Corbin, Daniel Andreas, authorMiyake, Garret, advisorFinke, Richard, committee memberRappé, Anthony, committee memberKipper, Matt, committee member2022-05-302022-05-302022https://hdl.handle.net/10217/235285Organocatalyzed atom transfer radical polymerization (O-ATRP) is a controlled radical polymerization method employing organic photoredox catalysts to mediate the synthesis of well-defined polymers. The success of this method derives from its reversible-deactivation mechanism, where polymers are activated by reduction of a chain-end C-Br bond to generate a reactive radical for chain growth, followed by deactivation of the polymer by reinstallation of the dormant bromide chain-end group. As a result, the polymer chain can be grown by reaction of the polymer radical with alkene-based monomers, but undesirable termination and side reactions can be suppressed by minimization of the radical concentration through deactivation. In this work, key mechanistic steps of O-ATRP are investigated to understand the fundamental limitations of this method and improve upon them. When N,N-diaryl dihydrophenazines were investigated, side reactions were identified in which alkyl radicals add to the phenazine core, leading to new core-substituted PC derivatives with non-equivalent catalytic properties. Employing these core-substituted PCs in O-ATRP showed these side reactions can be eliminated to improve polymerization control. In addition, the deactivation step of O-ATRP and related intermediates were studied, which revealed new side reactions that can limit polymerization efficiency as well as influences on the rate of deactivation. Finally, methods to exert control over the deactivation process were developed as a means of improving polymerization outcomes in challenging systems. For example, the intermediate responsible for deactivation was isolated and added to a polymerization to increase the rate of deactivation and limit side reactions in O-ATRP. Alternatively, a similar outcome could be achieved through in-situ electrolysis to increase the concentration of the desired intermediate during the polymerization. Ultimately, this work has yielded insight into important mechanistic processes in O-ATRP that will continue to benefit the development of this method.born digitaldoctoral dissertationsengCopyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.catalysispersistent radicalpolymerizationO-ATRPATRPphotoredoxText