Decoding the spectroscopic features and time scales of aqueous proton defects
Decoding the spectroscopic features and time scales of aqueous proton defects
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DOI：
10.1063/1.5023704
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发表时间：
2018-06-14
影响因子：
4.4
通讯作者：
Markland, Thomas E.
中科院分区：
文献类型：
--
作者：
Napoli, Joseph A.;Marsalek, Ondrej;Markland, Thomas E.
酸溶液由于存在多个相互作用的活性质子缺陷和反离子而表现出各种复杂的结构和动力学特征。然而，解开水氢键网络中质子缺陷的瞬态结构基序及其相互转化的机制仍然是一个艰巨的挑战。在这里，我们使用模拟治疗的电子和原子核的量子性质，以显示whowthe实验观察到的光谱特征和弛豫时间尺度可以阐明使用物理透明的坐标编码的质子缺陷的溶剂化环境的整体不对称性。我们证明，这个坐标可以用来区分的线性振动光谱中观察到的功能的极端，并解释分子运动引起的相互转换的时间尺度在最近的非线性实验中观察到的。该分析提供了质子结构和动力学的统一凝聚相图像，在其极端情况下，包括质子共享和光谱特征，类似于限制性本征[H3 O（H2O）（3）]（+）和Zundel [H（H2O）（2）]（+）气相结构，同时还描述了液相中丰富的相互转换环境。出版社：AIP Publishing
Acid solutions exhibit a variety of complex structural and dynamical features arising from the presence of multiple interacting reactive proton defects and counterions. However, disentangling the transient structural motifs of proton defects in the water hydrogen bond network and the mechanisms for their interconversion remains a formidable challenge. Here, we use simulations treating the quantum nature of both the electrons and nuclei to showhowthe experimentally observed spectroscopic features and relaxation time scales can be elucidated using a physically transparent coordinate that encodes the overall asymmetry of the solvation environment of the proton defect. We demonstrate that this coordinate can be used both to discriminate the extremities of the features observed in the linear vibrational spectrum and to explain the molecular motions that give rise to the interconversion time scales observed in recent nonlinear experiments. This analysis provides a unified condensed-phase picture of the proton structure and dynamics that, at its extrema, encompasses proton sharing and spectroscopic features resembling the limiting Eigen [H3O(H2O)(3)](+) and Zundel [H(H2O)(2)](+) gas-phase structures, while also describing the rich variety of interconverting environments in the liquid phase. Published by AIP Publishing.