关于P-arylphosphiranes的热碎片化的计算研究:这种方法是否产生了arylphosphinidenes?
Wai Han Lam1, Peter P Gaspar, David A Hrovat
1Departments of Chemistry, University of Washington, Box 351700, Seattle, Washington 98195-1700, USA.
Journal of the American Chemical Society
|July 7, 2005
概括
计算化学揭示了三重聚烯 (PhP) 通过一个阶段性途径产生,这种途径不那么内热,并且具有较低的激活屏障,而不是对单片 PhP 的协同碎片化.
科学领域:
- 计算化学是一种计算化学.
- 量子化学是一种量子化学.
- 有机化学 有机化学
背景情况:
- P-phenylphosphirane (1) 是一种可以经历热碎片化的分子.
- 了解碎片化路径和产品对于合成和机理学研究至关重要.
研究的目的:
- 为了研究P-phenylphosphirane (1) 的热碎片化到phenylphosphinidene (PhP) 和乙烯.
- 为了比较导致单元和三元PhP的碎片化途径的能量和立体化学.
主要方法:
- 使用了包括CASSCF,CASPT2,CCSDT和 (U) B3LYP在内的高级电子结构计算.
- 计算建模用于分析反应路径,过渡状态和能量障碍.
主要成果:
- 相比于对单片的协调碎片化,对三片的逐步碎片化具有较低的内热性 (21 kcal mol(-1)) 和较低的屏障 (12 kcal mol(-1)) .
- 一致的碎片化到单片PhP是立体特异的,而三片PhP的形成显示完全失去立体化学.
- 对二甲基-P-mesitylphosphirane的计算表明更具立体特异性的三重 MesP 形成,与实验数据保持一致.
结论:
- 由于能源需求较低,阶段性途径被青用于生成三重PhP.
- 在单基和三基胺基形成之间,立体化学结果有显著差异.
- MesP形成的高激活能量表明它可能需要催化或不同的反应条件.
相关概念视频
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