Achiral-Core-Metal Change in Isomorphic Enantiomeric AgAg and AuAg Clusters Triggers Circularly Polarized Phosphorescence.

Understanding how the chiral or achiral section in chiral nanostructures contributes to circularly polarized light emission (CPLE) at the atomic level is of fundamental importance. Here, we report two pairs of atomically precise enantiomers of homosilver () and heterometal () clusters. The geometrical chirality of arises from the chiral ligand and interface consisting of positive moieties of Ag(/-PS).

Stepwise Achievement of Circularly Polarized Luminescence on Atomically Precise Silver Clusters.

The weakly coordinated anionic nitrate ligands in a centrosymmetric Ag 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 Ag 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|) ≈ 5 × 10. This rational approach using joint functional ligands further opens a new avenue to diverse multifunctional metal clusters for promising applications.

Photoresponsive Propeller-like Chiral AIE Copper(I) Clusters.

A pair of propeller-like chiral trinuclear Cu clusters (R/S-Cu3) with unique photoinduced fluorescence enhancement were prepared. R/S-Cu3 showed intense variable luminescence after UV light irradiation, which was attributed to the stepwise oxidation of ligand in the clusters. It exhibited typical aggregation-induced emission (AIE) (α =17.

Smart Transformation of a Polyhedral Oligomeric Silsesquioxane Shell Controlled by Thiolate Silver(I) Nanocluster Core in Cluster@Clusters Dendrimers.

Using polyhedral oligomeric silsesquioxane (POSS) modified by a thiol group as a protected ligand, atom-precise multi-heteorocluster-based dendrimers Ag @POSS (1 a and 1 b) were assembled. Through the reactive -SH groups, six POSS shell ligands stabilize the central 12-core silver(I) cluster by diverse Ag-S interactions. When such Ag @POSS complex was stimulated by different solvents (acetone or tetrahydrofuran), the core Ag silver(I) cluster underwent reversible structural transformation between flattened cubo-octahedral (in 1 a) and normal cubo-octahedral (in 1 b); concomitantly shell POSS clusters rearranged from pseudo-octahedral to quasi-octahedral.