Femtosecond Spectroscopy of Reaction Coordinate Motion in Solution

芭芭拉教授在实验物理化学项目的支持下，对溶液中化学反应沿反应坐标运动的“实时”动力学进行了实验研究。系统的选择特别适合于理论解释，并允许对液相反应的基本见解。该研究直接影响到对与光合作用相关的金属-金属电荷转移反应和低温电子转移机理的认识。芭芭拉教授正在开发各种新型的超快光谱泵浦探测技术，并将其应用于基态和激发态的电子转移反应。利用超短激光脉冲的共振电子激发，制备了在过渡态附近呈几何分布的反应体系。然后用飞秒光谱学监测系统沿反应坐标的后续演变。各种理论模型和模拟被用来帮助解释实验结果。

Professor Barbara is supported by the Experimental Physical Chemistry Program in an experimental investigation in "real time" of the dynamics of motion along the reaction coordinate for chemical reactions in solution. Systems are chosen that are especially amenable to theoretical interpretation and that allow fundamental insight into liquid phase reactions. The research directly impacts on the understanding of metal-metal charge transfer reactions and low temperature electron transfer mechanisms relevant to photosynthesis. Professor Barbara is developing various novel pump-probe techniques for ultrafast spectroscopy and applying them to electron transfer reactions in both ground and excited states. Resonant electronic excitation by an ultrashort laser pulse is used to prepare a reaction system in a distribution of geometries near the transition state. The subsequent evolution of the system along the reaction coordinate is then monitored by femtosecond spectroscopy. Various theoretical models and simulations are used to aid in interpreting the experimental results.