An ab initio approach to understanding the specific ion effect
An ab initio approach to understanding the specific ion effect
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DOI：
10.1039/c2fd20113e
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发表时间：
2013-01-01
影响因子：
3.4
通讯作者：
Mundy, Christopher J.
中科院分区：
文献类型：
--
作者：
Baer, Marcel D.;Mundy, Christopher J.
虽然有一个共识，即大的，可极化的阴离子将吸附到空气-水界面，精确的相互作用，引起表面增强仍在争论。在此之前，我们已经证明，有一个显着的依赖于选择的分子相互作用潜力的I-吸附在空气-水界面。具体而言，基于密度泛函理论（DFT）的相互作用势导致吸附显着低于经验相互作用势，包括极化。我们还表明，基于DFT的相互作用势可以准确地捕获的结构的第一溶剂化壳的简单和多原子阴离子相比，多边缘X射线吸收精细结构（XAFS）实验。我们利用密度泛函理论来研究局部水化结构的SCN-和IO 3-表现出离液和kosmotropic特性。我们比较和对比的溶剂化结构的多原子阴离子与系列的卤素阴离子。我们可以将局部溶剂化结构与离子在霍夫迈斯特系列中的位置联系起来。
Although there is a consensus that large, polarizable anions will adsorb to the air-water interface, the precise interactions that give rise to surface enhancement are still being debated. Previously, we have demonstrated that there is a significant dependence on the choice of molecular interaction potential for I- adsorption at the air-water interface. Specifically, density functional theory (DFT) based interaction potentials lead to significantly less adsorption than empirical interaction potentials that include polarization. We have also demonstrated that DFT based interaction potentials can accurately capture the structure of the first solvation shell of both simple and polyatomic anions as compared to multi-edge X-ray absorption fine structure (XAFS) experiments. We utilize DFT to examine the local hydration structure of SCN- and IO3- that exhibit both chaotropic and kosmotropic characteristics. We compare and contrast the solvation structure of the polyatomic anions with the series of halide anions. A picture emerges where we can correlate local solvation structure to the ions' position in the Hofmeister series.