Supramolecular assembly guided by photolytic redox cycling

Abstract

In living systems, the formation of structures relies on balancing kinetic and thermodynamic influences powered by reversible covalent bond chemistry. Although synthetic efforts have replicated these processes to some extent, elucidating their combination is necessary to identify mechanisms that confer nature’s structural precision and flexibility within a complex environment. Here we design a photolytic reaction cascade where competing redox pathways control the transience, interconversion and production rates of thiol/disulfide supramolecular monomers in situ. In contrast to direct assembly by dissolution, cascade generation of the same monomers formed hierarchical assemblies with different structural order. Redox-induced cycling between thiol–disulfide formation led to the emergence of new secondary structures and chirality within the final assemblies. These multiple structural states found within the same molecular system demonstrate the concept of assembly plasticity engaged frequently in biology. We demonstrate the importance of reaction complexity in controlling supramolecular propagation and in expanding the library of nanoarchitectures that can be created. [Figure not available: see fulltext.]