Di-μ-benzoato-κ3 O,O′:O′;κ3 O:O,O′-bis­[(benzoato-κ2 O,O′)(1,10-phenanthroline-κ2 N,N′)cadmium]

Hong-Jin Li; Zhu-Qing Gao; Jin-Zhong Gu

doi:10.1107/S1600536811022185

. 2011 Jun 18;67(Pt 7):m919. doi: 10.1107/S1600536811022185

Di-μ-benzoato-κ³ O,O′:O′;κ³ O:O,O′-bis[(benzoato-κ² O,O′)(1,10-phenanthroline-κ² N,N′)cadmium]

Hong-Jin Li ^a, Zhu-Qing Gao ^a,^*, Jin-Zhong Gu ^b

PMCID: PMC3151832 PMID: 21836904

Abstract

The dinuclear title compound, [Cd₂(C₇H₅O₂)₄(C₁₂H₈N₂)₂], lies on a crystallographic twofold axis. The Cd^II ions are connected by two bridging benzoate anions and each ion is seven-coordinated by five O atoms from three benzoate ligands and by two N atoms from 1,10-phenanthroline. The benzoate ligands adopt two different coordination modes, acting as bidentate and bridging tridentate ligands. The discrete neutral molecules further extend their structure into a three-dimensional supramolecular framework by intermolecular π–π [interplanar distances of 3.392 (4) Å] and C—H⋯π stacking interactions [H–mean plane = 2.567 (4) and 2.781 (4) Å].

Related literature

For the structures and properties of cadmium compounds, see: Gu et al. (2007 ▶, 2011 ▶). For bond lengths and angles in related lead(II) compounds, see: Gu et al. (2011 ▶); Shi et al. (2008 ▶).

Experimental

Crystal data

[Cd₂(C₇H₅O₂)₄(C₁₂H₈N₂)₂]
M _r = 1069.65
Monoclinic,
a = 21.90 (2) Å
b = 10.023 (11) Å
c = 20.52 (2) Å
β = 103.759 (10)°
V = 4376 (8) Å³
Z = 4
Mo Kα radiation
μ = 1.04 mm⁻¹
T = 296 K
0.28 × 0.26 × 0.24 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2004 ▶) T _min = 0.761, T _max = 0.789
15316 measured reflections
4068 independent reflections
3002 reflections with I > 2σ(I)
R _int = 0.037

Refinement

R[F ² > 2σ(F ²)] = 0.040
wR(F ²) = 0.093
S = 1.12
4068 reflections
286 parameters
24 restraints
H-atom parameters constrained
Δρ_max = 0.80 e Å⁻³
Δρ_min = −0.62 e Å⁻³

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: SAINT (Bruker, 2004 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: DIAMOND (Brandenburg, 2006 ▶); software used to prepare material for publication: SHELXTL (Sheldrick, 2008 ▶).

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536811022185/zq2105sup1.cif

e-67-0m919-sup1.cif^{(19.8KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811022185/zq2105Isup2.hkl

e-67-0m919-Isup2.hkl^{(199.5KB, hkl)}

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

supplementary crystallographic information

Comment

Transition metal compounds have shown not only versatile architectures but also desirable properties, e.g. luminescent, magnetic, catalytic, and gas absorption and separation properties (Gu et al., 2007; 2011). In order to extend our investigations in this field, we designed and synthesized one dinuclear cadmium(II) compound, [Cd₂(C₇H₅O₂)₄(C₁₂H₈N₂)₂], and report its structure here.

The asymmetric unit of the title complex (Fig. 1) contains one Cd^II ion, two benzoate ligands, and one 1,10-phenanthroline molecule. Each Cd^II is seven-coordinate by five O atoms from three benzoate ligands, and two N atoms from 1,10-phenanthroline, and the coordination geometry around the Cd^II ion may be described as a distorted mono-capped trigonal prism. Two adjacent Cd^II units are connected by two bridging benzoate anions to generate a dinuclear complex. The dinuclear molecule lies on a crystallgraphic two-fold axis. The benzoate ligands adopt two different coordination modes acting as bidentate and bridging tridentate ligands.

The Cd—N bond distances of 2.347 (4) and 2.375 (4) Å and the Cd—O bond distances in the range of 2.265 (4)–2.493 (4) Å, are comparable to those reported for other Cd^II—O and Cd^II–N donor complexes (Gu et al., 2011; Shi et al., 2008).

In the crystal structure, π–π stacking interactions between adjacent 1,10-phenanthroline ligands are observed with interplanar distances of 3.392 (4) Å. Furthermore, adjacent benzene rings from benzoate ligands are involved in C—H···π stacking interactions (H—mean plane = 2.567 (4) Å). C–H···π stacking interactions between benzene rings from benzoate ligands and 1,10-phenanthroline ligands are also observed (H—mean plane = 2.781 (4) Å) . The discrete neutral molecules further extend their structure into a three-dimensional supramolecular framework by intermolecular π–π stacking interactions (Fig. 2).

Experimental

A mixture of Cd(CH₃COO)₂.2H₂O (0.14 g, 0.54 mmol), benzoic acid (0.12 g,1.0 mmol), 1,10-phenanthroline (0.11 g, 0.54 mmol), NaOH (0.04 g, 1.0 mmol), and water (10 ml) was stirred at room temperature for 15 min, and then sealed in a 25 ml Teflon-lined, stainless-steel Parr bomb. The bomb was heated at 433 K for 3 days. Upon cooling, the solution yielded single crystals of the title complex in ca 75% yield. Anal. Calcd for C₅₂H₃₆N₄O₈Cd₂: C,58.39; H, 3.39; N, 5.24. Found: C, 58.73; H, 3.17; N, 5.63.