Understanding the Effects of Liquid Structure on Chemical Bonds and Solvated Electrons Using Ultrafast Spectroscopy and Mixed Quantum/Classical Molecular Dynamics Simulation

该奖项由化学部化学结构、动力学和机理项目资助，加州大学洛杉矶分校的Benjamin J. Schwartz教授和两位研究生同事将进行一项理论研究计划，并辅以一些实验，通过研究简单的，原型模型系统理论工作将集中在分子动力学模拟上，结合了Schwartz和他的同事开发的严格的混合量子/经典方法，包括开发新的相互作用势，可以响应不同化学物种周围局部环境的变化。 模拟的重点将是1）了解不同的溶剂是否具有可以控制电子转移反应的动力学和/或支持溶剂化电子的预先存在的空腔，以及2）了解液体结构和动力学如何控制溶液中的化学键断裂和键形成。 伴随着模拟将是有限数量的飞秒激光实验，这些实验将直接测量各种不同溶剂中电荷转移到溶剂反应（产生溶剂化电子）的动力学，也可能测量简单双原子分子的光解动力学。 除了获得支持的研究的更广泛的科学影响外，参与该项目的年轻研究人员还将同时获得尖端理论和实验方法的经验。此外，该项目还将通过一项针对高中教师的外联方案，向传统上在科学领域代表性不足的群体的学生和洛杉矶地区的高中学生提供这些教育机会。最后，由于溶液相电子转移反应和化学键动力学在化学和生物学中无处不在，因此本提案中开发的方法和测量将增强本提案直接关注范围之外的许多研究领域。

In this award, funded by the Chemical Structure, Dynamics and Mechanisms-A Program of the Chemistry Division, Prof. Benjamin J. Schwartz of the University of California, Los Angeles and two graduate student colleagues will undertake a theoretical program of research, supplemented with some experiments, to develop a better understanding of solvated electrons and photodissociation reactions in solution through the study of simple, prototypical model systems. The theoretical work will center on molecular dynamics simulations incorporating a rigorous, mixed quantum/classical method that Schwartz and his colleagues have developed, including the development of new interaction potentials that can respond to changes in the local environment around different chemical species. The simulations' focus will be on 1) understanding whether or not different solvents have pre-existing cavities that can control the dynamics of electron transfer reactions and/or support solvated electrons, and 2) understanding how liquid structure and dynamics control chemical bond-breaking and bond formation in solution. Accompanying the simulations will be a limited number of femtosecond laser experiments that will directly measure the dynamics of charge-transfer-to-solvent reactions (that create solvated electrons) in a variety of different solvents and also possibly the photodissociation dynamics of simple diatomic molecules. Besides the broader scientific impacts of the research being supported, the young researchers working on this project will gain simultaneous experience in both cutting edge theoretical and experimental methods. Moreover, the project will provide these educational opportunities both to students from traditionally underrepresented groups in the sciences and to Los Angeles area high school students via an outreach program for high school teachers. Finally, because solution-phase electron transfer reactions and chemical bond dynamics are ubiquitous in chemistry and biology, the methods and measurements developed in this proposal will enhance many areas of research outside the immediate focus of this proposal.