Transmembrane halogen-bonding cascades.

Halogen bonds have recently been introduced as ideal to transport anions across lipid bilayer membranes. However, activities obtained with small transporters were not impressive, and cyclic arrays of strong halogen-bond donors above a calix[4]arene scaffold gave even weaker activities. Here, we report that their linear alignment for anion hopping along transmembrane rigid-rod scaffolds gives excellent activities with an unprecedented cooperativity coefficient m = 3.37.