Stoichiometric and polymorphic salt of imidazolium picrate monohydrate

Abstract

The asymmetric unit of the title co-crystal salt, 1H-imidazol-3-ium 2,4,6-trinitrophenolate monohydrate, C 4 H 7 N 2 + ÁC 6 H 2 N 3 O 7 À ÁH 2 O, contains one imidazolium cation, one picrate anion and one solvent water molecule of crystallization. The phenolic proton has been transferred to an imidazole N atom. In the crystal, the components are linked by N-HÁ Á ÁO and O-HÁ Á ÁO hydrogen bonds into a three-dimensional network which is further consolidated by weak C-HÁ Á ÁO hydrogen bonds. In addition, -stacking interactions occur between pairs of imidazolium cations and picrate anions. If only the classical N-HÁ Á ÁO and O-HÁ Á ÁO hydrogen bonds are considered, the component ions are linked into a three-dimensional threefold interpenetrating network of the topological type utp [or (10,3)-d]. Hirshfeld surface analysis indicates the crystal structure is mainly stabilized by HÁ Á ÁÁO contacts of the hydrogen bonds.