Integrating Circular Polarized Luminescence and Long Persistent Luminescence in Cu ₈ Cage‐Like Clusters via Ligand Engineering

Copper clusters with diverse luminescent properties are of particular interest. In this study, a series of Cu₈ clusters with cage-like structures was synthesized and characterized. By employing a stepwise ligand engineering strategy that progressively introduced circularly polarized luminescence (CPL) and long persistent luminescence (LPL) properties, we successfully synthesized R/S-Cu₈-Cl, the first copper cluster to demonstrate both CPL and LPL. The CPL originates from the chiral metal core induced by the chiral alkynyl ligand, whereas the LPL is attributed to the inherent properties of chlorine-modified triphenylphosphine, which is retained and modified after ligation. The polymethyl methacrylate (PMMA) film containing Cu₈ clusters displays lifetimes of up to 75.18 ms at room temperature and an afterglow exceeding 1.5 s, marking the longest luminescent lifetime recorded for molecular copper-cluster-based materials known to date. Additionally, R/S-Cu₈-Cl shows excitation-dependent luminescence and variations in luminescence when UV light is switched on and off, highlighting its potential for advanced anti-counterfeiting applications. This work not only presents innovative cage-like copper cluster structures but also offers new approaches for designing multifunctional clusters.