Kraack Jan Philip, Lotti Davide, Hamm Peter
Department of Chemistry, University of Zürich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland.
J Phys Chem Lett. 2014 Jul 3;5(13):2325-9. doi: 10.1021/jz500978z. Epub 2014 Jun 20.
Ultrafast dynamics of molecules at solid-liquid interfaces are of outstanding importance in chemistry and physics due to their involvement in processes of heterogeneous catalysis. We present a new spectroscopic approach to resolve coherent, time-resolved, 2D vibrational spectra as well as ultrafast vibrational relaxation dynamics of molecules adsorbed on metallic thin films in contact with liquids. The setup is based on the technique of attenuated total reflectance (ATR) spectroscopy, which is used at interfaces between materials that exhibit different refractive indices. As a sample molecule, we consider carbon monoxide adsorbed in different binding configurations on different metals and resolve its femtosecond vibrational dynamics. It is presented that mid-infrared, multidimensional ATR spectroscopy allows for obtaining a surface-sensitive characterization of adsorbates' vibrational relaxation, spectral diffusion dynamics, and sample inhomogeneity on the femtosecond time scale.
由于分子在固液界面的超快动力学参与了多相催化过程，因此在化学和物理学中具有极其重要的意义。我们提出了一种新的光谱方法，用于解析吸附在与液体接触的金属薄膜上的分子的相干、时间分辨二维振动光谱以及超快振动弛豫动力学。该装置基于衰减全反射（ATR）光谱技术，该技术用于具有不同折射率的材料之间的界面。作为样品分子，我们考虑一氧化碳以不同的结合构型吸附在不同的金属上，并解析其飞秒振动动力学。结果表明，中红外多维ATR光谱能够在飞秒时间尺度上对吸附质的振动弛豫、光谱扩散动力学和样品不均匀性进行表面敏感表征。
