Templated synthesis of cyclic poly(ionic liquid)s

Charged cyclic polymers, e.g. cyclic DNAs and polypeptides , play enabling roles in organisms, but their synthesis was challenging due to the well-known “polyelectrolyte effect”. To tackle the challenge, we developed a templated method to synthesize a library of imidazolium and pyridinium based cyclic poly(ionic liquid)s. Cyclic templates, cyclic polyimidazole and poly(2-pyridine), were synthesized first through ring-closure method by light-induced Diels−Alder click reaction. Through quaternization of cyclic templates followed by anion metathesis, the cyclic poly(ionic liquid)s were synthesized, which paired with varied counter anions.