Properties of 2,2,2-trifluoroethallol and water mixtures
Properties of 2,2,2-trifluoroethallol and water mixtures
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DOI：
10.1063/1.1330577
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发表时间：
2001-01-01
影响因子：
4.4
通讯作者：
Smith, PE
中科院分区：
文献类型：
--
作者：
Chitra, R;Smith, PE
2，2，2-三氟乙醇（TFE）是肽和蛋白质实验研究中常用的助溶剂。虽然浓度依赖性的TFE效应已经得到了很好的实验研究，TFE影响肽的溶解度和稳定性的确切机制仍然不清楚。在这里，我们报告的TFE/水混合物的不同组成的分子动力学模拟，试图提高我们的原子水平的理解的TFE/水混合物的性质。的趋势，在大多数属性的密度扩散常数，介电常数，和混合的histopies很好地再现，虽然与实验的定量一致性差。其他热力学性质的解决方案偏摩尔体积，衍生物的活性系数，和等温压缩性，也确定使用柯克伍德-布夫理论的混合物。Kirkwood-Buff分析表明混合物中TFE分子的显著聚集，特别是在低摩尔分数下，与实验一致。然而，使用当前的TFE和水模型夸大了TFE分子的聚集。结果表明，模拟数据和Kirkwood-Buff理论的结合为研究氢键混合物的热力学性质提供了有力的工具。(C)2001年美国物理学会。
2,2,2-trifluoroethanol (TFE) is a commonly used cosolvent in experimental studies of peptides and proteins. Although concentration-dependent TFE effects have been well studied experimentally, the exact mechanism by which TFE affects the solubility and stability of peptides is still unclear. Here we report molecular dynamics simulations of TFE/water mixtures of different composition in an attempt to improve our atomic level understanding of the properties of TFE/water mixtures. The trends in most properties-densities diffusion constants, dielectric constants, and enthalpies of mixing-were well reproduced, although quantitative agreement with experiment was poor. Other thermodynamic properties of the solutions-partial molar volumes, derivatives of-activity coefficients, and isothermal compressibilities-were also determined using the Kirkwood-Buff theory of mixtures. The Kirkwood-Buff analysis indicated significant aggregation of TFE molecules in the mixtures, especially at low mole fractions, in agreement with experiment. However, the aggregation of TFE molecules was exaggerated using the current TFE and water models. The results suggest that the combination of simulation data and Kirkwood-Buff theory provides a powerful tool for the investigation of the thermodynamic properties of hydrogen bonding mixtures. (C) 2001 American Institute of Physics.