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. Using ultrafast broadband time-resolved spectroscopy, 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. In addition, our experiments on neutral radical transition metal tripyrrindione systems with tunable redox-active chemistry have demonstrated controllable spin states, reversible antiferromagnetic coupling, and spin-dependent electronic relaxation.