Bis(2-amino-4-methyl­pyridinium) bis­(pyridine-2,6-dicarboxyl­ato)cuprate(II)

Hossein Aghabozorg; Azadeh Mofidi Rouchi; Behrouz Notash; Masoud Mirzaei

doi:10.1107/S1600536811001139

. 2011 Jan 15;67(Pt 2):m189. doi: 10.1107/S1600536811001139

Bis(2-amino-4-methylpyridinium) bis(pyridine-2,6-dicarboxylato)cuprate(II)

Hossein Aghabozorg ^a,^*, Azadeh Mofidi Rouchi ^a, Behrouz Notash ^b, Masoud Mirzaei ^c

PMCID: PMC3051671 PMID: 21522859

Abstract

The asymmetric unit of the title compound, (C₆H₉N₂)₂[Cu(C₇H₃NO₄)₂], contains half of a [Cu(pydc)₂]²⁻ (pydcH₂ is pyridine-2,6-dicarboxylic acid) anion and one protonated 2-amino-4-methylpyridine (2a4mpH)⁺ counter-ion. The anion is a six-coordinated complex with a distorted CuN₂O₄ octahedral geometry around the Cu^II ion. N—H⋯O and C—H⋯O hydrogen bonds along with π–π contacts between the pyridine rings of the (2a4mpH)⁺ cations [centroid–centroid distance = 3.573 (2) Å] stabilize the crystal structure.

Related literature

For background to proton-transfer compounds, see: Aghabozorg et al. (2008 ▶). For related structures see: Aghabozorg et al. (2011 ▶); Eshtiagh-Hosseini, Aghabozorg et al. (2010 ▶); Eshtiagh-Hosseini, Gschwind et al. (2010 ▶); Sharif et al. (2010 ▶).

Experimental

Crystal data

(C₆H₉N₂)₂[Cu(C₇H₃NO₄)₂]
M _r = 612.06
Monoclinic,
a = 24.034 (5) Å
b = 14.231 (3) Å
c = 7.9780 (16) Å
β = 107.01 (3)°
V = 2609.3 (10) Å³
Z = 4
Mo Kα radiation
μ = 0.9 mm⁻¹
T = 298 K
0.45 × 0.15 × 0.10 mm

Data collection

Stoe IPDS II diffractometer
Absorption correction: numerical [shape of crystal determined optically (X-RED32; Stoe & Cie, 2005 ▶)] T _min = 0.743, T _max = 0.846
8829 measured reflections
3509 independent reflections
2785 reflections with I > 2σ(I)
R _int = 0.061

Refinement

R[F ² > 2σ(F ²)] = 0.057
wR(F ²) = 0.119
S = 1.15
3509 reflections
201 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.39 e Å⁻³
Δρ_min = −0.30 e Å⁻³

Data collection: X-AREA (Stoe & Cie, 2005 ▶); cell refinement: X-AREA; data reduction: X-AREA; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811001139/bt5449sup1.cif

e-67-0m189-sup1.cif^{(19.3KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811001139/bt5449Isup2.hkl

e-67-0m189-Isup2.hkl^{(172.2KB, 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—H3A⋯O2ⁱ	0.92 (4)	1.77 (4)	2.662 (4)	163 (4)
N4—H4A⋯O1ⁱ	0.85 (5)	2.22 (5)	3.056 (4)	170 (4)
N4—H4B⋯O3	0.89 (5)	1.97 (5)	2.854 (4)	176 (4)
C7—H7⋯O1ⁱⁱ	0.93	2.58	3.250 (4)	130
C14—H14⋯O4ⁱⁱⁱ	0.93	2.42	3.160 (4)	136

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

Acknowledgments

We are grateful to the Islamic Azad University, North Tehran Branch, for financial support.

supplementary crystallographic information

Comment

Polycarboxylate ligands are widely applied to assemble supramolecular network decorated by coordination bonds, van der Waals interactions, and π –π stacking. 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, pydcH₂ have drawn extensive attentions. Continuing with our previous works on synthesizing coordination and proton transfer compounds (Aghabozorg et al. 2008, 2011), (Eshtiagh-Hosseini, Aghabozorg et al., 2010, Eshtiagh-Hosseini, Gschwind et al., 2010), (Sharif et al., 2010), herein, we planned the reaction between pydcH₂, 2a4mp, and copper^II nitrate trihydrate which resulted in the formation of (2a4mpH)⁺₂.[Cu(pydc)₂] crystals (Fig. 1). Crystal packing diagram related to the title compound is also rendered in the Fig. 2. In the anionic fragment, the Cu^II atom is six-coordinated by two nitrogen and four oxygen atoms from the carboxylate groups of two (pydc)^2- ligands, with bond length ranges of 1.911 (3)–2.029 (2) Å. The N1—Cu1—N2 [180.000 (1)°], O1—Cu1—O1 [146.67 (5)°] and O3—Cu1—O3 [160.23 (5)°] angles. The coordination environment around Cu^II is distorted octahedral. In the crystal structure of the title compound, there are intermolecular C—H···O and N—H···O hydrogen bonds (Table 1) and also π-π contacts between pyridine rings of (2a4mpH)⁺ with centroid-centroid distance Cg1···Cg1ⁱ equel to 3.573 (2) Å [symmetry code: (i) 2 - x, 2 - y,1 - z, where Cg1 is the centroid of ring N3/C9—C11/C13—C14]. (Fig. 2) stabilize the structure.

Experimental

A solution of pyridine-2,6-dicarboxylic acid (pydcH₂) (167 mg, 1 mmol) in 10 ml me thanol was added to a solution of 2-amino-4-methylpyridine (2a4mp) (216 mg, 0.6 mmol) in 10 ml me thanol and stirred for 4 hrs. Then a solution of Cu(NO₃)₂.3H₂O (240 mg, 1 mmol) in 3 ml me thanol was added to the solution of pydcH₂ and 2a4mp. To the resulted precipitate was added 1 ml of DMSO and stirred for several minutes under heating. By slove evaporation of this solution in room temprature, green crystals of the title compound were obtained after three week which were suitable for X-ray analysis (m.p 265–267 °C).