Potential Tomorrow’s Generation of Traffic Light Phosphors: New Copper Halide Cluster Complexes as Efficient Solid-State Emitters With Tunable Monochrome Colors

Luminescent copper complexes are under current scrutiny for potential materials and biomedical applications. In this contribution, strongly- luminescent copper(I) halide dimethylpyrazole cluster complexes have been prepared under variable synthetic methods and conditions, including solventless (via mechanical grinding) and in organic solvent-mediated (chloroform, acetonitrile or dichloromethane) reactions. The products isolated exhibited rather bright and tunable monochrome colors that correspond to those of traffic lights (red, green, and yellow) in the solid state. Multiple products were isolated by altering the reaction stoichiometry and/or aforementioned synthetic variables even for the same chemical composition. Characterization of these complexes is presented using Fourier-transform infrared (FTIR), thermogravimetric analysis (TGA), and nuclear magnetic resonance (NMR) spectroscopy to ascertain their purity and by UV/Vis absorption and photoluminescence (steady state and lifetimes) to characterize their photophysical properties.