Transient Two-Dimensional Electronic Spectroscopy: Coherent Dynamics at Arbitrary Times along the Reaction Coordinate
Transient Two-Dimensional Electronic Spectroscopy: Coherent Dynamics at Arbitrary Times along the Reaction Coordinate
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瞬态二维电子能谱：沿反应坐标任意时间的相干动力学
DOI：
10.1021/acs.jpclett.9b00826
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Wasielewski, Michael R.
中科院分区：
文献类型：
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作者：
Mandal, Aritra;Schultz, Jonathan D.;Wu, Yi-Lin;Coleman, Adam F.;Young, Ryan M.;Wasielewski, Michael R.
二维电子光谱（2DES）的最新进展使得能够识别接近平衡分子几何形状的凝聚相系统中脆弱的量子相干性。一般来说，传统的 2DES 无法测量与光物理过程相关的相干性，这些光物理过程有时会在初始准备态失相后显着发生，例如初始激发态演化为电荷转移态。我们演示了使用瞬态二维电子光谱（t-2DES）来探测由苝二酰亚胺（PDI）受体和苝（Per）供体组成的电子供体-受体二元体中的相干性。光化泵脉冲准备 PDI 的最低激发单线态，然后形成 PDI•––Per•+ 离子对，并使用 2DES 在光化脉冲后的不同时间对其进行探测。对观察到的相干性的分析提供了有关离子对形成反应坐标上任何时间的电子、振动和振动相互作用的信息。
Recent advances in two-dimensional electronic spectroscopy (2DES) have enabled identification of fragile quantum coherences in condensed-phase systems near the equilibrium molecular geometry. In general, traditional 2DES cannot measure such coherences associated with photophysical processes that occur at times significantly after the initially prepared state has dephased, such as the evolution of the initial excited state into a charge transfer state. We demonstrate the use of transient two-dimensional electronic spectroscopy (t-2DES) to probe coherences in an electron donor–acceptor dyad consisting of a perylenediimide (PDI) acceptor and a perylene (Per) donor. An actinic pump pulse prepares the lowest excited singlet state of PDI followed by formation of the PDI•––Per•+ion pair, which is probed at different times following the actinic pulse using 2DES. Analysis of the observed coherences provides information about electronic, vibronic, and vibrational interactions at any time along the reaction coordinate for ion pair formation.