改变形状的核 HO-(NH3) 与甲基化物发生反应
Xiangyu Wu1, Yang Hu1, Shaowen Zhang1
1Key Laboratory of Cluster Science of Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China.
微溶解的离子如HO-(NH3) 可以转化为新的核友,影响SN2反应. 溶解通常会增加反应屏障,核HOMO水平预测屏障高度.
科学领域:
- 计算化学计算化学
- 物理化学 物理化学
- 反应动力学 反应动力学
背景情况:
- 微溶解显著影响化学反应,特别是核替代 (SN2) 反应.
- 了解溶剂分子如何与核友相互作用,对于预测反应结果和动力学至关重要.
- 以前的研究往往集中在散装水溶解上,使得微溶解效应的探索较少.
研究的目的:
- 研究微溶解对涉及变形核友的SN2反应的影响.
- 阐明溶解影响反应屏障和核稳定性的机制.
- 建立核友性质 (HOMO水平,结合能) 和SN2反应障碍之间的相关性.
主要方法:
- 高级的初始计算,特别是CCSDT,被用来绘制潜在能量表面的地图.
- 这项研究研究了甲 (CH3Cl) 和微溶解氧化物 (HO-) 和胺 (NH2-) 核之间的离子分子SN2反应.
- 增量溶解模型被用来系统地评估氨 (NH3) 和水 (H2O) 分子的影响.
主要成果:
- 微溶解的HO-(NH3) n可以通过分子内质子转移转化为NH2- ((H2O) ((NH3) m,从而导致双重反应途径.
- 计算显示,HO-物种在能量方面比NH2-物种更受青,SN2反应障碍较低.
- 增加溶解率通常会提高SN2反应障碍的两条路径,水表现出比氨更强的稳定性.
结论:
- 该研究证实了在微溶解条件下α效应的存在.
- 溶剂分子的核稳定,反映在HOMO水平和结合能,与SN2反应屏障高度直接相关.
- 这项研究扩展了对SN2反应微溶效应的理解,超出了水环境.
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