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.