Solvent‐Mediated Reversible Intercluster Transformation and Chiroptical Inversion in Gold Nanoclusters for Time‐Resolved Information Encryption

Precise control over reversible intercluster conversion and chiroptical inversion in gold nanoclusters (AuNCs) is notoriously difficult. This work presents four chiral AuNCs capable of reversible intercluster transformations accompanied by dynamic circularly polarized luminescence (CPL) inversion and tunable emission colors. These nanoclusters exhibit a large luminescence dissymmetry factor ( g lum = −7.28 × 10 −3 ) and an absolute photoluminescence quantum yield (PLQY) reaching 90.95%, with their responsive chiroptical properties governed by hydrogen‐bonding interactions between solvent molecules and surface ligands. Comprehensive characterizations including single‐crystal x‐ray diffraction (SCXRD), variable‐temperature circular dichroism, time‐resolved FTIR and NMR spectroscopy confirm that O─H···O═S hydrogen bonds between dimethyl sulfoxide and ligand hydroxyl groups disturb intrinsic intra‐cluster structural equilibrium and trigger helicity inversion in crystalline cluster assemblies. Time‐resolved ESI‐MS and kinetic analysis further reveal that structural evolution originates from supramolecular rearrangement, enabling reversible interconversion between high‐ and low‐nuclearity AuNCs. Utilizing time‐dependent fluorochromism and switchable CPL signals, these chiral clusters are applicable to three‐dimensional data encryption and decryption. This study offers a universal hydrogen‐bonding modulation strategy to manipulate AuNC structural transitions and chiroptical responses, facilitating rational fabrication of chiral nanomaterials for optoelectronics and information encryption.