Reactivity of Radicals in Crystal Lattices

通过这一奖项，化学结构、动力学和机理计划支持辛辛那提大学的Anna Gudmundsdottir教授利用激光闪光光解和X射线结晶学相结合的方法，研究萘醌和乙烯基叠氮化物的固态光化学和光物理。这项研究的目的是阐明固态反应机理，并解释晶格结构如何影响反应活性。Gudmundsdottir教授将把这个项目的研究部分与一个旨在吸引高中生和本科生的教育项目结合起来，重点是加强来自科学代表性不足群体的学生的参与。学生将有机会参加以专业发展为重点的研究和教育活动。拟议的研究和发展性教学将加强辛辛那提大学化学系的基础设施，并作为该地区其他学校的外联计划。这项研究将通过鉴定它们的光产物并获得它们的X-射线结构来研究它们的固态光反应性。激光闪光光解将被用来表征晶体中形成的瞬时激发态和自由基，并确定它们的形成和衰减的动力学。总而言之，这些数据将使阐明详细的固态反应机理和解释晶格如何影响瞬时物种的行为和反应产物的选择成为可能。机理研究将得到理论计算的支持。计划中的研究将在光化学、活性中间体和固体化学领域带来新的知识。拟议的研究还将有助于设计晶体晶格，用于从自由基选择性地形成碳-碳键和碳-氮键，目标是将晶体用作无溶剂合成的基质。同时，这项研究将有助于太阳能电池和发光二极管等光响应设备的设计。

With this award, the Chemical Structure, Dynamics & Mechanism Program is supporting Professor Anna Gudmundsdottir at the University of Cincinnati to investigate the solid-state photochemistry and photophysics of naphthoquinones and vinyl azides, using a combination of laser flash photolysis and x-ray crystallography. The goal of this research is to elucidate solid-state reaction mechanisms and to explain how a crystal lattice structure can affect reactivity. Professor Gudmundsdottir will integrate the research components of this project with an educational program designed to attract both high school and undergraduate students, with a focus on enhancing participation of students from groups that are underrepresented in science. Students will be provided with an opportunity to participate in research and educational activities that focus on professional development. The proposed research and the developmental teaching will lead to enhanced infrastructure within the Chemistry Department at the University of Cincinnati and serve as an outreach program for other schools in the region. This research will investigate the solid-state photoreactivity of naphthoquinones and vinyl azides by identifying their photoproducts and acquiring their X-ray structures. Laser flash photolysis will be used to characterize the transient excited states and radicals which are formed in the crystals and to determine the kinetics for their formation and decay. Collectively, these data will make it possible to elucidate detailed solid-state reaction mechanisms and to explain how the crystal lattice affects behavior of transient species and selection of the reaction products. Mechanistic studies will be supported by theoretical calculations. The planed studies, will lead to new knowledge in the field of photochemistry, reactive intermediates and solid-state chemistry. The proposed research will also contribute toward the design of crystal lattices for selective carbon-carbon and carbon-nitrogen bond formation from radicals, with a goal of using crystals as a matrix for solvent-free synthesis. Simultaneously, this research will contribute to the design of photoresponsive devices, such as solar cells and light emitting diodes.