在水-DMSO二元混合物中的键寿命的非线性组成依赖性:疏水性相互作用的作用
Sangita Mondal1, Biman Bagchi1
1SSCU, Indian Institute of Science, Bangalore 560012, India.
The Journal of chemical physics
|July 9, 2024
概括
水和二甲基硫氧化物 (DMSO) 之间的键具有惊人的长寿命,在30%的DMSO下长10倍. 这是由于DMSO自我聚合,影响集体动力学和粘度.
科学领域:
- 物理化学 物理化学
- 化学物理 化学物理
- 计算化学的计算化学
背景情况:
- 在水溶液中的结是许多化学和生物过程的基础.
- 甲基二硫氧化物 (DMSO) 是一种常见的极性近极溶剂,具有独特的特性.
- 在DMSO-水混合物中的键的行为尚未完全理解,特别是关于组成依赖性的问题.
研究的目的:
- 为了研究水和DMSO之间的键的异常寿命.
- 阐明这些键的组成依赖背后的微观机制.
- 了解这些键对DMSO-水混合物的集体动力学和特性的影响.
主要方法:
- 计算机模拟用于微观结构和动态分析.
- 分析包括键寿命与局部协调号的相关性.
- 使用了自由能量表面计算和二维过渡状态速率理论.
主要成果:
- 水-DMSO键的寿命比水-水键要长得多,并且严重依赖于组成.
- 由于疏水性甲基组的吸引,产生"远程作用"效应,导致DMSO自我聚合,住分子运动.
- 随着DMSO度的增加,键断裂机制发生变化,集体动力学减慢.
结论:
- DMSO自我聚合是延长水-DMSO键寿命和异常行为的关键因素.
- 这种机制解释了粘度的组成依赖性,并且与自组装过程有关.
- 这项研究为了解混合溶剂中的键动态提供了一个新的框架.
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