Relaxation Processes in Aqueous Systems upon X-ray Ionization: Entanglement of Electronic and Nuclear Dynamics.
Relaxation Processes in Aqueous Systems upon X-ray Ionization: Entanglement of Electronic and Nuclear Dynamics.
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DOI：
10.1021/acs.jpclett.5b02665
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发表时间：
2016-01
期刊：
影响因子：
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通讯作者：
P. Slavíček;N. Kryzhevoi;E. F. Aziz;B. Winter
中科院分区：
文献类型：
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作者：
P. Slavíček;N. Kryzhevoi;E. F. Aziz;B. Winter
高能辐射与液相分子相互作用后的初级过程的知识相当有限。在本展望中，我们报道了一种新发现的弛豫过程，涉及相邻分子之间同时发生的自电离和质子转移，即质子转移介导的电荷分离（PTM-CS）过程。在PTM-CS中，具有半转移质子的瞬态在核心能级电离事件发生后的几飞秒内形成。高度非平衡瞬态的随后非辐射衰变导致一系列活性物质，这在任何水中的高能辐射过程中都没有被考虑到。在质子动力学作用下，非局部电子衰变过程惊人地加速。这种电子动力学和核动力学的强耦合是氢键体系的普遍现象，但其概率与水化几何结构密切相关。我们认为，新观察到的过程将影响未来的高能辐射化学相关建模，我们设想应用自电离光谱来识别溶液结构细节。
The knowledge of primary processes following the interaction of high-energy radiation with molecules in liquid phase is rather limited. In the present Perspective, we report on a newly discovered type of relaxation process involving simultaneous autoionization and proton transfer between adjacent molecules, so-called proton transfer mediated charge separation (PTM-CS) process. Within PTM-CS, transients with a half-transferred proton are formed within a few femtoseconds after the core-level ionization event. Subsequent nonradiative decay of the highly nonequilibrium transients leads to a series of reactive species, which have not been considered in any high-energy radiation process in water. Nonlocal electronic decay processes are surprisingly accelerated upon proton dynamics. Such strong coupling of electronic and nuclear dynamics is a general phenomenon for hydrogen-bonded systems, however, its probability correlates strongly with hydration geometry. We suggest that the newly observed processes will impact future high-energy radiation-chemistry-relevant modeling, and we envision application of autoionization spectroscopy for identification of solution structure details.