Novel Salts of Heterocyclic Polyamines and 5-Sulfosalicylic Acid: Synthesis, Crystal Structure, and Hierarchical Supramolecular Interactions

Abstract

A series of novel salts of heterocyclic polyamines with 5-sulfosalicylic acid (C4H7N4+)(C7H5O6S−)∙2(H2O) (1), (C4H6ClN4+)(C7H5O6S−)∙H2O (2), (C5H8N3+)(C7H5O6S−)∙H2O (3), (C5H7N6+)(C7H5O6S−)∙H2O (4), (C6H14N22+)(C7H4O6S2−)∙H2O (5), and (C14H19N2+)(C7H5O6S−) (6) have been successfully synthesized. Their crystal structures have been determined by single-crystal X-ray diffraction. Overall, compounds adopt a layered structure with aminium cations and 5-sulfosalicylic anions linked via water molecules. The solid-state architectures of these compounds are dominated by O(N,H)-H⋯O and N-H⋯N hydrogen bonds and stabilized by weak interconnects. C-Cl⋯π and S-O⋯π interactions, apart from π⋯π and C-H(O)⋯π, were reported. Diverse approaches were used to study the effect of substituents in the polyamines in solid-state arrangement. A Hirshfeld surface analysis, with associated 3D Hirshfeld surface maps and 2D fingerprint plots, molecular electrostatic potential, and energy frameworks were used to comprehensively investigate the nature and hierarchy of non-covalent interactions and inspect supramolecular differences. The contact enrichment ratio calculations provided deeper insight into the propensity of interconnects to influence crystal packing. The evaluation of the effects of H-bonding synthons resulting from different substituents in the polyamines on self-assemblies is also presented. In the context of crystal engineering, a specific intramolecular synthon via O-H⋯O observed in nearly all crystals can be employed in the pseudo-cyclic replacement strategy in the design of new molecules.