Gobas F A
Great Lakes Institute, University of Windsor, Ontario, Canada.
Sci Total Environ. 1991 Dec;109-110:89-104. doi: 10.1016/0048-9697(91)90172-b.
An experimental analysis is presented of the molecular interactions controlling the activity and solubility of chlorinated dibenzo-p-dioxins (PCDDs) in water. For this purpose, the enthalpy, entropy and free-energy contributions of fusion, vaporization, solvation and aqueous solution are determined. It is shown that, due to enthalpy-entropy compensation in the water, the solvation of hydrophobic organic chemicals in water is independent of molecular size, total surface area or molar volume. The observed relationship between the aqueous solubility and molar volume (or total surface area) is caused by the phenomenon that, with increasing molar volume, molecules require more energy to leave the pure (subcooled liquid) phase. This suggests that the relationship between aqueous solubility and molecular structure, and, consequently, many quantitative structure-activity relationships (QSARs) for hydrophobic organic substances, reflect molecular interactions between the solute molecules in the pure subcooled liquid phase rather than solute-water interactions.
本文对控制水中氯化二苯并 - 对 - 二噁英（PCDDs）活性和溶解度的分子相互作用进行了实验分析。为此，测定了熔化、汽化、溶剂化和水溶液的焓、熵及自由能贡献。结果表明，由于水中的焓 - 熵补偿，疏水性有机化学品在水中的溶剂化与分子大小、总表面积或摩尔体积无关。观察到的水溶性与摩尔体积（或总表面积）之间的关系是由以下现象引起的：随着摩尔体积的增加，分子离开纯（过冷液体）相需要更多能量。这表明水溶性与分子结构之间的关系，以及因此许多疏水性有机物质的定量构效关系（QSARs），反映的是纯过冷液相中溶质分子之间的分子相互作用，而非溶质 - 水相互作用。
