Reversible Zn ²⁺ ‐Activated Channel Transport Through Monomer‐Dimer Interconversion of Rotaxane

Inspired by natural ligand-gated ion channels, artificial counterparts are of great interest for understanding biological transport mechanisms and developing bioinspired functional systems. Here, we report a Zn²⁺-activated artificial ion channel from a [2]rotaxane. Its key components are: i) a sliding bis(benzo-18-crown-6) unit for K⁺ transport and ii) a Zn²⁺-responsive terpyridine thread that provides gating control. The monomeric rotaxane functions as an inactive carrier, whereas Zn²⁺-induced dimerization triggers a switch to a highly efficient channel transport mode. This transition is fully reversible with Zn²⁺ and competitive ligands. As the first biomimetic Zn²⁺-gated artificial ion channel, this work provides a novel design strategy for ligand-regulated transmembrane transporters.