在200纳米处对循环布坦的光碎片化:TDDFT与CASSCF电子衍射
Alberto Martín Santa Daría1, Javier Hernández-Rodríguez1, Lea M Ibele2
1Departamento de Química Física, Universidad de Salamanca, Salamanca 37008, Spain.
The Journal of chemical physics
|March 15, 2024
概括
这项研究模拟了循环布坦的光激发,揭示了键裂和超快速失活. 不同的电子结构方法产生不同的超快电子衍射光谱,突出了在化学动力学模拟中选择方法的重要性.
科学领域:
- 化学物理 化学物理
- 量子化学 是一个量子化学.
- 计算化学的计算化学
背景情况:
- 循环布坦光激发是理解分子动态的一个关键过程.
- 里德伯格态在光化学反应的初始阶段起着至关重要的作用.
研究的目的:
- 为了模拟200纳米的光激发的循环butanone到n-3s莱德伯格状态.
- 为了研究随后的债券裂变和失活路径.
- 为了比较不同电子结构方法对非adiabatic动态的结果.
主要方法:
- 经典轨迹是从维格纳分布开始的.
- 对于初始电子结构的时间依赖密度函数理论 (TD-B3LYP-D3/6-31+G**).
- 塔利的表面跳跃方法用于核传播.
- 国家平均的完整活动空间自相一致的场 (SA(6) -CASSCF(8,11) / aug-cc-pVDZ) 用于重新计算.
- 计算气相超快电子衍射光谱的计算.
主要成果:
- 在S1表面的预测键断裂.
- 观察到从n-3s Rydberg状态到nπ*状态的超快速失活.
- 证明三重态和较高单重态对早期动态 (第一个300 fs) 的影响最小.
- 使用两种电子结构方法获得的气相超快电子衍射光谱显著不同.
结论:
- 循环butanone光激发的初始动态是由特定的单元状态主导的.
- 电子结构方法的选择显著影响了非adiabatic动态和实验可观测的预测结果,如电子衍射光谱.
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