Dibromidobis­(4-hydr­oxy-1,5-dimethyl-2-phenyl-3-pyrazolone)zinc(II)

Pascale Lemoine; Bernard Viossat; Jean Daniel Brion; Alain Bekaert

doi:10.1107/S1600536808016838

. 2008 Jun 7;64(Pt 7):m891–m892. doi: 10.1107/S1600536808016838

Dibromidobis(4-hydroxy-1,5-dimethyl-2-phenyl-3-pyrazolone)zinc(II)

Pascale Lemoine ^a,^*, Bernard Viossat ^a, Jean Daniel Brion ^b, Alain Bekaert ^b

PMCID: PMC2961802 PMID: 21202758

Abstract

In the title compound, [ZnBr₂(C₁₁H₁₂N₂O₂)₂], the Zn(II) ion is coordinated by two Br atoms and two O atoms from two 4-hydroxyantipyrine molecules via the carbonyl O atoms, which act as monodentate ligands, giving rise to a distorted tetrahedral geometry. The values of the bond angles at the Zn atom are in the range 99.4 (1) to 113.2 (1)°. The presence of O—H⋯O and O—H⋯Br intramolecular hydrogen bonds can explain the difference between the two Zn—O [1.961 (3)/2.015 (3) Å] and the two Zn—Br [2.350 (1)/2.378 (1) Å] bond lengths. The crystal structure is governed by C—H⋯O, C—H⋯Br and Zn—Br⋯Cg(π-ring) interactions.

Related literature

For related literature, see: Bekaert et al. (2003 ▶, 2007 ▶); Filiz et al. (2008 ▶); Lemoine et al. (2007 ▶); Matzke et al. (2000 ▶); Melov et al., (1998 ▶); Panneerselvam et al. (1996 ▶); Tougu et al. (2008 ▶).

Experimental

Crystal data

[ZnBr₂(C₁₁H₁₂N₂O₂)₂]
M _r = 633.64
Tetragonal,
a = 9.824 (3) Å
c = 26.120 (3) Å
V = 2521 (1) Å³
Z = 4
Mo Kα radiation
μ = 4.18 mm⁻¹
T = 293 (2) K
0.17 × 0.16 × 0.15 mm

Data collection

Enraf-Nonius CAD-4 diffractometer
Absorption correction: none
15417 measured reflections
7354 independent reflections
3152 reflections with I > 2σ(I)
R _int = 0.091
3 standard reflections frequency: 60 min intensity decay: none

Refinement

R[F ² > 2σ(F ²)] = 0.035
wR(F ²) = 0.093
S = 0.90
7354 reflections
304 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.36 e Å⁻³
Δρ_min = −0.30 e Å⁻³
Absolute structure: Flack (1983 ▶), 3602 Friedel pairs
Flack parameter: −0.015 (9)

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994 ▶); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1995 ▶); program(s) used to solve structure: SIR92 (Altomare et al., 1994 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEPIII (Burnett & Johnson, 1996 ▶) and ORTEP-3 for Windows (Farrugia, 1997 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808016838/dn2351sup1.cif

e-64-0m891-sup1.cif^{(20.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808016838/dn2351Isup2.hkl

e-64-0m891-Isup2.hkl^{(352.6KB, 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
O5—H5⋯O24	0.82	1.94	2.734 (5)	164
O25—H25⋯Br1	0.82	2.40	3.212 (4)	169
C10—H10⋯O5ⁱ	0.93	2.47	3.378 (8)	165
C27—H27C⋯Br2ⁱⁱ	0.96	2.81	3.686 (7)	151

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

Table 2. Zn—Br⋯Cg(π-ring) interaction.

y—X(I)⋯Cg(J)	X⋯Cg	X-Perp	γ	Y—X⋯Cg
Zn1—Br1⋯Cg1ⁱ	3.671 (2)	3.646	6.76	132.21 (4)

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Symmetry code: (i) Inline graphic , , . Cg1 is the centroid of atoms Cl/N2/N3/C4/C5.

supplementary crystallographic information

Comment

Metals like Zn are expected to be involved in neurodegenerative diseases such as Alzheimer or Parkinson leading to neurofibrillary tangles degeneration and tau protein accumulation (Filiz et al.,2008; Tougu et al.,2008). These amyloi¨d plaques in the cortical brain are the sign of cerebral aging and associated with a neuronic a high level of metals. Much work (Melov et al., 1998) is now devoted to theses diseases since no real drug is available up to date. As researchers postulate that soft chelating drugs could interfere with free metal accumulation and neuronal collapsus, our idea was that phenazone (antipyrine), a well known antipyretic brain available drug, could become a soft chelating molecule upon hydroxylation in the 4-hydroxy derivative. For this reason and our knowledge in metal amide complexes, (Bekaert et al., 2007; Lemoine et al., 2007) we have prepared a new cristalline complex including Zn and 4-hydroxy-1,5-dimethyl-2-phenyl-3-pyrazolone (4-hydroxyantipyrine) which is of considerable interest as a antipyrine primary metabolite and which is the object of many biological studies the latter years, by example in the evaluation of the influence of diabete mellitus on antipyrine metabolism (Matzke et al., 2000). The hydroxyamide structure which is close to lactamide let us to test it as a metal pinch. Following our work concerning lactamide and zinc(II) complex (Bekaert et al., 2003), we now report a new zinc complex with 4-hydroxyantipyrine.

The title compound contains one monomeric tetrahedral zinc complex, [Zn(C₂₂H₂₄N₄O₄)Br₂]. The Zn atom is surrounded by two monodentate 4-hydroxyantipyrine ligands via the carbonyl O atom O4 (or O24) in the sp² lone-pair direction and two Br ligands (Fig. 1). The complex exhibits a distorted tetrahedral geometry around the zincII atom. The degree of deviation from an ideal tetrahedron is appreciable with the angles around Zn atom ranging from 99.4 (1) to 113.2 (1) °. The Zn—O and Zn—Br distances in the coordination polyhedron are 1.961 (3)/2.015 (3) Å and 2.351 (1)/2.379 (1)Å, respectively, in good agreement with those found in similar Zn^IItetrahedral coordination (Bekaert et al., 2003). The difference between the two Zn—O (or the two Zn—Br) bond lengths can be explained by the presence of the O5—H5···O24 (or O25—H25···Br1) intramolecular hydrogen bond (Table 1) which causes the stretching of the Zn—O24 (or Zn—Br1) bond. Each hydroxyantipyrine ligand consists of a pyrazole P1 (Cl/N2—N3/C4—C5) [or P3 (C2l/N22—N23/C24—C25)] and a phenyl ring P2 (C8—C13) [or P4 (C28—C33)] which are planar with maximum deviation of 0.017 (3) Å for N2 (first ligand) and 0.021 (3) Å for N23 (second ligand). The dihedral angles are 65.2 (2)° between P1 and P2 and 81.6 (2)° for P3 and P4, these values are significantly different from those reported in 4-hydroxyantipyrine [42.5 (1)°] (Panneerselvam et al.,1996).

The crystal packing is governed by weak C—H···O and Zn—Br···Cg1( centroid of the P1 plane) interactions (Tables1 and 2).

Experimental

The title compound, dibromido-bis[4-hydroxyantipyrine]zinc(II), was prepared by mixing 1.02 g (5 mmole) of 4-hydroxyantipyrine dissolved in hot acetic acid (10 ml, 353 K) and 10 ml of a solution of ZnBr2 (0.496 g, 2 mmole) in boiling acetic acid. Upon slow cooling, crystal suitable for X-ray diffraction were recovered.