Disodium dihydrogen pyridine-2,3,5,6-tetra­carboxyl­ate trihydrate

Fang-Hong Hu; Jian-Li Lin

doi:10.1107/S1600536810012870

. 2010 Apr 14;66(Pt 5):m524. doi: 10.1107/S1600536810012870

Disodium dihydrogen pyridine-2,3,5,6-tetracarboxylate trihydrate

Fang-Hong Hu ^a, Jian-Li Lin ^a,^*

PMCID: PMC2979161 PMID: 21579019

Abstract

In the title compound, 2Na⁺·C₉H₃NO₈ ²⁻·3H₂O, the asymmetric unit consists of two Na⁺ cations, one dihydrogen pyridine-2,3,5,6-tetracarboxylate dianion (H₂pdtc²⁻) and three water molecules coordinated to the Na⁺ cations. The configuration of the anion is stabilized by intramolecular O—H⋯O hydrogen bonding between vicinal carboxylate/carboxy groups. The Na⁺ cations are bridged by the H₂pdtc²⁻ dianions, generating layers extending infinitely in sheets parallel to (001), and further pillared by the water molecule linkers to build up a three-dimensional framework.

Related literature

For related compounds involving the pyridine-2,3,5,6-tetracarboxylic acid ligand, see: Zhang et al. (2010 ▶); Yang et al. (2008 ▶); Sun, Zhou & An (2009 ▶); Sun, Zhou & Yan (2009 ▶).

Experimental

Crystal data

2Na⁺·C₉H₃NO₈ ²⁻·3H₂O
M _r = 353.15
Triclinic,
a = 5.5844 (11) Å
b = 6.6770 (13) Å
c = 18.631 (4) Å
α = 81.34 (3)°
β = 86.77 (3)°
γ = 68.36 (3)°
V = 638.4 (2) Å³
Z = 2
Mo Kα radiation
μ = 0.23 mm⁻¹
T = 293 K
0.1 × 0.1 × 0.1 mm

Data collection

Rigaku R-AXIS RAPID diffractometer
Absorption correction: multi-scan (ABSCOR; Higashi, 1995 ▶) T _min = 0.97, T _max = 0.98
5075 measured reflections
2247 independent reflections
1780 reflections with I > 2σ(I)
R _int = 0.018

Refinement

R[F ² > 2σ(F ²)] = 0.043
wR(F ²) = 0.139
S = 1.14
2247 reflections
208 parameters
H-atom parameters constrained
Δρ_max = 0.55 e Å⁻³
Δρ_min = −0.33 e Å⁻³

Data collection: RAPID-AUTO (Rigaku, 1998 ▶); cell refinement: RAPID-AUTO; data reduction: CrystalStructure (Rigaku/MSC, 2004 ▶); 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: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810012870/ds2024sup1.cif

e-66-0m524-sup1.cif^{(20.2KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810012870/ds2024Isup2.hkl

e-66-0m524-Isup2.hkl^{(110.4KB, 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
O3—H3⋯O2	0.86	1.55	2.410	175
O7—H7⋯O6	0.86	1.55	2.402	175
O9—H9A⋯O1ⁱ	0.85	2.05	2.900	175
O9—H9B⋯O1ⁱⁱ	0.86	2.11	2.945	161
O10—H10A⋯O2ⁱⁱⁱ	0.88	2.21	3.024	153
O10—H10B⋯O8^iv	0.88	1.86	2.738	173
O11—H11A⋯O4^v	0.89	2.05	2.917	167
O11—H11B⋯O4^iv	0.88	2.08	2.949	170

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

Acknowledgments

This project was supported by the National Natural Science Foundation of China (grant No. 20072022), the Science and Technology Department of Zhejiang Province (grant No. 2006C21105), and the Education Department of Zhejiang Province. The authors also extend grateful thanks to the K. C. Wong Magna Fund of Ningbo University.

supplementary crystallographic information

Comment

A great many metal-polycarboxylate compounds with benzene-1,2,4,5-tetracarboxylic acid (H₄btec) as ligands have been designed and characterized (Zhang et al., 2010). Analogous in structure to H₄btec, only four complexes [Ni(H₂pdtc)(H₂O)₂].3H₂O (Yang et al., 2008), [Zn₄(pdtc)₂(phen)₂(H₂O)₂].20H₂O (Yang et al., 2008), [Cd(H₂pdtc)(H₂O)₃].3H₂O (Sun, Zhou & Yan, 2009) and [Ni₂(pdtc)(H₂O)₃(2,2'-bpy)].4H₂O (Sun, Zhou & An, 2009) about pyridine-2,3,5,6-tetracarboxylic acid (H₄pdtc) have been reported. The four coordination polymers are constructed by linking transition metal centres through the ligands. In this context, we represent a disodium salt of dihydrogen pyridine-2,3,5,6-tetracarboxylate dianion [Na₂(H₂pdtc)(H₂O)₃].

The asymmetric unit of the title compound consisits of two crystallographically independent Na cations, one dihydrogen pyridine-2,3,5,6-tetracarboxylate dianion (H₂pdtc^2-) and three water molecules (Fig. 1). The ligand is deprotonated at 2,5-positioned carboxylate groups. The values of the dihedral angle between the planes of the carboxylic groups and the planar pyridine ring are 3.7 (4)°, 2.0 (5)°, 10.5 (4)°, 2.4 (5)°, respectively. Both Na1 and Na2 ions are seven-coordinated with one N atom, two carboxylate O atoms and four water molecules at Na1 and five carboxylate O atoms and two water molecules at Na2, building highly distorted pentagonal–bipyramidal environment. The average value of the Na—O(water) length [2.494 (2) Å] is closer to the average Na—O (carboxylate) distance [2.498 (2) Å], and both are slightly smaller than the Na—N value [2.654 (2) Å]. The sodium cations are bridged by the (H₂pdtc^2-) to generate layers extending infinitely in sheets parallel to (001) (Fig. 2), and further pillared by the water molecule linkers (Fig. 3) to build up 3D framework, which is found to be stabilized by hydrogen bonds from water molecules to carboxylate O atoms (Table 1).

Experimental

0.0766 g (0.3 mmol) pyridine-2,3,5,6-tetracarboxylic acid and 0.024 g (0.6 mmol) NaOH were successively added to 10.0 ml H₂O and stirred at room temperature for 2 h, and the resulting colorless solution (pH = 3.48) was then transferred to a 50 ml beaker for slow evaporation at room temperature for several months, affording colorless block crystals (yield: 0.05 g).