Dynamics of Solvated Electrons in Clusters and Liquid Jets

该奖项由化学系化学结构、动力学和机制A （CSDM-A）项目资助，加州大学伯克利分校的Daniel M. Neumark教授和他的研究生同事正在研究孤立阴离子团簇和液体射流中多余电子的动力学。纽马克教授和他的团队的最终目标是更好地理解电子与凝聚态分子相互作用的方式。这项研究的结果将有助于更好地理解自由电子附着在DNA核碱基上并与之反应的方式，这是生物学上重要的放射化学过程的第一步。时间分辨光电子能谱（TRPES）方法将用于研究多余电子与孤立分子和凝聚相相互作用的动力学。TRPES将用于：(1)研究水和甲醇液体射流中电子激发电子的弛豫动力学；这些实验将有助于将先前簇阴离子的TRPES研究与先前体溶剂化电子的瞬态吸收测量联系起来；(2)研究分离的尿嘧啶和胸腺嘧啶分子及其分子簇与水的低能电子附着动力学；(3)研究液体射流中电子与核酸组分的相互作用。这些实验的最终目的是为了更好地理解低能电子与溶剂相互作用和与核酸反应的方式。这项工作将有助于阐明一些重要的生物放射化学。与纽马克教授一起工作的学生接受现代物理化学方法的培训。最近的学生已经进入高科技行业、学术界和美国政府工作。

In this award, funded by the Chemical Structure, Dynamics and Mechanisms A (CSDM-A) Program of the Division of Chemistry, Professor Daniel M. Neumark of the University of California - Berkeley and his graduate student colleagues are investigating the dynamics of excess electrons with isolated anion clusters and in liquid jets. The ultimate goal of the work by Professor Neumark and his group is to develop a better understanding of the ways in which electrons interact with molecules in condensed phases. The results of this research will help develop a better understanding of the ways in which free electrons can attach to and react with DNA nucleobases, a first step in a biologically important radiochemical process. Time-resolved photoelectron spectroscopy (TRPES) methods will be used to study the dynamics of excess electrons interacting with isolated molecules and in condensed phases. TRPES will be used to: (1) study the relaxation dynamics of electronically excited electrons in liquid jets of water and methanol; these experiments will help to link previous TRPES studies of cluster anions to previous transient absorption measurement of bulk solvated electrons; (2) study the dynamics of low-energy electron attachment to isolated uracil and thymine molecules as well as clusters of these molecules with water; and (3) investigate the interaction of electrons with nucleic acid constituents in a liquid jet. The ultimate aim of these experiments is to develop a better understanding of the ways in which low-energy electrons interact with solvent and react with nucleic acids. This work will help to illuminate some important biological radiochemistry. Students working with Prof. Neumark receive training in modern physical chemistry methods. Recent students have gone on to careers in high-tech industries, academia, and the U. S. Government.