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

• Published in: Acta crystallographica. Section E, Crystallographic communications Vol. 77; no. Pt 1; pp. 34 - 41
• Main Authors: Archana, Sreeramapura D, Kavitha, Channappa N, Yathirajan, Hemmige S, o, Sabine, Glidewell, Christopher
• Format: Journal Article
• Language: English
• Published: International Union of Crystallography 01.01.2021
• Subjects: Research Communications
• ISSN: 2056-9890; 2056-9890
• DOI: 10.1107/S2056989020015959

Co-crystallization from methanol of 3-amino-1H-pyrazole with 3,5-di-nitro-benzoic acid produces 3-amino-1H-pyrazol-2-ium 3,5-di-nitro-benzoate monohydrate, C3H6N3 +·C7H3N2O6 -·H2O, (I), while similar co-crystallization of this pyrazole with an equimolar qu-antity of fumaric acid produces bis-(3-amino-1H-pyrazol-2-ium) fumarate-fumaric acid (1/1), 2C3H6N3 +·C4H2O4 2-·C4H4O4, (II). The reaction of 3-amino-1H-pyrazole with a dilute solution of nitric acid in methanol yields a second, ortho-rhom-bic 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.