Poly[tetra­kis(μ4-4,6-dimethyl-5-nitro­benzene-1,3-dicarboxyl­ato-κ2 O 1:O 1′:O 3:O 3′)bis­(pyridine-κN)dizinc]

Qing-Yu Ma; Rui-Fang Guan; Guo-Zhong Li

doi:10.1107/S1600536811013092

. 2011 Apr 13;67(Pt 5):m586. doi: 10.1107/S1600536811013092

Poly[tetrakis(μ₄-4,6-dimethyl-5-nitrobenzene-1,3-dicarboxylato-κ² O ¹:O ^1′:O ³:O ^3′)bis(pyridine-κN)dizinc]

Qing-Yu Ma ^a,^*, Rui-Fang Guan ^a, Guo-Zhong Li ^a

PMCID: PMC3089336 PMID: 21754309

Abstract

In the title complex, [Zn₂(C₁₀H₇NO₆)₂(C₅H₅N)₂]_n, the repeat unit is a centrosymmetic tetra-carboxylato-O,O’-bridged dimer in which each Zn^II atom is five-coordinated by four O atoms from different dianionic 4,6-dimethyl-5-nitroisophthalate ligands [Zn—O = 2.0283 (18)–2.0540 (19) Å] and one N atom from a pyridine molecule [Zn—N = 2.030 (2) Å] in the axial site of a slightly distorted square-pyramidal coordination sphere. The Zn⋯Zn separation is 2.9750 (6) Å. The complex dimers are extended into a two-dimensional polymeric structure parallel to (100) through bridges provided by the second carboxylate group of the ligand.

Related literature

For the structure of a similar but discrete tetra-carboxylato-bridged Zn₂ dimer, see: Yu et al. (2011 ▶).

Experimental

Crystal data

[Zn(C₁₀H₇NO₆)(C₅H₅N)]
M _r = 381.64
Monoclinic,
a = 10.2947 (9) Å
b = 11.8526 (10) Å
c = 12.8501 (11) Å
β = 97.933 (2)°
V = 1553.0 (2) Å³
Z = 4
Mo Kα radiation
μ = 1.62 mm⁻¹
T = 298 K
0.12 × 0.10 × 0.08 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.824, T _max = 0.879
8899 measured reflections
3525 independent reflections
2750 reflections with I > 2σ(I)
R _int = 0.029

Refinement

R[F ² > 2σ(F ²)] = 0.033
wR(F ²) = 0.081
S = 1.03
3525 reflections
217 parameters
H-atom parameters constrained
Δρ_max = 0.43 e Å⁻³
Δρ_min = −0.43 e Å⁻³

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT-Plus (Bruker, 2007 ▶); data reduction: SAINT-Plus; 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 global, I. DOI: 10.1107/S1600536811013092/zs2089sup1.cif

e-67-0m586-sup1.cif^{(21KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811013092/zs2089Isup2.hkl

e-67-0m586-Isup2.hkl^{(169.4KB, hkl)}

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

Acknowledgments

This work was supported by the Scientific and Technological Project of Shandong Province (2008SGG0809) and Doctoral Foundation of Shandong Province (2009SBS0913).

supplementary crystallographic information

Comment

The title complex [Zn₂(C₁₀H₇NO₆)₂(C₅H₅N)₂]_n (I) was obtained by chance when we were attempting to prepare some porous metal-organic framework materials by the reaction of 4,6-dimethyl-5-nitroisophthalic acid with Zn(NO₃)₂. In (I), the repeating unit is a centrosymmetic tetra-carboxylato O,O' bridged dimer (Fig. 1) in which each Zn^II is five-coordinated by four O atoms from different dianionic 4,6-dimethyl-5-nitroisophthalate ligands [Zn—O, 2.0283 (18)–2.0540 (19) Å] and one N atom from a pyridine molecule [Zn—N, 2.030 (2) Å] in the axial site of a slightly distorted square pyramidal coordination sphere. Each of the Zn atoms has an approximately square-pyramidal environment, with four O atoms in a plane and the pyridine N atom at the apical site. The Zn—Zn separation in the dimer is 2.9750 (6) Å. This dimeric unit is similar to that found in the structure of the tetra-benzoato-bridged but discrete Zn₂ dimer with 4-(dimethylamino)pyridine (Yu et al., 2011). The complex dimers in (I) are extended into a two-dimensional polymer structure through bridges provided by the second carboxylate group of the ligand (Figs. 2, 3).

Experimental

4,6-Dimethyl-5-nitroisophthalic acid (2 mg, 0.0046 mmol) and Zn(NO₃)₂ (4 mg, 0.0137 mmol) were dissolved in 1 ml of a mixed DMSO–H₂O solvent (2:1) and 2 drops pyridine were added. This solution was sealed in a Pyrex glass tube and heated to 120° C over a period of 10 h, and then maintained at this temperature for 50 h, after which it was cooled to room temperature over 17 h. Colourless rod crystals were obtained, which were filtered, washed with water and dried in air.