Louisiana Tech University, Ruston, Louisiana 71270, USA.
J Chem Phys. 2017 Oct 28;147(16):161703. doi: 10.1063/1.4984114.
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.
开发了新的分子模型，这些模型经过从头算计算进行了参数化，用于描述空气-水界面处的 HBr 和 HI。这些模型用于比较空气-水界面如何影响 NaX 和 HX 的离解，其中 X 为 Cl、Br 或 I，以及它们在界面上的倾向。使用明确描述质子共享的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 从接触离子对解离到溶剂分离的程度大于 NaX 解离。此外，HX 比 NaX 更倾向于界面，这是由于与所有研究的物种相比，氢离子具有最大的界面活性。因此，在空气-水界面附近的接触离子对和溶剂分离离子对中，HX 的平均解离构型是解离的氢原子相对于 X 原子更朝向空气的方向。
