Syntheses of amide based anion receptors and investigation of their associations with anions and their molecular structures using proton NMR titration and DFT methods

The synthesized disubstituted isophthalamide and pyridine-2,6dicarboxamide derivatives of nine compounds were prepared. Their association constants with tetrabutylammonium fluoride (TBA·F), tetrabutylammonium chloride (TBA·Cl), tetrabutylammonium bromide (TBA·Br), tetrabutylammonium dihydrogenphosphate (TBA·H2PO4), tetrabutylammonium hydrogensulphate (TBA·HSO4) and tetrabutylammonium nitrate (TBA·NO3) were obtained by 1H NMR titration technique. The optimized structures of compounds 1–9 and their association with F−, Cl−, Br−, H 2 PO 4 - , HSO 4 - and NO 3 - were obtained using the B3LYP/6-31+G(d) method. The most favorable complex of compound 3 with Br− was found. The high association constants of complexes 1–6 with F− are expected. Associations of all receptors with anions are exothermic and spontaneous reactions. Thermodynamic properties of all associations obtained using B3LYP/6-31+G(d) method are reported.