Two 3-amino-1H-pyrazol-2-ium salts containing organic anions, and an orthorhombic polymorph of 3-amino-1H-pyrazol-2-ium nitrate

Co-crystallization from methanol of 3-amino-1H-pyrazole with 3,5-di­nitro­benzoic acid produces 3-amino-1H-pyrazol-2-ium 3,5-di­nitro­benzoate monohydrate, C3H6N3+·C7H3N2O6−·H2O, (I), while similar co-crystallization of this pyrazole with an equimolar qu­antity of fumaric acid produces bis­(3-amino-1H-pyrazol-2-ium) fumarate–fumaric acid (1/1), 2C3H6N3+·C4H2O42−·C4H4O4, (II). The reaction of 3-amino-1H-pyrazole with a dilute solution of nitric acid in methanol yields a second, ortho­rhom­bic polymorph of 3-amino-1H-pyrazol-2-ium nitrate, C3H6N3+·NO3−, (III). In each of (I)–(III), the bond distances in the cation provide evidence for extensive delocalization of the positive charge. In each of (I) and (II), an extensive series of O—H⋯O and N—H⋯O hydrogen bonds links the components into complex sheets, while in the structure of (III), the ions are linked by multiple N—H⋯O hydrogen bonds into a three-dimensional arrangement. Comparisons are made with the structures of some related compounds.