A one-dimensional zigzag coordination polymer: catena-poly[[[triaqua­cadmium(II)]-[μ-2,2′-(5-methyl-1,3-phenyl­enedi­oxy)diacetato-κ4 O,O′:O′′,O′′′]] monohydrate]

Ying Lin; Yun Wei; Xian-Wen Wei; Hong-Tao Zhang

doi:10.1107/S1600536807068031

. 2008 Jan 4;64(Pt 2):m280–m281. doi: 10.1107/S1600536807068031

A one-dimensional zigzag coordination polymer: catena-poly[[[triaquacadmium(II)]-[μ-2,2′-(5-methyl-1,3-phenylenedioxy)diacetato-κ⁴ O,O′:O′′,O′′′]] monohydrate]

Ying Lin ^a, Yun Wei ^a, Xian-Wen Wei ^a, Hong-Tao Zhang ^a,^*

PMCID: PMC2960183 PMID: 21201262

Abstract

In the title one-dimensional coordination polymer, {[Cd(C₁₁H₁₀O₆)(H₂O)₃]·H₂O}_n, the 2,2′-(5-methyl-1,3-phenylenedioxy)diacetate dianions connect Cd^II ions in a head-to-tail fashion to generate zigzag chains. The coordination geometry of the Cd atom is distorted pentagonal bipyramidal. There are O—H⋯O hydrogen bonds between the carboxyl O atoms, the aqua ligands and the uncoordinated water molecules.

Related literature

For related literature on coordination polymers, see: Burrows et al. (2004 ▶); Hong et al. (2006 ▶); Janiak (2000 ▶, 2003 ▶); Kitagawa et al. (2004 ▶); Moulton & Zaworotko (2001 ▶); Russell et al. (2001 ▶).

Experimental

Crystal data

[Cd(C₁₁H₁₀O₆)(H₂O)₃]·H₂O
M _r = 422.66
Triclinic,
a = 7.3792 (11) Å
b = 8.6946 (12) Å
c = 11.9495 (17) Å
α = 85.294 (19)°
β = 82.52 (2)°
γ = 88.44 (2)°
V = 757.47 (19) Å³
Z = 2
Mo Kα radiation
μ = 1.49 mm⁻¹
T = 298 (2) K
0.24 × 0.08 × 0.02 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.717, T _max = 0.971
5397 measured reflections
2647 independent reflections
2121 reflections with I > 2σ(I)
R _int = 0.037

Refinement

R[F ² > 2σ(F ²)] = 0.040
wR(F ²) = 0.093
S = 0.98
2647 reflections
200 parameters
H-atom parameters constrained
Δρ_max = 0.41 e Å⁻³
Δρ_min = −0.75 e Å⁻³

Data collection: SMART (Bruker, 2000 ▶); cell refinement: SAINT (Bruker, 2000 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997 ▶); molecular graphics: SHELXTL (Sheldrick, 2000 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536807068031/ob2104sup1.cif

e-64-0m280-sup1.cif^{(20.7KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536807068031/ob2104Isup2.hkl

e-64-0m280-Isup2.hkl^{(130KB, hkl)}

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

Table 1. Selected geometric parameters (Å, °).

Cd—O9	2.262 (4)
Cd—O7	2.297 (4)
Cd—O1	2.303 (3)
Cd—O6ⁱ	2.331 (4)
Cd—O8	2.381 (4)
Cd—O5ⁱ	2.432 (4)
Cd—O2	2.573 (4)

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O9—Cd—O7	167.09 (14)
O9—Cd—O1	85.66 (14)
O9—Cd—O8	92.24 (14)
O7—Cd—O8	88.31 (14)
O1—Cd—O8	130.96 (13)
O6ⁱ—Cd—O8	80.48 (13)
O9—Cd—O5ⁱ	88.92 (13)
O9—Cd—O2	83.86 (14)
O8—Cd—O2	77.69 (12)
O5ⁱ—Cd—O2	146.90 (12)

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Symmetry code: (i) Inline graphic .

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O7—H7B⋯O8ⁱⁱ	0.85	2.08	2.875 (5)	156
O7—H7C⋯O5ⁱⁱⁱ	0.85	2.00	2.846 (5)	174
O8—H8C⋯O9^iv	0.85	2.51	3.263 (5)	148
O8—H8C⋯O10^v	0.85	2.38	3.008 (7)	131
O8—H8D⋯O2^iv	0.85	2.14	2.808 (5)	136
O9—H9E⋯O1^vi	0.85	1.92	2.752 (5)	165
O9—H9F⋯O10^vii	0.85	2.10	2.659 (6)	123
O10—H10C⋯O6	0.85	2.08	2.731 (6)	133
O10—H10D⋯O2^v	0.85	1.95	2.793 (6)	170

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

Acknowledgments

This work was funded by the Doctoral Research Launch Foundation of Anhui Normal University and the Youth Research Foundation of Anhui Normal University (grant No. 2006xqn64).

supplementary crystallographic information

Comment

Supramolecular self-assembly of coordination polymers have been one of the areas of rapid growth in chemistry recently, owing to their intriguing molecular topologies and useful properties, such as molecular recognition, electronic, optical, magnetic and catalytic properties (Janiak, 2003; Kitagawa et al., 2004). Generally, the structure of such a molecular architecture is governed by coordination interaction and other non-covalent interactions such as hydrogen bonding and π-π stacking as well as the conformations of ligands depending on their rigidity and flexibility (Russell et al., 2001; Moulton & Zaworotko, 2001; Burrows et al., 2004). To date, there is a great research interest focused on the coordination interaction, hydrogen bonding and π-π stacking as well as the rigidity of ligands, whereas there is scant attention to the influence of the flexibility of ligands on the structure of coordination polymer. In order to further understand the role of the flexibility of ligands in the self-assembly of coordination polymers, we have designed and synthesized a ligand bearing the flexible group, 2,2'-(5-methyl-1,3-phenylenedioxy)diacetic acid (abbreviated to H₂5-mpdoa), and employed it with Cd^II ion to assemble the title coordination polymer, (I), [Cd(5-mpdoa)(H₂O)₃]_n^.nH₂O.

As shown in Fig. 1, the coordination geometry of the Cd^II atom is a distorted pentagonal bipyramid. The equatorial positions are occupied by four carboxyl O atoms (O1, O2, O5ⁱ, O6ⁱ, symmetry code (i) x - 1, y, z + 1) from two symmetry related 5-mpdoa ligands and the aqua O8 atom. The aqua O7 and O9 atoms are located at the axial vertices of the pentagonal bipyramid. Both two carboxylate groups of the 5-mpdoa ligands, O1/C1/O2 and O5ⁱ/C11ⁱ/O6ⁱ, chelate the Cd^IIatom in the same mode. The O5/C11/O6 carboxylate is almost coplanar with the benzene ring C3—C8, whereas the O1/C1/O2 carboxylate has a slightly twisted from the benzene ring with the dihedral angle of 10.7 (7)°. Due to the flexibility of the molecule induced by the σ-rotation of the C—O bond (selected torsion angles are listed in Table 1), the 5-mpdoa ligand adopts a W-shape conformation.

The 5-mpdoa ligands connect the neighbouring Cd^II atoms in a head-to-tail mode to construct an infinite zigzag chain which runs along the [101] direction. Such a supramolecular geometry could be regarded as a result of the cooperation of coordination interaction, the symmetry and the flexibility of ligand molecule as well as the hydrogen bonds. All zigzag chains are packing together through an amount of hydrogen bonding interactions between the carboxyl O atoms, the aqua ligands and the lattice water molecules (Fig. 2, Table 2). The shortest center-center distance between two adjacent benzene rings of the different chains is 4.997 (15) Å, indicating no interchain π-π interaction of 5-mpdoa (Janiak et al., 2000).

Experimental

The H₂5-mpdoa ligand, 2,2'-(5-methyl-1,3-phenylenedioxy)diacetic acid, was synthesized from 5-methylbenzene-1,3-diol and 2-chloroacetic acid according to a literature method reported by Hong et al. (2006). Cd(CH₃COO)₂^.2(H₂O) (26.8 mg, 0.10 mmol) and H₂5-mpdoa (24.0 mg, 0.10 mmol) were dissolved in 10 ml water. The resulting yellow solution was filtered and the filtrate was left at room temperature. Yellow column-like crystals were obtained (25.5 mg, yield ca 60%) after several weeks by slow evaporation of the solvent.