catena-Poly[[diaquaterbium(III)]-tetrakis(μ2-pyridine-4-carboxylato-κ2 O:O′)-[diaquaterbium(III)]-bis(μ2-pyridine-4-carboxylato-κ2 O:O′)]

Xiangfei Zhang; Bin Zhai

doi:10.1107/S1600536811038487

. 2011 Sep 30;67(Pt 10):m1439–m1440. doi: 10.1107/S1600536811038487

catena-Poly[[diaquaterbium(III)]-tetrakis(μ₂-pyridine-4-carboxylato-κ² O:O′)-[diaquaterbium(III)]-bis(μ₂-pyridine-4-carboxylato-κ² O:O′)]

Xiangfei Zhang ^a, Bin Zhai ^a,^*

PMCID: PMC3201511 PMID: 22065634

Abstract

The title complex, [Tb₂(C₆H₄NO₂)₆(H₂O)₄]_n, was isolated under hydrothermal conditions using the ligand pyridine-4-carboxylic acid (HL) and Tb₂O₃. The deprotonated L ²⁻ ligands adopt bridging coordination modes. The central Tb^III atom is bridged by L ²⁻ ligands, forming a polymeric chain parallel to the a axis. Supramolecular O—H⋯N interactions link the chains, building up a layer parallel to (010). O—H⋯O hydrogen bonds also occur. Two of the pyridine rings are disordered by rotation around the central C—N direction with occupancy ratios of 0.53 (1):0.47 (1).

Related literature

For the properties of metal-organic coordination polymers, see: Bradshaw et al. (2004 ▶); Singh & Roesky (2007 ▶); Rosi et al. (2002 ▶); Thirumurugan & Natarajan (2005 ▶); Thirumurugan et al. (2008 ▶); Forster & Cheetham (2002 ▶); Fan & Zhu (2007 ▶).

Experimental

Crystal data

[Tb₂(C₆H₄NO₂)₆(H₂O)₄]
M _r = 1122.52
Monoclinic,
a = 9.7008 (10) Å
b = 19.813 (2) Å
c = 11.6253 (12) Å
β = 112.009 (1)°
V = 2071.6 (4) Å³
Z = 2
Mo Kα radiation
μ = 3.46 mm⁻¹
T = 293 K
0.26 × 0.20 × 0.18 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2008a ▶) T _min = 0.466, T _max = 0.575
11208 measured reflections
4055 independent reflections
2998 reflections with I > 2σ(I)
R _int = 0.026

Refinement

R[F ² > 2σ(F ²)] = 0.035
wR(F ²) = 0.105
S = 1.11
4055 reflections
259 parameters
148 restraints
H-atom parameters constrained
Δρ_max = 0.78 e Å⁻³
Δρ_min = −1.60 e Å⁻³

Data collection: SMART (Bruker, 1997 ▶); cell refinement: SAINT (Bruker, 1997 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008b ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008b ▶); molecular graphics: PLATON (Spek, 2009 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablock(s) I. DOI: 10.1107/S1600536811038487/dn2711sup1.cif

e-67-m1439-sup1.cif^{(23.2KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811038487/dn2711Isup2.hkl

e-67-m1439-Isup2.hkl^{(198.8KB, 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
O7—H71⋯N3ⁱ	0.84	1.96	2.787 (7)	168
O7—H72⋯N2ⁱⁱ	0.84	1.98	2.802 (5)	167
O8—H81⋯N1ⁱⁱⁱ	0.85	2.01	2.837 (7)	163
O8—H82⋯O7^iv	0.85	2.16	3.002 (5)	171

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

Acknowledgments

This work was supported by the National Natural Science Foundation of China (grant No. 21001071), the Natural Science Research Program of the Education Department of Henan Province (2010A150018) and the Youth Fund Program of Shangqiu Normal University.

supplementary crystallographic information

Comment

Nowadays the connection of metal-organic coordination polymers based on transition metals and multifunctional bridging ligands has proven to be a promising field due to their intriguing and beautiful topologies and potential functions in material chemistry (Singh & Roesky, 2007; Forster & Cheetham, 2002 ). Great effort has been devoted to prepare such materials (Rosi et al., 2002; Thirumurugan & Natarajan, 2005; Fan & Zhu, 2007; Bradshaw et al., 2004; Thirumurugan et al., 2008), for example, multidentate aromatic polycarboxylic acids including benzene-1,2-dicarboxylate, benzene-1,3-dicarboxylate, benzene-1,4-dicarboxylate, benzene-1,2,3-tricarboxylate, benzene-1,2,4-tricarboxylate, benzene-1,3,5- tricarboxylate and benzene-1,2,4,5-tetracarboxylate have been widely used for the syntheses of coordination polymers of transition metal ions, and the syntheses are mainly through the direct interaction between the metal ions and carboxylate groups to construct one-, two-, and three-dimensional networks in a variety of coordination modes. In general, carboxylate positions, functional groups and ligand conformations are important for syntheses of these hybrid materials. The ligand pyridine-4-carboxylic acid (H₂L) has proven to be a good building block for constructing functional coordination polymers. On the other hand, Tb³⁺ complex is strongly fluorescent, having a large fluorescence quantum yield and very long fluorescence lifetime.

In compound I, each Tb^III atom is bonded to six Oatoms from six different carboxylates (Tb–O = 2.424 (3)–2.491 (4) Å) and two water molecules (Tb–O_w = 2.531 (3)–2.559 (3) Å). The coordination geometry around Tb atom can also be described as a distorted square antiprism with O–Tb–O bond angles ranging from 70.52 (11) to 147.15 (11)°. Adjacent two Tb centers are connected together via four bridging carboxylates with the Tb···Tb distances of 4.349 Å, which are further extended by other two L^2-ligand to generate an infinite chain (Figure 1) which develop parallel to the a axis. All carboxylate groups in (I) adopt bridging modes and the potential N-donor coordination site still remains free.

O-H···N supramolecular interactions link the chain to form layers parallel to the (0 1 0) plane (Table 1, Fig. 2). There are also O-H···O intramolecular hydrogen bonds within the chains (Table 1).

Experimental

Synthesis of [TbL₃(H₂O)₂]_n (I). A mixture of H₂L (0.3 mmol), Tb₂O₃(0.1 mmol) and H₂O (15 mL) were placed in a 25 mL Teflon-lined steel vessel and heated to 180 °C for 5 days, then cooled to room temperature. The resulting colorless block-shaped crystals of (I) were washed several times by water and diethyl ether. Elemental analysis calcd for (I) (%): C, 38.52; H, 2.87; N, 7.49. Found: C, 38.46; H, 2.94; N,7.45. Selected IR spectra for (I): ν (cm^-1) = 3449 s, 1632 s, 1401 m,745 m.