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

Junli Gao; Xiaopeng Xuan

doi:10.1107/S1600536809025896

. 2009 Jul 11;65(Pt 8):m900. doi: 10.1107/S1600536809025896

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

Junli Gao ^a, Xiaopeng Xuan ^a,^*

PMCID: PMC2977393 PMID: 21583360

Abstract

The title compound, [Pb₂(CH₃COO)₂(C₇H₅O₂)₂(C₁₂H₈N₂)₂]·2H₂O, consists of dimeric units built up around a crystallographic centre of symmetry and two non-coordinating water molecules. Each Pb^II unit is six-coordinated by a bidentate 1,10-phenanthroline (phen) ligand, a monodentate acetate anion and a bidentate benzoate anion, which also acts as a bridge linking the two Pb^II atoms. The crystal packing is stabilized by O—H⋯O hydrogen bonds and by π–π interactions between the phen rings of neighboring molecules, with a centroid–centroid distance of 3.577 (3) Å.

Related literature

For information on the coordination chemistry of lead, see: Shimoni-Livny et al. (1998 ▶). For related structures, see: Li & Yang (2004 ▶); Xuan et al. (2008 ▶); Xuan & Zhao (2007 ▶); Zhao et al. (2007 ▶); Zhu et al. (2004 ▶).

Experimental

Crystal data

[Pb₂(C₂H₃O₂)₂(C₇H₅O₂)₂(C₁₂H₈N₂)₂]·2H₂O
M _r = 1171.15
Monoclinic,
a = 11.809 (4) Å
b = 13.910 (5) Å
c = 12.290 (4) Å
β = 107.392 (4)°
V = 1926.5 (11) Å³
Z = 2
Mo Kα radiation
μ = 8.79 mm⁻¹
T = 294 K
0.11 × 0.07 × 0.05 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 1997 ▶) T _min = 0.445, T _max = 0.668
16820 measured reflections
4417 independent reflections
3343 reflections with I > 2σ(I)
R _int = 0.044

Refinement

R[F ² > 2σ(F ²)] = 0.029
wR(F ²) = 0.057
S = 1.03
4417 reflections
263 parameters
18 restraints
H-atom parameters constrained
Δρ_max = 0.73 e Å⁻³
Δρ_min = −0.85 e Å⁻³

Data collection: SMART (Bruker, 1997 ▶); cell refinement: SAINT (Bruker, 1997 ▶); 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 ▶); software used to prepare material for publication: publCIF (Westrip, 2009 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809025896/sj2634sup1.cif

e-65-0m900-sup1.cif^{(22.7KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809025896/sj2634Isup2.hkl

e-65-0m900-Isup2.hkl^{(216.4KB, hkl)}

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

Table 1. Selected bond lengths (Å).

Pb1—O3	2.399 (3)
Pb1—O2	2.426 (3)
Pb1—O1	2.565 (3)
Pb1—O1ⁱ	2.828 (3)
Pb1—N2	2.619 (4)
Pb1—N1	2.688 (4)

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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
O5—H2W⋯O3ⁱⁱ	0.83	2.15	2.958 (5)	166
O5—H1W⋯O4	0.83	2.11	2.928 (5)	169

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Symmetry code: (ii) Inline graphic .

Acknowledgments

We are grateful to the Youth Natural Science Foundation of Henan Normal University for financial support.

supplementary crystallographic information

Comment

Because of the increasing impact of the toxic heavy metal lead on the natural environment, the coordination behavior of lead ion has received more and more attention. Lead(II) is capable of exhibiting a variable coordination number and geometry with or without a stereochemically active lone pair of electrons (Shimoni-Livny et al. 1998). Among such compounds, a number of centrosymmetric dinuclear lead(II) compounds with 1,10-phenanthroline (phen) or its derivatives and oxygen donor ligands have been structurally characterized (Li & Yang, 2004, Xuan et al. 2008, Xuan & Zhao, 2007, Zhao et al. 2007, Zhu et al. 2004,). Recently, we obtained the title lead(II) complex containing two different kinds of anions, by the reaction of lead acetate, sodium benzoate and phen in ethanol/water mixtures.

The crystal structure of the title compound consists of dimeric units [Pb₂(C₂H₃O₂)₂(C₇H₅O₂)₂(C₁₂H₈N₂)₂], related by a crystallographic inversion centre (Fig. 1), and two uncoordinated water molecules. Both the acetate and benzoate anions are coordinated to each Pb(II) atom and a carboxylate oxygen of each benzoate anion forms a bridge between the two inversion related lead atoms. Each lead atom is chelated by the two N atoms of phen with Pb—N distances of 2.619 (4), and 2.688 (4) Å, three carbonyl oxygen atoms of two benzoate anions and one carbonyl oxygen atoms of an acetate anion. The weak Pb—O bridging interactions form a four-membered Pb₂O₂ quadrilateral with a Pb—Pb separation of 4.289 (5) Å.

The crystal structure is stabilized by intermolecular O—H···O hydrogen bonds (Table 1 and Figure 2). The uncoordinated water molecules participate in hydrogen bonding to oxygen atoms of the acetate anions. The crystal packing is further stabilized by π-π stacking interactions between adjacent phen molecules. The centroid-centroid distance between Cg1 (N1/C8—C11/C19) and Cg2 (N2/C14—C18)[symmetry code: 1 - x, -y, 1 - z] is 3.575 (3) Å.

Experimental

A solution (10 ml) of ethanol containing 1,10-phenanthroline (0.5 mmol) and sodium benzoate (1 mmol) was added slowly to a aqueous solution (10 ml) containing lead acetate trihydrate (0.5 mmol). The mixture was refluxed for 5 h and the resulting white precipitate was filtered. Block-like single crystals were obtained by slow evaporation of the filtrate at room temperature after five days.