High-Performance Artificial Lithium Channel Enabled by a Brominated Organic Imine Cage

Despite extensive advancements in the design of artificial transporters for K⁺, Cl^- and water, the development of Li⁺-selective systems has remained comparatively neglected, largely due to its smaller ionic radius and higher hydration energy that pose significant design challenges. To date, only three classes of artificial Li⁺ transporters have been reported. In this work, we introduce a novel fourth class of artificial Li⁺ channels, constructed from unique self-assembling organic imine cages that form membrane-spanning porous architectures. By incorporating bromine substituents, the resulting channel exhibits not only the highest Li⁺ transport activity (EC₅₀ of 0.017 mol‰, relative to lipids) but also unprecedented selectivity, with Li⁺/Na⁺ and Li⁺/K⁺ selectivity factors of 44 and 52 respectively, marking a new benchmark in transmembrane Li⁺ transport performance.