Abstract
Photoluminescent copper(I) iodide ligand complexes [Cu4I4L4] (L=organic ligand) are of special interest due to their display of stimuli response characteristics and use in light-emitting devices, such as sensors and inks. Three known [Cu4I4L4] complexes with ligands pyridine, 2,4,6-trimethylpyridine, 5-ethyl-2-methylpyridine and one entirely new [Cu4I4L4] complex with a 4-cyanopyridine ligand were synthesized and characterized to determine the potential application of copper(I) complexes in place of rare earth metals currently used in photoluminescent devices. These complexes were characterized using the solid-state techniques Far-IR and XRD to verify successful ligand ligation and complex crystallinity. Thermochromism and magnetic susceptibility were also measured. Solution characterization was conducted by assessing the complex solubility in different solvents and collecting 1H NMR, fluorescence emission, and UV-Vis spectra. Emission quantum yield calculations were also conducted using ShimadzuRF6000 software. The thermochromism exhibited by the [Cu4I4L4] complexes suggested a relationship between the electron donating or withdrawing properties of the ligand. However, it was determined that the [Cu4I4L4] complexes were susceptible to solvent effects and degraded relatively quickly in solution. Complex degradation also appeared to be accelerated by photoexcitation. These solvent effects quenched fluorescent emission and possibly facilitated pseudo-Jahn-Teller distortion of the [Cu4I4L4] complex.