Poly[(μ2-nitrato-κ2 O:O′)(μ2-pyrimidin­ium-2-carboxyl­ato-κ2 O:O′)lithium(I)]

Wojciech Starosta; Janusz Leciejewicz

doi:10.1107/S1600536811019520

. 2011 May 28;67(Pt 6):m818. doi: 10.1107/S1600536811019520

Poly[(μ₂-nitrato-κ² O:O′)(μ₂-pyrimidinium-2-carboxylato-κ² O:O′)lithium(I)]

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

PMCID: PMC3120533 PMID: 21754689

Abstract

In the structure of the title compound, [Li(C₅H₄N₂O₂)(NO₃)]_n, the Li^I ion is coordinated by two carboxylate O atoms donated by two ligands and two nitrate O atoms in a distorted tetrahedral geometry. Li^I ions, bridged by carboxylate O atoms, form molecular ribbons composed of dimeric units. Two nitrate O atoms link the ribbons into molecular layers parallel to (001). Hydrogen bonds are active between protonated heterocyclic N atoms as donors and carboxylate O atoms as acceptors. The layers are held together by van der Waals interactions.

Related literature

For the polymeric structures of some metal complexes with a pyrimidine-2-carboxylate ligand, see: Rodríguez-Diéguez et al. (2007 ▶, 2008 ▶); Zhao & Liu (2010 ▶); Zhang et al. (2008a ▶). For structures built of monomeric molecules, see: Kokunov & Gorbunova (2007 ▶); Antolić et al. (2000 ▶); Zhang et al. (2008b ▶); Suares-Varela et al. (2008 ▶).

Experimental

Crystal data

[Li(C₅H₄N₂O₂)(NO₃)]
M _r = 193.05
Orthorhombic,
a = 12.403 (3) Å
b = 9.3290 (19) Å
c = 12.810 (3) Å
V = 1482.2 (5) Å³
Z = 8
Mo Kα radiation
μ = 0.15 mm⁻¹
T = 293 K
0.49 × 0.48 × 0.14 mm

Data collection

Kuma KM-4 four-circle diffractometer
Absorption correction: analytical (CrysAlis RED; Oxford Diffraction,2008 ▶) T _min = 0.782, T _max = 0.939
4248 measured reflections
2179 independent reflections
1504 reflections with I > 2σ(I)
R _int = 0.158
3 standard reflections every 200 reflections intensity decay: 3.8%

Refinement

R[F ² > 2σ(F ²)] = 0.050
wR(F ²) = 0.153
S = 0.97
2179 reflections
131 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.43 e Å⁻³
Δρ_min = −0.32 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/S1600536811019520/kp2322sup1.cif

e-67-0m818-sup1.cif^{(13.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811019520/kp2322Isup2.hkl

e-67-0m818-Isup2.hkl^{(107.2KB, hkl)}

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

Table 1. Selected bond lengths (Å).

O1—Li1	1.978 (3)
O11—Li1	1.967 (3)
Li1—O12ⁱ	2.001 (4)
Li1—O2ⁱⁱ	2.019 (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
N2—H2⋯O1ⁱⁱⁱ	0.90 (3)	1.68 (3)	2.5762 (17)	174 (3)

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Symmetry code: (iii) Inline graphic .

supplementary crystallographic information

Comment

The structure of the title compound contains Li^I ions, each coordinated by two ligand carboxylato and two nitrato O atoms at the apieces of a distorded trigonal pyramid. Its base is composed of coplanar carboxylato O1, nitrato O11 and O12^II atoms (Fig. 1). The Li^I ion is shifted by 0.0548 (2)Å above this plane. The carboxylato O2^III atom is at the apex of the pyramid. The Li—O bond distances fall in the range from 1.967 (3) to 2.019 (3) Å, commonly observed in the structures of Li complexes with carboxylate ligands (Table 1). The Li1—N1 bond distance of 2.467 (3)Å as too long was not allowed for in coordination of the Li ion The pyrimidine ring is planar with r.m.s. of 0.0074 (2) Å]. A hydrogen atom attached to the hetero-ring N2 atom, clearly visible on the Fourier map, maintains the charge balance. It links the N2 atom with the carboxylato O^I atom via a hydrogen bond of 2.5762 (17) Å. Bond distances and bond angles within the pyrimidine ring do not differ from those reported earlier in the structures of other metal complexes with the title ligand. The carboxylate group C7/O1/O2 makes with the ring a dihedral angle of 14.81 (2)°. Two Li^I ions, one coordinated by the carboxylato O1 atom, the other by the second carboxylato O2 atom of the same ligand form molecular ribbons composed of dimeric units (Fig. 2). The latter bridged by nitrato O11 and O12^II atoms give rise to molecular layers. While the nitrato O11 atom coordinates a Li^I ion in one ribbon plane, the O12 atom is bonded along the crystal c axis to a Li^I ion in an adjacent ribbon; the O11—N11—O12 bond angle is 120.44 (17)°. The third nitrato O13 atomis not involved in the coordination. The NO₃ group is planar with r.m.s. of 0.0023 (0) Å. It makes a dihedral angle of 28.8 (2)° with the ribbon plane. Since the bridging nitrate O12 atom is in a terminal position and it is bonded to the Li^I ion in the middle of an adjacent ribbon, a layer is formed. A sequence of open channels which propagate along crystal a direction form a layer parallel to the ab plane. The layers stacked along the crystal c direction are held together by van der Waals type interactions. A variety of polymeric molecular patterns have been recently observed in the structures of a number of divalent metal complexes with the title ligand, for example: Mn(II) (Rodríguez-Diéguez et al., 2008; Zhang et al., 2008a); Fe(II) and Co(II) (Rodríguez-Diéguez et al., 2007; Zhao & Liu, 2010); Ca(II) Zhang et al., 2008a), complexes. Structures built of monmeric molecules have been also reported: in a Ag(I) complex by Kokunov & Gorbunova, (2007); in a Cu(II) complex by Suares-Varela et al., (2008) and Zhang et al., (2008a). The structures of two Co(II) complexes have been determined by Antolić et al., (2000) and Zhang et al., (2008b).

Experimental

50 mL of an aqueous solution containing 1 mmol of pyrimidine-2-carbonitrile (Aldrich) and 1 mmol of lithium nitrate hydrate were boiled with constant stirring under reflux for 6 h. After cooling to room temperature 1 N HNO₃ was added dropwise until the pH reached 6. Then the solution was stirred for 3 h. After evaporation to dryness the residue was repeatedly dissolved in water and evaporated at room temperature until colourless single crystals of the title compound were deposited. The crystals were washed with cold methanol and dried in the air.