Poly[di-μ2-aqua-μ2-(5-methyl­pyrazine-2-carboxyl­ato)-(5-methyl­pyrazine-2-carboxyl­ato)-μ3-nitrato-trilithium]

Wojciech Starosta; Janusz Leciejewicz

doi:10.1107/S1600536811024548

. 2011 Jun 30;67(Pt 7):m1000–m1001. doi: 10.1107/S1600536811024548

Poly[di-μ₂-aqua-μ₂-(5-methylpyrazine-2-carboxylato)-(5-methylpyrazine-2-carboxylato)-μ₃-nitrato-trilithium]

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

PMCID: PMC3152134 PMID: 21836828

Abstract

The asymmetric unit of the title compound, [Li₃(C₆H₅N₂O₂)₂(NO₃)(H₂O)₂]_n contains three Li^I ions, two ligand anions, two water molecules and a nitrate anion. Related by a centre of inversion, they form a centrosymmetric molecular cluster in which one of the Li^I ions shows trigonal–bipyramidal and the other two distorted tetrahedral coordination. Li^I ions are bridged by water O atoms and carboxylate O atoms donated by one of the ligands. The clusters, bridged by two nitrato O atoms, form molecular columns along [010], which are held together by O—H⋯O and O—H⋯N hydrogen bonds and π–π interactions [centroid–centroid distances = 3.694 (1) and 3.796 (1) Å].

Related literature

For the structure of a lithium complex with 3-aminopyrazine-2-carboxylate and aqua ligands, see: Starosta & Leciejewicz (2010 ▶). The structures of two complexes with pyridazine carboxylate ligands have been also determined, see: Starosta & Leciejewicz (2011a ▶,b ▶). For the structure of a Li^I complex with pyrimidine carboxylate and nitrate ligands, see: Starosta & Leciejewicz (2011c ▶).

Experimental

Crystal data

[Li₃(C₆H₅N₂O₂)₂(NO₃)(H₂O)₂]
M _r = 393.10
Monoclinic,
a = 13.0222 (1) Å
b = 7.2288 (1) Å
c = 18.5819 (2) Å
β = 100.760 (1)°
V = 1718.45 (3) Å³
Z = 4
Cu Kα radiation
μ = 1.10 mm⁻¹
T = 293 K
0.23 × 0.20 × 0.07 mm

Data collection

Oxford Diffraction Xcalibur Ruby diffractometer
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2010 ▶) T _min = 0.672, T _max = 1.000
15696 measured reflections
3215 independent reflections
2787 reflections with I > 2σ(I)
R _int = 0.026

Refinement

R[F ² > 2σ(F ²)] = 0.040
wR(F ²) = 0.122
S = 1.07
3215 reflections
277 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.35 e Å⁻³
Δρ_min = −0.31 e Å⁻³

Data collection: CrysAlis PRO (Oxford Diffraction, 2010 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; 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 datablock(s) I, global. DOI: 10.1107/S1600536811024548/kp2334sup1.cif

e-67-m1000-sup1.cif^{(26.7KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811024548/kp2334Isup2.hkl

e-67-m1000-Isup2.hkl^{(157.7KB, hkl)}

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

Table 1. Selected bond lengths (Å).

Li1—O11ⁱ	2.029 (3)
Li1—O11	2.039 (3)
Li1—O1	2.085 (3)
Li1—O4	2.114 (3)
Li1—N11	2.293 (3)
Li2—O12ⁱ	1.958 (3)
Li2—O4	1.965 (3)
Li2—O5	1.970 (3)
Li2—O2ⁱⁱ	2.163 (3)
Li3—O31	1.978 (3)
Li3—O5	2.025 (4)
Li3—O1	2.039 (3)
Li3—N31	2.117 (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
O4—H41⋯O32ⁱⁱⁱ	0.85 (2)	1.92 (2)	2.7449 (15)	165.3 (19)
O4—H42⋯N12^iv	0.85 (2)	2.03 (2)	2.8414 (17)	159.0 (19)
O5—H52⋯N32^v	0.84 (2)	2.05 (2)	2.8550 (17)	162 (2)
O5—H51⋯O31ⁱⁱⁱ	0.86 (2)	1.85 (2)	2.7055 (15)	172 (2)

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

Acknowledgments

Thanks are due to Dr J. K. Maurin for collecting the diffraction data on the instrument at the Institute of Atomic Energy, Swierk.

supplementary crystallographic information

Comment

The asymmetric unit of the title compound contains three Li^I ions, two 5-methylpyrazine-2-carboxylate anions, two water molecules and a nitrate anion (Fig. 1). The coordination environment of the Li1 ion is composed of N11, O11ⁱ, O1, O4 and O11 atoms. The latter three form a base of a distorted trigonal bipyramid, N11,O11ⁱ atoms are at its apices. Li1 ion is 0.0097 (2)Å out of the basal plane. The Li2 ion is coordinated by water O4, O5, carboxylate O12ⁱ and nitrate O2ⁱⁱⁱ atoms which form a distorted tetrahedral coordination environment. The same distorted tetrahedral coordination geometry shows the Li3 ion sorrounded by N31, O31, O1 and O5 atoms. The observed Li—O and Li—N bond distances (Table 1) are typical of Li complexes with azine carboxylate ligands. Both methylpyrazine rings are planar with r.m.s. of 0.0074 (1)Å for ring 1 and 0.0069 (1)Å for ring 3; carboxylate groups C17/O11/O12 and C37/O31/O32 make with relevant rings dihedral angles of 11.2 (1)°, and 11,0(1)°, respectively. The nitrate anion is planar [r.m.s. 0.0002 (1) Å]. Its O1 atom acts as bidentate and bridges Li1 and Li3 ions, while the O2 atom chelates the Li2 ion. Nitrato O3 atom is not coordinated at all. Li1 and Li1ⁱ ions bridged by bidentate carboxylate O11 and O11ⁱ form a core of a centrosymmetric cluster composed of Li1 and Li3 ions bridged by bidentate nitrato O1 atom, Li1 and Li2 bridged by the aqua O4 atom, Li2 and Li3 bridged by the aqua O5 atom. The clusters bridged via nitrato O1 and O2 atoms, form molecular columns along the direction [010] and they are held together by a network of hydrogen bonds in which aqua O4 and O5 molecules are as donors and carboxylate O31 and O32 atoms are acceptors. π-π interactions between methylpyrazine rings of adjacent columns are defined: the centres of gravity of the ring (N11, C12, C13, N12, C15, C16) and its symmetry generated hetrerocyclic rings [2-x, -1/2+y,5/2-z; 2-x,1/2+y,5/2-z] both are separated by 3.694 (1) Å, and the ring (N31, C32, C33, N32, C35, C36) operated by symmetry [1-x, -1/2+y, 3/2-z; 1-x, 1/2+y, 3/2-z] generates two equal stacking contacts of 3.796 (1) Å (Fig. 2). However, their shifts are about 3.5 Å. Molecular columns composed of centrosymmetric dimers have been also observed in the structure of a Li^I complex with 3-aminopyrazine-2-carboxylate and water ligands (Starosta & Leciejewicz, 2010). Molecular layers built of centrosymmetric dimers have been reported in the structure of a complex with pyridazine-4-carboxylate and water ligands (Starosta & Leciejewicz, 2011a) while centrosymmetric molecular ribbons bridged by nitrate ions form double-layers in the structure of a complex with pyrimidine-2-carboxylate and nitrate ligands (Starosta & Leciejewicz, 2011b). On the other hand, monomeric molecules, in which a Li^I ion is chelated by ligand N,O bonding group and two aqua O atoms constitute the structure of a complex with pyridazine-3-carboxylate and water ligands (Starosta & Leciejewicz, 2011a).

Experimental

Hot aqueous solutions, one containig 1 mmol of 5-methylpyrazine-2-carboxylic acid (Aldrich), the other 1 mmol of lithium (I) nitrate were mixed and boiled under reflux with constant stirring for 5 h. Left for evaporation at room temperature. After a couple of days yellow single-crystal plates of the title complex deposited on the bottom of a crystallization pot. Crystals were washed with cold ethanol and dried in air.