When
Presenter
Laura Sawyer
3rd Year Optical Sciences PhD Student - Huxter Lab, University of Arizona
Abstract
Over recent years, light-mediated catalysis has taken a front seat as a powerful strategy for the chemical activation of small molecules. The field of photocatalysis includes a wide range of potential activation pathways in which light is used to drive the catalytic process. Absorption of light brings the catalyst into an excited state, increasing the potential to undergo chemical transformation that would otherwise be difficult or even unattainable. Despite wide application in fields such as drug discovery, green chemistry and renewable chemistry, the mechanisms of photoredox catalysis remain poorly understood. Optical ultrafast spectroscopic techniques can be used to track processes central to photoredox catalysis such as charge transfer, intersystem crossing, and internal conversion.
By applying ultrafast optical techniques to photoredox catalytic systems, we can gain insight into its mechanisms by following the evolution of the catalytic excited state. Using time correlated single photon counting, transient absorption spectroscopy, and two-dimensional electronic spectroscopy, we can map the mechanisms of the photoredox catalysis, including the effects of excited state radicals, dimerization, and solvated electrons in photoredox catalysis cycles. In this seminar, the focus will be on Rhodamine 6G and its' history as a lasing medium and its' future as a photocatalyst.
Bio-sketch
Laura Sawyer is a 4th year PhD student in the College of Optical Sciences. She is part of Dr. Vanessa Huxter's Ultrafast Nonlinear Spectroscopy Group. As a non-arizona native, Laura completed her Bachelor's degree in Electrical Engineering at Western New England University. When not in the lab, she's assisting with optical science recruitment initiatives or driving out into the mountains to go hiking.