Stepwise Achievement of Circularly Polarized Luminescence on Atomically Precise Silver Clusters

The weakly coordinated anionic nitrate ligands in a centrosymmetric Ag₂₀ cluster are replaced in a stepwise manner by chiral amino acids and two achiral luminescent sulfonic-group-containing ligands while nearly maintaining the original silver(I) cage structure. This surface engineering enables the atomically precise Ag₂₀ clusters to exhibit the high-efficiency synergetic effects of chirality and fluorescence, producing rare circularly polarized luminescence among the metal clusters with a large dissymmetry factor of (|g_lum|) ≈ 5 × 10^-3. This rational approach using joint functional ligands further opens a new avenue to diverse multifunctional metal clusters for promising applications.