理论研究电子,质子和质子合电子转移在铁双-imidazoline复合体中的理论研究
N Iordanova1, H Decornez, S Hammes-Schiffer
1Department of Chemistry, 152 Davey Laboratory, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
Journal of the American Chemical Society
|July 18, 2001
概括
这项研究揭示了电子转移 (ET) 和质子合电子转移 (PCET) 速率在铁复合体中是相似的,由于补偿能量因素. 质子转移 (PT) 更快,由溶液重组驱动.
科学领域:
- 计算化学是一种计算化学.
- 反应机制的反应机制
- 无机化学 无机化学 无机化学
背景情况:
- 实验研究表明,在铁二-伊米达复合体中,电子转移 (ET) 和质子合电子转移 (PCET) 的速率相似.
- 观察到,在这些系统中,质子转移 (PT) 比ET和PCET都快得多.
- 了解这些反应动态对于设计新的催化剂和材料至关重要.
研究的目的:
- 从理论上研究和比较单个电子转移 (ET),单个质子转移 (PT) 和质子合电子转移 (PCET) 的机制.
- 阐明控制铁二胺达复合体中ET,PCET和PT反应之间观察到的速率差异的因素.
- 通过实验数据验证理论模型,包括反应速率和的动态同位素效应.
主要方法:
- 在理论计算中采用多态连续理论.
- 用于溶液的多态价值键模型和溶剂的介电连续.
- 在PCET中对转移的核进行了量子力学处理,并对质子振动波函数进行了电子合的平均值.
主要成果:
- 理论计算准确地复制了ET和PCET的实验速率和动同位素效应.
- ET和PCET速率的相似性归因于PCET的较低外层溶剂重组能量与ET的更高电子合之间的补偿.
- 质子转移 (PT) 呈现出一个从根本上不同的,由溶液重组主导的电子增离子机制,解释了其更快的速度.
结论:
- 电子合和重组能量的相互作用决定了ET,PCET和PT的相对速率.
- 由于质子振动波功能的有限重叠导致电子合减少,PCET比PT慢.
- 该研究为理解过渡金属复合体中复杂的电子和质子转移过程提供了理论框架.
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