Water Diffusion Proceeds via a Hydrogen-Bond Jump Exchange Mechanism
Water Diffusion Proceeds via a Hydrogen-Bond Jump Exchange Mechanism
复制标题
DOI：
10.1021/acs.jpclett.2c00825
复制
发表时间：
2022-05-23
影响因子：
5.7
通讯作者：
Laage, Damien
中科院分区：
文献类型：
--
作者：
Gomez, Axel;Piskulich, Zeke A.;Laage, Damien
水分子的自扩散在生物化学、医学成像、材料科学和工程中的广泛基本过程中起着关键作用。然而，其分子机制和水氢键网络重排所起的作用尚不清楚。在这里，我们结合联合收割机分子动力学模拟和分析建模，以确定水扩散的分子机制。我们建立了水扩散系数和氢键跳跃交换之间的定量联系，并确定了确定潜在的充满活力的障碍的功能。因此，我们提供了一个统一的框架，以了解在液态水的平移，旋转和氢键动力学之间的耦合。它解释了为什么这些不同的动力学不一定表现出相同的温度依赖性，虽然它们都是由相同的氢键交换事件。水扩散的理解在过冷条件下和复杂的水系统，包括离子，生物和封闭的解决方案，水运输的后果进行了讨论。
The self-diffusion of water molecules plays a key part in a broad range of essential processes in biochemistry, medical imaging, material science, and engineering. However, its molecular mechanism and the role played by the water hydrogen-bond network rearrangements are not known. Here we combine molecular dynamics simulations and analytic modeling to determine the molecular mechanism of water diffusion. We establish a quantitative connection between the water diffusion coefficient and hydrogen-bond jump exchanges, and identify the features that determine the underlying energetic barrier. We thus provide a unified framework to understand the coupling between translational, rotational, and hydrogen-bond dynamics in liquid water. It explains why these different dynamics do not necessarily exhibit identical temperature dependences although they all result from the same hydrogen-bond exchange events. The consequences for the understanding of water diffusion in supercooled conditions and for water transport in complex aqueous systems, including ionic, biological, and confined solutions, are discussed.