New molecular models, parameterized to ab initio calculations, were developed to describe HBr and HI at the air-water interface. These were used to compare how the air-water interface influenced dissociation of NaX and HX, with X being Cl, Br, or I, and also their propensity for the interface. The polarizable multistate empirical valence bond method, which explicitly describes proton sharing, was used to model HX. Results showed that the air-water interface suppressed HX dissociation from a contact ion pair to a solvent separated to a greater degree than NaX dissociation. Furthermore, HX had a greater propensity for the interface than NaX, which was a consequence of the hydronium ion having a greatest interfacial activity of all species studied. As a consequence of this, the average configuration of dissociated HX, while in both contact ion and solvent separated ion pairs near the air-water interface, is with the dissociated hydrogen oriented more towards the air than the X atom.

中文翻译：

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空气-水界面处钠和卤化氢的比较


开发了新的分子模型，参数化为从头计算，用于描述空气-水界面处的 HBr 和 HI。这些用于比较空气-水界面如何影响 NaX 和 HX 的解离，其中 X 是 Cl、Br 或 I，以及它们对界面的倾向。使用明确描述质子共享的可极化多态经验价键方法来模拟 HX。结果表明，空气-水界面抑制 HX 从接触离子对到分离溶剂的解离程度比 NaX 解离程度更大。此外，HX 比 NaX 具有更大的界面倾向，这是水合氢离子在所有研究的物种中具有最大界面活性的结果。因此，在空气-水界面附近的接触离子和溶剂分离离子对中，离解的 HX 的平均构型是离解的氢比 X 原子更倾向于空气。