Simple Iron Halides Enable Electrochemically Mediated ATRP in Nonpolar Media

An electrochemicallycontrolledatomtransferradicalpolymerization(eATRP) was successfully carriedout with a minimal amount (ppm-level) of FeBr3 catalyst in a nonpolar solvent, specifically anisole.Traditionally,nonpolar media have been advantageous for Fe-based ATRP, but their low conductivity has hindered any electrochemical application.This study introduces the application of electrocatalytic methods in a highly nonpolar polymerization medium. Precise control over the polymerization was obtained by employing anhydrous anisole with only 400 ppm of FeBr3 and applying a negative overpotential of 0.3 V. Additionally, employing an undivided cell setup with two simple iron wire electrodes resulted in a significant 15-fold reduction in electrical resistance compared to traditional divided cell setups.This enabled the production of polymers with a dispersity of ≤1.2. Lastly, an examination of kinetic and thermodynamic aspects indicated that the ppm-level catalysis was facilitated by the high ATRP equilibrium constant of Fe catalysts in nonpolar environments.