Heterogeneous Oxidations of Organic Molecules: Mechanisms & Dynamics

在化学系有机动力学项目的支持下，科罗拉多大学博尔德分校的巴尼·埃里森教授将探索碳氢膜在固/气界面和液/气界面上的反应性。这些实验的目的是为了识别介导碳氢薄膜氧化的活性自由基。将产生烷基过氧基Roo，必须对其进行彻底的表征。埃里森计划使用超热超音速喷射来产生CH3CH2自由基束，并产生基质隔离的乙基过氧基CH3CH2OO。我们将完整地研究基质隔离的ETOO自由基的偏振红外光谱。气溶胶结合的过氧基的一个重要命运是与NO反应，然后裂解成NO2和烷氧基，或者异构化成烷基硝酸盐。因此，埃里森建议在基质中生成CH3OO-NO加合物，并使用FTIR来探索其性质。与能源部EMSL实验室的D.Ray博士合作，Ellison将使用钛宝石激光器，通过二次谐波产生(SGH)的非线性光学过程，在液体/大气压界面检测表面结合的过氧基。SHG实验将在水溶液和空气之间的界面上搜索Roo自由基。埃里森教授与南加州大学的B.Koel教授合作，计划探索臭氧氧化烯烃薄膜的过程，并研究在界面上臭氧氧化烯烃的机理。在臭氧与烯烃薄膜的研究中，Ellison&Amp；Koel将生产最简单的Criegee中间体CH2OO的样品，并使用FITR在基质中进行研究。这里提出的这类实验研究将为理论家预测和模拟真实的气溶胶并了解环境中碳氢膜的氧化机制提供基础。有机和高分子化学计划支持科罗拉多大学博尔德分校的巴尼·埃里森教授，他与其他化学家共同研究工作的历史悠久。埃里森的实验室定期与NOAA的空气工程实验室和NSF的NCAR实验室的大气化学家合作。倒置胶束模型是与V.Vaida(科罗拉多大学)和A.Tuck(NOAA)合作的，灵感来自NOAA的现场数据。埃里森继续与能源部位于科罗拉多州戈尔登的NREL实验室的化学家合作研究生物质燃烧，并与能源部位于华盛顿州里士满的EMSL实验室和加利福尼亚州南加州大学的表面化学家合作研究生物质燃烧。所有这些小组都在研究与挥发性有机化合物(VOCs)的对流层命运、大气中有机气溶胶的化学分析和动力学以及气/固和气/液界面的化学和光谱性质有关的超复杂化学问题。埃里森和他的学生为这些实验室提供了“有机化学观点”。

With the support of the Organic Dynamics Program in the Chemistry Division, Professor Barney Ellison at the University of Colorado at Boulder will explore the reactivity of hydrocarbon films at a solid/gas interface and at a liquid/gas interface. These experiments are aimed at the identification of reactive radicals that mediate the oxidation of hydrocarbon films. Alkylperoxyl radicals, ROO, will be produced that must be thoroughly characterized. Ellison plans to use hyperthermal supersonic jets to produce beams of the CH3CH2 radical and to generate matrix-isolated ethylperoxyl radicals, CH3CH2OO. The polarized infrared spectroscopy of matrix-isolated EtOO radicals will be completely studied. An important fate of aerosol-bound peroxyl radicals will be reaction with NO followed by either fragmentation to NO2 and an alkoxy radical, or isomerization to an alkyl nitrate. Consequently, Ellison proposes to produce the CH3OO-NO adduct in a matrix and use an FTIR to explore its properties. In collaboration with Dr. D. Ray at the DOE's EMSL labs, Ellison will use a Ti:Sapphire laser to detect surface-bound peroxyl radicals at a liquid/atmospheric pressure interface via the non-linear optical process of second harmonic generation (SGH). The SHG experiment will search for ROO radicals at an interface between an aqueous solution and air. In collaboration with Prof. B. Koel at USC, Professor Ellison plans to explore the oxidation of alkene films with O3 and to study the mechanisms of olefin oxidation with O3 at an interface. In the study of O3 with olefin films, Ellison & Koel will produce samples of the simplest Criegee intermediate, CH2OO, and study it in matrices using FITR. Experimental studies of the sort proposed here will provide a basis for theorists to predict and model real aerosols and to understand the oxidation mechanisms of hydrocarbon films in the environment.The Organic and Macromolecular Chemistry Program supports Professor Barney Ellison at the University of Colorado at Boulder who has a long history of joint research efforts with other chemists. Ellison's lab collaborates regularly with atmospheric chemists at NOAA's Aeronomy Labs and the NSF's NCAR labs. The inverted micelle model was a collaboration with V. Vaida (University of Colorado) and A. Tuck (NOAA) and was inspired by NOAA's field data. Ellison continually works with chemists studying biomass burning at the DOE's NREL labs in Golden, CO and with surface chemists at the DOE's EMSL labs in Richmond, WA and at USC in Calif. All of these groups are pursuing hypercomplex chemical problems having to do with the tropospheric fate of volatile organic compounds (VOCs), the chemical analysis and dynamics of organic aerosols in the atmosphere, and the chemical and spectroscopic properties of gas/solid and gas/liquid interfaces. Ellison and his students provide these labs with an "organic chemistry point-of-view."