Achiral-Core-Metal Change in Isomorphic Enantiomeric Ag 12 Ag 32 and Au 12 Ag 32 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 ( R / S -Ag 12 Ag 32 ) and heterometal ( R / S- Au 12 Ag 32 ) clusters. The geometrical chirality of R / S -Ag 12 Ag 32 arises from the chiral ligand and interface consisting of positive moieties of Ag 32 ( R / S -PS) 24 . The circular dichroism of R / S -Ag 12 Ag 32 is active, but CPLE-silent. A complete metal change from Ag 12 to Au 12 in the achiral core section of S 2- @M 12 @S 8 engenders isomorphous heterometal R / S -Au 12 Ag 32 , which activates CPLE. We further quantify the contributions of achiral and chiral sections and for the first time unveil that heterometal bonding (Au 12 -Ag 32 ) at the linkage varies the delocalization of orbitals and proportion of achiral and chiral section in electron transition-involved orbitals, thus activating CPLE. Based on these unique atomically precise homochiral metal clusters, our work provides a new insight into the contributions of achiral and chiral sections to the origin of chiroptical response of chiral metal clusters, paving the way to advance the development of CPLE nanoparticles.