Naphthochromenones: Organic Bimodal Photocatalysts Engaging in Both Oxidative and Reductive Quenching Processes

Twelve naphthochromenone photocatalysts (PCs)were synthesized on gram scale. They absorb across the UV/Visrange and feature an extremely wide redox window (up to3.22 eV) that is accessible using simple visible light irradiationsources (CFL or LED). Their excited-state redox potentials,PC*/PCC(up to 1.65 V) and PCC+/PC* (up to1.77 V vs.SCE), are such that these novel PCs can engage in bothoxidative and reductive quenching mechanisms with strongthermodynamic requirements. The potential of these bimodalPCs was benchmarked in synthetically relevant photocatalyticprocesses with extreme thermodynamic requirements. Theirability to efficiently catalyze mechanistically opposite oxida-tive/reductive photoreactions is a unique feature of theseorganic photocatalysts, thus representing a decisive advancetowards generality, sustainability, and cost efficiency in photo-catalysis.