Supramolecular salts of 5,7-dimethyl-1,8-naphthyridine-2-amine and acids through classical H-Bonds and other intermolecular interactions

Abstract This article demonstrates 5,7-dimethyl-1,8-naphthyridine-2-amine based organic salts formation of crystalline solids 1 – 9 , in which the acidic units have been integrated via a variety of non-covalent bonds. Addition of equivalents of the acidic units to the solution of 5,7-dimethyl-1,8-naphthyridine-2-amine generates the single protonated species which direct the anions. The nine compounds crystallize as their salts with the acidic H transferred to the aromatic N of the 5,7-dimethyl-1,8-naphthyridine-2-amine. In 2 , 3 , 4 , and 7 the methyl substituted N-rings were protonated, while others were protonated at the NH 2 substituted N-ring. All salts have been characterized via IR, mp, EA and XRD technique. The major driving force for the salt formation is attributed to the classical H-bonds from 5,7-dimethyl-1,8-naphthyridine-2-amine and the acids. Other extensive intermolecular interactions also play great functions in space association of the molecular assemblies in the relevant crystals. The common R 2 2 (8) graph set has been observed in all salts due to the H-bonds and other intermolecular interactions, except 2 , 4 , and 6 . For the synergistic interactions of the various non-covalent bonds, all salts displayed 3D structures.