分子光开关的超快电子放松通路四旋旋风
Kurtis D Borne1, Joseph C Cooper2, Michael N R Ashfold3
1J.R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, KS, USA.
Nature chemistry
|February 2, 2024
概括
研究人员研究了四旋风.
科学领域:
- 摄影化学的使用.
- 分子动力学分子动力学
- 量子化学 是一个量子化学.
背景情况:
- 诺伯纳迪烯和四旋旋异构体通过光诱导的超快切换来储存和释放大量的化学能量.
- 之前的研究在紫外线激发时检测到这些异构体中的超快分子动力学,但无法追踪电子放松到基本状态.
- 了解完整的放松途径对于利用这种能量储存能力至关重要.
研究的目的:
- 在紫外线刺激后实验研究四旋风的电子放松通路.
- 阐明四旋风中兴奋状态放松的机制和时间尺度.
- 为了确定放松后的norbornadiene/quadricyclane的产品分支比.
主要方法:
- 时间分辨率的气相极紫外线光电谱学.
- 非adiabatic分子动力学模拟.
- 在201nm的紫外线激发.
主要成果:
- 确定了两个相互竞争的途径,用于将激发四旋风的电子放松到基本状态.
- 一个快速的路径 (<100 fs) 涉及合到价值电子状态.
- 一条缓慢的路径 (几百 fs) 涉及跨越瑞德伯格状态的初始运动.
- 这两种途径都在不同的时间尺度上促进同位素相互转换.
- 在返回地面状态后立即观察到约3:2的预测norbornadiene/quadricyclane产品比.
结论:
- 该研究成功地追踪了四旋风的完全电子放松到基本状态.
- 描述了两个不同的放松路径,在时间尺度和电子状态合方面有所不同.
- 这些发现为这些分子异构体的能量储存和释放机制提供了关键的见解.
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