基结合相互作用的起源
Dominic J Pascoe1, Kenneth B Ling2, Scott L Cockroft1
1EaStCHEM School of Chemistry, University of Edinburgh , Joseph Black Building, David Brewster Road, Edinburgh EH9 3FJ, U.K.
Journal of the American Chemical Society
|October 7, 2017
概括
键是16组元素之间的相互作用,与键一样强,但与溶剂无关. 这些分子相互作用是由轨道移位驱动的,而不是静电力,影响分子识别.
科学领域:
- 化学学
- 分子相互作用
- 计算化学
背景情况:
- 键与键相似,涉及16组元素,在各种化学领域中至关重要.
- 石墨烯键的能量意义和起源仍然存在争议,特别是它们对溶剂效应的依赖.
研究的目的:
- 通过实验量化研究素结合相互作用的能量.
- 检查替代剂和溶剂对素键强度和特性的影响.
- 为了阐明基键的物理化学起源.
主要方法:
- 使用合成分子平衡来测量超过160个实验性的自由能量.
- 研究了各种素接触物 (O·S,O·Se,S·S) 和相关的C·H接触物 (O·HC,S·HC).
- 在13种不同的溶剂中分析了替代剂和溶剂效应.
主要成果:
- 实验发现,最强的石化键的强度与传统的键相当.
- 与键不同的是,键强度与溶剂极性,极化性和键能力具有惊人的独立性.
- 无论接触类型如何,都确定了捐赠单双和接受者抗结合轨道之间的轨道移位 (n → σ*) 是主导的稳定相互作用.
结论:
- 碳酸键主要由轨道移位控制,解释了它们的强度和溶剂独立性.
- 静电,溶和范德瓦尔斯力不能充分解释观察到的实验趋势.
- 轨道移位在结构控制和分子识别中起着关键作用,突出显示了其在化学系统中的重要性.
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