Atomically precise nanoclusters with reversible isomeric transformation for rotary nanomotors

Abstract

Thermal-stimuli responsive nanomaterials hold great promise in designing multifunctional intelligent devices for a wide range of applications. In this work, a reversible isomeric transformation in an atomically precise nanocluster is reported. We show that 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 the Gibbs free energy is the driving force for the transformation. This work offers a strategy for rational design and development of atomically precise nanomaterials via ligand tailoring and alloy engineering for a reversible stimuli-response behavior required for intelligent devices. 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.

Atomically precise metal nanoclusters are an emerging class of precision nanomaterials and hold potential in many applications. Here, the authors devise a [Au₁₃Ag₁₂(PPh₃)₁₀Cl₈]⁺ nanocluster with two conformational isomers that can reversibly convert in response to temperature, and hence acts as a rotary nanomotor.