作为易斯基的冠烯:对质子和离子结合的计算建模
M V Frash1, A C Hopkinson, D K Bohme
1Department of Chemistry, Centre for Research in Mass Spectrometry, York University, Toronto, Ontario, Canada.
Journal of the American Chemical Society
|July 6, 2001
概括
计算机建模揭示了冠烯的存在.
科学领域:
- 计算化学计算化学
- 超分子化学 超分子化学
- 材料科学 材料科学 材料科学
背景情况:
- 冠烯是一种曲的多环芳,是先进材料的基本组成部分.
- 了解它与质子和离子的反应性对于设计新型分子架构和功能材料至关重要.
研究的目的:
- 通过计算来研究冠烯分子上的质子位点和能量.
- 为了确定离子在冠烯上首选的结合位置和能量.
- 分析使用NMR化学转移和NICS.在质子化后对冠烯的芳香度变化.
主要方法:
- 密度函数理论 (DFT) 计算使用B3LYP函数与6-311G(d,p) 和6-31G(d,p) 基础集.
- 对离子相互作用的质子亲和力和结合能量的分析.
- 计算 (7) Li NMR 化学转移和核独立化学转移 (NICS) 以探测芳香度.
主要成果:
- 质子化优先发生在最内层的碳原子,形成稳定的西格玛复合体,质子亲和度为203 kcal mol ((-1).
- 电离子在凸起面上的6环上优先结合,在面上很容易移动,但在边缘周围有很高的障碍.
- 碗对碗的反转具有中等的激活能量 (7-12 kcal mol ((-1)),计算的Li ((+) 结合能量为44 kcal mol ((-1).
结论:
- 冠烯表现出明显的质子化偏好,中心碳是最有利的地方.
- 阳离子结合受到冠烯的曲率和环状结构的影响,这对宿主-客人化学有影响.
- 对NMR转移和NICS的计算分析为客结合时的电子结构和芳香度调制提供了洞察力.
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