Ultrafast relaxation dynamics of ionic liquids using solvated electrons as a probe

在这个项目中，我们将研究离子液体中溶剂化电子的光解产生的超快驰豫动力学。实验技术，如飞秒泵浦探测吸收和时间分辨率为？100fs的偏振敏感光谱，将被用来研究这些液体中分子间和分子内的基本相互作用。作为光谱探测器，溶剂化电子将在光解过程中产生，随后的驰豫过程将被监测。虽然瞬时吸收技术可以识别和表征这种液体中溶剂化电子的光学响应，但偏振相关光谱将把重点放在结构和电子性质上。例如，双脉冲和三脉冲序列将允许使用时间分辨吸收光谱来表征溶剂化电子的形成、复合和驰豫步骤。另一方面，瞬变各向异性作为一种极化敏感工具，探索了离子液体中溶剂化电子的随时间变化的取向变化。这些研究的结果可以与高温离子液体中溶剂化电子的超快动力学相比较，在高温离子液体中，库仑相互作用与扩散离子运动相结合决定了超快响应。因此，这项研究将对离子液体中潜在的光化学和光物理过程提供更深刻的理解。

In this project the ultrafast relaxation dynamics of ionic liquids will be investigated upon photolytic generation of solvated electrons. Experimental techniques such as femtosecond pump-probe absorption and polarization-sensitive spectroscopy with a time resolution of ¿ 100fs will be used to study fundamental inter- and intramolecular interactions in these liquids. As a spectroscopic probe solvated electrons will be generated photolytically and the subsequent relaxation processes will be monitored. While transient absorption techniques can identify and characterize the optical response of solvated electrons in such liquids, polarization-dependent spectroscopy will direct the focus towards structural and electronic properties. For example, two- and three-pulse sequences will allow for a characterization of the formation, recombination and relaxation steps of solvated electrons using time-resolved absorption spectroscopy. On the other hand, transient anisotropy as a polarization-sensitive tool explores the time-dependent orientational changes of solvated electrons in ionic liquids. The results of these studies can be compared to the ultrafast dynamics of solvated electrons in high-temperature ionic liquids where Coulombic interactions in combination with diffusive ionic motions determine the ultrafast response. As a result, this study will provide a more profound understanding of the underlying photo-chemical and photo-physical processes in ionic liquids.