Pyridine Lability and Its Implications for Uranyl Photocatalyst Candidates

Authors: Henry Eaton, Isadora Luce, Colin Clark, Claire Besson, John Swierk

Field of Study: Science, Technology, Engineering, and/or Math

Program Affiliation: Undergraduate Research Award (URA)

Faculty Mentors: John Swierk, Claire Besson

Easel: 4

Timeslot: Afternoon

Abstract: Photocatalysis, the study of light-driven reactions, may enable new organic transformations under mild conditions. However, photocatalysts tend to be composed of rare metals such as ruthenium and iridium; therefore, their cost remains a stumbling block. Uranyl photocatalysts offer an inexpensive alternative to existing photocatalyst metals and have been shown to be effective at cleaving and functionalizing C-H bonds through a direct hydrogen atom transfer mechanism. Here, we investigate the equatorial ligand dynamics in photocatalysts of the type UO2(acetylacetonate)2(R-pyridine), demonstrating that pyridine lability appears to be directly correlated with the photocatalytic dehydrogenation yield of 1-phenylethanol, a model reaction for uranyl photocatalysts. Pyridine ligand dynamics are quantified, and their implications for synthetic strategy, experimental design, and photocatalytic mechanism briefly discussed.