Tuning luminescence in gold(i)-phosphine complexes: structural, photophysical, and theoretical insights

Abstract

Gold(i) complexes featuring phosphine ligands functionalized with chromophores such as triphenylene, phenanthrene, and carbazole were synthesized and systematically studied to explore the relationship between molecular structure and luminescence properties. Comprehensive photophysical characterization revealed that the coordination environment and chromophore positioning significantly influence intersystem crossing, phosphorescence, and aggregation behavior. In solution, aggregation-induced phenomena were probed using computational tools, including density functional theory (DFT) and noncovalent interaction (NCI) analysis, revealing diverse π-stacking and Au⋯π interactions. Distinct photophysical trends were identified among the three series of compounds, with triphenylene derivatives exhibiting aggregation-induced emission broadening and phenanthrene derivatives showing strong heavy atom effects. The combination of experimental and theoretical insights provides a foundation for designing luminescent materials with tunable properties for optoelectronic applications.