在低介电常数溶剂中,离子配对和宿主-客体复合
Jason W Jones1, Harry W Gibson
1Virginia Polytechnic Institute and State University, Department of Chemistry, Blacksburg, Virginia 24061-0212, USA.
Journal of the American Chemical Society
|June 5, 2003
概括
这项研究引入了一个新的平衡模型,用于低介电介质中的离子复合,并考虑离子配对. 该模型澄清了明显的绑定不一致性,揭示了主机-客户端系统的 counterion 独立复杂化常数.
科学领域:
- 超分子化学 超分子化学
- 物理化学 物理化学
- 化学热力学化学热力学
背景情况:
- 离子物种在低介电介质中的复杂化通常涉及离子配对,使平衡分析复杂化.
- 以前的模型经常忽视或过度简化离子配对的作用,导致不准确的结合常量.
- 了解这些相互作用对于设计选择性主机-客户系统至关重要.
研究的目的:
- 开发一种对离子复合的平衡治疗方法,明确包含离子配对.
- 通过实验验证模型,使用二zylammonium盐和二-24-crown-8之间的伪多素形成.
- 证明模型能够解决明显结合常数中的度依赖波动的能力.
主要方法:
- 开发一个理论平衡模型,包括离子配对解离常数 (K(ipd)).
- 使用二zylammonium盐和二-24-皇冠-8.8的实验性调查伪达的形成.
- 对度依赖的明显关联常数 (K(a,exp)) 的分析,以确定真正的复杂化常数 (K(ap)).
主要成果:
- 显而易见的K (a,exp) 值被证明受到离子配对的影响,而不仅仅是复杂化.
- 对于与皇冠以太主体的自由阴离子客物种的复杂化常数 (K(ap)) 是独立于对应物.
- 开发的模型成功地解释了实验观测,并允许诊断离子配对程度.
结论:
- 拟议的平衡模型通过包括离子配对,更准确地描述了低介电介质中的离子复合.
- 对外离子对表面结合常数的影响可以归因于离子配对效应.
- 这种方法为分析涉及离子物种和离子配对的宿主-客系统提供了可通用的方法.
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