Fluorinated leaning pillar[6]arene: synthesis, structure and selective iodide anion binding by anion-π interactions.

Anion recognition has continuously attracted significant attention due to its important role in environmental and biological sciences. Here, we have designed and synthesized an electron-deficient fluorinated leaning pillar[6]arene 1 that contains two tetrafluoro-benzene units. The electron-deficient fluorinated leaning pillar[6]arene 1 is capable of selectively recognizing iodide anions to form a host-guest complex with 1 : 1 stoichiometry driven by anion-π interactions. Our work ascribes this selective recognition to the preorganization of macrocycles, suitable cavity size, and the effect of anion-π interactions. The innovative application of this macrocycle offers us a new avenue for the design of selective receptors for anions and electron-deficient macrocyclic arenes.