CFM Lunch Seminar

Talk Title:  “Photochemical Upconversion: Past, Present, and Future Applications”

Transition metal-based photosensitizers are of significant value for promoting numerous light-activated processes and chemical transformations relying on excited state electron and energy transferreactions. Historically, the most extensively used inorganic photosensitizers have been confined to nd6 (n = 3, 4, or 5) electron configurations and their associated metal-to-ligand charge transfer (MLCT) excited states. This  presentation will discuss the unique and unexpected photochemistry and photophysics in several distinct transition-metal-containing photosensitizers derived from earth-abundant elements spanning the transition block. In some instances, ligand-to-metal charge transfer (LMCT) states dominate excited state decay, while long-lived MLCT excited states have been successfully engineered in others, and triplet ligand-centered excited states dominate in some instances. These designer earth-abundant chromophores have been implemented in a variety of photoactivation schemes harnessing photochemical upconversion to generate light, initiate free-radical polymerization chemistry, promote photoredox chemistry, and enable photocatalytic chemo-thermal energy storage schemes. Fundamental design principles, detailed static and time-resolved spectroscopic investigations, and representative examples illustrating these photo processes will be highlighted.

Castellano Bio:
Felix (Phil) N. Castellano earned a B.A. in Chemistry from Clark University in 1991 and a Ph.D. in Chemistry from Johns Hopkins University in 1996 with Jerry Meyer. Following an NIH Postdoctoral Fellowship at the University of Maryland, School of Medicine, with Joseph R. Lakowicz, he accepted a position as Assistant Professor at Bowling Green State University in 1998. He was promoted to Associate Professor in 2004, to Professor in 2006, and was appointed Director of the Center for Photochemical Sciences in 2011. In 2013, he moved his research program to North Carolina State University, where he is the Goodnight Innovation Distinguished Chair and Professor in the Department of Chemistry. He was appointed a Fellow of the Royal Society of Chemistry (FRSC) in 2015, earned the I-APS Award in Photochemistry in 2019, was elected an AAAS Fellow in 2020, and was recognized with the North Carolina American Chemical Society’s Lectureship Award in 2023. He is also the inaugural Editor-in-Chief of Chemical Physics Reviews, a peer-reviewed journal from AIP Publishing. His current research focuses on metal-organic chromophore photophysics and energy transfer, photochemical upconversion, thermally activated delayed photoluminescence processes, solar fuels photochemistry, electrocatalysis, photoredox catalysis, photochemical synthesis, ultrafast transient bond-making, and bond-breaking processes, excited state electron transfer, photochemical NMR spectroscopy, and NMR hyperpolarization phenomena.