Di-μ-chlorido-bis­[(2,2′-bibenzimidazole)chloridocadmium(II)]

Ge Liu

doi:10.1107/S1600536808040968

. 2008 Dec 10;65(Pt 1):m37. doi: 10.1107/S1600536808040968

Di-μ-chlorido-bis[(2,2′-bibenzimidazole)chloridocadmium(II)]

Ge Liu ^a,^*

PMCID: PMC2967883 PMID: 21581509

Abstract

The title binuclear complex, [Cd₂Cl₄(C₁₄H₁₀N₄)₂], was synthesized by the hydrothermal reaction of CdCl₂ and the ligand 2,2′-bibenzimidazole. The molecule lies on an inversion center and the metal center displays a strongly distorted trigonal-bipyramidal geometry. The Cd^II ions are coordinated by two N atoms from the organic ligand, and by one terminal and two bridging chloride anions. The crystal structure involves intermolecular N—H⋯Cl hydrogen bonds, resulting in a one-dimensional supramolecular structure.

Related literature

For the synthesis of 2,2′-bibenzimidazole, see: Fieselmann et al. (1978 ▶). For general properties of Cd^II-based complex polymers, see: Meng et al. (2004 ▶).

Experimental

Crystal data

[Cd₂Cl₄(C₁₄H₁₀N₄)₂]
M _r = 835.12
Monoclinic,
a = 11.824 (2) Å
b = 10.784 (2) Å
c = 22.828 (5) Å
β = 91.10 (3)°
V = 2910.1 (10) Å³
Z = 4
Mo Kα radiation
μ = 1.86 mm⁻¹
T = 293 (2) K
0.17 × 0.16 × 0.12 mm

Data collection

Rigaku R-AXIS RAPID-S diffractometer
Absorption correction: none
14677 measured reflections
3337 independent reflections
2840 reflections with I > 2σ(I)
R _int = 0.035

Refinement

R[F ² > 2σ(F ²)] = 0.033
wR(F ²) = 0.060
S = 1.14
3337 reflections
190 parameters
H-atom parameters constrained
Δρ_max = 0.29 e Å⁻³
Δρ_min = −0.34 e Å⁻³

Data collection: RAPID-AUTO (Rigaku, 1998 ▶); cell refinement: RAPID-AUTO; data reduction: CrystalStructure (Rigaku/MSC, 2002 ▶); 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 I, global. DOI: 10.1107/S1600536808040968/bh2211sup1.cif

e-65-00m37-sup1.cif^{(17.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808040968/bh2211Isup2.hkl

e-65-00m37-Isup2.hkl^{(163.8KB, hkl)}

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

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

Cd1—N4	2.305 (2)
Cd1—N1	2.338 (2)
Cd1—Cl2	2.4602 (8)
Cd1—Cl1	2.5725 (10)
Cd1—Cl1ⁱ	2.5903 (10)

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N4—Cd1—Cl2	118.63 (6)
N4—Cd1—Cl1	144.04 (6)
Cl2—Cd1—Cl1	96.65 (3)
N1—Cd1—Cl1ⁱ	154.49 (6)

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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
N3—H16⋯Cl2ⁱⁱ	0.86	2.39	3.221 (2)	163

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Symmetry code: (ii) Inline graphic .

Acknowledgments

The author thanks Chifeng University for supporting this work.

supplementary crystallographic information

Comment

Bibenzimidazole has the potential to function as a bis-bidentate nitrogen ligand by coordinating to metal ions as a chelate. On the other hand, Cd^II-containing coordination polymers have attracted much attention as they are able to bond to different donors ligands simultaneously, because of the Cd^II large radius. Various coordination modes and potential applications in catalysis, fluorescent materials, NLO materials and so on (Meng et al. 2004) have been described. Here we report the crystal structure of the title complex prepared from CdCl₂ and bibenzimidazole ligand (see experimental).

As show in Fig. 1, the complex lies on an inversion center, and Cd atoms have strongly distorted trigonal-bipyramidal geometry, being coordinated by two N atoms from the organic ligand, and by one terminal and two bridging Cl^- anions. The two Cd centers are bridged by two chloride ions to give a dinuclear cadmium complex. Intermolecular N—H···Cl hydrogen bonds extend the dinuclear complex to a one dimensional chain in the crystal structure (Fig. 2).

Experimental

A mixture of CdCl₂ (0.073 g, 0.40 mmol), bibenzimidazole (0.070 g, 0.30 mmol) and H₂O (10 ml) was placed in a Teflon reactor, then heated to 433 K at 10.8 K/h; after maintaining the reaction at 433 K for three days, it was cooled to 303 K at 10.8 K/h. Crystals suitable for X-ray analysis were obtained.