Exploration of Ozonolysis in Multiple Media

通过这个奖项，有机和大分子化学项目支持了卡内基-梅隆大学尼尔·m·多纳休教授的工作。本研究将探讨控制不饱和烃与臭氧在气相和冷表面上的臭氧分解反应的基本反应动力学。当臭氧与烯烃双键反应时形成的原生臭氧破裂时，控制哪些键断裂的因素以及控制反应产物的确切结构的因素将被确定。通过将计算研究与多相实验动力学相结合，该研究将分离出可能负责控制臭氧-烯烃反应化学行为的因素。通过研究环烯烃和非环烯烃，我们将揭示碰撞能量传递的细节和反应碎片之间的能量分布。环烯烃的反应产物是拴在一起的，反应能量完全集中在一个片段上，而非环烯烃则产生两个片段，每个片段都有一个能量分布。这项研究的更广泛影响之一是它对了解空气污染的影响。臭氧分解在城市和区域大气化学中产生重要的自由基；因此，它在光化学烟雾的形成中起着核心作用。它也是超细有机气溶胶的主要来源，这是一个重大的健康危害。因此，了解臭氧分解的机理细节对于制定城市空气质量控制策略至关重要。当臭氧侵入建筑物并与各种家用和工业溶剂发生反应时，气溶胶的产生也是一个重大的公共卫生问题。这些问题将成为课程发展的基石，围绕着臭氧分解示范，适用于公立和本科教育。同样重要的是，在一个基础化学研究将对公众相当关注的问题产生重大影响的领域培训年轻科学家。

With this award, the Organic and Macromolecular Chemistry Program supports the work of Professor Neil M. Donahue of Carnegie-Mellon University. This research will probe the basic reaction dynamics controlling ozonolysis reactions between unsaturated hydrocarbons and ozone in the gas phase and on cold surfaces. The factors which control which bonds break when the primary ozonide, formed when ozone reacts with alkene double bonds, breaks up and what controls the exact structure of the resulting reaction products will be determined. By combining computational studies with experimental kinetics in multiple phases, the research will isolate factors potentially responsible for governing the chemical behavior of ozone-alkene reactions. By studying both cycloalkenes, where the reaction products are tethered and the reaction energy thus resides entirely in a single fragment, and non-cyclic alkenes, which yield two fragments that each possess a distribution of energies, the research will reveal details of collisional energy transfer and the energy distribution among the reaction fragments.Among the broader impacts of this research is its impact in learning about air pollution. Ozonolysis is responsible for significant radical production in urban and regional atmospheric chemistry; it thus plays a central role in photochemical smog formation. It is also a major source of ultrafine organic aerosols, which are a significant health hazard. Consequently, understanding the mechanistic details of ozonolysis is vital to developing control strategies for urban air quality. Aerosol generation initiated when ozone invades buildings and reacts with various household and industrial solvents is also a significant public health concern. These issues will serve as a cornerstone for curricular development revolving around an ozonolysis demonstration suitable for both public and undergraduate education. Also important is the training of young scientists in an area where basic fundamental chemical studies will have a significant impact on a problem of considerable concern to the public.