RUI: Overall Rate Constant and Nitrate Branching Ratio Measurements for the Reactions of Alkene-Derived Peroxy Radicals with Nitric Oxide

对流层臭氧的形成和破坏取决于许多因素。 过氧化氢和有机过氧自由基氧化一氧化氮是气相化学反应的关键之一。 对于过氧化氢和较小的有机过氧化氢自由基，反应几乎完全通过一氧化氮转化为二氧化氮伴随着烷氧基自由基的形成而进行。 后者通常与氧反应形成过氧化氢自由基。 更大和更复杂的，多取代的有机过氧自由基表现出第二反应途径，导致有机硝酸盐的形成。 这第二个反应通道的速率系数已经研究了一些简单的，直链的烷基过氧自由基，但数据是稀疏和不一致的更复杂的自由基，如那些来自羟基自由基与烯烃（含双键的烃）的反应。 本研究涉及的有机过氧自由基加一氧化氮反应动力学和分支比的系统检查，以形成有机硝酸盐的自由基衍生自一些含有2至5个碳原子的烯烃。 羟基自由基-烯烃反应生成的过氧自由基称为β-羟基过氧自由基，研究相对较少。 湍流化学电离质谱技术将用于控制实验条件和量化反应产物的产率。 研究将作为温度的函数进行。 这些数据将是非常有用的大气化学建模，但也可以用来建立结构反应性的关系，可能会允许预测产量从其他，未测量的species.This研究将进行在一个本科院校的本科研究助理在该项目中的显着利用。

The tropospheric chemistry of ozone formation and destruction depends on many factors. One of the key gas-phase chemical reactions is the oxidation of nitric oxide by hydroperoxyl and organic peroxyl radicals. For hydroperoxyl and smaller organic peroxyl radicals, the reactions proceed almost exclusively by conversion of nitric oxide to nitrogen dioxide accompanied by formation of alkoxy radicals. The latter usually react with oxygen to form hydroperoxyl radicals. Larger and more complex, multiply substituted organic peroxyl radicals exhibit a second reaction pathway, leading to the formation of organic nitrates. The rate coefficients for this second reaction channel have been studied for some simple, straight-chained alkylperoxy radicals, but data are sparse and inconsistent for more complex radicals, such as those derived from the reaction of hydroxyl radicals with alkenes (double bond containing hydrocarbons). This study involves the systematic examination of the organic peroxyl radical plus nitric oxide reaction kinetics and branching ratios to form organic nitrates for radicals derived from a number of alkenes containing two to five carbon atoms. The peroxy radicals derived from hydroxyl radical-alkene reactions are called beta-hydroxy peroxy radicals, and have been studied relatively little. The technique of turbulent flow chemical ionization mass spectroscopy will be used to control the experimental conditions and quantify the yields of reaction products. Studies will be performed as a function of temperature. These data will be extremely useful for atmospheric chemical modeling, but can also be used to build structure-reactivity relationships that may allow prediction of yields from other, unmeasured species.This research will be carried out at an undergraduate institution with significant utilization of undergraduate research assistants in the project.