Conformationally Flexible Cleft Receptor for Chloride Anion Transport

The design and synthesis of a cleft-shaped bis-diarylurea receptor for chloride anion transport is reported in this work. The receptor is based on the foldameric nature of N,N'-diphenylurea upon its dimethylation. The bis-diarylurea receptor exhibits a strong and selective affinity for chloride over bromide and iodide anions. A nanomolar quantity of the receptor efficiently transports the chloride across a lipid bilayer membrane as a 1:1 complex (EC₅₀ = 5.23 nm). The work demonstrates the utility of the N,N'-dimethyl-N,N'-diphenylurea scaffold in anion recognition and transport.