Laurie Butler of the University of Chicago is supported by an award from the Chemical Structure, Dynamics and Mechanisms program to study the dynamics of radical intermediates relevant to the chemistry of the troposphere. Butler and her research group investigate the branching between product channels of unstable radical intermediates as a function of internal energy under collisionless conditions. Three classes of chemical systems are studied: 1) reactions of chlorine atoms with unsaturated organic compounds, 2) reactions of chlorine atoms with volatile organic compounds and 3) reactions of organic compounds involving NO2. Experiments employ 1) velocity map imaging with photoionization detection of radical intermediates and products and 2) product velocity and angular distribution measurements in molecular beam scattering apparatuses with either electron bombardment or tunable VUV ionization detection. The experiments are complemented by ab initio electronic structure calculations.
The motivations for the research are threefold: contributing to fundamental understanding of an important class of chemical reactions, providing challenging tests for theoretical calculations, and developing predictive models for atmospheric chemistry. High school students, undergraduates, graduate students and postdoctoral associates are actively involved in carrying out this research.