Tetrafluoroterephthalonitrile as an anion‐π donor: theoretical evaluation and application to anion recognition

The ability of perfluorinated terephthalonitrile to act as an anion‐π donor fragment in anion receptors is evaluated. New receptors combining an urea and a perfluorinated terephthalonitrile motif into a single architecture have been designed and synthesized. Their molecular recognition properties towards Cl$^−$ , Br$^−$ and I$^−$ , have been studied in solution by means of 1 H and 19 F NMR as well as photophysical experiments. A complementary electrospray ionization‐tandem mass spectrometry study confirmed the ranking of recognition properties between the receptors. A further theoretical evaluation of binding properties confirmed the association constant trend and suggests a main contribution of the urea motif weakly complemented by a η$^2$‐type anion‐π interaction.