Symmetry Breaking in Chiral Gold Nanoclusters by Ansa‐Metallamacrocycles Strain

ABSTRACT Chiral nanomaterials have recently stimulated significant interest in both fundamental research and practical applications (e.g., nanoprobes for biomolecular recognition). However, achieving chiral nanoclusters is still a major challenge. Herein, we report an effective strategy that affords achiral diphosphine ligand‐protected, chiral Au 11 nanoclusters. Synchrotron radiation X‐ray diffraction solves the chiral structure of Au 11 (dppp) 5 Cl 3 (dppp = 1,3‐bis(diphenylphosphino)propane) and further reveals that the critical feature of bidentate binding of diphosphine induces the unique ansa‐metallamacrocycle pattern (i.e., the “Au─P─CH 2 CH 2 CH 2 ─P─Au” staple). All the possible ansa‐metallamacrocycle patterns are transferred to the most robust pattern by “ligand confinement,” giving rise to the chiral enantiomers. Using Density Functional Theory (DFT), we show that the chirality can emerge due to the low energy barriers facilitating the transformation of the symmetric Au 11 core into the corresponding asymmetric chiral cluster, driven by a favorable fit of ligand bridges. This new type of chiral nanomaterial holds promise in chiral sensing/recognition and enantioselective applications.