Chain Motifs of Acid Molecules Formed by Symmetric O···H···O and Asymmetric O–H···O Hydrogen Bonds for Salts of Miconazole with Isomeric Pyridinedicarboxylic Acids

Single-crystal X-ray structures of four new salts of miconazole with isomeric pyridine-2,n-dicarboxylic acids (n = 3, 4, 5, 6) are described. These structures exhibit chain substructures formed by acid molecules, highlighting their role as favorable motifs in the supramolecular architectures of multicomponent crystals. Symmetric O···H···O hydrogen bonds drive the formation of unique polymeric chain motifs, whereas asymmetric O–H···O hydrogen bonds generate common monoperiodic supramolecular chains. Both types of interactions are characterized using the quantum theory of atoms in molecules (QTAIM) approach. The QTAIM analysis reveals significant differences in the properties of these two types of hydrogen bonds, indicating that symmetric hydrogen bonds are significantly stronger and more covalent in nature than asymmetric ones. Furthermore, for molecular pairs extracted from polymeric chain substructures, DFT calculations are employed to describe the proton-transfer profile and rationalize the formation of symmetric interactions in the solid state.