Assembly-Induced Strong Circularly Polarized Luminescence of Spirocyclic Chiral Silver(I) Clusters

Spirocyclic Ag-9 clusters, as a new form of intrinsically chiral metal clusters, were constructed through vertex-sharing of two in-situ-generated heteroaryl diide-centered metal rings. Such core-peripheral type clusters exhibit versatile photoluminescent and chiroptical behavior under different aggregation conditions. In contrast to a ligand-based fluorescence emission in a diluted solution of the clusters, a solvent polarity-caused assembly gives rise to new cluster-based phosphorous luminescence owing to radiative mode switching and aggregation-induced emission. Assembly of cluster enantiomers leads to micrometer-long helical nanofibers, whose handedness is determined by absolute configuration of individual spirocyclic clusters. Benefiting from exciton couplings of helical arrangements of chelating ligands at molecular and microscopic levels, the assembled film of cluster enantiomers exhibits circularly polarized luminescence with a high anisotropy factor (0.16).

Automated summary

The study involved constructing spirocyclic Ag-9 clusters by vertex-sharing of in-situ-generated heteroaryl diide-centered metal rings, demonstrating versatile photoluminescent and chiroptical behavior. Under different aggregation conditions, assembly led to cluster-based phosphorous luminescence and micrometer-long helical nanofibers. Exciton couplings of chelating ligands at molecular and microscopic levels in the assembled film of cluster enantiomers resulted in circularly polarized luminescence with a high anisotropy factor (0.16).