Reversible helical polymerization of supramolecular toroidal objects

Although great efforts have been made to construct reversible helical supramolecular polymers through self-assembly, the hierarchical helical polymerization of toroidal objects still remains a challenge. Herein, we report that the toroidal architectures assembled from achiral dimeric macrocyclic building blocks are able to undergo reversible helical polymerization through spiral opening in response to heatingcooling cycles. In the presence of enantiomerically pure 2-butanol as a chiral regulator, the polymerization of achiral toroids generates helical polymers with a preferred handedness due to chirality transfer. Reversible helical polymerization of toroids with rapid response to heatingcooling cycles and helicity control in the presence of a chiral regulator.