马库斯交叉关系在H原子抽象反应的空间中,通过非对角热力学得到了增强
Jan Kovář1,2, Erik Andris3, Zuzanna Wojdyla1
1J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Dolejškova 3, 18223 Prague, Czech Republic.
The Journal of chemical physics
|October 9, 2025
概括
在生物学和合成中至关重要的H原子抽象 (HAA) 反应,通过增强的马库斯交叉关系 (MCR) 更好地预测. 这种改进的模型包含了异步性,揭示了它对反应动力学的重大影响,特别是在HAT反应中.
科学领域:
- 化学动力学 化学动力学
- 理论化学 理论化学
- 有机反应机制 有机反应机制
背景情况:
- 质子合电子转移 (PCET) 和原子转移 (HAT) 反应,称为H原子抽象 (HAA) 反应,是生物系统和有机合成的基础.
- 马库斯交叉关系 (MCR) 框架,最初用于电子转移,已经应用于理解HAA反应动力学.
- 正规的MCR将反应动力学与自我交换反应联系起来,但对于复杂的HAA过程可能有局限性.
研究的目的:
- 为300多个H原子抽象 (HAA) 反应全面研究正统的马库斯交叉关系 (MCR) 的适用性和局限性.
- 为了确定超出标准MCR影响HAA反应动力学的关键热力学因素.
- 开发一个增强的理论框架来预测HAA反应速率.
主要方法:
- 进行了300多个H原子抽象 (HAA) 反应的理论分析.
- 评估了正规马库斯交叉关系 (MCR) 的预测准确性.
- 在MCR框架中纳入了非对角热力学因素,特别是异步和挫折.
主要成果:
- 正规的MCR显示了在各种系统中准确预测HAA反应动力学的局限性.
- 偏斜的热力学因素,特别是异步性 (质子和电子转移之间的不平衡),显著提高了MCR的预测能力.
- 改进的模型显示,与PCET类反应相比,HAT反应的改善更为明显.
- 描述了一个"伪反转区域",其中更多的强力反应表现出更高的自由能量障碍.
结论:
- 需要一个增强的理论框架来准确地描述HAA反应动力学,超越了正规的马库斯交叉关系 (MCR).
- 异步是主导的离对角热力学因素,提高了MCR对HAA反应的预测准确度.
- 这种精细的模型提供了对H原子抽象机制的更好理解,并突出了HAA化学中非对角效应的重要性.
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