Poly[[triaqua­(μ3-4-oxidopyridine-2,6-dicarboxyl­ato)europium(III)] monohydrate]

Dong-Yu Lv; Zhu-Qing Gao; Jin-Zhong Gu

doi:10.1107/S1600536810048518

. 2010 Nov 30;66(Pt 12):m1694–m1695. doi: 10.1107/S1600536810048518

Poly[[triaqua(μ₃-4-oxidopyridine-2,6-dicarboxylato)europium(III)] monohydrate]

Dong-Yu Lv ^a,^*, Zhu-Qing Gao ^b, Jin-Zhong Gu ^a

PMCID: PMC3011704 PMID: 21589349

Abstract

In the title coordination polymer, {[Eu(C₇H₂NO₅)(H₂O)₃]·H₂O}_n, the Eu^III atom is eight-coordinated by a tridentate 4-oxidopyridine-2,6-dicarboxylate (hpc) trianion, two monodentate hpc anions and three water molecules, forming a distorted bicapped trigonal–prismatic coordination geometry. The hpc ligands bridge adjacent Eu^III ions, forming infinite double chains. Adjacent chains are further connected by hpc ligands into sheets. O—H⋯O hydrogen bonds then generate a three-dimensional supramolecular framework.

Related literature

For the structures and properties of lanthanide coordination compounds, see: He et al. (2010 ▶); Kustaryono et al. (2010 ▶); Zhu, Sun et al. (2009 ▶); Wong et al. (2006 ▶). For the use of multi-carboxylate and heterocyclic acids in coordination chemistry, see: Li et al. (2008 ▶); Luo et al. (2008 ▶) and for the dicarboxylate ligand H₃CAM (H₃CAM is 4-hydroxy-pyridine-2,6-dicarboxylic acid), see: Gao et al. (2006 ▶, 2008 ▶). For the isotypic structure {[Dy(CAM)(H₂O)₃]·H₂O}_n, see: Gao et al. (2006 ▶). For bond lengths and angles in other complexes with eight-coordinate Eu^III, see: Li et al. (2008 ▶); Zhu, Ikarashi et al. (2009 ▶)

Experimental

Crystal data

[Eu(C₇H₂NO₅)(H₂O)₃]·H₂O
M _r = 404.12
Monoclinic,
a = 10.0041 (15) Å
b = 7.5456 (11) Å
c = 15.528 (2) Å
β = 104.890 (1)°
V = 1132.8 (3) Å³
Z = 4
Mo Kα radiation
μ = 5.58 mm⁻¹
T = 296 K
0.35 × 0.32 × 0.31 mm

Data collection

Bruker APEX CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 1997 ▶) T _min = 0.246, T _max = 0.277
4884 measured reflections
2023 independent reflections
1856 reflections with I > 2σ(I)
R _int = 0.074

Refinement

R[F ² > 2σ(F ²)] = 0.026
wR(F ²) = 0.065
S = 1.06
2023 reflections
196 parameters
12 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.82 e Å⁻³
Δρ_min = −1.69 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: SHELXTL ▶.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810048518/hb5735sup1.cif

e-66-m1694-sup1.cif^{(19.5KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810048518/hb5735Isup2.hkl

e-66-m1694-Isup2.hkl^{(99.5KB, hkl)}

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

Table 1. Selected bond lengths (Å).

Eu1—O5ⁱ	2.327 (2)
Eu1—O8	2.401 (3)
Eu1—O7	2.416 (3)
Eu1—O1	2.432 (2)
Eu1—O2ⁱⁱ	2.433 (2)
Eu1—O3	2.440 (2)
Eu1—O6	2.445 (3)
Eu1—N1	2.498 (3)

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

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O6—H1W⋯O9ⁱⁱⁱ	0.90 (2)	1.85 (3)	2.696 (3)	158 (4)
O6—H2W⋯O9^iv	0.87 (2)	2.15 (3)	2.962 (4)	156 (4)
O7—H4W⋯O3ⁱⁱⁱ	0.86 (2)	2.09 (3)	2.805 (3)	141 (4)
O8—H5W⋯O1ⁱⁱ	0.86 (2)	1.84 (2)	2.684 (4)	168 (4)
O8—H6W⋯O4^v	0.87 (2)	1.83 (2)	2.696 (4)	173 (4)
O9—H7W⋯O2^vi	0.86 (2)	2.26 (3)	3.059 (4)	155 (5)
O9—H8W⋯O4	0.86 (2)	1.84 (2)	2.692 (4)	172 (6)

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

supplementary crystallographic information

Comment

The design and synthesis of lanthanide coordination polymers have achieved great progress over the past decades(He et al., 2010; Kustaryono et al., 2010). These coordination polymers have shown not only their versatile architectures but also their desirable properties luminescent, magnetic, catalytic, and gas absorption and separation properties (Zhu et al., 2009; Wong et al., 2006). Many multi-carboxylate or heterocylic carboxylic acids are used for this purpose (Li et al., 2008; Luo et al., 2008). In the designed synthesis of the lanthanide coordination polymers, 4-hydroxy-pyridine-2,6-dicarboxylic acid (H₃CAM) is an excellent pyridine dicarboxylate ligand (Gao et al., 2006; Gao et al., 2008),which can afford at most one nitrogen atom and five O coordination sites. In order to extend the investigation in this field, we designed and synthesized one lanthanidecoordination polymer [Eu(CAM)(H₂O)₃]_n.nH₂O, and report its structure here.

The title compound is located on a twofold helical axis of symmetry, which is isomorphous with {[Dy(CAM)(H₂O)₃].H₂O}_n (Gao et al., 2006). As shown in Fig.1, the asymmetrical unit of the cell contains one Eu (III) ion, one CAM liangd, three coordinated water molecules, and one guest water molecule. Eu atom is eight-coordinated with seven oxygen atoms from three individual CAM ligands and three coordinated water molecules and one nitrogen atom from the CAM ligand, forming a distorted bicapped square-prismatic coordination geometry.

Important bond distances and angles are presented in Table 1. The Eu–O bond distances [2.327 (2) to 2.445 (3) Å]are shorter than the Eu–N bond distance [2.498 (3) Å], which are in good with those observed in other Eu (III) complexes (Li et al., 2008; Zhu et al., 2009). The CAM ligands adopt a µ₃-pentadentate coordination mode, as shown in Fig.1. The CAM ligands bridge the adjacent Eu^III ions to form infinite double chains (Fig.2). The adjacent chains are further connected by the coordination of the CAMligands and Eu^III ions to form two-dimensional sheet (Fig.3), which are further extended into three-dimensional supramolecular frameworks through H-bond interactions (Table 4).

Experimental

To a solution of europium nitrate hexahydrate (0.134 g, 0.3 mmol) in water (5 ml) was added an aqueous solution (5 ml) of the ligand (0.060 g, 0.3 mmol) and a drop of triethylamine. The reactants were sealed in a 25-ml Teflon-lined, stainless-steel Parr bomb. The bomb was heated at 433 K for 3 days. The cool solution yielded colourless blocks in ca 60% yield. Anal. Calcd for C₇H₁₀EuNO₉: C, 20.80; H, 2.49; N, 3.47. Found: C, 20.51; H, 2.77; N, 3.12.