Dynamic self-assembly mediated by stored and released electrons in pimer supramolecular polymers of chromophore amphiphiles

Abstract

Reversible self-assembly of supramolecular polymers plays a critical role in living systems, exemplified by the cell cytoskeleton. Analogous synthetic systems could be functional in the spatiotemporal control of chemical reactions, design of active matter, and energy storage for use on demand. We report an energy-storing supramolecular system that reversibly converts from small aggregates of molecules to supramolecular polymers. The aminonaphthalimide chromophore amphiphile monomer is conjugated to a methyl viologen moiety that converts energy from visible light, chemical fuels, an electrochemical bias, or X-rays to store electrons and trigger the formation of a polymeric pimer, accompanied by conversion from a solution to a hydrogel. Supramolecular polymerization is synergistically triggered by π-π stacking and π-radical pimerization that stores electrons in the assembly. These electrons can be released, generating reactive oxygen species, which proceed to oxidize an organic substrate in the absence of visible light, thus providing a model system for dark photocatalysis.