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An alternative synthetic route towards the widely employed electroactive poly(TEMPO methacrylate) (PTMA) via a thermally robust methoxyamine-protecting group is demonstrated herein. Protection of the radical moiety of hydroxy-TEMPO with a methyl functionality and subsequent esterification with methacrylic anhydride allows the high-yielding formation of the novel monomer methyl-TEMPO methacrylate (MTMA). The polymerization of MTMA to poly(MTMA) (PMTMA) is investigated via free radical polymerization and reversible addition–fragmentation chain-transfer polymerization (RAFT), a reversible-deactivation radical polymerization technique. Cleavage of the temperature-stable methoxyamine functionality by oxidative treatment of PMTMA with meta-chloroperbenzoic acid (mCPBA) releases the electroactive PTMA. The redox activity of PTMA was confirmed by cyclic voltammetry in lithium-ion coin cells.

This thesis investigated the development of novel nitroxide radical polymer materials for imaging and energy storage applications. Profluorescent redox-responsive polymers were prepared which displayed enhanced sensitivity and extended observation times over conventional small-molecule probes. Furthermore, the application of nitroxide radical polymers as energy storage materials was explored. For this purpose, an improved synthetic methodology for such materials is presented. Finally, a novel organic high-voltage electroactive material was developed and successfully demonstrated in lithium-ion battery prototypes.

Profluorescent nitroxides (PFNs) have emerged as an important class of imaging agents for monitoring intracellular redox status and levels of oxidative stress. However, the fast reduction of nitroxides upon incubation within cells limits the window of opportunity for detection. By increasing the concentration of nitroxides per fluorophore, their reduction to the corresponding hydroxylamines and the subsequent switch-on of fluorescence can be delayed. Herein the preparation of nitroxide-containing polymers of different chain length coupled to a fluorophore is reported and their reduction with pentafluorophenylhydrazine is examined. The fluorescence switch-on kinetics and radical concentrations are monitored by fluorescence and electron paramagnetic resonance spectroscopy and compared to a conventional PFN bearing a single nitroxide moiety. The polymeric PFNs display significant delays in reduction and fluorescence switch-on and higher turn-on ratios than their single-nitroxide counterparts. The results of this study indicate that polymeric PFNs are a promising architecture for future imaging agents.