Poly[[(μ-3-amino­pyrazine-2-carboxyl­ato-κ3 N 1,O:O′)diaqua­(μ-oxalato-κ4 O 1,O 2:O 1′,O 2′)lanthanum(III)] monohydrate]

Shan Gao; Seik Weng Ng

doi:10.1107/S1600536811034404

. 2011 Aug 27;67(Pt 9):m1301. doi: 10.1107/S1600536811034404

Poly[[(μ-3-aminopyrazine-2-carboxylato-κ³ N ¹,O:O′)diaqua(μ-oxalato-κ⁴ O ¹,O ²:O ^1′,O ^2′)lanthanum(III)] monohydrate]

Shan Gao ^a, Seik Weng Ng ^b,^c,^*

PMCID: PMC3200678 PMID: 22058888

Abstract

The water-coordinated La^III atom in the title compound, {[La(C₅H₄N₃O₂)(C₂O₄)(H₂O)₂]·H₂O}_n, is N,O-chelated by a 3-aminopyrazine-2-carboxylate ion; this ion links adjacent metal atoms to form a chain parallel to [010]. The oxalate ion serves as a bis-bidentate chelate that links adjacent metal atoms to form a chain parallel to [001]. The two bridging ions give rise to a layer motif parallel to (100) in which the La^III atom exists in a distorted tricapped trigonal prismatic geometry. Extensive hydrogen bonding between the constituents stabilizes the structure.

Related literature

For a related structure, see: Leciejewicz et al. (2004 ▶). For pyrazinecarboxylic acid decomposition with subsequent oxalate formation, which has been documented in other lanthanum systems, see: Li et al. (2006 ▶).

Experimental

Crystal data

[La(C₅H₄N₃O₂)(C₂O₄)(H₂O)₂]·H₂O
M _r = 419.09
Monoclinic,
a = 18.2193 (5) Å
b = 10.5507 (3) Å
c = 13.1307 (5) Å
β = 105.292 (1)°
V = 2434.70 (13) Å³
Z = 8
Mo Kα radiation
μ = 3.56 mm⁻¹
T = 293 K
0.14 × 0.12 × 0.08 mm

Data collection

Rigaku RAXIS-RAPID IP diffractometer
Absorption correction: multi-scan (ABSCOR; Higashi, 1995 ▶) T _min = 0.636, T _max = 0.764
11571 measured reflections
2780 independent reflections
2408 reflections with I > 2σ(I)
R _int = 0.038

Refinement

R[F ² > 2σ(F ²)] = 0.025
wR(F ²) = 0.064
S = 1.03
2780 reflections
213 parameters
11 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 1.19 e Å⁻³
Δρ_min = −0.90 e Å⁻³

Data collection: RAPID-AUTO (Rigaku, 1998 ▶); cell refinement: RAPID-AUTO; data reduction: CrystalClear (Rigaku/MSC, 2002 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: X-SEED (Barbour, 2001 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536811034404/qk2018sup1.cif

e-67-m1301-sup1.cif^{(23.6KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811034404/qk2018Isup2.hkl

e-67-m1301-Isup2.hkl^{(136.6KB, 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
O1W—H11⋯O6ⁱ	0.84 (1)	1.89 (1)	2.720 (3)	169 (3)
O1W—H12⋯N2ⁱⁱ	0.84 (1)	2.00 (1)	2.842 (3)	175 (3)
O2W—H21⋯O5ⁱⁱⁱ	0.84 (1)	1.95 (1)	2.787 (3)	175 (4)
O2W—H22⋯O3W	0.84 (1)	2.16 (2)	2.908 (4)	148 (4)
O3W—H31⋯O2W^iv	0.84 (1)	2.19 (1)	3.017 (4)	165 (4)
O3W—H32⋯N3ⁱⁱⁱ	0.84 (1)	2.33 (2)	3.152 (5)	165 (4)
N3—H1⋯O2	0.88 (1)	2.06 (3)	2.711 (3)	130 (3)
N3—H2⋯O3^v	0.88 (1)	2.10 (1)	2.967 (3)	167 (3)

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

Acknowledgments

This work was supported by the Key Project of the Natural Science Foundation of Heilongjiang Province (grant No. ZD200903), the Innovation Team of the Education Bureau of Heilongjiang Province (grant No. 2010td03), the Key Project of the Education Bureau of Heilongjiang Province (grant No. 12511z023) and the University of Malaya.

supplementary crystallographic information

Comment

The chelating ability of the 3-aminopyrazine-2-carboxylate anion is probably similar to that of the pyrazine-2-carboxylate anion, and the crystal structures of a number of lanthanum carboxylates have been reported. Hydrated lanthanum tris(pyrazine-2-carboxylate) adopts a chain motif (Leciejewicz et al., 2004). The additional amino substitution in the 3-aminopyrazine-2-carboxylate should be expected to consolidate the crystal structure of the title lanthanum derivative through extensive hydrogen bonding. The water-coordinated La^III atom in La(H₂O)₂(C₂O₄)(C₅H₄N₃O₂).H₂O (Scheme I, Fig. 1) is N,O-chelated by an 3-aminopyrazine-2-carboxylate ion; this ion links adjacent metal atoms to form a chain parallel to [010]. The presence of an oxalate ion is explained by the decomposition of 3-aminopyrazine-2-carboxylic acid; the oxalate ion serves as a bis-bidentate chelate that links adjacent metal atoms. The two bridging ions give rise to a layer motif parallel to [100] in which the La^III atom exists in a nine-coordinate environment. The geometry is best described as a distorted tricapped trigonal prism. The upper prism triangle is made up of the atoms O1, O4 and O2w, and the lower prism triangle by the atoms O2, O5 and O1w.

The layers interact with the lattice water molecules to generate a three-dimensional hydrogen-bonded network (Table 1).

Experimental

Lanthanum nitrate hexahydrate (0.5 mmol) and 3-aminopyrazine-2-carboxylic acid (2 mmol) were dissolved in water (15 ml). The solution was sealed in a 25 ml Teflon-lined stainless steel bomb and held at 443 K for 3 d. The bomb was gradually cooled to room temperature, and colorless prismatic crystals were obtained.