Conformational Transition‐Triggered Thermosensitive Tautomerization in Gold Nanoclusters for Optical Thermometry

ABSTRACT The structural tautomerism of nanoclusters plays an indispensable role in establishing dynamic structure–activity relationship models and designing nanocluster‐based intelligent functional materials, yet precise control of this dynamic process remains challenging. This study proposes a steric‐hindrance‐driven conformational switching strategy, achieving spatial torsion of a Au 1 (SR) 2 motif on Au 24 (SR) 16 nanoclusters. The conformational transition alters spatial proximity and electron cloud density of Au 24 (SR) 16 , thereby modulating reaction kinetics to trigger or inhibit its global structural tautomerism. Crystallographic analysis and density functional theory (DFT) calculations confirm that ligand steric effects and metal–ligand interactions govern the tautomeric pathway. The equilibrium dynamics of this tautomeric system demonstrates pronounced temperature dependence, wherein a mathematical relationship between the absorbance and temperature is established, thus endows it with the function of a nano‐thermometer, showing a temperature measurement error of ≤0.3°C. In addition, this conformational switching strategy is demonstrated to be extensible to other gold nanocluster systems, thereby establishing its broad applicability. This work offers a paradigm for designing functional nanomaterials through dynamic conformational reconstruction.