Redox-Selective Macromolecular Electrolysis for Sequential Functionalization and Deconstruction

This study demonstrates that selective macromolecular electrolysis can be achieved on copolymers containing redox-orthogonal targets by controlling the externally applied voltage. We designed macromolecules containing phthalimide (E_1/2 = -1.8 V vs Ag/AgNO₃) and tetrachlorophthalimide (E_1/2 = -1.3 V vs Ag/AgNO₃) (meth)acrylates that have significantly different reduction potentials such that they are separately redox-addressable. The polymer-centered radicals generated by decarboxylation can either undergo (1) hydrogen atom transfer to form olefinic repeat units or (2) β-scission to deconstruct the polymer backbone. Our results reveal selective electrochemical control over postpolymerization modifications, which enables sequential transformations that tune the glass transition temperature of electrochemically generated copolymers over a range of -54 to 125 °C. This method was also shown to maintain its selectivity in a polymer blend and provided access to copolymers (poly(styrene-co-propylene-co-ethylene)) that would be challenging to prepare in other ways. These results demonstrate the potential of macromolecular electrolysis for selective material functionalization and degradation. This approach expands the toolbox for postpolymerization modification and targeted polymer degradation with applications in macromolecular information processing, spatiotemporal patterning, and producing materials with complex architectures that are driven by external stimuli.