Computer experiments on aqueous solutions. III. Monte Carlo calculation on the hydration of tertiary butyl alcohol in an infinitely dilute aqueous solution with a new water–butanol pair potential
Computer experiments on aqueous solutions. III. Monte Carlo calculation on the hydration of tertiary butyl alcohol in an infinitely dilute aqueous solution with a new water–butanol pair potential
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III. 具有新的水-丁醇对势的无限稀水溶液中叔丁醇水合的计算机实验。
DOI：
10.1063/1.446867
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发表时间：
1984
期刊：
影响因子：
--
通讯作者：
H. Touhara
中科院分区：
文献类型：
--
作者：
K. Nakanishi;K. Ikari;S. Okazaki;H. Touhara
采用NVT系综中的大都会方案，对298.15 K、常密度的叔丁醇（TBA）无限稀水溶液进行了Monte Carlo计算.分子总数为216个，其中一个是TBA。对于水-水相互作用，使用MCY（Matsuoka-Clementi-Yoshimine）势，而对于水-TBA相互作用，通过使用STO-3G基组对380多种不同二聚体构型进行从头计算LCAO SCF MO计算，并随后使用非线性优化方法将由此获得的MO数据多参数拟合为适当的势函数，确定了新的对势。在Monte Carlo运行中，3 600 000配置已产生和最终2 000 000配置已被用于获得能量和结构信息的水化结构的TBA。如在先前研究的甲醇溶液的情况下，通过引入一个TBA分子，水的势能和结构趋于稳定，并且TBA和周围的水分子之间的两个强氢键有利于形成庞大且稳定的水合壳，其包括协同连接的疏水水合结构。这在TBA周围的水的密度图中清楚地示出，其可视化水的显著结构化。TBA周围的冰山状结构比甲醇更明显。
Monte Carlo calculations have been carried out for an infinitely dilute aqueous solution of tertiary butylalcohol (TBA) at 298.15 K and ordinary density by the Metropolis scheme in an NVT ensemble. The total number of molecules is 216, one of which is TBA. For water–water interaction, the MCY (Matsuoka–Clementi–Yoshimine) potential is used, whereas a new pair potential is determined for water–TBA interaction from ab initio LCAO SCF MO calculations for more than 380 different dimeric configurations with an STO‐3G basis set and subsequent multiparameter fitting of MO data thus obtained to an appropriate potential function with a nonlinear optimization method. In the Monte Carlo run, 3 600 000 configurations have been generated and final 2 000 000 configurations have been used to obtain energetic and structural information on the hydration structure of TBA. As in the case of the methanol solution studied previously, the potential energy and structure of water tend to be stabilized by the introduction of one TBA molecule, and two strong hydrogen bonds between TBA and the surrounding water molecules favor the formation of a bulky and stable hydration shell which includes cooperatively connected hydrophobic hydration structures. This is clearly shown in density diagrams for water around TBA which visualize remarkable structuration of water. The iceberglike structure around TBA is more pronounced than that of methanol.