Lee B
Division of Computer Research and Technology, National Institutes of Health, Bethesda, Maryland 20892.
Biopolymers. 1991 Jul;31(8):993-1008. doi: 10.1002/bip.360310809.
The experimental thermodynamic data for the dissolution of five simple hydrocarbon molecules in water were combined with the solute-solvent interaction energy from a computer simulation study to yield data on the enthalpy change of solvent reorganization. Similar data were generated for dissolving these same solute molecules in their respective neat solvents using the equilibrium vapor pressure and the heat of vaporization data for the pure liquid. The enthalpy and the free energy changes upon cavity formation were also estimated using the temperature dependence of the solute-solvent interaction energy. Both the enthalpy and T delta S for cavity formation rapidly increase with temperature in both solvent types, and the free energy of cavity formation can be reproduced accurately by the scaled particle theory over the entire temperature range in all cases. These results indicate that the characteristic structure formation around an inert solute molecule in water produces compensating changes in enthalpy and entropy, and that the hydrophobicity arises mainly from the difference in the excluded volume effect.
将五个简单烃分子在水中溶解的实验热力学数据与计算机模拟研究得到的溶质 - 溶剂相互作用能相结合，以得出溶剂重组焓变的数据。利用纯液体的平衡蒸气压和汽化热数据，针对这些相同的溶质分子溶解在各自纯溶剂中的情况生成了类似的数据。还利用溶质 - 溶剂相互作用能的温度依赖性估算了空穴形成时的焓变和自由能变化。在两种溶剂类型中，空穴形成的焓变和TΔS均随温度迅速增加，并且在所有情况下，空穴形成的自由能在整个温度范围内都能通过定标粒子理论准确再现。这些结果表明，水中惰性溶质分子周围的特征结构形成会产生焓和熵的补偿性变化，并且疏水性主要源于排除体积效应的差异。
