在MLCT激发状态下超快速的结构重组,用于溶液中的铜 (I) 双类
George B Shaw1, Christian D Grant, Hideaki Shirota
1Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
Journal of the American Chemical Society
|January 30, 2007
概括
这项研究揭示了在光激发过程中铜复合体的超快速结构平,独立于溶剂效应. 这些发现对于理解激发状态动态和开发新的太阳能材料至关重要.
科学领域:
- 摄影化学的使用.
- 协调化学 协调化学
- 材料科学 材料科学 材料科学
背景情况:
- 铜复合体中的金属-合体电荷转移 (MLCT) 转换涉及电子配置变化和几何重新排列.
- 之前的研究表明,在MLCT状态的[Cu(I) ((dmp) ((2))) ((+)) 状态下,弗兰克 - 康登状态平坦化和溶剂结合.
研究的目的:
- 为了研究[Cu(I) ((dmp) ((2))) ((+)) 和[Cu(I) ((dpp) ((2))) ((+)) 的超快兴奋状态结构动力学.
- 为了阐明在MLCT过渡期间短暂的光谱变化的结构起源.
- 了解溶剂特性对激发状态动态的作用.
主要方法:
- 在具有不同介电常数,粘度和热扩散度的溶剂中进行过渡吸收光谱学.
- 光向上转换光谱法用于测量单点光动态.
- 激光启动的时间分辨率X射线吸收光谱 (LITR-XAS) 用于结构洞察.
主要成果:
- 观察到溶剂独立的内部球体放松,尽管大幅度的几何运动.
- 在MLCT状态[Cu{I}{dmp}{2}}{+}]中确定了一种超快速 (77 fs) 平面化过程.
- 单点光动力学表明,在弗兰克-康登几何学上存在快速消活路径.
结论:
- 在铜复合体的MLCT状态中发生了一种意想不到的超快的几何平.
- 内部球体放松是一个主要的过程,在很大程度上独立于溶剂相互作用.
- 这些发现指导了未来的超快X射线研究和用于太阳能应用的铜复合体的设计.
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