Kinetic and Mechanistic Studies of Criegee Intermediate Reactivity

化学学部的环境化学科学项目资助加州大学欧文分校的Craig Murray教授探索Criegee中间体的化学反应性。甲烷中间体是在大气中起重要作用的活性化学物质。它们有助于颗粒的形成，从而影响空气质量、健康和气候。实验室实验测量中间浓度随时间的变化，以确定它们与大气中微量气体反应的速度。该研究项目为研究生和本科生提供技术实验室和其他可转移技能的培训，为他们在学术界或工业界的职业生涯做好准备。默里教授的推广项目在当地几所高中建立了空气质量和天气监测站。室外和室内颗粒传感器在每个位置提供长期数据。学生和教师参与开发使用移动粒子传感器与智能手机接口的项目。这一拓展部分扩大了参与范围，鼓励学生继续参与STEM活动，无论是在课堂内外。利用激光闪光光解瞬态吸收光谱仪定量研究了克里吉中间反应与微量大气气体的温度依赖动力学。实验考察了Criegee中间体与多功能挥发性有机化合物的反应动力学，分析了光解共生成的自由基种类，并探讨了水蒸气作为潜在催化剂的作用。互补的量子化学和动力学计算提供了对详细反应机制的进一步了解。该研究生成数据来测试和完善大气的化学模型，并探索气相物种的反应如何导致可能影响空气质量、健康和气候的二次有机气溶胶颗粒的形成。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The Environmental Chemical Sciences program of the Chemistry Division funds Professor Craig Murray of the University of California, Irvine to explore the chemical reactivity of Criegee intermediates. Criegee intermediates are reactive chemical species that play an important role in the atmosphere. They contribute to particle formation, which can affect air quality, health and climate. Laboratory experiments measure the intermediate concentrations over time to determine the speed of their reaction with atmospheric trace gases. The research project provides training for graduate and undergraduate students on technical laboratory and other transferable skills that will prepare them for careers in academia or industry. Professor Murray's outreach program establishes air quality and weather monitoring stations at several local high schools. Outdoor and indoor particle sensors provide long-term data at each location. Student and teacher participants develop projects that use mobile particle sensors interfaced with smartphones. This outreach component broadens participation and encourages students to continue to participate in STEM activities, both inside and outside the classroom. A laser flash photolysis transient absorption spectroscopy apparatus is used to quantify the temperature-dependent kinetics of Criegee intermediate reactions with trace atmospheric gases. The experiments examine the kinetics of reactions of Criegee intermediates with multifunctional volatile organic compounds to analyze photolytically co-generated radical species and explore the role of water vapor as a potential catalyst. Complementary quantum chemical and kinetics calculations provide further insight into the detailed reaction mechanisms. The research generates data to test and refine chemical models of the atmosphere and explores how reactions of gas-phase species lead to the formation of secondary organic aerosol particles that may affect air quality, health, and climate.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.