Quan Weike, Wang Zihao, Shi Yueqing, Liang Kangkai, Bi Liya, Zhou Hao, Yin Zhiyuan, Li Wan-Lu, Li Shaowei
Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0309, United States.
Program in Materials Science and Engineering, University of California, San Diego, La Jolla, California 92093-0418, United States.
J Am Chem Soc. 2025 Feb 5;147(5):4504-4510. doi: 10.1021/jacs.4c16218. Epub 2025 Jan 22.
Controlling molecular actions on demand is a critical step toward developing single-molecule functional devices. Such control can be achieved by manipulating the interactions between individual molecules and their nanoscale environment. In this study, we demonstrate the conformational transition of a single pyrrolidine molecule adsorbed on a Cu(100) surface, driven by vibrational excitation through tunneling electrons using scanning tunneling microscopy. We identify multiple transition pathways between two structural states, each governed by distinct vibrational modes. The nuclear motions corresponding to these modes are elucidated through density functional theory calculations. By leveraging fundamental forces, including van der Waals interactions, dipole-dipole interactions, and steric hindrance, we precisely tune the molecule-environment coupling. This tuning enables the modulation of vibrational energies, adjustment of transition probabilities, and selection of the lowest-energy transition pathway. Our findings highlight how tunable force fields in a nanoscale cavity can govern molecular conformational transitions, providing a pathway to engineer molecule-environment interactions for targeted molecular functionalities.
按需控制分子行为是开发单分子功能器件的关键一步。这种控制可以通过操纵单个分子与其纳米级环境之间的相互作用来实现。在本研究中，我们利用扫描隧道显微镜，通过隧穿电子的振动激发，展示了吸附在Cu(100)表面的单个吡咯烷分子的构象转变。我们确定了两个结构状态之间的多个转变途径，每个途径由不同的振动模式控制。通过密度泛函理论计算阐明了与这些模式相对应的核运动。通过利用包括范德华相互作用、偶极-偶极相互作用和空间位阻在内的基本力，我们精确地调节了分子-环境耦合。这种调节能够调制振动能量、调整转变概率并选择最低能量的转变途径。我们的研究结果突出了纳米级腔中可调谐力场如何控制分子构象转变，为设计具有目标分子功能的分子-环境相互作用提供了一条途径。
