论文标题
用局部软X射线探针监测的烯醇酮互变异构化中的超快电荷迁移动力学
Ultrafast Charge Migration Dynamics in Enol Keto Tautomerization Monitored with a Local Soft-X-Ray Probe
论文作者
论文摘要
质子耦合的电子转移（PCET）是管理重要反应的基本机制，从光合作用中的水分拆分到氢燃料电池的氧气还原。质子和电子电荷分布运动的相互作用可能因连续方案而异，并且基本步骤在超快时间尺度上发生。我们通过一项模拟研究表明，飞秒软X射线光谱学为光诱导的分子内烯醇* $ \ rightarrow $ keto*互变异反应提供了关键的见解。在电子激发时，对2-（2-羟基苯基 - ）苯甲唑的电子和核动力学进行了全面量子处理，这表明了从核心轨道到边缘轨道的局部激发光谱特征如何显示出Hatom，捐赠和接受位点的电荷迁移的独特阶段。我们的发现表明，紫外线/X射线泵探针光谱学为探测超快电子结构重排的独特方法是对理解PCET机制必不可少的光诱导的化学反应。
Proton-coupled electron transfer (PCET) is the underlying mechanism governing important reactions ranging from water splitting in photosynthesis to oxygen reduction in hydrogen fuel cells. The interplay of proton and electronic charge distribution motions can vary from sequential to concerted schemes, with elementary steps occurring on ultrafast time scales. We demonstrate with a simulation study that femtosecond soft-X-ray spectroscopy provides key insight into the PCET mechanism of a photoinduced intramolecular enol* $\rightarrow$ keto* tautomerization reaction. A full quantum treatment of electronic and nuclear dynamics of 2-(2-hydroxyphenyl-)benzothiazole upon electronic excitation reveals how spectral signatures of local excitations from core to frontier orbitals display the distinct stages of charge migration for the H atom, donating, and accepting sites. Our findings indicate UV/X-ray pump-probe spectroscopy provides a unique way to probe ultrafast electronic structure rearrangements in photoinduced chemical reactions essential to understanding the mechanism of PCET.
