Here, we report the determination of acidity constants of eight amino amides through the use of Nuclear Magnetic Resonance (NMR) to carry out the selective crystallization of diprotonated (a), monoprotonated (b), and neutral species (c) derived from these compounds. Crystallographic studies of compounds 2 a, 6 a, 7 a, 8 a, 2 b, 3 b, 6 b and 2 c revealed that the presence of substituents at the C8 and C10 positions determines the conformation of the molecule regardless of its degree of protonation. Although diprotonated species (a) have the same conformation and similar hydrogen bonding patterns, the supramolecular structures of these compounds are different. Furthermore, chloride ions and solvent molecules play an outstanding role in stabilizing the supramolecular structure of these compounds. This phenomenon restricts the π⋅⋅⋅π interactions between benzimidazole groups and consequently limits the possibility of aggregation in amino amides 1-8.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.