Calix[4]arenes with perfluorinated alcoholic functions at the upper rim: anew class of neutral anion receptors

Two or four perfluorinated alcoholic functions were successfully introduced at the upper rim of calix[4]arenes, affording a new type of neutral recept or for anion recognition; preliminary binding studies indicate that the dif unctionalized receptors 3a and 3b are selective for Y-shaped carboxylate io ns over spherical anions which are, on the contrary, more efficiently bound by the tetraalcohol 6.