在与n-octanol相关的乙醇中分子间和分子内结合的相互作用
Markus M Hoffmann1, Troy N Smith1, Gerd Buntkowsky2
1Department of Chemistry and Biochemistry, State University of New York Brockport, Brockport, NY 14420, USA.
分子动力学模拟揭示了以太醇结构如何影响结和物理性质. 在特定的乙醇中形成分子内键,影响密度和扩散.
科学领域:
- 物理化学 物理化学
- 计算化学计算化学
背景情况:
- 乙醇是多功能化合物,在各种工业中都有应用.
- 了解它们的键对于预测物理性质至关重要.
- 分子动力学 (MD) 模拟为研究分子相互作用提供了强大的工具.
研究的目的:
- 调查以太功能的位置对n-octanol和相关的以太醇中的结的作用.
- 阐明分子内和分子间的键和宏观物理性质之间的关系.
- 在模拟这些系统时,比较OPLS-AA和CHARMM力场的性能.
主要方法:
- 使用了经典的全原子分子动力学 (MD) 模拟.
- 采用了两个突出的力场:OPLS-AA和CHARMM.
- 研究了一系列以太醇,在以太和基组之间具有不同的碳链长度.
主要成果:
- 在3-布托西醇和4-氧醇中,分子内键是显著的,在较长链类型中则不那么显著,在短链类型中则不存在.
- 分子间的键在基组 (OH-OH) 之间比在基和基 (OH-OE) 之间更强.
- 温度升高会减少分子间的键,但会略微增加分子内键和分子紧性.
- 辐射分布函数 (RDF) 显示在整个力场和温度中具有一致的特征,主要在强度上有所不同.
- 确定了特定的稳定二元体,如1-hexyloxymethanol中的OH-OE二元体.
- 由于二面电位的变化,OPLS-AA和CHARMM在预测联的数量上有所不同.
结论:
- 乙醇结构决定了分子内和分子间结的程度和稳定性.
- 结合模式与密度,自我扩散和粘度等物理性质直接相关.
- 使用OPLS-AA和CHARMM的MD模拟提供了对以太酒精行为有价值的见解,在定量预测方面存在显著差异.
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