A Non-Bornian Analysis of the Gibbs Energy of Hydration for Organic Ions
A Non-Bornian Analysis of the Gibbs Energy of Hydration for Organic Ions
复制标题
有机离子水合吉布斯能的非博恩分析
DOI：
10.1039/c4ra02422b
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
and T. Osakai
中科院分区：
文献类型：
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作者：
W. Murakami;M. Yamamoto;K. Eda;and T. Osakai
最近，非Bornian模型被成功地应用于计算球形离子（主要是无机离子）的水合吉布斯能（ΔG°hyd）。在该模型中，由于Born型离子-溶剂间的长程静电相互作用对ΔG°hyd的贡献很小，因此没有明确地包含在ΔG°hyd的计算中，而短程相互作用（包括库仑相互作用、极化相互作用和电荷转移相互作用）被认为是决定离子ΔG°hyd的主要因素。由离子的表面积缩放的ΔG°hyd可以由离子的表面场强度（E）的二次函数给出。在本研究中，非Bornian模型被进一步应用于带电荷基团的有机离子。采用Gaussian 09程序包，在B3 LYP/6-311++G（2d，p）水平上优化了真空中离子的几何构型，并采用Mulliken、Merz-Kollman（MK）、自然布居分析（NPA）、Hirshfeld和ChelpG方法计算了离子的部分原子电荷.引入一个新的子程序，我们可以估计离子表面（货车van der Waals表面或溶剂可及表面（SAS））上的局部电场。这使得我们能够通过使用109个离子的ΔG°hyd的实验值来进行基于非Bornian模型的回归分析。当选择NPA-SAS组合时，获得了最佳回归结果，给出的平均绝对误差为4.3 kcal mol−1。非Bornian模型将提供一种简单而相对准确的确定离子ΔG°hyd的方法。
Recently, a non-Bornian model was successfully applied to evaluate the Gibbs energy of hydration (ΔG°hyd) for spherical ions (mainly inorganic ions). In this model, the long-range, Born-type electrostatic ion–solvent interaction is not explicitly included in the calculation of ΔG°hyd, since its contribution is small, whereas the short-range interaction, including Coulomb, polarization, and charge-transfer interactions, is considered as the dominant factor that determines the ΔG°hyd of ions. The ΔG°hyd scaled by the surface area of an ion can be given by a quadratic function of the surface field strength (E) of the ion. In this study, the non-Bornian model was further applied to organic ions with charged groups. Using the Gaussian 09 program package, the geometries of ions in vacuum were optimized at the B3LYP/6-311++G(2d,p) level, and the partial atomic charges were computed in the Mulliken, Merz-Kollman (MK), natural population analysis (NPA), Hirshfeld, and ChelpG methods. Introducing a new subprogram, we could estimate local electric fields on the ion surface (van der Waals surface or solvent-accessible surface (SAS)). This enabled us to perform regression analyses based on the non-Bornian model, by using the experimental values of ΔG°hyd for 109 ions. When the NPA-SAS combination was chosen, the best regression result was obtained, giving the mean absolute error of 4.3 kcal mol−1. The non-Bornian model would provide a simple and relatively accurate way of determining ΔG°hyd of ions.