Two-Dimensional Impulsively Stimulated Resonant Raman Spectroscopy of Molecular Excited States
Two-Dimensional Impulsively Stimulated Resonant Raman Spectroscopy of Molecular Excited States
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DOI：
10.1103/physrevx.10.011051
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发表时间：
2020-02-28
影响因子：
12.5
通讯作者：
Scopigno, Tullio
中科院分区：
文献类型：
--
作者：
Fumero, Giuseppe;Schnedermann, Christoph;Scopigno, Tullio
监测分子中电子自由度和振动自由度之间的相互作用对我们理解其结构动力学至关重要。这通常是由于缺乏能够以高时间和频率分辨率检测不同能量尺度的光谱探针而受到阻碍。相干拉曼光谱可以在超快时间尺度上将多维光谱的能力与结构灵敏度结合起来。在这里，我们开发了一种基于三色的二维脉冲受激拉曼技术，该技术可以利用共振拉曼增强来选择性地探测分子中不同活性位点之间的振动模式耦合。三个暂时延迟的脉冲产生核波包，其演变报告在潜在的势能表面上，我们使用图解方法破译，使我们能够分配光谱特征的起源。我们通过揭示光激发后绿色荧光蛋白的超快动力学中的振动耦合来对该方法进行基准测试。
Monitoring the interactions between electronic and vibrational degrees of freedom in molecules is critical to our understanding of their structural dynamics. This is typically hampered by the lack of spectroscopic probes able to detect different energy scales with high temporal and frequency resolution. Coherent Raman spectroscopy can combine the capabilities of multidimensional spectroscopy with structural sensitivity at ultrafast timescales. Here, we develop a three-color-based 2D impulsive stimulated Raman technique that can selectively probe vibrational mode couplings between different active sites in molecules by taking advantage of resonance Raman enhancement. Three temporally delayed pulses generate nuclear wave packets whose evolution reports on the underlying potential energy surface, which we decipher using a diagrammatic approach enabling us to assign the origin of the spectroscopic signatures. We benchmark the method by revealing vibronic couplings in the ultrafast dynamics following photo-excitation of the green fluorescent protein.