Synthesis, structure and Hirshfeld surface analysis of pyridinium derivative crystals

Slow evaporation methods were employed to grow single crystals of 3-acetylpyridinium picrate (I), 4-acetylpyridinium picrate (II), and pyridin-4-ylmethanaminium 2,2-diphenylacetate hydrate (III). Crystal (I) and (III) crystallize triclinic crystal system with a centric (Pī) space group and (II) crystallize in a monoclinic system with a centric (P21/c) space group. Various types of non-covalent interactions take part successfully in the construction of 3D networks in the compounds. Optical reflectance measurements showed 2.57, 2.66, and 4.45 eV as band gaps for (I), (II) and (III) respectively. TG/DTA analysis reveals the thermal pattern of the compounds. Intermolecular interactions are quantified by Hirshfeld surface analysis.