Poly[[hexa­aqua­(μ2-oxalato-κ4 O 1,O 2:O 1′,O 2′)bis­(μ3-pyridine-2,4-dicarboxyl­ato-κ4 N,O 2:O 2′:O 4)dilanthanum(III)] monohydrate]

Fwu Ming Shen; Shie Fu Lush

doi:10.1107/S160053681104668X

. 2011 Nov 9;67(Pt 12):m1731–m1732. doi: 10.1107/S160053681104668X

Poly[[hexaaqua(μ₂-oxalato-κ⁴ O ¹,O ²:O ^1′,O ^2′)bis(μ₃-pyridine-2,4-dicarboxylato-κ⁴ N,O ²:O ^2′:O ⁴)dilanthanum(III)] monohydrate]

Fwu Ming Shen ^a, Shie Fu Lush ^b,^*

PMCID: PMC3238643 PMID: 22199534

Abstract

In the polymeric title compound, {[La₂(C₇H₃NO₄)₂(C₂O₄)(H₂O)₆]·H₂O}_n, the La³⁺ cation is nine-coordinated in a distorted LaNO₈ tricapped trigonal–prismatic geometry formed by three pyridinedicarboxylate anions, one oxalate anion and three water molecules. The oxalate anion is located on an inversion center. The oxalate and pyridinedicarboxylate anions bridge the La³⁺ cations, forming a two-dimensional polymeric complex parallel to (010). Intermolecular O—H⋯O hydrogen bonding and weak C—H⋯O hydrogen bonding is present in the crystal structure and π–π stacking [centroid–centroid distance = 3.571 (3) Å] is observed between parallel pyridine rings of adjacent molecules. The uncoordinated water molecule shows an occupancy of 0.5.

Related literature

For related structures, see: Aghabozorg et al. (2011 ▶); Li et al. (2007 ▶); Wang et al. (2009 ▶).

Experimental

Crystal data

[La₂(C₇H₃NO₄)₂(C₂O₄)(H₂O)₆]·H₂O
M _r = 822.16
Triclinic,
a = 6.4614 (8) Å
b = 6.6844 (8) Å
c = 14.0796 (17) Å
α = 89.735 (2)°
β = 85.266 (2)°
γ = 73.135 (2)°
V = 579.85 (12) Å³
Z = 1
Mo Kα radiation
μ = 3.73 mm⁻¹
T = 295 K
0.30 × 0.10 × 0.10 mm

Data collection

Bruker SMART 1000 CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2001 ▶) T _min = 0.686, T _max = 0.950
5023 measured reflections
2046 independent reflections
1795 reflections with I > 2σ(I)
R _int = 0.035

Refinement

R[F ² > 2σ(F ²)] = 0.032
wR(F ²) = 0.093
S = 1.09
2046 reflections
175 parameters
H-atom parameters constrained
Δρ_max = 2.14 e Å⁻³
Δρ_min = −2.13 e Å⁻³

Data collection: SMART (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: PLATON (Spek, 2009 ▶); software used to prepare material for publication: PLATON.

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S160053681104668X/xu5376sup1.cif

e-67-m1731-sup1.cif^{(20.5KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S160053681104668X/xu5376Isup2.hkl

e-67-m1731-Isup2.hkl^{(102.6KB, hkl)}

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

Table 1. Selected bond lengths (Å).

La1—N1	2.726 (4)
La1—O1ⁱ	2.454 (4)
La1—O3ⁱⁱ	2.541 (5)
La1—O4	2.551 (5)
La1—O5	2.543 (4)
La1—O6ⁱⁱⁱ	2.550 (5)
La1—O7	2.604 (7)
La1—O8	2.553 (5)
La1—O9	2.612 (7)

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

Table 2. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O7—H7A⋯O4ⁱⁱ	0.84	2.08	2.911 (8)	168
O7—H7B⋯O10^iv	0.83	1.71	2.533 (12)	168
O8—H8A⋯O2^v	0.83	1.83	2.660 (7)	173
O8—H8B⋯O6^vi	0.96	2.03	2.914 (7)	153
O9—H9A⋯O6^vi	0.88	2.27	2.987 (8)	138
O9—H9B⋯O10	0.85	1.73	2.390 (14)	133
O10—H10A⋯O5ⁱⁱ	0.83	2.24	2.885 (12)	135
O10—H10A⋯O8ⁱⁱ	0.83	2.29	2.924 (15)	133
O10—H10B⋯O9^vii	0.85	1.77	2.591 (17)	163
C5—H5A⋯O3ⁱⁱ	0.93	2.49	3.164 (7)	130

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Symmetry codes: (ii) Inline graphic ; (iv) ; (v) ; (vi) ; (vii) .

Acknowledgments

This work was supported financially by Yuanpei University, Taiwan.

supplementary crystallographic information

Comment

The pyridine-2,4-dicarboxylic acid (pdcH2) has important coordination functions to metals by either carboxylate bridges between metal centers, to form dimeric complexes or tridentate (O, N, O') chelation to metal ions. Some pydc complexes have been reported (Li et al., 2007; Wang et al., 2009; Aghabozorg et al., 2011).

The symmetric unit of the title compound,{[(LaC₇H₃NO₄)(C₂O₄)_0.5(H₂O)₃]₂.(H₂O)}_n, contains two La^III atoms, two pyridine-2,4-dicarboxylate(pydc) ligands, one oxalate ligand and six coordinated water molecules. The oxalate ligand are both chelating and bridging, forming an oxalate-bridged dinuclear complex. The La^III is nine-coordinated in a distorted tricapped trigonal prismatic geometry by N,O atom from a pydc ligand, two O atoms from two pydc ligands, two O atoms from one oxalate ligand and three O atoms from coordinated water molecules (shown as Fig. 1, Table 1). The geometric center of the dimer lies on an inversion center.

The crystal structure contains weak O—H···O and non-classical C—H···O hydrogen bonds. The π-π stacking between two pyridine rings of (pydc) anion fragments with distances of 3.570 (3) Å (1 - x, 1 - y,1 - z) are observed (Fig. 3). The uncoordinated water molecule shows half-occupation.

Experimental

La(NO₃)₃.6H2O (0.1096 g, 0.25 mmole), pydridine-2,4-dicarboxylic acid (0.0418 g, 0.25 mmol) and 4,4'-dipyridine (0.0464 g, 0.25 mmol) were mixed in 10 ml of deionized water. After stirring for 30 min, the mixture was placed in a 23 ml Teflon-lined reactor which was heated under autogenous pressure to 418 K for 48 h and then allowed to cool to room temperature. The brown transparent single crystals were obtained in 41.3% yield (based on La).