A Chemistry Departmental Seminar featuring Phil Castellano (NCSU)

Transition metal-based photosensitizers are of significant value for promoting numerous light-activated processes and chemical transformations relying on excited state electron and energy transfer reactions. 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 photophysics discovered in several distinct transition-metal-containing photosensitizers derived from the earth-abundant metal ions Cu(I) and Cr(III). Cu(I)-based MLCT excited states, as well as intramolecularly sensitized ligand-field excited states in light-harvesting Cr(III) chromophores, will be described. The ultrafast dynamics of these novel chromophores probed in the UV, Vis, and near-IR, along with conventional static, dynamic, and temperature-dependent photoluminescence spectroscopy, will also be detailed.