分子内H键的极限
Thomas A Hubbard, Alisdair J Brown1, Ian A W Bell1
1Afton Chemical Limited , London Road, Bracknell, Berkshire RG12 2UW, U.K.
Journal of the American Chemical Society
|December 10, 2016
概括
当分子内部的键靠近时,它们的强度更大,且它们的值取决于距离. 这影响了分子识别,因为内部键往往超过外部键.
科学领域:
- 物理化学
- 分子生物物理学
- 超分子化学
背景情况:
- 键对于分子识别过程至关重要.
- 由于竞争的预组织和灵活性因素,预测键形成的能量是具有挑战性的.
研究的目的:
- 根据链接长度量化分子内键的强度.
- 了解分子灵活性对键能量的影响.
- 确定与分子结构中的可旋转键相关的能量损失.
主要方法:
- 对分子内相互作用能量的实验测量.
- 连接器分离键捐赠点和接受点的系统变化
- 对键强度的距离依赖影响的分析.
主要成果:
- 对分子内键强度观察到与距离相关的值.
- 当通过≥6个旋转键分离时,键显著较弱 (<-1kJmol-1).
- 较强的内部键 (-5到-9kJ mol-1) 在≤5旋转器中被观察到,超过了外部接受器.
- 对于具有≥4个可旋转键的分子,每个转子的能量损失为~5-6kJmol−1.
结论:
- 由可旋转键数量量化的分子灵活性对分子内键强度产生了关键影响.
- 观察到的取决于距离的值凸显了强键的形状预组织的重要性.
- 了解这些能量贡献对于设计具有特定识别特性的分子至关重要.
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