Bis(3,5-dimethyl-1H-pyrazole-κN 2)(pyridine-2,6-dicarboxyl­ato-κ3 O 2,N,O 6)copper(II)

Yuan-Yuan Lin; Yan-Ping Yu; Bing-Xin Liu; Liang-Jun Zhang

doi:10.1107/S1600536809004577

. 2009 Feb 18;65(Pt 3):m279. doi: 10.1107/S1600536809004577

Bis(3,5-dimethyl-1H-pyrazole-κN ²)(pyridine-2,6-dicarboxylato-κ³ O ²,N,O ⁶)copper(II)

Yuan-Yuan Lin ^a, Yan-Ping Yu ^a, Bing-Xin Liu ^a,^*, Liang-Jun Zhang ^b

PMCID: PMC2968447 PMID: 21582065

Abstract

In the crystal structure of the title compound, [Cu(C₇H₃NO₄)(C₅H₈N₂)₂], the Cu^II cation assumes a distorted trigonal–bipyramidal coordination geometry formed by a pyridine-2,6-dicarboxylate dianion and two 3,5-dimethyl-1H-pyrazole molecules. N—H⋯O hydrogen bonding is present in the crystal structure.

Related literature

For general background, see: Haanstra et al. (1990 ▶); Mukherjee (2000 ▶).

Experimental

Crystal data

[Cu(C₇H₃NO₄)(C₅H₈N₂)₂]
M _r = 420.91
Triclinic,
a = 8.4572 (12) Å
b = 8.5083 (12) Å
c = 13.942 (2) Å
α = 72.986 (2)°
β = 85.500 (2)°
γ = 66.760 (2)°
V = 880.7 (2) Å³
Z = 2
Mo Kα radiation
μ = 1.28 mm⁻¹
T = 295 K
0.23 × 0.15 × 0.13 mm

Data collection

Bruker APEX CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.775, T _max = 0.845
4570 measured reflections
3036 independent reflections
2497 reflections with I > 2σ(I)
R _int = 0.020

Refinement

R[F ² > 2σ(F ²)] = 0.044
wR(F ²) = 0.106
S = 1.05
3036 reflections
248 parameters
H-atom parameters constrained
Δρ_max = 0.67 e Å⁻³
Δρ_min = −0.55 e Å⁻³

Data collection: SMART (Bruker, 2004 ▶); cell refinement: SAINT (Bruker, 2004 ▶); data reduction: SAINT; program(s) used to solve structure: SIR92 (Altomare et al., 1993 ▶); 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/S1600536809004577/xu2458sup1.cif

e-65-0m279-sup1.cif^{(18.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809004577/xu2458Isup2.hkl

e-65-0m279-Isup2.hkl^{(145.9KB, hkl)}

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

Table 1. Selected bond lengths (Å).

Cu—N11	1.917 (3)
Cu—N21	2.172 (3)
Cu—N31	1.994 (3)
Cu—O11	2.025 (2)
Cu—O13	2.006 (2)

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Table 2. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N22—H22A⋯O14ⁱ	0.86	2.10	2.888 (4)	151
N32—H32A⋯O12ⁱⁱ	0.86	2.06	2.860 (4)	155

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

Acknowledgments

This project was supported by the Educational Development Foundation of Shanghai Educational Committee, China (grant No. AB0448).

supplementary crystallographic information

Comment

Complexes with pyrazole-based ligands are a frequent subject of chemical investigations giving an opportunity for a better understanding the relationship between the structure and the activity of the active site of metalloproteins (Haanstra et al., 1990). Nowadays, attention is paid to the design of various pyrazole ligands with special structural properties to fulfill the specific stereochemical requirements of a particular metal-binding site (Mukherjee, 2000). In our systematic studies on transition metal complexes with the pyrazole derivatives, the title compound was prepared and its X-ray structure is presented here.

The molecular structure of the title compound is shown in Fig. 1. The compound assumes a distorted triangular bipyramid coordination geometry (Table 1), formed by a pyridine-2,6-dicarboxylate dianion and two 3,5-dimethyl-1-H-pyrazole molecules. Tridentate ligand pyridine-2,6-dicarboxylate dianion chelates to the Cu atom by a N atom of pyridine ring and two O atoms of carboxyl groups with a meridional configuration. Monodentate ligand 3,5-dimethyl-1-H-pyrazole coordinated to the Cu atom by N atoms of pyrazole rings with the 1.917 (3) Å and 1.994 (3) Å of Cu—N bound distance. The adjacent molecules are linked together via N—H···O hydrogen bonding (Table 2) between carboxy groups of pyridine-2,6-dicarboxylate dianion and uncoordinated N atom of 3,5-dimethyl-1-H-pyrazoleto, forming the supra-molecular structure (Fig. 2).

Experimental

An ethanol–water solution (1:1, 20 ml) containing 1-carboxamide-3,5-dimethylpyrazole (0.14 g, 1 mmol) and CuCl₂.2H₂O (0.17 g, 1 mmol) was mixed with an aqueous solution (10 ml) of pyridine-2,3-dicarboxylic acid (0.17 g, 1 mmol) and NaOH (0.08 g, 2 mmol). The mixture was refluxed for 6 h. After cooling to room temperature the solution was filtered. Single crystals were obtained from the filtrate after 3 d.