分子液体中的空洞和疏水溶解性的理论
1Department of Chemistry, University of California, Berkeley 94720, USA.
Journal of the American Chemical Society
|January 1, 1990
概括
这项研究表明,液态水是液态水.
科学领域:
- 物理化学 物理化学
- 计算化学计算化学
- 溶解科学 溶解科学
背景情况:
- 了解溶剂对溶解物行为的影响在化学中至关重要.
- 水和有机溶剂之间的溶解差异通常归因于水的独特键结构.
- 另一种假设认为,分子大小起到更重要的作用.
研究的目的:
- 研究各种分子溶剂中原子大小空洞的形成过程.
- 测试该假设的分子大小,而不是结,主要解释水和非水性溶剂之间的溶解差异.
- 为了比较液态水与硬球溶剂的自由体积特征.
主要方法:
- 使用了整洁液体的热配置数据.
- 计算了原子大小的硬球形腔的形成工作.
- 采用缩放粒子模型来预测惰性气体在液态水中的可溶性.
主要成果:
- 液态水具有较高的分数自由体积,但与有机溶剂相比,它分布在较小的口袋中.
- 水中的空洞形成工作与可比的有机溶剂中的空洞形成工作有很大不同.
- 缩放粒子模型低估了TIP4P水中的空洞工作,对于原子大小的空洞,空洞工作约为20%.
结论:
- 自由体积分布的结构差异,而不仅仅是键,是了解水中的溶解的关键.
- 与较大的分子溶剂相比,水的较小分子大小导致惰性气体的空腔形成不太有利.
- 在液体结构的背景下,原子大小的空洞应该被认为是亚宏观的.
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