Non-Born-Oppenheimer Molecular Dynamics Observed by Coherent Nuclear Wave Packets
Non-Born-Oppenheimer Molecular Dynamics Observed by Coherent Nuclear Wave Packets
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DOI：
10.1021/acs.jpclett.9b03488
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发表时间：
2020-02-06
影响因子：
5.7
通讯作者：
Joo, Taiha
中科院分区：
文献类型：
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作者：
Kim, JunWoo;Kim, Chul Hoon;Joo, Taiha
光化学反应的反应动力学通常通过基于Born-Oppenheimer（BO）近似的反应坐标来描述。然而，电子和原子核之间的强相互作用，通常发生在圆锥形的交叉点，打破BO近似，并具有光化学反应的效率的主要后果。尽管它的重要性，相关的研究到非BO动力学是稀缺的。本文研究了10-羟基苯并[h]喹啉（HBQ）分子中激发态分子内质子转移（ESIPT）的非BO动力学。基于时间分辨率为11 fs的瞬态吸收测量和基于密度泛函理论的模型计算，通过波包分析确定了HBQ非绝热表面上代表分子动力学的237和794 cm（-1）处的两个相干振动模。HBQ中的强库仑场效应导致ESIPT在OH伸缩模的约两个周期内完成。这项工作铺平了道路的时域研究分子动力学超越BO近似在其他光化学反应。
The reaction dynamics of a photochemical reaction is typically described by reaction coordinates based on the Born-Oppenheimer (BO) approximation. A strong interaction between electrons and nuclei, conventionally occurring at conical intersections, however, breaks the BO approximation and has major consequences for the efficiency of a photochemical reaction. Despite its importance, related studies into the non-BO dynamics are scarce. Here, we investigate the non-BO dynamics of excited-state intramolecular proton transfer (ESIPT) occurring in 10-hydroxybenzo[h]quinoline (HBQ). Two coherent vibrational modes at 237 and 794 cm(-1) representing molecular dynamics on a diabatic surface in HBQ are identified by a wave packet analysis based on a transient absorption measurement with a time resolution of 11 fs and with a density functional theory-based model calculation. It is also revealed that the strong Coulomb field effect in HBQ leads to the completion of ESIPT within about two cycles of the OH stretching mode. The work paves the way for time-domain studies of molecular dynamics beyond the BO approximation in other photochemical reactions.