(262g) Atomically Precise Nanoclusters with Reversible Isomeric Transformation for Rotary Nanomotors

Metal nanoclusters with well-identified crystal structures have drawn significant attention as emerging nanomaterials in fundamental research and application in fields including photoluminescence, catalysis, sensing, medicine, and biolabeling owing to their unique physical and chemical properties. Recently, thermal-stimuli responsive nanomaterials hold great promise in designing multifunctional intelligent devices for a wide range of applications. Despite recent advances in controllable synthesis and structure determination of atomically precise nanoclusters, the concept of reversible conformational isomerization for metal nanoclusters has not yet been explored. In this work, we report the discovery of a stimuli-responsive nanocluster that shows reversible conformational isomerism. The biicosahedral [Au₁₃Ag₁₂(PPh₃)₁₀Cl₈]SbF₆ nanoclusters composed of two icosahedral Au₇Ag₆ units by sharing one common Au vertex can produce two temperature-responsive conformational isomers with complete reversibility, which forms the basis of a rotary nanomotor driven by temperature. Differential scanning calorimetry analysis on the reversible isomeric transformation demonstrates that Gibbs free energy is the driving force for the transformation. This work offers a strategy for rational design of atomically precise nanomaterials, that the reversible stimuli-response behavior required for intelligent devices could be regulated via ligand tailoring and alloy engineering. The two temperature-driven, mutually convertible isomers of the nanoclusters open up an avenue to employ ultra-small nanoclusters (1 nm) for the design of thermal sensors and intelligent catalysts.