Oxacalix[2]arene[2]triazine based ion-pair transporters

Heteracalixaromatics are a new generation of macrocyclic hosts showing a unique structure and versatile recognition properties towards various guests. Amazingly, the application of heteracalixaromatics as membrane transporters or ion channels has never been explored. We reported herein the elaborated design of a series of oxacalix[2]arene[2]triazine-based derivatives 1–10 and their ion transport properties. Among these compounds, 3, 8–10 can mediate the transport of chloride across the lipid bilayer of EYPC with activity (EC₅₀) ranging from 0.43 to 8.23 μM. These compounds serve as ion carriers during the transport process, and the transport activity is both anion- and cation-dependent, suggesting a Cl⁻/M⁺ ion-pair transport model. Structure–activity studies indicate that hydrogen bonding, electron deficiency of the triazine rings, lipophilicity and macrocyclic frameworks are essential for ion transport.