Unraveling non-covalent coupling in single-molecule junctions: Enabling high-performance stimuli-responsive molecular electronics

作者：Teng Zhang, Tianwei Li, Jinshi Li, Zifan Yu, Hong Chen, Meijing Li, Jingxian Yu, Shijie Zhen, Zujin Zhao · 发表于：Chemical Engineering Journal · 年份：2025 · DOI：10.1016/j.cej.2025.165691 · 被引用次数：4 · 研究领域：Molecular Junctions and Nanostructures、Quantum and electron transport phenomena、Nanowire Synthesis and Applications

A comprehensive understanding of charge transport in non-covalent coupling is crucial for rational design and delicate fabrication of single-molecule functional devices but rarely developed. Herein, we show that the non-covalent coupling between the active component of the molecule (hexaphenylbenzene, HPB) and the electrode allows for stimuli-responsive single molecular junction with good performance, ensuring non-covalent molecule-electrode bonding. The HPB units are directly coupled to the electrode, without chemical anchoring groups. In particular, we find a marked bias dependence for the modulation of single-molecule junctions where transmission is mediated through non-covalent electrode-molecule bonding. Meanwhile, two photoresponsive HPB oxime esters are also designed and their iminyl radicals generated via photochemical N − O bond homolysis can react with the gold electrode surface to form covalent Au − N bonds, resulting in the formation of robust and highly stable single-molecule junctions. These results demonstrate that through spatial conjugation, the non-covalent coupling of HPB with the electrode forms a robust and highly conductive single-molecule junction on the gold electrode surface, with conductivity that can be modulated by simple external stimuli, leading to efficient molecular devices with high switching ratios and providing a unique insight into the structural and electrical studies of non-covalent interactions.