Vanessa Huxter
Physical
Department of Chemistry and Biochemistry
University of Arizona
Description
Title: Photophysics of Photocatalytic and Radical Systems
Abstract: Photoredox catalysis has enabled researchers to overcome previously intractable problems in organic synthesis. The use of light to drive catalysis has allowed for more selective reactions that generate both simple and complex molecules from renewable and economical starting materials under mild conditions. The dynamics of these catalysts following photoexcitation determines their efficiency. A direct time-resolved photophysical view of reactions is essential to construct the full kinetic scheme, observe the intermediates, and thereby link dynamics to structure. Through the use of ultrafast broadband transient absorption and two-dimensional electronic spectroscopy across a wide range of time and energy scales, the Huxter group studies photoinduced single-electron transfer and electronic dynamics in photoredox catalytic and radical systems. These studies have revealed complex mechanisms of photoredox catalytic reactions, including the involvement of reduced solvent as intermediates, multiple photoproducts as well as many productive and unproductive pathways. Experiments on neutral radical tripyrrindione systems with tunable redox-active chemistry have demonstrated controllable spin states, reversible antiferromagnetic coupling, and spin-dependent electronic relaxation.