Tetra­kis(μ-2-iodo­benzoato-κ2 O:O′)bis­[aqua­copper(II)]

Ömür Aydın; Nagihan Çaylak Delibaş; Hacali Necefoğlu; Tuncer Hökelek

doi:10.1107/S1600536812010367

. 2012 Mar 14;68(Pt 4):m409–m410. doi: 10.1107/S1600536812010367

Tetrakis(μ-2-iodobenzoato-κ² O:O′)bis[aquacopper(II)]

Ömür Aydın ^a, Nagihan Çaylak Delibaş ^b, Hacali Necefoğlu ^a, Tuncer Hökelek ^c,^*

PMCID: PMC3343818 PMID: 22589792

Abstract

In the centrosymmetric binuclear title complex, [Cu₂(C₇H₄IO₂)₄(H₂O)₂], the two Cu^II ions [Cu⋯Cu = 2.6009 (5) Å] are bridged by four 2-iodobenzoate (IB) ligands. The four nearest O atoms around each Cu^II ion form a distorted square-planar arrangement, the distorted square-pyramidal coordination being completed by the O atom of the water molecule at a distance of 2.1525 (16) Å. The dihedral angle between the benzene ring and the carboxylate group is 25.67 (13)° in one of the independent IB ligands and 6.44 (11)° in the other. The benzene rings of the two independent IB ligands are oriented at a dihedral angle of 86.61 (7)°. In the crystal, O—H⋯O interactions link the molecules into a two-dimensional network. π–π contacts between the benzene rings [centroid–centroid distances = 3.810 (2) and 3.838 (2) Å] may further stabilize the structure.

Related literature

For niacin, see: Krishnamachari (1974 ▶). For N,N-diethylnicotinamide, see: Bigoli et al. (1972 ▶). For related structures, see: Speier & Fulop (1989 ▶); Usubaliev et al. (1980 ▶); Hökelek et al. (1995 ▶, 2009a ▶,b ▶,c ▶, 2011 ▶); Necefoğlu et al. (2010a ▶,b ▶).

Experimental

Crystal data

[Cu₂(C₇H₄IO₂)₄(H₂O)₂]
M _r = 1151.14
Triclinic,
a = 7.3563 (2) Å
b = 10.7448 (3) Å
c = 10.9066 (3) Å
α = 83.167 (3)°
β = 72.779 (2)°
γ = 77.227 (2)°
V = 801.73 (4) Å³
Z = 1
Mo Kα radiation
μ = 5.23 mm⁻¹
T = 100 K
0.39 × 0.36 × 0.24 mm

Data collection

Bruker Kappa APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.150, T _max = 0.285
14335 measured reflections
3987 independent reflections
3818 reflections with I > 2σ(I)
R _int = 0.025

Refinement

R[F ² > 2σ(F ²)] = 0.019
wR(F ²) = 0.045
S = 1.16
3987 reflections
207 parameters
2 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.61 e Å⁻³
Δρ_min = −0.66 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: ORTEP-3 for Windows (Farrugia, 1997 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶) and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812010367/bq2345sup1.cif

e-68-0m409-sup1.cif^{(18.5KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812010367/bq2345Isup2.hkl

e-68-0m409-Isup2.hkl^{(191.4KB, hkl)}

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

Table 1. Selected bond lengths (Å).

Cu1—O1	1.9814 (16)
Cu1—O2ⁱ	1.9577 (16)
Cu1—O3	1.9533 (16)
Cu1—O4	1.9610 (16)

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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
O5—H51⋯O1ⁱⁱ	0.83 (3)	2.09 (3)	2.839 (2)	152 (3)
O5—H52⋯O4ⁱⁱ	0.83 (3)	2.56 (4)	3.171 (2)	132 (3)

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Symmetry code: (ii) Inline graphic .

Acknowledgments

The authors are indebted to Anadolu University and the Medicinal Plants and Medicine Research Centre of Anadolu University, Eskişehir, Turkey, for the use of X-ray diffractometer.

supplementary crystallographic information

Comment

As a part of our ongoing investigation on transition metal complexes of nicotinamide (NA), one form of niacin (Krishnamachari, 1974), and/or the nicotinic acid derivative N,N-diethylnicotinamide (DENA), an important respiratory stimulant (Bigoli et al., 1972), the title compound was synthesized and its crystal structure is reported herein.

The title compound is a binuclear compound, consisting of four iodobenzoate (IB) ligands. The structures of similar complexes of the Cu²⁺, Zn²⁺ and Co²⁺ ions, [Cu(C₆H₅COO)₂(C₅H₅N)]₂ (Usubaliev et al., 1980); [Cu(C₆H₅CO₂)₂(Py)]₂ (Speier & Fulop, 1989); [Cu₂(C₆H₅COO)₄(C₁₀H₁₄N₂O)₂] (Hökelek et al., 1995) [Cu₂(C₈H₇O₂)₄(C₆H₆N₂O)₂] (Necefoğlu et al., 2010a) [Zn₂(C₁₁H₁₄NO₂)₄(C₁₀H₁₄N₂O)₂] (Hökelek et al., 2009a); [Zn₂(C₈H₈NO₂)₄(C₁₀H₁₄N₂O)₂].2H₂O (Hökelek et al., 2009b); [Zn₂(C₉H₁₀NO₂)₄(C₁₀H₁₄N₂O)₂] (Hökelek et al., 2009c); [Zn₂(C₈H₇O₂)₄(C₁₀H₁₄N₂O)₂] (Necefoğlu et al., 2010b) and [Co₂(C₁₁H₁₄NO₂)₄(C₁₀H₁₄N₂O)₂] (Hökelek et al., 2011) have also been determined. In these structures, the benzoate ion acts as a bidentate ligand.

The title dimeric complex, [Cu₂(IB)₄(H₂O)₂], has a centre of symmetry and two Cu^II atoms are surrounded by four IB groups and two water molecules. The IB groups act as bridging ligands. The Cu···Cu' distance is 2.6009 (5) Å. The average Cu-O distance is 2.0012 (16) Å (Table 1), and four O atoms of the bridging IB ligands around each Cu atom form a distorted square plane. The Cu atom lies 0.1869 (3) Å below the least-squares plane. The average O-Cu-O bond angle is 92.48 (7)°. A distorted square-pyramidal arrangement around each Cu atom is completed by the water O atom at 2.1525 (16) Å from the Cu atom (Table 1). The O5-Cu1···Cu1' angle is 176.38 (5)° and the dihedral angle between plane through Cu1, O1, O2, C1, Cu1', O1', O2', C1' and the plane through Cu1, O3, O4, C8, Cu1', O3', O4', C8' is 89.13 (6)°. The dihedral angles between the planar carboxylate groups [(O1/O2/C1) and (O3/O4/C8)] and the adjacent benzene rings A (C2-C7) and B (C9-C14) are 25.67 (13) and 6.44 (11) °, respectively, while that between rings A and B is A/B = 86.61 (7)°.

In the crystal structure, intermolecular O-H···O interactions (Table 2) link the molecules into a two-dimensional network, in which they may be effective in the stabilization of the structure. The π–π contacts between the benzene rings, Cg1—Cg1ⁱ and Cg2—Cg2ⁱⁱ [symmetry codes: (i) 1 - x, -y, 1 - z, (ii) 2 - x, 1 - y, -z, where Cg1 and Cg2 are the centroids of the rings A (C2-C7) and B (C9-C14), respectively] may further stabilize the structure, with centroid-centroid distances of 3.810 (2) and 3.838 (2) Å].

Experimental

The title compound was prepared by the reaction of CuSO₄.5H₂O (1.25 g, 5 mmol) in H₂O (100 ml) with sodium 2-iodobenzoate (2.70 g, 10 mmol) in H₂O (50 ml). The mixture was set aside to crystallize at ambient temperature for one day, giving green single crystals.