Helically foldable diphenylureas as anion receptors: Modulation of the binding affinity by the chain length

Article abstract of DOI:10.1021/ol302266w

Using a series of diphenylureas capable of folding to helical conformations, the binding trends have been compared between two anions of different sizes, chloride and sulfate. The binding constant for the sulfate ion steadily increases from monomer to pen