Poly[[aqua-μ6-benzene-1,2,3-tricarboxyl­ato-μ3-hydroxido-dizinc] hemihydrate]

Chao-Hong Ma; Qiang Liu; Xiu-Yan Wang; Xian-Wu Dong; Yu-Jie Li

doi:10.1107/S1600536811055358

. 2012 Jan 7;68(Pt 2):m103–m104. doi: 10.1107/S1600536811055358

Poly[[aqua-μ₆-benzene-1,2,3-tricarboxylato-μ₃-hydroxido-dizinc] hemihydrate]

Chao-Hong Ma ^a, Qiang Liu ^a, Xiu-Yan Wang ^a, Xian-Wu Dong ^a, Yu-Jie Li ^a,^*

PMCID: PMC3274850 PMID: 22346797

Abstract

In the title compound, {[Zn₂(C₉H₃O₆)(OH)(H₂O)]·0.5H₂O}_n, there are three independent Zn^II atoms present; two are located on special positions, viz a twofold rotation axis and an inversion centre, and the third is located in a general position. The Zn^II atom on the inversion centre is six-coordinated by four O atoms from four different benzene-1,2,3-tricarboxylate anions and two OH⁻ anions. The Zn^II atom located on a twofold axis is four coordinated by two O atoms from two different benzene-1,2,3-tricarboxylate anions and two OH⁻ anions. The third Zn^II atom, located in a general position, is five coordinated by three O atoms from three different benzene-1,2,3-tricarboxylate anions, one OH⁻ anion and one water molecule. Each benzene-1,2,3-tricarboxylate anion bridges six Zn^II atoms, and the OH⁻ anion bridges three Zn^II atoms, resulting in the formation of a three-dimensional framework. A series of O—H⋯O hydrogen bonds involving the benzene-1,2,3-tricarboxylate anions, the OH⁻ anion and the coordinating and the two water solvent molecules further stablize the crystal structure. The two solvent water molecules show occupancies of 0.5 and 0.25.

Related literature

For complexes of benzene tricarboxylic acids, see: Chui et al. (1999 ▶); Majumder et al. (2005 ▶). For related structures, see: Wu et al. (2009 ▶).

Experimental

Crystal data

[Zn₂(C₉H₃O₆)(OH)(H₂O)]·0.5H₂O
M _r = 381.89
Tetragonal,
a = 12.8412 (2) Å
c = 27.2647 (7) Å
V = 4495.85 (15) Å³
Z = 16
Mo Kα radiation
μ = 4.31 mm⁻¹
T = 293 K
0.28 × 0.23 × 0.21 mm

Data collection

Oxford Diffraction Gemini R Ultra diffractometer
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2007 ▶) T _min = 0.312, T _max = 0.399
9288 measured reflections
2048 independent reflections
1402 reflections with I > 2σ(I)
R _int = 0.051

Refinement

R[F ² > 2σ(F ²)] = 0.035
wR(F ²) = 0.090
S = 0.94
2048 reflections
198 parameters
8 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.80 e Å⁻³
Δρ_min = −0.53 e Å⁻³

Data collection: CrysAlis PRO (Oxford Diffraction, 2007 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis RED (Oxford Diffraction, 2007 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶) and DIAMOND (Brandenburg, 1998 ▶); software used to prepare material for publication: SHELXTL and publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536811055358/su2346sup1.cif

e-68-0m103-sup1.cif^{(20.7KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811055358/su2346Isup2.hkl

e-68-0m103-Isup2.hkl^{(99KB, 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
O1W—H1WA⋯O2W	0.86 (2)	2.37 (4)	3.121 (7)	146 (6)
O1W—H1WB⋯O2ⁱ	0.86 (2)	2.28 (5)	2.981 (6)	139 (6)
O1W—H1WB⋯O5ⁱⁱ	0.86 (2)	2.40 (4)	3.084 (6)	137 (5)
O7—H7O⋯O3ⁱⁱⁱ	0.79 (2)	2.38 (2)	3.174 (5)	179 (5)
O2W—H2WA⋯O3W^iv	0.64	2.30	2.776 (18)	134
O3W—H3WA⋯O2W^v	0.86	1.94	2.776 (18)	164
O3W—H3WB⋯O4^vi	0.90	2.24	2.811 (15)	121

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

Acknowledgments

We thank Jilin Agricultural Science and Technology College for support.

supplementary crystallographic information

Comment

The title compound consists of three crystallographically unique Zn^II cations, two of which are located on special positions, one benzene-1,2,3-tricarboxylate anion, an OH^- anion (O7), a coordinated water molecule (O1W), and two disordered solvent water molecules (Fig. 1).

Atom Zn1 is located on an inversion center and is six coordinated by four oxygen atoms from four symmetry related 1,2,3-tricarboxybenzene anions and two symmetry related OH^- anions. The Zn1—O(carboxylate) distances are 2.022 (4) and 2.199 (3) Å. The Zn1—O7(OH^-) distance is 2.089 (3) Å. Atom Zn2, also located on a 2-fold axis, is four coordinated by two oxygen atoms from two symmetry related 1,2,3-tricarboxybenzene anions and two symmetry related OH^- anions. The Zn2—O (carboxylate) and Zn2—O7 distances are 1.943 (4) Å and 1.948 (3) Å, respectively. Atom Zn3, locate in a general position, is five coordinated by three oxygen atoms from three different 1,2,3-tricarboxybenzene anions, one OH^- anion and one water molecule (O1W). The Zn3—O(carboxylate) distances are 1.935 (4), 1.984 (3) and 2.008 (4) Å. The Zn3—O7 distance is 2.069 (4) Å, and the Zn3—O1W distance is 2.136 (5) Å. The Zn—O (carboxylate) distances are similar to those observed in related structures (Wu et al., 2009).

Each benzene-1,2,3-tricarboxylate anion bridges six Zn^II centers, and the OH^- anion bridges three Zn^II centers, leading to the formation of an infinite three-dimensional framework (Fig. 2). A series of O—H···O hydrogen bonds (Table 1) involving the tricarboxybenzene anions, the OH^- anion and the coordinating and two solvent water molecules (both of which are only partially occupied), further stabilize the crystal structure (Table 1).

Experimental

A mixture of benzene-1,2,3-tricarboxylic acid (0.063 g, 0.3 mmol), NaOH (0.036 g, 0.9 mmol), and Zn(Ac)₂ (0.066 g, 0.3 mmol), in 10 ml H₂O was sealed in 18 ml Teflon-lined stainless steel container. The container was heated to 433 K and held at that temperature for 72 h. It was then cooled to room temperature at a rate of 10 K per hour and block-like colourless crystals of the title compound were isolated.