Birth of the Hydrated Electron via Charge-Transfer-to-Solvent Excitation of Aqueous Iodide
Birth of the Hydrated Electron via Charge-Transfer-to-Solvent Excitation of Aqueous Iodide
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DOI：
10.1021/acs.jpclett.2c03460
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发表时间：
2023-01-19
影响因子：
5.7
通讯作者：
Mundy, Christopher J.
中科院分区：
文献类型：
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作者：
Carter-Fenk, Kevin;Johnson, Britta A.;Mundy, Christopher J.
在实验室实验中产生水合电子的主要手段是激发溶质（如I-（aq））的电荷转移到溶剂（CTTS）状态，但e-（aq）生成的初始步骤从未直接使用从头算分子动力学模拟。我们报道了第一个这样的模拟，结合基态和激发态模拟的I-（aq）的库仑势的波动的新生溶剂化电子经历的详细分析，出现的是一个两个步骤的图片的e-（aq）从CTTS状态开始的演变：I-（aq）+ h nu-* I-*（aq）-* I中心点（aq）+ e-（aq）。值得注意的是，平衡基态的e-（aq）从I-*（aq）演变而没有任何非绝热跃迁，仅仅是溶剂重组的结果。这里使用的方法应适用于其他光化学电子转移过程中的解决方案，一类重要的问题直接相关的电子转移和能量转移。
A primary means to generate hydrated electrons in laboratory experiments is excitation to the charge-transfer-to-solvent (CTTS) state of a solute such as I-(aq), but this initial step in the genesis of e-(aq) has never been simulated directly using ab initio molecular dynamics. We report the first such simulations, combining ground-and excited-state simulations of I-(aq) with a detailed analysis of fluctuations in the Coulomb potential experienced by the nascent solvated electron. What emerges is a two-step picture of the evolution of e-(aq) starting from the CTTS state: I-(aq) + h nu-* I-*(aq)-* I center dot(aq) + e-(aq). Notably, the equilibrated ground state of e-(aq) evolves from I-*(aq) without any nonadiabatic transitions, simply as a result of solvent reorganization. The methodology used here should be applicable to other photochemical electron transfer processes in solution, an important class of problems directly relevant to photocatalysis and energy transfer.