Piperazine-1,4-diium bis­(2-carb­oxy-1H-pyrazole-4-carboxyl­ate) tetra­hydrate

Xin-Hui Zhou

doi:10.1107/S160053681003655X

. 2010 Sep 18;66(Pt 10):o2578. doi: 10.1107/S160053681003655X

Piperazine-1,4-diium bis(2-carboxy-1H-pyrazole-4-carboxylate) tetrahydrate

Xin-Hui Zhou ^a,^*

PMCID: PMC2983173 PMID: 21587560

Abstract

The asymmetric unit of the title compound, C₄H₁₂N₂ ²⁺·2C₅H₃N₂O₄ ⁻·4H₂O, comprises one-half of a piperazine-1,4-diium cation, which lies on an inversion centre, a 2-carboxy-1H-pyrazole-4-carboxylate anion and two water molecules. An extensive network of intermolecular O—H⋯O, N—H⋯O, N—H⋯N and C—H⋯O hydrogen bonds between the cations, anions and water molecules leads to a three-dimensional supramolecular framework.

Related literature

For 3,5-pyrazoledicarboxylic acid, see: King et al. (2003 ▶); Pan et al. (2001 ▶). For reference structural data, see: Li & Su (2007 ▶); Reviriego et al. (2006 ▶).

Experimental

Crystal data

C₄H₁₂N₂·2C₅H₃N₂O₄·4H₂O
M _r = 470.41
Monoclinic,
a = 8.3363 (13) Å
b = 16.246 (3) Å
c = 7.3930 (11) Å
β = 90.812 (3)°
V = 1001.2 (3) Å³
Z = 2
Mo Kα radiation
μ = 0.14 mm⁻¹
T = 291 K
0.15 × 0.14 × 0.12 mm

Data collection

Bruker SMART APEX CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2000 ▶) T _min = 0.980, T _max = 0.984
5265 measured reflections
1946 independent reflections
1524 reflections with I > 2σ(I)
R _int = 0.051

Refinement

R[F ² > 2σ(F ²)] = 0.059
wR(F ²) = 0.147
S = 1.10
1946 reflections
169 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.41 e Å⁻³
Δρ_min = −0.23 e Å⁻³

Data collection: SMART (Bruker, 2000 ▶); cell refinement: SAINT (Bruker, 2000 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: DIAMOND (Brandenburg, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S160053681003655X/om2361sup1.cif

e-66-o2578-sup1.cif^{(15.2KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S160053681003655X/om2361Isup2.hkl

e-66-o2578-Isup2.hkl^{(95.8KB, hkl)}

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
N1—H1⋯O5ⁱ	0.84 (3)	1.93 (3)	2.746 (3)	167 (3)
O2—H2⋯O4ⁱⁱ	0.87 (3)	1.65 (3)	2.520 (2)	175 (3)
N3—H3A⋯O4	0.88 (3)	2.36 (3)	2.918 (3)	121 (2)
N3—H3A⋯N2	0.88 (3)	2.01 (3)	2.865 (3)	162 (3)
N3—H3B⋯O3ⁱⁱⁱ	0.88 (3)	2.20 (3)	2.999 (3)	150 (3)
O5—H5B⋯O6	0.85 (4)	2.00 (4)	2.831 (3)	166 (3)
O5—H5A⋯O6^iv	0.92 (4)	1.96 (4)	2.833 (3)	157 (3)
O6—H6C⋯O3^v	0.93 (3)	1.85 (3)	2.779 (3)	173 (3)
O6—H6D⋯O3^vi	0.76 (3)	2.14 (3)	2.858 (3)	158 (4)
C6—H6B⋯O5^vii	0.97	2.53	3.348 (4)	142
C7—H7A⋯O1^viii	0.97	2.53	3.091 (3)	117

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

Acknowledgments

This research was supported financially by Nanjing University of Posts and Telecommunications (grant No. NY209032).

supplementary crystallographic information

Comment

Hydrogen bonding, as the strongest and most directional intermolecular force, has been intensively investigated in organic crystalline solids. The ligand, 3,5-pyrazoledicarboxylic acid, known both as a multiple proton donor and acceptor, has six potential hydrogen-bond sites involving both the nitrogen atoms of the pyrazole ring and all of the carboxylate O atoms. and it can form mono-, di- and trianionic ligand species through deprotonation (King et al. 2003; Pan et al. 2001).

We report here the synthesis and structure of piperazine-1,4-diium bis(2-carboxy-1H-pyrazole-4-carboxylate) tetrahydrate, as shown in Fig.1, which was obtained from a solution of 3,5-pyrazoledicarboxylic acid, Cd(NO₃)₂.4H₂O and piperazine. Bond distances and angles are normal (Li & Su, 2007; Reviriego et al. 2006). The asymmetric unit of the title compound comprises one half of the piperazine-1,4-diium cation, which lies about an inversion centre, a 2-carboxy-1H-pyrazole-4-carboxylate anion and two water molecules. In the crystal structure molecules are interlinked by hydrogen bonds (Table 1 and Fig. 2). The 2-carboxy-1H-pyrazole-4-carboxylate anoins are interconnected with each other through the O2—H2···O4ⁱⁱⁱ hydrogen bonds. The 2-carboxy-1H-pyrazole-4-carboxylate anions are connected with the piperazine-1,4-diium cations through the N3—H3A···O4, N3—H3A···N2, N3—H3B···O3^iv and C7—H7A···O1^viii hydrogen bonds to form the three-dimensional supramolecular framework.

Experimental

A mixture of 3,5-pyrazoledicarboxylic acid (0.2 mmol, 34.8 mg), Cd(NO₃)₂.4H₂O (0.1 mmol, 30.8 mg), piperazine (0.2 mmol, 17.2 mg) and H₂O (8 ml) was sealed in a 15 ml Teflon-lined bomb and heated at 150°C for 5 days. The reaction mixture was slowly cooled to room temperature to obtain the colorless block crystals of (I) suitable for X-ray diffraction analysis.