转子选择性电荷转移通路的温度依赖性在提供者-桥梁-受体分子中与寡合体氨和p-phenylethynylene桥梁
Amy M Scott1, Michael R Wasielewski
1Department of Chemistry and Argonne-Northwestern Solar Energy Research (ANSER) Center, Northwestern University, Evanston, Illinois 60208-3113, USA.
Journal of the American Chemical Society
|February 16, 2011
概括
研究捐赠者-桥梁-受体分子中的电荷重组,揭示了温度依赖的途径. 扭转运动影响单元重组,而三元重组显示积极的激活能量障碍.
科学领域:
- 摄影化学的使用.
- 分子动力学分子动力学
- 电子转移是指电子的转移.
背景情况:
- 捐赠者-桥梁-受体分子对于理解电荷重组动力学至关重要.
- 旋转选择性电荷重组受分子结构和温度的影响.
- 激进对系统间交叉 (RP-ISC) 在旋转动力学中起着关键作用.
研究的目的:
- 调查自旋选择性分子内电荷重组 (CR) 的温度依赖性.
- 阐明不同分子桥梁 (氨和p-phenylethynylene) 在CR途径中的作用.
- 为了确定单元和三元CR路径的激活能量和障碍物.
主要方法:
- 纳米秒短暂吸收光谱法被采用.
- 实验是在静态磁场的存在下进行的.
- 使用动力分析来提取速度常数 (k ((CR), k ((CRS), k ((CRT), k ((ST)).
主要成果:
- 在300 K的p-phenylethynylene桥梁中观察到CR路径的交叉.
- 通过诺桥的单点CR表现出由于扭矩运动而导致的负激活能量.
- 通过所有桥梁的三重CR通道显示了积极的激活能量,屏障范围从1100到4500厘米.
结论:
- 该研究强调了自旋选择性CR的复杂温度依赖性.
- 分子桥显著调节CR路径及其温度依赖性.
- 半古典电子转移理论可以模拟对扭转运动的观察到的激活障碍.
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