Bis(2-amino-4-methyl­pyridinium) trans-diaqua­bis­(pyrazine-2,3-dicarboxyl­ato)cuprate(II) hexa­hydrate

Hossein Eshtiagh-Hosseini; Fabienne Gschwind; Nafiseh Alfi; Masoud Mirzaei

doi:10.1107/S1600536810023081

. 2010 Jun 23;66(Pt 7):m826–m827. doi: 10.1107/S1600536810023081

Bis(2-amino-4-methylpyridinium) trans-diaquabis(pyrazine-2,3-dicarboxylato)cuprate(II) hexahydrate

Hossein Eshtiagh-Hosseini ^a,^*, Fabienne Gschwind ^b, Nafiseh Alfi ^a, Masoud Mirzaei ^a

PMCID: PMC3007013 PMID: 21587740

Abstract

The title compound, (C₆H₉N₂)₂[Cu(C₆H₂N₂O₄)₂(H₂O)₂]·6H₂O, consists of a mononuclear trans-[Cu(pzdc)₂(H₂O)₂]²⁻ dianion (pzdc is pyrazine-2,3-dicarboxylate) and two [ampyH]⁺ cations (ampy is 2-amino-4-methylpyridine) with six water molecules of solvation. The Cu^II atom is hexacoordinated by two pzdc groups and two water molecules. The coordinated water molecules are in trans-diaxial positions and the pzdc dianion acts as a bidentate ligand through an O atom of the carboxylate group and the N atom of the pyrazine ring. There are diverse hydrogen-bonding interactions, such as N—H⋯O and O—H⋯O contacts, which lead to the formation of a three-dimensional supramolecular architecture.

Related literature

For the crystal structure of pyrazine-2,3-dicarboxylic acid (pzdcH₂), see: Takusagawa & Shimada (1973 ▶). For complexes of pzdcH₂ with manganese and zinc, see: Eshtiagh-Hosseini et al. (2010a ▶,b ▶). For the structure of bis(2,4,6-triamino-1,3,5-triazin-1-ium) pyrazine-2,3-dicarboxylate tetrahydrate, see: Eshtiagh-Hosseini et al. (2010c ▶). For a review articleon water cluster chemistry, see: Aghabozorg et al. (2010 ▶).

Experimental

Crystal data

(C₆H₉N₂)₂[Cu(C₆H₂N₂O₄)₂(H₂O)₂]·6H₂O
M _r = 758.17
Triclinic,
a = 6.9075 (14) Å
b = 8.4710 (17) Å
c = 14.505 (3) Å
α = 78.28 (3)°
β = 83.62 (3)°
γ = 85.81 (3)°
V = 824.8 (3) Å³
Z = 1
Mo Kα radiation
μ = 0.75 mm⁻¹
T = 293 K
0.3 × 0.2 × 0.1 mm

Data collection

Stoe IPDS 2 diffractometer
Absorption correction: for a sphere [modified Dwiggins (1975 ▶) interpolation procedure] T _min = 0.743, T _max = 0.745
17015 measured reflections
4684 independent reflections
4282 reflections with I > 2σ(I)
R _int = 0.046

Refinement

R[F ² > 2σ(F ²)] = 0.036
wR(F ²) = 0.092
S = 1.04
4684 reflections
268 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.36 e Å⁻³
Δρ_min = −0.52 e Å⁻³

Data collection: X-AREA (Stoe & Cie, 2009 ▶); cell refinement: X-RED (Stoe & Cie, 2009 ▶); data reduction: X-RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: DIAMOND (Crystal Impact, 2009 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810023081/fj2310sup1.cif

e-66-0m826-sup1.cif^{(18.5KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810023081/fj2310Isup2.hkl

e-66-0m826-Isup2.hkl^{(224.8KB, 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
N3—H13⋯O4ⁱ	0.82	1.91	2.7221 (19)	169
N4—H14A⋯O8ⁱⁱ	0.77	2.12	2.8879 (19)	177
N4—H14B⋯O3ⁱ	0.84 (2)	2.07 (2)	2.903 (2)	168 (2)
O5—H5B⋯O7ⁱ	0.79 (3)	1.92 (3)	2.703 (2)	173 (3)
O5—H5A⋯O4ⁱ	0.82 (3)	2.09 (3)	2.8556 (18)	157 (3)
O8—H8B⋯O1ⁱⁱⁱ	0.76 (3)	2.03 (3)	2.7838 (18)	173 (3)
O6—H6B⋯O4ⁱⁱⁱ	0.81 (4)	2.06 (4)	2.839 (2)	162 (3)
O7—H17B⋯O8^iv	0.76 (4)	2.04 (4)	2.797 (2)	172 (4)

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

Acknowledgments

Ferdowsi University of Mashhad is gratefully acknowledged for financial support.

supplementary crystallographic information

Comment

Dicarboxylate ligands are widely used to assemble supramolecular network organized by coordination bonds, hydrogen bonds and π –π stacking interaction. Due to the manifold N- and O-donors of pyridine or pyrazine-(di)carboxylic ligands, metal pyridine- or pyrazine dicarboxylates can contrast versatile structural motifs, which finally aggregate to generate various supramolecular architectures with interesting properties. As ones of the dicarboxylate ligands, pzdcH₂ have drawn extensive attentions. For the first time, Takusagawa & Shimada (1973) by single crystal X-ray diffraction, determined the structure of pzdcH₂. Continuing with our previous works on synthesizing coordination compounds via proton transfer mechanism including zinc atom (Eshtiagh-Hosseini et al., 2010a), manganese atom (Eshtiagh-Hosseini et al., 2010b), Bis(2,4,6-triamino-1,3,5-triazin-1-ium) pyrazine-2,3-dicarboxylate tetrahydrate (Eshtiagh-Hosseini et al., 2010c), herein, we planned the reaction between pzdcH₂, ampy, and copper(II) choloride which resulted in the formation of (ampy)₂[Cu(pzdc)₂(H₂O)₂]. 6H₂O (Fig. 1). Crystal packing diagram related to the title compound is also rendered in the Fig. 2. As you can see, the equatorial plane is occupied by two (pzdc)^2- ligands coordinating through the pyridine nitrogen and one oxygen of the deprotonated carboxylate groups. The two coordinated water molecules occupy axial plane. This compound consists of an anionic moiety, trans-[Cu(pzdc)₂(H₂O)₂]^2- complex, counter-ions, (ampy)⁺, and six uncoordinated water molecules. The Cu—O and Cu—N bond distances related to (pzdc)^2- ligand in herein presented compound are in the category of 1.9644 (13) Å , and 1.9840 (14) Å, respectively. These observerd bond lenghts are comprable with Zn(II) polymeric coordination compound which recently reported by our research group (Eshtiagh-Hosseini et al., 2010a ). In this polymeric compound which consist of only (pzdc)^2- coordinative ligand, {(C₃H₁₂N₂)₂[Zn(C₁₀H₂O₈)₂]}_n, Zn—O and Zn—N bond distances are 2.0317 (15) to 2.2437 (15) Å, and 2.0901 (18) Å, respectively. These data show in this polymeric compound Zn—O bond distance is longer than herein presented compound. The intermolecular forces between the anionic and cationic parts in the title compound consist of hydrogen bonding and ion pairing interactions. Indeed, six uncoordinated water molecules increase the number of hydrogen bonds in the crystalline network and lead to the formation of (H₂O)_nclusters throughout the crystalline network (see Review article by Aghabozorg et al. 2010).

Experimental

A solution of pzdcH₂ (0.18 mmol, 0.03 mg) in water (10 ml) refluxed for 1 hr, then a solution of CuCl₂.6H₂O (0.02 mmol, 0.01 g) was added dropwise and continued refluxing for 6 hrs at 60°C. The obtained blue solution gave blue block like crystals of title compound after slow evaporation of solvent at room temperatur.