Spectral Signatures of Ultrafast Excited-State Intramolecular Proton Transfer from Computational Multi-edge Transient X-ray Absorption Spectroscopy
Spectral Signatures of Ultrafast Excited-State Intramolecular Proton Transfer from Computational Multi-edge Transient X-ray Absorption Spectroscopy
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DOI：
10.1021/acs.jpclett.1c02483
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发表时间：
2021-10-04
影响因子：
5.7
通讯作者：
Khalil, Munira
中科院分区：
文献类型：
--
作者：
Loe, Caroline M.;Liekhus-Schmaltz, Chelsea;Khalil, Munira
激发态分子内质子转移 (ESIPT) 是一种具有多种应用的基本化学过程。超快 ESIPT 涉及电子和原子运动的耦合，主要使用飞秒光谱进行研究。 X 射线光谱法特别有用，因为它是元素特异性的，并且能够对质子供给原子和质子接受原子进行直接、单独的探测。在此，我们报告了一项计算研究，以解决 10-羟基苯并[h]喹啉 (HBQ)（一种分子内氢键化合物）中的 ESIPT。我们使用线性响应时间相关密度泛函理论 (LR-TDDFT) 结合从头算分子动力学 (AIMD) 和时间分辨 X 射线吸收光谱 (XAS) 计算来跟踪超快激发态动力学。我们的结果揭示了氧和氮 K 边缘 ESIPT 期间和之后耦合电子和原子运动的清晰 X 射线光谱特征，为未来的 X 射线自由电子激光器实验铺平了道路。
Excited-state intramolecular proton transfer (ESIPT) is a fundamental chemical process with several applications. Ultrafast ESIPT involves coupled electronic and atomic motions and has been primarily studied using femtosecond optical spectroscopy. X-ray spectroscopy is particularly useful because it is element-specific and enables direct, individual probes of the proton-donating and -accepting atoms. Herein, we report a computational study to resolve the ESIPT in 10-hydroxybenzo[h]quinoline (HBQ), an intramolecularly hydrogen bonded compound. We use linear-response time-dependent density functional theory (LR-TDDFT) combined with ab initio molecular dynamics (AIMD) and time-resolved X-ray absorption spectroscopy (XAS) computations to track the ultrafast excited-state dynamics. Our results reveal clear X-ray spectral signatures of coupled electronic and atomic motions during and following ESIPT at the oxygen and nitrogen K-edge, paving the way for future experiments at X-ray free electron lasers.