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

T S Yamuna; Jerry P Jasinski; Derek R Scadova; H S Yathirajan; Manpreet Kaur

doi:10.1107/S1600536813022204

. 2013 Aug 14;69(Pt 9):o1425–o1426. doi: 10.1107/S1600536813022204

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

T S Yamuna ^a, Jerry P Jasinski ^b,^*, Derek R Scadova ^b, H S Yathirajan ^a, Manpreet Kaur ^a

PMCID: PMC3884487 PMID: 24427058

Abstract

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].

Related literature

For biological properties of pyrazole derivatives, see: Hall et al. (2008 ▶); Isloor et al. (2009 ▶); Patel et al. (2010 ▶); Samshuddin et al. (2010 ▶). For the chemistry of aminopyrazoles, see: Giuseppe et al. (1991 ▶). For the medicinal activity of pyrazoles, see: Vinogradov et al. (1994 ▶). For related structures, see: Dobson & Gerkin (1998 ▶); Foces-Foces et al. (1996 ▶); Hemamalini & Fun (2010 ▶); Thanigaimani et al. (2012 ▶). For hydrogen-bond graph-set motifs, see: Bernstein et al. (1995 ▶). For standard bond lengths, see: Allen et al. (1987 ▶). graphic file with name e-69-o1425-scheme1.jpg

Experimental

Crystal data

C₃H₆N₃ ⁺·C₂F₃O₂ ⁻
M _r = 197.13
Monoclinic,
a = 10.9292 (8) Å
b = 10.9332 (6) Å
c = 13.7002 (13) Å
β = 107.939 (9)°
V = 1557.5 (2) Å³
Z = 8
Cu Kα radiation
μ = 1.58 mm⁻¹
T = 173 K
0.16 × 0.14 × 0.06 mm

Data collection

Agilent Xcalibur (Eos, Gemini) diffractometer
Absorption correction: multi-scan (CrysAlis PRO and CrysAlis RED; Agilent, 2012 ▶) T _min = 0.662, T _max = 1.000
9227 measured reflections
3031 independent reflections
2343 reflections with I > 2σ(I)
R _int = 0.030

Refinement

R[F ² > 2σ(F ²)] = 0.048
wR(F ²) = 0.136
S = 1.05
3031 reflections
338 parameters
All H-atom parameters refined
Δρ_max = 0.24 e Å⁻³
Δρ_min = −0.23 e Å⁻³

Data collection: CrysAlis PRO (Agilent, 2012 ▶); cell refinement: CrysAlis PRO; 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.

Supplementary Material

Crystal structure: contains datablock(s) I. DOI: 10.1107/S1600536813022204/lh5637sup1.cif

e-69-o1425-sup1.cif^{(27.8KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536813022204/lh5637Isup2.hkl

e-69-o1425-Isup2.hkl^{(166.5KB, hkl)}

Click here for additional data file.^{(3.3KB, cml)}

Supplementary material file. DOI: 10.1107/S1600536813022204/lh5637Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1A—H1AA⋯O1A ⁱ	0.85 (3)	2.28 (3)	2.936 (3)	134 (2)
N1A—H1AB⋯O2A ⁱⁱ	0.91 (3)	1.99 (3)	2.884 (3)	169 (3)
N2A—H2AA⋯O1A ⁱⁱ	0.94 (3)	1.85 (3)	2.778 (2)	171 (3)
N3A—H3AA⋯O2A	0.93 (3)	1.78 (3)	2.705 (2)	172 (3)
N1B—H1BA⋯O2B ⁱⁱⁱ	0.84 (3)	2.18 (3)	2.962 (2)	153 (2)
N1B—H1BB⋯O2B ^iv	0.90 (3)	2.03 (3)	2.929 (3)	173 (2)
N2B—H2BA⋯O1B ^iv	0.95 (3)	1.81 (3)	2.756 (2)	174 (2)
N3B—H3BA⋯O1B ^v	0.91 (3)	1.82 (3)	2.728 (2)	171 (2)

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) ; (v) .

Acknowledgments

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 crystallographic information

1. Comment

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 crystal structures of some related compounds, viz., 3-aminopyrazole-4-carboxylic acid (Dobson & Gerkin, 1998), 4-(3,5-dimethylpyrazol-1-yl)benzoic acid trifluoroacetate (Foces-Foces et al., 1996), 2-amino-5-methylpyridinium trifluoroacetate (Thanigaimani et al., 2012) and 2-amino-5-chloropyridinium trifluoroacetate (Hemamalini & Fun, 2010) have been reported. In view of the importance of the title compound this paper reports its crystal structure.

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).

In the crystal packing (Fig. 2), the A/B type 3-aminopyrazolium cations interact with the carboxylate groups of the A/B type trifluoroacetate anions through N—H···O hydrogen bonds, forming R₂²(8), R₂⁴(8), R₂⁴(10), R₄⁴(16) and R₄⁴(18) (Bernstein et al., 1995) ring motifs.

2. 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).