catena-Poly[[aqua­(3-methyl­benzoato-κ2 O,O′)lead(II)]-μ-3-methyl­benzoato-κ4 O:O,O′:O′]

Jun Dai; Juan Yang; Xiaobing An

doi:10.1107/S1600536809019771

. 2009 Jun 6;65(Pt 7):m709–m710. doi: 10.1107/S1600536809019771

catena-Poly[[aqua(3-methylbenzoato-κ² O,O′)lead(II)]-μ-3-methylbenzoato-κ⁴ O:O,O′:O′]

Jun Dai ^a, Juan Yang ^b,^*, Xiaobing An ^b

PMCID: PMC2969469 PMID: 21582655

Abstract

The reaction of lead(II) acetate and 3-methylbenzoic acid (MBA) in aqueous solution yielded the title polymer, [Pb(C₈H₇O₂)₂(H₂O)]_n. The asymmetric unit contains two Pb^II atoms, four MBA ligands and two water molecules. Each Pb^II cation is heptacoordinated and chelated by four carboxylate O atoms from two MBA ligands. The Pb atoms are bridged through the carboxylate O atoms from another two MBA ligands, leading to a central Pb₂O₂ core. The Pb—O bond lengths are in the range 2.325 (3)–2.757 (4) Å. The intra- and interdimer Pb⋯Pb distances are 4.2942 (3) and 4.2283 (3) Å, respectively, indicating little direct metal–metal interaction. The coordinating water molecules and carboxylate O atoms are involved in extensive O—H⋯O hydrogen-bonding interactions. The complex has an extended ladder-like chain structure and the chains are assembled by hydrogen bonds and π–π interactions [centroid–centroid distance = 3.6246 (3) Å] into a three-dimensional supramolecular structure.

Related literature

For general background to metal-organic frameworks and their applications, see: Hamilton et al. (2004 ▶); Meng et al. (2003 ▶); Fan & Zhu (2006 ▶); Wang et al. (2006 ▶); Masaoka et al. (2001 ▶). For related structures, see: Shi et al. (2007 ▶).

Experimental

Crystal data

[Pb(C₈H₇O₂)₂(H₂O)]
M _r = 495.48
Monoclinic,
a = 7.1745 (3) Å
b = 42.745 (2) Å
c = 10.7126 (5) Å
β = 90.765 (1)°
V = 3285.0 (3) Å³
Z = 8
Mo Kα radiation
μ = 10.29 mm⁻¹
T = 296 K
0.36 × 0.17 × 0.12 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2007 ▶) T _min = 0.144, T _max = 0.300
40611 measured reflections
8096 independent reflections
6265 reflections with I > 2σ(I)
R _int = 0.056

Refinement

R[F ² > 2σ(F ²)] = 0.035
wR(F ²) = 0.061
S = 1.03
8096 reflections
397 parameters
H-atom parameters constrained
Δρ_max = 0.87 e Å⁻³
Δρ_min = −1.00 e Å⁻³

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; 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/S1600536809019771/fj2218sup1.cif

e-65-0m709-sup1.cif^{(24KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809019771/fj2218Isup2.hkl

e-65-0m709-Isup2.hkl^{(396.1KB, hkl)}

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

Table 1. Selected bond lengths (Å).

Pb1—O4	2.386 (3)
Pb1—O1	2.424 (3)
Pb1—O3	2.594 (3)
Pb1—O5	2.603 (3)
Pb1—O2	2.622 (4)
Pb1—O9	2.724 (4)
Pb1—O6ⁱ	2.751 (3)
Pb2—O6	2.325 (3)
Pb2—O8	2.494 (4)
Pb2—O3ⁱⁱ	2.538 (3)
Pb2—O7	2.565 (4)
Pb2—O10	2.665 (3)
Pb2—O4	2.712 (3)
Pb2—O5	2.757 (4)

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

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O9—H9A⋯O8	0.82	2.03	2.805 (5)	158
O9—H9B⋯O7ⁱ	0.82	2.25	3.017 (5)	156
O10—H10B⋯O2	0.82	2.12	2.881 (5)	153
O10—H10A⋯O1ⁱⁱ	0.82	1.97	2.774 (5)	166

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

Acknowledgments

The authors acknowledge the Doctoral Foundation of Henan Polytechnic University (B2008–58 648265).

supplementary crystallographic information

Comment

Interest in porous metal-organic frameworks (MOFs) has been driven by the prospect of generating a wide range of materials with useful properties for applications such as ion-exchange, nonlinear optics and catalysis (Hamilton et al., 2004; Meng et al., 2003; Fan et al. 2006). On the other hand, lead(II) compounds have been increasingly studied (Shi et al. 2007) owing to their possible applications in different fields, especially in environmental protection due to the toxicity of lead and in biological systems for its diverse interactions with biological molecules. As an important family of multidentate O-donor ligands, aromatic carboxylate ligands have been extensively employed in the preparation of metal-organic complexes because of their potential properties and intriguing structural topologies (Wang et al., 2006; Masaoka et al. 2001). Herein, we report the structure of the title complex.

The asymmetric unit of the title complex, [Pb₂(C₈H₇O₂)₄(H₂O)₂]_n, contains two Pb^II cation, four MBA ligands and two coordinating water molecule, as illustrated in Fig. 1. The two Pb atoms are connected via two bridging O atoms belonging to two MBA ligands, resulting the central Pb₂O₂ core tetratomic ring. The Pb—O bond lengths are in the range of 2.325 (3) to 2.757 (4) Å (Table 1). The average distance of two Pb atoms is 4.2942 Å, which leads to the weak metal-metal interactions. This coordination polymer structure presents extended ladder-like chain along the a axis direction. The coordinating water molecules and carboxylate O atoms are involved in extensive O—H···O hydrogen-bonding interactions (Table 2). These chains are assembled by H-bonds and π-π interactions to three-dimensional supramolecular structure.

Experimental

A mixture of Pb(CH₃COO)₂ 3H2O (0.1992 g, 0.52 mmol), MBA (0.1139 g, 0.84 mmol), melamine (0.0255 g, 0.20 mmol) and distilled water (10 ml) was sealed in a 25 ml Teflon-lined stainless autoclave (Shi et al. 2007). The mixture was heated at 373 K for 5 days to give colorless crystals suitable for X-ray diffraction analysis.