Excellence in Research: A Computational Study of the Gas-Phase Reactions of Simple Epoxides and their Radicals

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With this award, the Chemical Structure, Dynamics, and Mechanisms-B program is supporting Professor Kathleen Morgan and her students at Xavier University of Louisiana to study the chemistry of epoxides, a type of volatile organic compound which is commonly found in the atmosphere. Increasingly, citizens are recognizing the potential dangers of industrial plants that produce and store hazardous chemicals, and one major concern is the release of volatile organic compounds (VOC) into the air they breathe. This study is concerned with the 'epoxide' class of compounds. Ethylene oxide and propene oxide are common commodity chemicals of the epoxide family with a variety of important commercial purposes but they are also carcinogenic. Understanding the fate of these and related VOC in the atmosphere, through knowledge of likely decomposition mechanisms and rates, is critical. The proposed computational modeling study seeks to extend our understanding of the degradation reactions, and has the potential to suggest new reactions that can remediate pollutants. The study is designed for full participation by undergraduate research students from Xavier University of Louisiana, a primarily undergraduate and Historically Black College or University (HBCU), where the majority of students are African American women, and science majors. The computational analyses provide excellent training experiences for undergraduates that will prepare them for graduate studies and careers in STEM (science, technology, engineering and mathematics) fields. This study will also enable students to connect basic science research to the real-world problems that underlie this project. The proposed computational study is concerned with gas-phase radical reactions of simple epoxides. Epoxides of interest include ethylene oxide, propene oxide, cis- and trans-2-butene oxide, 2-methylpropene oxide, and epifluorohydrin. Three types of calculations, using commercially-available software, will be considered to explore the influence of substituents on epoxide reactivity: (1) epoxide bond dissociation energies; (2) degradation of parent epoxides and/or their radical counterparts; and (3) addition reactions of hydroxyl radical and other radical species to epoxides. Together, these calculations will provide insight into the behavior of epoxides in the gas phase, and the effects of substituents on epoxide reactivity and decomposition products. Through this project, the detailed training program for undergraduate minority students is expected to make an important contribution to the development of a diverse workforce for the nation.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.