catena-Poly[[[diaqua­cadmium]-μ-2,2′-(1,2-phenyl­enedi­oxy)diacetato] mono­hydrate]

Huan-Fu Hou; Xiu-Ling Zhang

doi:10.1107/S1600536811004867

. 2011 Feb 16;67(Pt 3):m342. doi: 10.1107/S1600536811004867

catena-Poly[[[diaquacadmium]-μ-2,2′-(1,2-phenylenedioxy)diacetato] monohydrate]

Huan-Fu Hou ^a, Xiu-Ling Zhang ^a,^b,^*

PMCID: PMC3052000 PMID: 21522271

Abstract

In the title coordination complex, {[Cd(C₁₀H₈O₆)(H₂O)₂]·H₂O}_n the Cd^II atom is seven-coordinated in a distorted pentagonal–bipyramidal geometry, the pentagonal plane comprising four O-atom donors from the 2,2′-(1,2-phenylenedioxy)diacetate chelate ligand together with a bridging carboxylate O-atom donor, with the axial sites occupied by two water molecules. The resulting helical chains extend along the b axis and are interconnected by extensive O—H⋯O hydrogen-bonding interactions, which also involve the water molecule of solvation, giving a three-dimensional structure.

Related literature

For rigid polycarboxylate ligands, see: Liu et al. (2010 ▶); Rao et al. (2004 ▶). For flexible carboxylate complexes, see: Dai et al. (2009 ▶)

Experimental

Crystal data

[Cd(C₁₀H₈O₆)(H₂O)₂]·H₂O
M _r = 390.61
Monoclinic,
a = 7.624 (1) Å
b = 7.156 (1) Å
c = 23.190 (2) Å
β = 93.083 (1)°
V = 1263.4 (3) Å³
Z = 4
Mo Kα radiation
μ = 1.77 mm⁻¹
T = 296 K
0.25 × 0.20 × 0.14 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2001 ▶) T _min = 0.671, T _max = 0.787
7467 measured reflections
2893 independent reflections
2676 reflections with I > 2σ(I)
R _int = 0.017

Refinement

R[F ² > 2σ(F ²)] = 0.020
wR(F ²) = 0.049
S = 1.05
2893 reflections
181 parameters
H-atom parameters constrained
Δρ_max = 0.52 e Å⁻³
Δρ_min = −0.43 e Å⁻³

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SIR97 (Altomare et al., 1999 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536811004867/zs2094sup1.cif

e-67-0m342-sup1.cif^{(19.8KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811004867/zs2094Isup2.hkl

e-67-0m342-Isup2.hkl^{(142.1KB, 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—H11W⋯O3Wⁱ	0.84	2.11	2.892 (3)	154
O1W—H12W⋯O1ⁱⁱ	0.84	1.87	2.686 (2)	164
O2W—H21W⋯O6ⁱⁱⁱ	0.84	2.06	2.873 (3)	165
O2W—H22W⋯O3W^iv	0.84	2.03	2.860 (3)	170
O3W—H31W⋯O6	0.84	2.09	2.887 (3)	157
O3W—H32W⋯O2^v	0.85	1.99	2.835 (2)	176

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

Acknowledgments

This work was supported financially by the National Natural Science Foundation of China (grant No. 20971018), the Natural Science Foundation of Shandong Province (grant No. ZR2010BL010) and the Key Technologies R&D Program of Shandong Province (grant No. 2010GWZ20251).

supplementary crystallographic information

Comment

Rigid polycarboxylate ligands have been employed extensively for the construction of metal-organic polymers, e.g. 1,3-benzenedicarboxylate, 1,3,5-benzenetricarboxylate and 4,4'-biphenyldicarboxylate (Liu et al., 2010; Rao et al., 2004). Compared to rigid ligands with a single conformation, flexible ligands may adopt variable conformations when coordinated to metal ions, making it more difficult to predict and control the final coordination networks. Therefore using flexible ligands in the formation of coordination polymers may generate novel complexes with interesting topologies and attractive properties (Dai et al., 2009). The title compound {[(C₁₀H₈O₆)(H₂O)₂Cd] . H₂O}_n (I), was prepared from the reaction of the flexible carboxylate ligand, the 1,2-phenylenedioxydiacetate dianion (PDA) with Cd^II and the structure is reported here.

In (I) (Fig. 1) the Cd^II cation is seven-coordinated, involving two carboxyl and two phenoxy O donors (O2, O3, O4, O5) from a PDA ligand [Cd—O range 2.2424 (19) Å–2.5285 (16) Å], and a bridging carboxylate O donor (O6) [Cd—Oⁱ, 2.3596 (15) Å] [for symmetry code (i), see Table 1], which lie in the pentagonal plane of a distorted pentagonal bipyramid. Two water molecules (O1W, O2W) occupy the axial sites (Cd—O, 2.296 (2), 2.316 (2) Å]. The bond angles about Cd^II are in the range of 61.11 (5) to 165.45 (5) °. The mononuclear units of (I) are connected via the bridging O6ⁱ atoms to give helical chains extending along the b axis of the unit cell (Fig. 2). The chains are further inter-connected by extensive hydrogen-bonding interactions (Table 1) involving also the water molecule of solvation (O3W), giving rise to the three-dimensional molecular architecture (Fig. 3).

Experimental

A mixture of 1,2-phenylenedioxydiacetic acid (H₂PDA) (0.023 g, 0.1 mmol) and Cd(NO₃)₂ . 4H₂O (0.038 g, 0.1 mmol) in H₂O (7.0 ml) was placed in a 16 ml Teflon-lined stainless steel vessel and heated to 160 °C for 72 h, giving colorless block crystals of (I), which were collected by filtration. The crystals obtained were washed with water and dried in air. Yield: 0.029 g (74% based on Cd).