NMR, FTIR and DFT study of the interaction of the benzoate anion with meso-octamethylcalix[4]pyrrole

► Benzoate anion forms a strong complex with meso-octamethylcalix[4]pyrrole. ► The anion is symmetrically bound by two pairs of hydrogen bonds to oxygens. ► The bound anion is prone to fast exchange with a free anion of the same kind.