trans-Diaqua­bis­[5-carb­oxy-4-carboxyl­ato-2-(4-pyridinio)-1H-imidazol-1-ido-κ2 N 3,O 4]zinc(II)

Xia Li; Ling-Zhi Du; Ben-Lai Wu; Hong-Yun Zhang

doi:10.1107/S1600536810031855

. 2010 Aug 28;66(Pt 9):m1178–m1179. doi: 10.1107/S1600536810031855

trans-Diaquabis[5-carboxy-4-carboxylato-2-(4-pyridinio)-1H-imidazol-1-ido-κ² N ³,O ⁴]zinc(II)

Xia Li ^a,^*, Ling-Zhi Du ^a, Ben-Lai Wu ^b, Hong-Yun Zhang ^b

PMCID: PMC3007913 PMID: 21588565

Abstract

In the title complex, [Zn(C₁₀H₆N₃O₄)₂(H₂O)₂], the Zn^II atom is located on a twofold rotation axis and is coordinated by two trans-positioned N,O-bidentate and zwitterionic 5-carboxy-4-carboxylato-2-(4-pyridinio)-1H-imidazol-1-ide (H₂PIDC⁻) ligands and two water molecules, defining a distorted octahedral environment. The complete solid-state structure can be described as a three-dimensional supramolecular framework, stabilized by extensive hydrogen-bonding interactions involving the coordinated water molecules, uncoordinated imidazole N atom, protonated pyridine N and carboxylate O atoms of the H₂PIDC⁻ ligands.

Related literature

For related structures, see: Li, Liu et al. (2009 ▶); Li, Wu et al. (2009 ▶). For the preparation of 2-(pyridin-4-yl)-1H-imidazole-4,5-dicarboxylic acid, see: Sun et al. (2006 ▶).

Experimental

Crystal data

[Zn(C₁₀H₆N₃O₄)₂(H₂O)₂]
M _r = 565.76
Monoclinic,
a = 7.4138 (9) Å
b = 20.204 (3) Å
c = 13.4778 (17) Å
β = 97.008 (1)°
V = 2003.7 (4) Å³
Z = 4
Mo Kα radiation
μ = 1.31 mm⁻¹
T = 173 K
0.27 × 0.17 × 0.10 mm

Data collection

Rigaku Mercury CCD diffractometer
Absorption correction: multi-scan (CrystalClear; Rigaku, 2000 ▶) T _min = 0.754, T _max = 0.878
9235 measured reflections
2488 independent reflections
1957 reflections with I > 2σ(I)
R _int = 0.031

Refinement

R[F ² > 2σ(F ²)] = 0.031
wR(F ²) = 0.090
S = 1.04
2488 reflections
178 parameters
1 restraint
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.34 e Å⁻³
Δρ_min = −0.37 e Å⁻³

Data collection: CrystalClear (Rigaku, 2000 ▶); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810031855/jh2196sup1.cif

e-66-m1178-sup1.cif^{(18.3KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810031855/jh2196Isup2.hkl

e-66-m1178-Isup2.hkl^{(122.3KB, hkl)}

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

Table 1. Selected bond lengths (Å).

Zn1—O2	2.0713 (15)
Zn1—O1	2.1407 (18)
Zn1—N1	2.1592 (17)

Open in a new tab

Table 2. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1B⋯N2ⁱ	0.82 (3)	2.08 (3)	2.898 (3)	178 (3)
N3—H3⋯O5ⁱⁱ	0.88	1.89	2.755 (2)	169
O4—H4A⋯O3	0.89 (2)	1.58 (2)	2.459 (2)	173 (3)

Open in a new tab

Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

This work was supported by the National Natural Science Foundation of China (20771094, 20671083), the Science and Technology Key Task of Henan Province (0524270061) and the China Postdoctoral Science Foundation (20070410877).

supplementary crystallographic information

Comment

Multifunctional connector 2-(pyridin-4-yl)-1H-imidazole-4,5-dicarboxylate acid (H₃PIDC), a rigid N-heterocyclic carboxylate, has great potential for coordinative interactions and hydrogen bonding, showing more interesting traits in the construction of MOFs. It can be successively deprotonated to generate various species with different proton numbers, and hence may result in a large diversity of supramolecular architectures. Very recently, we have reported several supramolecular architectures (Li, Wu et al., 2009; Li, Liu et al., 2009) base on ligand 2-(pyridin-4-yl)-1H-imidazole-4,5-dicarboxylic acid. As an extension of our previous investigations, we have isolated a new Zn(II) complex, [Zn(H₂PIDC)₂(H₂O)₂], (I), by the reaction of H₃PIDC and Zn(II) diacetate under the hydrothermal condition. We report here the single-crystal structure of this complex.

As shown in Fig. 1, the molecule of (I) is a discrete neutral monomer, in which the Zn atom resides on a crystallographic inversion centre and the asymmetric unit contains one-half of the [Zn(H₂PIDC)₂(H₂O)₂] formula unit. Each Zn atom is six-coordinated by N₂O₄ with two chelating rings from two H₂PIDC ligands arranged symmetrically in the equatorial plane and two water molecules occupying the apical sites, showing a distorted octahedral geometry (Table 1). In this complex, one carboxyl group and imidazole group are deprotonated and the pyridyl group is protonated, and the ligand bears a formal charge of -1, and the uncoordinated carboxylate atoms O3 and O4 form an intramolecular hydrogen bond (Table 2). All non-H atoms in the imidazole-4,5-dicarboxyl group are nearly coplanar [the mean deviation is 0.075 (3) Å], and the dihedral angle between imidazole group and pyridine group is 11.4 (2) °.

A three-dimensional supramolecular network is constructed via hydrogen-bonding interactions involving the coordinated water molecules, uncoordinated imidazole N atom, protonated pyridine N and carboxylate O atoms of the H₂PIDC^- ligands (Table 2 and Fig. 2).

Experimental

A mixture of zinc diacetate dihydrate (0.022 g, 0.1 mmol), 2-(pyridin-4-yl)-1H-imidazole-4,5-dicarboxylic acid (0.024 g, 0.1 mmol) (Sun et al., 2006), NaOH (0.004 g, 0.1 mmol) and water (10 ml) was sealed into a Teflon-lined stainless autoclave and heated at 413 K for 3 days, then cooled to room temperature gradually and colourless block crystals of (I) were obtained. Analysis calculated for C₂₀H₁₆ZnN₆O₁₀: C 42.46, H 2.85, N 14.85; found: C 42.82, H 2.73, N 14.70.