Regulation of Reaction Pathways in Coordinated Chains by Directional Mechanical Force

作者：Z. F. Xu, Xin Li, Jie Li, Huamei Chen, Yu Wang, Yu Wang, Mingjun Zhong, Shimin Hou, Qian Shen, Xue Zhang, Ziyong Shen, Jing‐Tao Lü, Lian‐Mao Peng, Kai Wu, Jing Liu, Yajie Zhang, Song Gao, Yongfeng Wang, Yongfeng Wang · 发表于：ACS Nano · 年份：2025 · DOI：10.1021/acsnano.4c13622 · 被引用次数：12 · 研究领域：Force Microscopy Techniques and Applications、Advanced Electron Microscopy Techniques and Applications、Mechanical and Optical Resonators

Mechanochemistry refers to chemical reactions induced by mechanical forces. Due to different reaction mechanisms, products obtained through mechanochemistry can be distinct from those produced by thermochemistry and photochemistry. Scanning probe microscopy is a powerful tool for studying single-molecule mechanochemical processes. Mechanical force is a vector that has both magnitude and direction. Previous studies have focused on triggering reactions by forces and measuring their magnitude. In this work, we use the direction of the force to regulate the reaction pathway in a spin-crossover coordinated chain. The chains are prepared via the dehydrogenated coordination reaction between tetrahydroxybenzene molecules and Ni atoms on Au(111). The Ni atoms in the chain alternate between a high-spin state and a low-spin state. By altering Ni–O bond lengths and O–Ni–O angles through the directional mechanical force, a chemical process occurs, and the spin state of Ni undergoes a transition. With the attraction from a Au tip, the Ni atom is pulled from high-spin to low-spin state. With the repulsion from a C 60 -functionalized tip, the low-spin Ni atom is pushed to the high-spin state. The force to induce the reaction is measured by qPlus atomic force microscopy. This study provides an approach for regulating chemical pathways.