLCT/LLCT/ILCT. Photoluminescence quantum yields of and are 19 and 11%, with average lifetimes of 21.55 and 6.57 μs, respectively. and were coated on prototype LED bulbs for light-emitting performance.