Molecular origin of the hydrophobic effect: Analysis using the angle-dependent integral equation theory
Molecular origin of the hydrophobic effect: Analysis using the angle-dependent integral equation theory
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DOI：
10.1063/1.2823733
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发表时间：
2008-01-14
影响因子：
4.4
通讯作者：
Kinoshita, Masahiro
中科院分区：
文献类型：
--
作者：
Kinoshita, Masahiro
结合多极水模型，用含角积分方程理论研究了疏水效应的分子起源。非极性溶质的溶剂化的热力学量（过量）分解成平移和取向的贡献。平移的贡献是相当大的结果，溶质溶解度的温度依赖性，例如，可以很好地再现模型简单的流体，其中的颗粒通过强吸引力的潜力，如水和颗粒尺寸是一样小的水。四氯化碳的溶剂化的热力学量，其分子大小是水的1.9倍，大约是一个数量级小于水的溶剂化的热力学量，并且对溶剂-溶剂吸引相互作用的强度和温度极不敏感。取向对溶剂化能和熵的贡献进一步分解为溶质-水对相关项和溶质-水-水三重态及高阶相关项。有人认为，形成高度有序的结构所产生的增强氢键不发生在附近的溶质。我们的主张是，疏水效应归因于非常小的分子尺寸和水的强烈吸引力的相互作用的相互作用，而不一定是它的氢键性质。(c)2008年美国物理学会。
The molecular origin of the hydrophobic effect is investigated using the angle-dependent integral equation theory combined with the multipolar water model. The thermodynamic quantities of solvation (excess quantities) of a nonpolar solute are decomposed into the translational and orientational contributions. The translational contributions are substantially larger with the result that the temperature dependence of the solute solubility, for example, can well be reproduced by a model simple fluid where the particles interact through strongly attractive potential such as water and the particle size is as small as that of water. The thermodynamic quantities of solvation for carbon tetrachloride, whose molecular size is similar to 1.9 times larger than that of water, are roughly an order of magnitude smaller than those for water and extremely insensitive to the strength of solvent-solvent attractive interaction and the temperature. The orientational contributions to the solvation energy and entropy are further decomposed into the solute-water pair correlation terms and the solute-water-water triplet and higher-order correlation terms. It is argued that the formation of highly ordered structure arising from the enhanced hydrogen bonding does not occur in the vicinity of the solute. Our proposition is that the hydrophobic effect is ascribed to the interplay of the exceptionally small molecular size and the strongly attractive interaction of water, and not necessarily to its hydrogen-bonding properties. (c) 2008 American Institute of Physics.