Surface Structural Symmetry Breaking of Highly Symmetrical Ag Nanoclusters.

An in-depth understanding of the structural symmetry of nanoclusters benefits the investigation of structure-property correlations. In this study, we accomplished the symmetry breaking of the surface structures of a highly symmetrical Ag nanocluster. The Ag nanocluster exhibited a highly axisymmetry, while this nanocluster underwent structural symmetry breaking in the presence of large-sized counterions as an asymmetric factor, giving rise to an Ag nanocluster with a bare surface and a symmetric overall structure. Despite both the Ag and Ag nanoclusters exhibiting comparably electronic structures, the highly symmetrical Ag nanocluster displayed a significantly higher photoluminescence intensity compared to the asymmetrical Ag nanocluster, which has been rationalized from the perspective of their structures and symmetry. Overall, this study presents a novel silver cluster pair with controllably symmetrical or asymmetrical surface structures, allowing for an atomic-level understanding of how structural symmetry influences the photoluminescence of metal nanoclusters.