Hiding in the Crowd: Spectral Signatures of Overcoordinated Hydrogen-Bond Environments
Hiding in the Crowd: Spectral Signatures of Overcoordinated Hydrogen-Bond Environments
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DOI：
10.1021/acs.jpclett.9b01781
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发表时间：
2019-10-17
影响因子：
5.7
通讯作者：
Markland, Thomas E.
中科院分区：
文献类型：
--
作者：
Morawietz, Tobias;Urbina, Andres S.;Markland, Thomas E.
具有过量氢键伙伴的分子在基本化学过程中起着至关重要的作用，从过冷水中的异常扩散到水质子缺陷的运输和疏水溶质周围水的有序化。在这里，我们表明，过协调的氢键环境可以确定在环境和过冷制度的液态水相结合的实验拉曼多元曲线分辨率测量和机器学习加速量子模拟。特别是，我们发现，OH基团出现在光谱区域通常与非氢键物种实际上对应于氢键形成过协调的环境中。我们进一步表明，只有这些物种表现出人口的营业额作为温度的函数，这是强大的，并持续在恒定的压力和密度条件下。因此，这项工作提供了一个新的工具来识别，解释和阐明拥挤的氢键网络的光谱特征。
Molecules with an excess number of hydrogen-bonding partners play a crucial role in fundamental chemical processes, ranging from anomalous diffusion in supercooled water to transport of aqueous proton defects and ordering of water around hydrophobic solutes. Here we show that overcoordinated hydrogen-bond environments can be identified in both the ambient and supercooled regimes of liquid water by combining experimental Raman multivariate curve resolution measurements and machine learning accelerated quantum simulations. In particular, we find that OH groups appearing in spectral regions usually associated with non-hydrogen-bonded species actually correspond to hydrogen bonds formed in overcoordinated environments. We further show that only these species exhibit a turnover in population as a function of temperature, which is robust and persists under both constant pressure and density conditions. This work thus provides a new tool to identify, interpret, and elucidate the spectral signatures of crowded hydrogen-bond networks.