3-Amino-1H-pyrazol-2-ium trifluoroacetate

The asymmetric unit of the title salt, C3H6N3 +·C2F3O2 −, contains two independent 3-aminopyrazolium cations and two independent trifluoroacetate anions. The F atoms of both anions were refined as disordered over two sets of sites, with common occupancy ratios of 0.639 (12):0.361 (12). In the crystal, the cations and anions are linked via N—H⋯O hydrogen bonds, forming chains along [100] and [010].

TSY thanks the University of Mysore for research facilities and is also grateful to the Principal, Maharani's Science College for Women, Mysore, for giving permission to do research. JPJ acknowledges the NSF-MRI program (grant No. CHE-1039027) for funds to purchase the X-ray diffractometer.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: LH5637). Pyrazoles are an important class of heterocyclic compounds and many pyrazole derivatives are reported to have a broad spectrum of biological properties, e.g. antibacterial and anti-inflammatory activities (Patel et al., 2010), anticancer (Hall et al., 2008), antimicrobial (Samshuddin et al., 2010), anti-inflammatory, antidepressant, anticonvulsant and anti-HIV properties (Isloor et al., 2009). The chemistry of aminopyrazoles has been extensively investigated in the past (Giuseppe et al., 1991). The considerable biological and medicinal activities of pyrazoles (Vinogradov et al., 1994) for which aminopyrazoles are preferred precursors, have stimulated our investigations.
The asymmetric unit of the title compound consists of two crystallographically independent 3-aminopyrazolium cations (A and B) and two trifluoroacetate anions (A and B) (Fig. 1). Each 3-aminopyrazolium cation is planar, with a maximum deviation of 0.0006 (2) Å for atom N2A in cation A and 0.0005 (2) Å for atom N2B in cation B. In the cations, atoms N3A and N3B are protonated. The F atoms of both anions are disordered over two sets of positions, with occupancy ratios of 0.639 (12):0.361 (12). Bond lengths and are normal (Allen et al., 1987).

Experimental
A mixture of commercially available 3-aminopyrazole and trifluoroacetic acid (1:3 v/v) were stirred for 15 minutes at room temperature. X-ray quality crystals were formed on slow evaporation. (m.p.: 463-468 K).

Refinement
All H atoms were located in a difference Fourier map and refined independently with isotropic displacement parameters

Computing details
Data collection: CrysAlis PRO (Agilent, 2012); cell refinement: CrysAlis PRO (Agilent, 2012); data reduction: CrysAlis RED (Agilent, 2012); program(s) used to solve structure: SUPERFLIP (Palatinus & Chapuis, 2007); program(s) used to refine structure: SHELXL2012 (Sheldrick, 2008); molecular graphics: OLEX2 (Dolomanov et al., 2009); software used to prepare material for publication: OLEX2 (Dolomanov et al., 2009).  The asymmetric unit of the title compound. Displacement ellipsoids are drawn at the 30% probability level. All disorder components are shown. where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 0.24 e Å −3 Δρ min = −0.23 e Å −3 Special details Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.