Diaqua­[5,5′-dicarb­oxy-2,2′-(ethane-1,2-di­yl)bis­(1H-imidazole-4-carboxyl­ato)]cobalt(II)

Ying Wang; Xin-Lian Gao

doi:10.1107/S1600536811019672

. 2011 May 28;67(Pt 6):m815. doi: 10.1107/S1600536811019672

Diaqua[5,5′-dicarboxy-2,2′-(ethane-1,2-diyl)bis(1H-imidazole-4-carboxylato)]cobalt(II)

Ying Wang ^a,^*, Xin-Lian Gao ^b

PMCID: PMC3120334 PMID: 21754687

Abstract

In the title complex, [Co(C₁₂H₈N₄O₈)(H₂O)₂], the Co^II atom is coordinated by two N and two O atoms of the tetradentate 5,5′-dicarboxy-2,2′-(ethane-1,2-diyl)bis(1H-imidazole-4-carboxylate) anion. The slightly distorted octahedral coordination environment is completed by the O atoms of two water molecules in axial positions. An intramolecular O—H⋯O hydrogen bond between the carboxy and carboxylate groups stabilizes the molecular configuration. Adjacent molecules are linked through O—H⋯O and N—H⋯O hydrogen bonds between the carboxy/carboxylate groups, water molecules and imidazole fragments into a three-dimensional network.

Related literature

For background to complexes based on 1H-imidazole-4,5-dicarboxylic acid and its derivatives, see: Das et al. (2010 ▶); Sun et al. (2010 ▶); Zhang et al. (2010 ▶).

Experimental

Crystal data

[Co(C₁₂H₈N₄O₈)(H₂O)₂]
M _r = 431.19
Orthorhombic,
a = 24.683 (5) Å
b = 27.885 (6) Å
c = 8.7340 (17) Å
V = 6012 (2) Å³
Z = 16
Mo Kα radiation
μ = 1.21 mm⁻¹
T = 293 K
0.18 × 0.14 × 0.09 mm

Data collection

Rigaku Saturn CCD diffractometer
Absorption correction: multi-scan (CrystalClear; Rigaku/MSC, 2006 ▶) T _min = 0.811, T _max = 0.899
7187 measured reflections
2693 independent reflections
2223 reflections with I > 2σ(I)
R _int = 0.046

Refinement

R[F ² > 2σ(F ²)] = 0.047
wR(F ²) = 0.079
S = 1.01
2693 reflections
245 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.37 e Å⁻³
Δρ_min = −0.35 e Å⁻³
Absolute structure: Flack (1983) ▶, 1126 Friedel pairs
Flack parameter: 0.20 (2)

Data collection: CrystalClear (Rigaku/MSC, 2006 ▶); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: XP in SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536811019672/wm2487sup1.cif

e-67-0m815-sup1.cif^{(21.2KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811019672/wm2487Isup2.hkl

e-67-0m815-Isup2.hkl^{(132.5KB, hkl)}

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

Table 1. Selected bond lengths (Å).

Co1—O10	2.043 (4)
Co1—N3	2.044 (4)
Co1—N1	2.048 (4)
Co1—O9	2.118 (4)
Co1—O1	2.153 (3)
Co1—O5	2.168 (4)

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—H3⋯O2	0.85	1.65	2.461 (5)	157
O7—H7⋯O6	0.85	1.72	2.550 (5)	166
O10—H3W⋯O3ⁱ	0.85	2.18	2.799 (5)	129
N2—H2A⋯O6ⁱⁱ	0.86	2.16	2.904 (5)	145
N4—H4A⋯O5ⁱⁱⁱ	0.86	2.04	2.878 (5)	166
O9—H1W⋯O4^iv	0.85	1.89	2.730 (5)	170
O9—H2W⋯O7^v	0.85	2.06	2.834 (5)	150
O10—H4W⋯O8^vi	0.85	2.22	2.958 (5)	145

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

supplementary crystallographic information

Comment

A large number of metal complexes constructed from the ligand 1H-imidazole-4,5-dicarboxylic acid or its derivatives have been reported. This ligand shows versatile binding modes and high binding capacity with almost all soft and hard metal ions (Das et al., 2010; Sun et al., 2010; Zhang et al., 2010). In order to further explore complexes with novel structures, we obtained the title complex [Co(H₄eidc)(H₂O)₂], (I), through the reaction of 2,2'-(ethane-1,2-diyl)bis(1H-imidazole-4,5-dicarboxylic acid (H₆eidc) with cobalt dichloride.

As shown in Figure 1, the Co(II) cation in (I) is hexacoordinated and features a slightly octahedral coordination environment. N1, O1, N3, O5 atoms from the tetradentate H₄eidc^2- anion coordinate to the cation in a chelating fashion and O9, O10 atoms from water molecules complete the coordination polyhedron. Atoms N1, N3, O1, O5 and Co are nearly co-planar (the mean deviation from the plane is 0.08 Å). The bond angle between the O atoms of the two water molecules and the metal is 171.87 (13) °. As shown in Figure 2, intramolecular O—H···O hydrogen bonds between the carboxyl/carboxylate groups stabilize the molecular configuration whereas O—H···O and N—H···O hydrogen bonds between the water molecules and carboxylate O atoms and between imidazole groups and carboxylate O atoms of adjacent molecules consolidate the crystal packing.

Experimental

The ligand 2,2'-(ethane-1,2-diyl)bis(1H-imidazole-4,5-dicarboxylic acid (0.05 mmol) in methanol (4 ml) was added dropwise to a methanol solution (3 ml) of cobalt dichloride (0.05 mmol). The resulting solution was allowed to stand at room temperature. After four weeks red crystals with good quality were obtained from the filtrate and dried in air.