在pyrenylurea-nitrobenzene pi-stacked protophanes中依赖桥梁的电荷分离的动力学和机制
Frederick D Lewis1, Pierre Daublain, Grace B Delos Santos
1Department of Chemistry, Northwestern University, Evanston, Illinois 60208, USA. lewis@chem.northwestern.edu
Journal of the American Chemical Society
|April 6, 2006
概括
这项研究探讨了分子结构如何影响烯和酸分子中的电子转移. 研究人员发现,改变桥梁群的数量会改变电子流的方向性.
科学领域:
- 有机化学 有机化学
- 摄影化学的使用.
- 超分子化学 超分子化学
背景情况:
- 合成了具有烯和酸末群的三级二和多氨基基基.
- 这些分子形成了折叠的"原"结构,具有pi-stacked arenes.
研究的目的:
- 研究烯和酸单片状态的电子特性和行为.
- 了解这些系统中电荷分离和重组的机制.
主要方法:
- 五秒宽带探波光谱学被用来研究激发状态动态.
- 通过与参考分子进行比较来分配短暂的行为.
主要成果:
- 直接观察快速的内部转换和系统间交叉过程.
- 超快速的电荷分离 (约. 100 fs) 通过内部转化在未结合的供体-接受体尿素中.
- 单桥尿素中的电荷转移和重组速度较慢,通过超级交换.
- 在二桥系统中,作为受体的pyrene单片状态的作用逆转.
结论:
- 二桥接组的数量显著影响电子转移方向性.
- 桥氧化潜力的变化和超交换速率常数决定了电子转移路径.
- 分子设计提供了对激发状态电子转移过程的控制.
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