美国伊利诺伊大学芝加哥分校Nan Jiang团队报道了通过原子方法控制局部等离子体激元在单个分子内实现位置选择性激活。相关研究成果发表在2022年1月3日出版的《美国化学会杂志》。

贵金属纳米结构的局域表面等离子体（LSPs）辅助的化学反应，如键的解离和形成，在太阳能到化学能的转换中具有广阔的前景。然而，由于等离子体激元场的横向分布相对较大，在单个分子中存在多个化学等效部分的情况下，精确控制局部等离子体激元以激活分子的特定部分是很少的。

该文中，研究人员报道了在扫描隧道显微镜（STM）结中吸附在Cu（100）表面的多功能分子内的特定分子位点（C–Si键）的等离子体辅助离解。要激活的分子位置可以通过仔细定位尖端并使尖端非常接近分子（原子方法）来选择，从而在尖端的尖端实现等离子体纳米限制。此外，在亚分子尺度上，多个反应位点以顺序方式被激活，并通过STM形貌和密度泛函理论（DFT）建模创建和可视化不同的产物集。由局域表面等离子体激元实现位置选择性激活的意味着键选择等离子体激元诱导化学分子尺度分辨率的实现。

附：英文原文

Title: Controlling Localized Plasmons via an Atomistic Approach: Attainment of Site-Selective Activation inside a Single Molecule

Author: Sayantan Mahapatra, Jeremy F. Schultz, Linfei Li, Xu Zhang, Nan Jiang

Issue&Volume: January 3, 2022

Abstract: Chemical reactions such as bond dissociation and formation assisted by localized surface plasmons (LSPs) of noble metal nanostructures hold promise in solar-to-chemical energy conversion. However, the precise control of localized plasmons to activate a specific moiety of a molecule, in the presence of multiple chemically equivalent parts within a single molecule, is scarce due to the relatively large lateral distribution of the plasmonic field. Herein, we report the plasmon-assisted dissociation of a specific molecular site (C–Si bond) within a polyfunctional molecule adsorbed on a Cu(100) surface in the scanning tunneling microscope (STM) junction. The molecular site to be activated can be selected by carefully positioning the tip and bringing the tip extremely close to the molecule (atomistic approach), thereby achieving plasmonic nanoconfinement at the tip apex. Furthermore, multiple reactive sites are activated in a sequential manner at the sub-molecular scale, and different sets of products are created and visualized by STM topography and density functional theory (DFT) modeling. The illustration of site-selective activation achieved by localized surface plasmons implies the realization of molecular-scale resolution for bond-selected plasmon-induced chemistry.

DOI: 10.1021/jacs.1c11547

Source: https://pubs.acs.org/doi/10.1021/jacs.1c11547