(582b) Advances in Organophotocatalysis: Reaction Mechanisms and Applications in Organic and Polymer Synthesis

Interest in photocatalysis for organic and polymer synthesis has grown significantly in recent years. While ruthenium and iridium complexes characterize by excellent photochemical and photophysical properties, organic dyes have been repeatedly reported as more accesible, greener, and versatile alternatives. We first discuss recent advances in the use of organic dyes as photocatalysts, centering on the variations in the photocatalytic reaction mechanisms, e.g. single-electron transfer (SET), proton-coupled electron transfer (PCET), 2e^-/H⁺ transfer and 2e^-/2H⁺ transfer, and on the complexity of linking photochemical and non-photochemical reaction steps. The main challenges for the implementation of organophotocatalysis at industrial scales, high irradiation doses and low yields, are highlighted as starting points to introduce our efforts to design reaction systems based on the particularities of each mechanism. A study of reaction times and yields for reactions induced by methylene blue, eosin Y, and Rose Bengal is presented to propose design criteria that maximize the yields with exposure times in the order of minutes. This mechanism-driven photoreactor design is presented for batch, semi-batch and continuous reaction systems, comparing quantum yields and light penetration. Finally, an outlook of the future of organophotoctalysis in organic and polymer chemistry is given to showcase the promising advantages and the challenges ahead to expand its use to a greater number of chemical processes.