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

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

doi:10.1107/S160053681101840X

. 2011 May 20;67(Pt 6):m778. doi: 10.1107/S160053681101840X

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

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

PMCID: PMC3120329 PMID: 21754661

Abstract

In the centrosymmetric dinuclear title compound, [Pb₂(C₇H₅O₂)₄(C₁₂H₈N₂)₂], two Pb²⁺ ions are connected by two tridentate bridging benzoate anions. The Pb²⁺ ion is seven-coordinated by five O atoms from three benzoate anions and two N atoms from the 1,10-phenanthroline ligands. The benzoate anions adopt two different coordination modes, one bidentate–chelating and one tridentate bridging–chelating. The three-dimensional supramolecular framework is achieved by intermolecular π–π stacking interactions, with a shortest centroid–centroid distance of 3.617 (4) Å.

Related literature

For bond lengths and angles in other lead(II) compounds, see: Fan et al. (2006 ▶); Hu et al. (2011 ▶).

Experimental

Crystal data

[Pb₂(C₇H₅O₂)₄(C₁₂H₈N₂)₂]
M _r = 1259.23
Triclinic,
a = 9.011 (3) Å
b = 10.923 (3) Å
c = 11.920 (4) Å
α = 83.760 (3)°
β = 87.626 (3)°
γ = 71.601 (3)°
V = 1106.6 (6) Å³
Z = 1
Mo Kα radiation
μ = 7.66 mm⁻¹
T = 293 K
0.28 × 0.26 × 0.24 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2004 ▶) T _min = 0.223, T _max = 0.261
7969 measured reflections
4059 independent reflections
3296 reflections with I > 2σ(I)
R _int = 0.041

Refinement

R[F ² > 2σ(F ²)] = 0.034
wR(F ²) = 0.069
S = 0.96
4059 reflections
298 parameters
H-atom parameters constrained
Δρ_max = 1.95 e Å⁻³
Δρ_min = −1.35 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 & Putz, 2005 ▶); software used to prepare material for publication: SHELXTL (Sheldrick, 2008 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S160053681101840X/wm2486sup1.cif

e-67-0m778-sup1.cif^{(19.8KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S160053681101840X/wm2486Isup2.hkl

e-67-0m778-Isup2.hkl^{(198.9KB, hkl)}

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

Table 1. Selected bond lengths (Å).

Pb1—O4	2.394 (4)
Pb1—N1	2.578 (5)
Pb1—O1	2.584 (4)
Pb1—N2	2.703 (5)
Pb1—O2	2.723 (5)
Pb1—O3	2.788 (5)
Pb1—O3ⁱ	2.924 (5)

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Symmetry code: (i) Inline graphic .

supplementary crystallographic information

Comment

Lead(II) compounds have been increasingly studied owing to their interesting physical and chemical properties (Fan et al., 2006; Hu et al., 2011). In order to extend our investigations in this field, we crystallised the lead(II) title compound [Pb₂(C₇H₅O₂)₄(C₁₂H₈N₂)₂], and report its structure here.

The asymmetric unit of the title complex (Fig. 1) contains one Pb²⁺ ion, two benzoate anions, and one 1,10-phenanthroline ligand. The Pb²⁺ ion is seven-coordinated by five O atoms from three benzoate ligands and by two N atoms from 1,10-phenanthroline. The coordination environment around the Pb²⁺ ion may be described as a distorted mono-capped trigonal prism. Two adjacent Pb^II complexes are connected by two bridging benzoate anions to generate a centrosymmetric dinuclear unit. The benzoate anions adopt two kinds of coordination modes, viz. a bidentate chelating and a tridentate bridging-chelating mode.

The Pb—N and Pb—O bond lengths range between 2.578 (5)–2.703 (5) Å and 2.394 (4)–2.924 (5) Å, respectively. These values are in good agreement with those reported for other Pb(II)—O and Pb(II)—N donor complexes (Fan et al., 2006; Hu et al., 2011).

In the crystal structure, π—π stacking interactions between adjacent 1,10-phenanthroline ligands [centroid—centroid distance = 3.617 (4) Å] are observed. Furthermore, adjacent benzene rings from benzoate anions are also involved in π—π stacking interactions [centroid—centroid distance = 4.083 (3) Å]. π—π stacking interactions between adjacent 1,10-phenanthroline ligands and benzene rings from benzoate anions [centroid—centroid distance = 3.945 (4) Å] are also observed. These interactions of the discrete neutral molecules lead to a three-dimensional supramolecular framework (Fig. 2).

Experimental

A mixture of Pb(CH₃COO)₂^.3H₂O (0.20 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 autoclave. The autoclave was heated at 433 K for 3 d. Upon cooling, the solution contained single crystals of the title complex in ca 80% yield. Anal./calc. for C₂₆H₁₈N₂O₄Pb: C, 49.60; H, 2.88; N, 4.45; found: C, 49.43; H, 3.07; N, 4.13.