μ-4,4′-Bipyridine-κ2 N:N′-bis­[bis­(2-chloro­benzoato-κ2 O,O′)lead(II)]

Tian-Jun Feng

doi:10.1107/S1600536811022422

. 2011 Jun 18;67(Pt 7):m935. doi: 10.1107/S1600536811022422

μ-4,4′-Bipyridine-κ² N:N′-bis[bis(2-chlorobenzoato-κ² O,O′)lead(II)]

Tian-Jun Feng ^a,^*

PMCID: PMC3152032 PMID: 21836919

Abstract

In the title dinuclear complex, [Pb₂(C₇H₄ClO₂)₄(C₁₀H₈N₂)], the Pb^II atom is five-coordinated by four carboxylate O atoms from two 2-chlorobenzoate ligands and one N atom from a bridging 4,4′-bipyridine (4,4′-bpy) ligand, displaying a hemi-directed coordination. The 4,4′-bpy ligand has an inversion center at the mid-point of the central C—C bond. The empty side of the metal ion is capped by two carboxylate O atoms from a neighboring molecule, with weak Pb⋯O contacts [Pb⋯O = 3.069 (2) and 3.071 (3) Å]. The crystal structure is stabilized by C—H⋯O hydrogen bonds and π–π stacking interactions between the benzene and pyridine rings [centroid–centroid distance = 3.749 (3) Å].

Related literature

For general background to 2-chlorobenzoate complexes, see: Gomez & Corbella (2009 ▶); Motokawa et al. (2010 ▶). For general background to 4,4′-bipyridine complexes, see: Biradha et al. (2006 ▶). For hemi- and holo-directed geometries of lead(II) complexes, see: Shimoni-Livny et al. (1998 ▶).

Experimental

Crystal data

[Pb₂(C₇H₄ClO₂)₄(C₁₀H₈N₂)]
M _r = 1192.79
Orthorhombic,
a = 21.9370 (13) Å
b = 7.4569 (5) Å
c = 23.2379 (14) Å
V = 3801.3 (4) Å³
Z = 4
Mo Kα radiation
μ = 9.18 mm⁻¹
T = 296 K
0.30 × 0.28 × 0.22 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.092, T _max = 0.145
15375 measured reflections
3398 independent reflections
2712 reflections with I > 2σ(I)
R _int = 0.032

Refinement

R[F ² > 2σ(F ²)] = 0.026
wR(F ²) = 0.081
S = 1.09
3398 reflections
244 parameters
H-atom parameters constrained
Δρ_max = 0.84 e Å⁻³
Δρ_min = −0.53 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: SHELXTL (Sheldrick, 2008 ▶) and Mercury (Macrae et al., 2006 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536811022422/hy2436sup1.cif

e-67-0m935-sup1.cif^{(21.2KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811022422/hy2436Isup2.hkl

e-67-0m935-Isup2.hkl^{(166.8KB, hkl)}

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

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C15—H15⋯O1ⁱ	0.93	2.40	3.239 (7)	150
C16—H16⋯O2ⁱⁱ	0.93	2.55	3.361 (6)	146
C19—H19⋯O4	0.93	2.39	3.026 (5)	125

Open in a new tab

Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

The authors acknowledge Lanzhou Jiaotong University for supporting this work.

supplementary crystallographic information

Comment

In the structural investigation of 2-chlorobenzoate complexes, it has been found that 2-chlorobenzoic acid (2-Hcbz) functions as a multidentate ligand with versatile binding and coordination modes (Gomez & Corbella, 2009; Motokawa et al., 2010). As is well known, 4,4'-bipyridine (4,4'-bpy) ligand can act in bidentate bridging or monodentate terminal modes (Biradha et al., 2006). In this paper, we report the crystal structure of the title compound, a new Pb(II) complex obtained by the reaction of 2-Hcbz, 4,4'-bpy and lead(II) acetate in an alkaline aqueous solution.

As depicted in Fig. 1, the Pb^II atom is coordinated by four O atoms from two 2-cbz ligands and one N atom from a µ-4,4'-bpy ligand. The coordination environment of the Pb^II atom is hemidirected. The empty sapce around the metal ion is filled by the stereochemically active 6S² electron pair (Shimoni-Livny et al., 1998) and two Pb···O contacts [Pb1···O1ⁱ = 3.069 (2), Pb1···O3ⁱ = 3.071 (3) Å. Symmetry code: (i) 1/2-x, 1/2+y, z]. The µ-4,4'-bpy ligand, having an inversion center at the mid-point of the central C—C bond, bridges two Pb atoms, with a Pb1···Pb1ⁱⁱ distance of 12.073 (3) Å [symmetry code: (ii) -x, 3-y, -z]. The interactions of the structural components are governed by Pb···O contacts, C—H···O hydrogen bonds (Table 1) and π–π stacking interactions. The centroid–centroid distance between the benzene ring of a 2-cbz ligand and the pyridine ring of a 4,4'-bpy at (x, -1+y, z) is 3.749 (3) Å (Fig. 2).

Experimental

A mixture of lead acetate (1 mmol, 0.325 g), 2-Hcbz (1 mmol, 0.156 g), 4,4'-bpy (1 mmol, 0.156 g), NaOH (1.5 mmol, 0.06 g) and H₂O (12 ml) was placed in a 23 ml Teflon-lined reactor, which was heated at 433 K for three days and then cooled to room temperature at a rate of 10 K h^-1. The colorless crystals obtained were washed with water and dried in air.