LEAPS-MPS: Fluorous Photocatalysts for the Activation of Organic Compounds

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In this project, co-funded by the Directorate for Mathematical and Physical Sciences (MPS) and the Established Program to Stimulate Competitive Research (EPSCoR), and managed by the Chemistry Division, Professor Lorenzo Mosca and his students at the University of Rhode Island will perform studies to advance the applications of organic photocatalysts in functional group transformations and C–H bond activation of organic substrates. Efficient and robust photocatalysts will be needed to perform chemical transformations in greener, more economical ways. Such photocatalysts will be both resistant to photodegradation and amenable to easy recovery and purification. Professor Mosca and his students will design and synthesize fluorous photocatalysts with absorption spanning the visible and near-UV visible wavelength ranges, study the photophysical and electrochemical performance thereof in both fluorous and non-fluorous environments, and demonstrate their successful application in organic transformations. This research will generate new insights into the design of robust and recyclable photocatalysts for more efficient organic syntheses. Prof. Mosca and his students will perform outreach and provide mentorship to students in regional high schools serving underrepresented groups from urban and suburban neighborhoods, with a focus on engagement of the students with STEM disciplines and on improving retention rates in lower-level college classes. Professor Mosca and his research group will prepare and study fluorous organic photocatalysts with the goal of improving their resistance to photodegradation and photobleaching, increasing recovery of the intact photocatalyst from reaction mixtures, and lengthening the usable lifespan of the photocatalyst. Comprehensive photophysical and electrochemical characterization of the prepared photocatalysts will inform the design of successive generations of photocatalysts, enabling selective organic transformations. These studies will constitute a critical step in pursuing the selective tuning of catalytic activity in fluorous and non-fluorous phases, whereby competing reaction pathways can be enhanced or suppressed by using different reaction environments. Two commonly competing reaction pathways for an organic compound are photoredox reactions, involving reduction or oxidation of the substrate, and atom transfer reactions with no net charge generation, each with different reaction product outcomes. Prof. Mosca and his students will demonstrate the use of fluorous photocatalysts for the tuning of organic functional group transformations as well as C–H bond activation reactions by leveraging the properties of fluorous phases alone or in combination with traditional organic and aqueous phases.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.