标题： 结合几何效应影响的异氰基-金属相互作用的单分子振动表征 显示英文标题

标题： Single-Molecule Vibrational Characterization of Binding Geometry Effects on Isocyanide-Metal Interactions

摘要： 异氰基与金属的结合由σ给电子和π反馈键决定，这影响了异氰基伸缩振动模式的能量——这是配体-金属相互作用的一个特征探针。 尽管分子异氰基-金属体系中结构与光谱之间存在广泛的关联，但异氰基与金属晶体表面的相互作用仍知之甚少，在这些体系中配体往往以多种几何构型结合。 传统的振动光谱技术，如红外和拉曼光谱，缺乏分辨这些非均相构型所需的分子尺度分辨率。 相比之下，扫描隧道显微镜（STM）辅助下的非弹性电子隧穿光谱（STM-IETS）能够直接可视化配体吸附的几何构型及其振动特征。 利用STM-IETS，我们研究了一种吸附在金属上的间三联苯异氰基配体，并发现吸附在Cu(100)表面上的几何构型会显著改变异氰基的伸缩频率，这一变化甚至大于用Ag(111)替代Cu(100)时的变化。 密度泛函理论证实这种频移源于异氰基-金属结合中的原子尺度差异。 本研究阐明了原子尺度结合如何影响异氰基配体的振动特征——这是理解异氰基-金属相互作用时常被忽视的因素。 显示英文摘要

摘要： Isocyanide-metal binding is governed by sigma-donation and pi-back-bonding, which affects the energy of the isocyanide stretching mode-a characteristic probe for ligand-metal interactions. While extensive correlations exist between structure and spectroscopy in molecular isocyanide-metal systems, isocyanide interactions with metallic crystalline surfaces, where ligands often bind in various geometries, remain poorly understood. Conventional vibrational spectroscopies, such as infrared and Raman, lack the molecular-scale resolution needed to distinguish these inhomogeneous configurations. In contrast, inelastic electron tunneling spectroscopy with scanning tunneling microscopy (STM-IETS) enables direct visualization of ligand adsorption geometries and their vibrational signatures. Using STM-IETS, here we investigate a matal-adsorbed m-terphenyl isocyanie ligand and find that adsorption geometry on Cu(100) induces a significant shift in isocyanide stretching frequency, even greater than replacing Cu(100) with Ag(111). Density functional theory confirms this shift arises from atomic-scale variations in isocyanide-metal binding. This study elucidates how atomic-scale binding influences the vibrational signatures of isocyanide ligands-an often-overlooked factor in understanding isocyanide-metal interactions.