在基于氨酸的捐赠器-桥梁-接受器系统中,桥依赖电子转移
K Kilså1, J Kajanus, A N Macpherson
1Department of Physical Chemistry and Department of Organic Chemistry, Chalmers University of Technology, SE-412 96 Göteborg, Sweden.
Journal of the American Chemical Society
|July 18, 2001
概括
在捐赠者-桥梁-接受器系统中研究了光诱导电子转移. 结合式桥梁促进电子传输,而非结合式桥梁允许能量传输,合取决于能量差距.
科学领域:
- 摄影化学的使用.
- 分子电子学分子电子学
- 超分子化学 超分子化学
背景情况:
- 捐赠者桥接收器 (DBA) 系统对于人工光合作用和分子装置至关重要.
- 了解DBA系统中的电子传递机制是设计高效的光采集和电荷传输材料的关键.
研究的目的:
- 研究具有不同桥梁电子结构的DBA系统中的光诱导电子转移.
- 阐明桥梁单元在决定电子与能量传输路径中的作用.
- 量化捐赠者和接受者部分之间的电子合.
主要方法:
- 合成DBA系统与色氨酸捐赠体,金色氨酸接受体和各种桥梁染色体.
- 皮秒短暂吸收光谱检测激发状态动态.
- 分析使用马库斯和雷姆-韦勒方程来确定电子转移参数.
主要成果:
- 带有pi结合桥梁的系统表现出依赖溶剂的火率,这表明了马库斯类型的电子转移.
- 带有断裂的结合桥的系统显示了溶剂独立的火,与Förster能量转移相一致.
- 图秒光谱学只在pi-结合系统中证实了色胺基的阴离子形成.
- 电子合被估计为5-20厘米-1的结合系统,与能量差距相关.
结论:
- 桥梁单元的电子结构批判性地控制了光诱导的电荷转移路径 (电子与能量转移).
- 电子合受捐赠者和桥梁激发状态之间的能量差距的影响,与量子力学的预测保持一致.
- 带有联桥的DBA系统显示了高效的光诱导电子转移,为先进的分子电子应用铺平了道路.
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