Poly[aqua­(μ3-pyridazine-4-carboxyl­ato-κ2 O:O:O′)lithium]

Wojciech Starosta; Janusz Leciejewicz

doi:10.1107/S1600536811008634

. 2011 Mar 12;67(Pt 4):m425–m426. doi: 10.1107/S1600536811008634

Poly[aqua(μ₃-pyridazine-4-carboxylato-κ² O:O:O′)lithium]

Wojciech Starosta ^a, Janusz Leciejewicz ^a,^*

PMCID: PMC3099971 PMID: 21753953

Abstract

The structure of the title compound, [Li(C₅H₃N₂O₂)(H₂O)]_n, is composed of centrosymmetric dimers in which two Li^I ions are bridged by a carboxylate O atom, each donated by a ligand, acting in a bidentate mode. The second carboxylato O atoms bridge the dimers to Li^I ions in adjacent dimers, forming molecular layers parallel to (001). Each Li^I ion is coordinated by two bridging carboxylate O atoms, a bridging carboxylate O atom donated by the adjacent dimer and an aqua O atom, resulting in a distorted tetrahedral coordination geometry. The layers are held together by O—H⋯N hydrogen bonds in which coordinated water O atoms act as donors and ligand hetero-ring N atoms as acceptors.

Related literature

For the crystal structure of a Pb(II) complex with pyridazine-4-carboxylate and water ligands, see: Starosta & Leciejewicz, (2009 ▶) and for the structure of a Mg(II) complex, see: Starosta & Leciejewicz, (2011b ▶). For the structure of pyridazine-4-carboxylic acid hydrochloride, see: Starosta & Leciejewicz, (2008 ▶) and for the structure of a Li^I complex with pyridazine-3-carboxylate and water ligands, see: Starosta & Leciejewicz, (2011a ▶).

Experimental

Crystal data

[Li(C₅H₃N₂O₂)(H₂O)]
M _r = 148.05
Monoclinic,
a = 8.1673 (16) Å
b = 9.6908 (19) Å
c = 8.0248 (16) Å
β = 97.08 (3)°
V = 630.3 (2) Å³
Z = 4
Mo Kα radiation
μ = 0.13 mm⁻¹
T = 293 K
0.30 × 0.28 × 0.12 mm

Data collection

Kuma KM-4 four-circle diffractometer
Absorption correction: analytical (CrysAlis RED; Oxford Diffraction, 2008) ▶ T _min = 0.946, T _max = 0.973
1958 measured reflections
1843 independent reflections
1208 reflections with I > 2σ(I)
R _int = 0.077
3 standard reflections every 200 reflections intensity decay: 2.1%

Refinement

R[F ² > 2σ(F ²)] = 0.039
wR(F ²) = 0.128
S = 1.02
1843 reflections
108 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.33 e Å⁻³
Δρ_min = −0.28 e Å⁻³

Data collection: KM-4 Software (Kuma, 1996 ▶); cell refinement: KM-4 Software; data reduction: DATAPROC (Kuma, 2001 ▶); 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/S1600536811008634/kp2313sup1.cif

e-67-0m425-sup1.cif^{(13.5KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811008634/kp2313Isup2.hkl

e-67-0m425-Isup2.hkl^{(90.8KB, hkl)}

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

Table 1. Selected bond lengths (Å).

O1—Li1	1.967 (2)
Li1—O2ⁱ	1.909 (3)
Li1—O3	1.915 (3)
Li1—O1ⁱⁱ	1.946 (2)

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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
O3—H32⋯N1ⁱⁱⁱ	0.86 (3)	1.93 (3)	2.7910 (18)	175 (3)
O3—H31⋯N2^iv	0.85 (3)	2.33 (3)	3.1272 (19)	155 (2)

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

supplementary crystallographic information

Comment

The structural unit of the title compound is a centrosymmetric dimer composed of two Li^I ions bridged by a bidentate carboxylate O1 atom, each donated by one of two symmetry related ligands. The ligand carboxylate group C7/O1/O2 makes with the O1/Li1/O1^(II)/Li1^(II) plane a dihedral angle of 10.9 (1)°, while the dihedral angle between this carboxylate group and the pyridazine ring is 43.4 (2)°. The pyridazine ring is almost planar with r.m.s. of 0.0148 (2) Å. Both ligand's heterocyclic N atoms remain coordination inactive. Bond distances and bond angles within the ligand molecule fit the values reported earlier in the structures of pyridazine-4-carboxylic acid hydrochloride (Starosta & Leciejewicz, 2008) and other metal complexes with the title ligand. The Li^I ion is coordinated by the bridging carboxylato O1 and O1^(II)atoms, a bridging carboxylato O2^(I) atom donated by the adjacent dimer and the aqua O3 atom resulting in a distorted tetrahedral coordination. The observed Li—O bond distances which fall in the range from 1.909 (3) to 1.946 (2)Å are characteristic for all Li^I complexes with carboxylate ligands. Carboxylato O2 atoms bridge the dimers into molecular layers which are approximately parallel to the crystal bc plane. The structure of a layer can be visualized as composed of corrugated loops with four equal sides and the dimers at their apices. Hydrophobic parts of pairs of pyridazine rings are directed inside the loop with the closet distance of 4.91 (1)Å between the ring centers while the heterocyclic N atoms are directed outside and participate in a network of hydrogen bonds. The latter consists of coordinated water molecules acting as donors and the pyridazine N atoms in an adjacent layer as acceptors. They form centrosymmetric rings which give rise to a three-dimensional structure. Discrete dinuclear molecules were reported to constitute the structure of a Pb(II) complex with the title ligand, in which two symmetry related metal ions are bridged by a pair of ligands via their heterocyclic N atoms and two pairs of aqua O atoms. Each Pb(II) ion is also coordinated by two carboxylate O atoms of another ligand (Starosta & Leciejewicz, 2009). On the other hand, the structure of a Mg(II) complex is built of discrete centrosymmetric molecules in which the metal ion is coordinated by only one carboxylato O atom of two ligands and two pairs of aqua O atoms in octahedral geometry. Heterocyclic N atoms do not act in coordination mode (Starosta & Leciejewicz, 2011b). Discrete monomers have been also reported to constitute the structure of a Li^I complex with the pyridazine-3-carboxylate and water ligands. A Li^I ion is coordinated by ligand N,O chelating group and two aqua O atoms in a terahedral mode (Starosta & Leciejewicz, 2011a).

Experimental

The title compound was obtained by boiling under reflux with stirring 50 ml of an aqueous solution containig 1 mmol of pyridazine-4-carboxylic acid (Aldrich) and 1 mmol of LiOH (Aldrich). The solution was boiled for two h. After cooling to room temperature a 1 N solution of HCl was added dropwise until the pH reached the value of 5.5 and then left to crystallize. Ten days later, colourless crystalline plates were found after evaporating to dryness. They were recrystallized from water a couple of times until well formed single crystals were found. They were washed with cold ethanol and dried in air.