Structure determination and Hirshfeld surface analysis of new cocrystal and salt forms of 5-aminotetrazole with hydroxy- and nitro-substituted carboxylic acids

Abstract

Two new crystalline solids, namely, 5-aminotetrazole–3,5-dihydroxybenzoic acid–water (1/4/6), CH3N5·4C7H6O4·6H2O (I), and 5-aminotetrazolium 3,5-dinitrosalicylate, CH4N5 +·C7H3N2O7 − (II), have been synthesized and characterized by single-crystal X-ray diffraction and Hirshfeld surface analysis. The crystal packing arrangements of I and II are governed by N—H...O and O—H...O hydrogen-bonding interactions. In cocrystal I, adjacent acid molecules are linked through O—H...O hydrogen bonds, forming a dimer with an R 2 2(8) motif. In salt II, the tetrazolium cation and acid anion are linked through N—H...O hydrogen bonds to also form a dimer with an R 2 2(8) motif. Further N—H...O and O—H...O hydrogen bonds help to stabilize the crystal packing, along with aromatic π–π stacking interactions in I and carbonyl...π interactions in II. The Hirshfeld surface analysis and fingerprint plots reveal that O...H/H...O interactions contribute 34.4% of the total interactions in the crystal packing of cocrystal I and 36.7% in salt II.

Pharmaceutical Properties of the Phloretin–4,4′-Bipyridine Cocrystal: Structure Analysis, Drug Release Profile, and Antioxidant Activity Research

“…The Hirshfeld surface of the cocrystal could be analyzed to observe the interaction between the components in the cocrystal more clearly. , According to the space occupied by molecules in the crystal, the surface of Hirshfeld divides different molecular fragments according to the electron density of the crystal and then analyzes the intermolecular interaction force and visualizes the types and regions of intermolecular contact in the crystal. The Hirshfeld surface of the cocrystal and the corresponding two-dimensional fingerprint were generated by CrystalExplorer 21.5. d i and d e respectively represent the closest distance between the atoms inside the surface and the closest distance between the atoms outside the surface, while d norm measures the contact distance between molecules in the corresponding region .…”