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.

Sreeramapura D Archana,Hemmige S Yathirajan,Sabine Foro,Channappa N Kavitha,Christopher Glidewell

doi:10.1107/s2056989020015959

Sreeramapura D Archana, Hemmige S Yathirajan + Show 3 more

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https://doi.org/10.1107/s2056989020015959

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Abstract

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.

Highlights

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+ÁC7H3N2O6ÀÁH2O, (I), while similar co-crystallization of this pyrazole with an equimolar quantity of fumaric acid produces bis(3-amino-1Hpyrazol-2-ium) fumarate–fumaric acid (1/1), 2C3H6N3+ÁC4H2O42ÀÁC4H4O4, (II)
In each of (I) and (II), an extensive series of O—HÁ Á ÁO and N—HÁ Á ÁO hydrogen bonds links the components into complex sheets, while in the structure of (III), the ions are linked by multiple N—HÁ Á ÁO hydrogen bonds into a threedimensional arrangement
As part of a general study of novel pyrazole derivatives (Asma et al, 2018; Kiran Kumar et al, 2020; Shaibah et al, 2020a,b; Shreekanth et al, 2020), we have synthesized two organic salts derived from 3-amino-1Hpyrazole, namely 3-amino-1-pyrazol-2-ium 3,5-dinitrobenzoate monohydrate (I) (Fig. 1 and Scheme) and bis(3-amino-1pyrazol-2-ium) fumarate fumaric acid (II) (Fig. 2), whose molecular and supramolecular structures are reported here

Summary

Chemical context

Pyrazoles exhibit a very wide range of pharmacological and other biological activities, which have recently been extensively reviewed (Ansari et al, 2017; Karrouchi et al, 2018). As part of a general study of novel pyrazole derivatives (Asma et al, 2018; Kiran Kumar et al, 2020; Shaibah et al, 2020a,b; Shreekanth et al, 2020), we have synthesized two organic salts derived from 3-amino-1Hpyrazole, namely 3-amino-1-pyrazol-2-ium 3,5-dinitrobenzoate monohydrate (I) (Fig. 1 and Scheme) and bis(3-amino-1pyrazol-2-ium) fumarate fumaric acid (II) (Fig. 2), whose molecular and supramolecular structures are reported here. We have isolated a second polymorph of 3-amino-1-pyrazol-2-ium nitrate (III). When crystallized from methanol, this compound forms an orthorhombic polymorph in space group Pna; a monoclinic polymorph in space group P21/c, isolated from aqueous solution has recently been reported (Yamuna et al, 2020). E77, 34–41 discuss the molecular and supramolecular structures of both polymorphs of the nitrate salt

Structural commentary

Supramolecular features

Synthesis and crystallization

Database survey

Refinement