飞秒时间分辨光电子成像研究溶剂化团簇负离子激发态动力学

项目名称： 飞秒时间分辨光电子成像研究溶剂化团簇负离子激发态动力学

项目编号： No.21303199

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 数理科学和化学

项目作者： 刘本康

作者单位： 中国科学院大连化学物理研究所

项目金额： 24万元

中文摘要： 溶剂化团簇负离子为研究溶剂化效应提供了一种近似于理想的微溶剂模型，对于在分子水平上深入的理解溶剂对化学反应过程的调控作用具有重要的意义。本项目首先利用纳秒激光溅射金属靶材，并将载有溶剂分子的载气对溅射产物进行冷却，通过质量门选择技术，选择出特定尺寸的溶剂化团簇负离子。接着利用飞秒时间分辨的光电子成像技术对选择好的负离子体系的激发态动力学进行研究。 以金属原子负离子络合的溶剂化团簇负离子为模型，研究电荷由核心离子向溶剂分子转移的动力学特征及伴随的溶剂网络再分布过程，对比不同溶剂尺寸及溶剂种类下的实验结果形成溶剂尺寸、溶剂网络构型对上述过程影响的系统性认识。以金属团簇负离子络合的溶剂化团簇负离子为模型研究溶剂体系对解离过程以及解离产物间可能伴随的电荷转移的调控作用。通过上述研究加深对溶剂动力学过程的认识，为建立从气相向体相演化的完整认识提供重要的实验依据。

中文关键词： 团簇负离子；飞秒激光；光电子速度成像；；

英文摘要： Solvated clusters anions have been served as ideal micro-solvations for the studies of solvation effects and showed to be of fundamental importance in gaining a molecular-level understanding of solvent-controlled chemistry. The solvated clusters anions are generated by pulsed laser vaporization of metal target, and then are cooled by carrier gas with solvented molecules. Utilization of mass-selected, solvated clusters anions of specific composition and size are prepared.The ultrafast dynamics of excited states of these anions are then studied by femtosecond time-resolved photoelectron imaging. As for the metal anonic-containing solvated cluster anions, femtosecond time-resolved photoelectron imaging has been used to study the dynamics of the charge-transfer-to-solvent transition and solvent rearrangement. A fundamental understanding of electron solvation dynamics will be gained by comparing the results of different sizes and solvents. Solvation-induced photofragmentation dynamics will be studied for the metal clusters anomic-containing solvated cluster anions.The study of solvation-induced dynamics is important to construct a seamless description of matter as it evolves from gas to condensed phase as the number of solvent particles increases.

英文关键词： cluster anions；femtosecond laser；photoelectron velocity map imaging；；