Excess Electrons in Clusters and Liquid Jets

水合电子在物理科学的许多领域都很重要。它们在核反应堆的辐射化学中起着关键作用，它们介导了电离辐射对DNA的损伤。在这项由化学系化学结构、动力学和机制计划资助的奖项中，加州大学伯克利分校的Daniel Neumark教授和他的研究生同事将对负电荷团簇中的过剩电子进行光谱和动力学研究，这些团簇是大量水合电子的有用模型系统。这些研究将使用时间分辨光电子成像(TRPEI)进行，这是一种飞秒泵浦-探测技术。这项研究将寻求表征DNA亚基中过剩电子的气相反应性，负电荷水团簇中电子吸收的时间演变，以及汞团簇阴离子中俄歇发射的衰减。此外，一个项目将开发一种液体喷射技术，对散装水中的水合电子进行与时间无关和时间分辨的光电子能谱。概述的研究将产生一些更广泛的科学影响，因为溶解电子在许多科学领域都普遍存在，包括大气化学、生物和医学。汞团簇阴离子的实验将揭示量子点的光物理，从而与太阳能转换有关。在这个项目中培训的研究生将在实验和理论化学物理研究方面获得重要的技能。

Hydrated electrons are important in many areas of the physical sciences. They play a key role in the radiation chemistry in nuclear reactors, and they mediate the damage to DNA caused by ionizing radiation. In this award, funded by the Chemical Structure, Dynamics and Mechanisms Program of the Chemistry Division, Prof. Daniel Neumark of the University of California, Berkeley and his graduate student colleagues will carry out spectroscopic and dynamical studies of excess electrons in negatively charged clusters, which serve as useful model systems for bulk hydrated electrons. These studies will be done using time-resolved photoelectron imaging (TRPEI), a femtosecond pump-probe technique. The research will seek to characterize the gas phase reactivity of excess electrons in DNA subunits, the time evolution of electronic absorption in negatively charged water clusters, and Auger emission decay in mercury cluster anions. In addition, a project will develop a liquid jet technique to conduct both time-independent and time resolved photoelectron spectroscopy of hydrated electrons in bulk water.The studies outlined will have a number of broader scientific impacts, since solvated electrons are ubiquitous in a number of scientific areas including atmospheric chemistry, biology, and medicine. The experiments on mercury cluster anions will shed light the photophysics of quantum dots and thus have relevance to solar energy conversion. The graduate students trained in this program will acquire significant skills in experimental and theoretical chemical physicsresearch.