Experimental and theoretical determination of the temperature dependent rate constant for the reaction of hydroxyl radicals with some volatile organic compounds

Air pollution and in particular photochemical smog is still an important environmental problem due to its impact on human health. One of the main contributors is tropospheric ozone, the primary component of photochemical smog. Some of the main illnesses related to high ozone levels are respiratory infections and lung inflammation as well as exacerbating illnesses such as asthma from both acute and chronic exposure. Controlling ozone levels is challenging, because ozone is not directly emitted into the atmosphere but is a secondary pollutant produced from chemical reactions of primary emissions, both biogenic and anthropogenic. Thus control of ozone in the troposphere requires an accurate understanding of the chemistry leading to its production. The primary step in the production of tropospheric ozone is the reaction of hydroxyl radicals with volatile organic compounds. For this reason a thorough understanding of the reactions of individual volatile organic compounds with hydroxyl radicals is needed. This dissertation focuses on the reaction of the hydroxyl radical with three volatile organic compounds: allyl alcohol, 1-propanol and propionaldehyde. These reactions are studied using a discharge-flow tube technique in addition to laser induced fluorescence detection of the OH radical. In addition, theoretical computational calculations of the potential energy surface of these reactions were performed to give insight into the reaction mechanisms.