基于过渡状态理论的解决方案中速率系数的计算与启发性纠正的极化连续模型相结合:分子间迪尔斯-阿尔德反应作为案例研究
Yu-Ichiro Izato1, Mitsuo Koshi2, Atsumi Miyake1
1Graduate School of Information and Environment Sciences, Yokohama National University, 79-7 Tokiwadai, Hodogaya-ku, Yokohama, Japan. izato-yuichiro-tk@ynu.ac.jp.
Physical chemistry chemical physics : PCCP
|August 9, 2024
概括
这项研究通过开发更现实的分区函数来完善液相反应的过渡状态理论 (TST). 新方法改进了计算,与传统方法相比,可以更好地预测反应速率.
科学领域:
- 计算化学的计算化学
- 化学动力学 化学动力学
- 物理化学 物理化学
背景情况:
- 过渡状态理论 (TST) 与量子力学/极化连续模型 (QM/PCM) 结合,对于研究液相反应速率至关重要.
- 传统的QM/PCM方法通常使用理想气体处理 (IGT) 进行分区功能,该方法通过忽视溶剂阻碍的分子运动来高估.
研究的目的:
- 开发一种更准确的方法来计算液相中的分区函数.
- 通过结合真实的溶剂对溶液热力学的影响来改善反应速率的预测.
- 为了完善液相化学反应的TST计算.
主要方法:
- 制定了分区函数,考虑溶剂阻碍的溶解物转换和旋转模式.
- 整合了一个配置分区功能,使用标准度的格子模型.
- 根据局部系统的统计热力学推导的热力学函数和速率系数.
- 在G4//ωB97X-D/6-311++G(d,p) /IEF-PCM理论层面进行QM/PCM计算.
主要成果:
- 由于改进了计算,拟议的方法比IGT方法产生了较低的激活吉布斯能量.
- 新方法高估了1-2个数量级的速率系数,而IGT低估了同等数量.
- 差异突出了本地化 (拟议) 和非本地化 (IGT) 系统观点之间的差异.
结论:
- 开发的方法为TST计算提供了更现实的液态表示.
- 准确的分区函数公式对于弥合理论预测和实验反应速率之间的差距至关重要.
- 需要进一步精细化,以准确地建模液体系统在局部和非局部状态之间的中间性质.
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