Bis[μ-3,5-bis­(pyridin-2-yl)-1H-pyrazole]­bis­[di­bromido­iron(III)]

Nagisa Katsuta; Akio Mishima; Akira Fuyuhiro; Shinya Hayami; Satoshi Kawata

doi:10.1107/S1600536813026573

. 2013 Oct 2;69(Pt 11):m574. doi: 10.1107/S1600536813026573

Bis[μ-3,5-bis(pyridin-2-yl)-1H-pyrazole]bis[dibromidoiron(III)]

Nagisa Katsuta ^a, Akio Mishima ^a, Akira Fuyuhiro ^b, Shinya Hayami ^c, Satoshi Kawata ^a,^*

PMCID: PMC3884243 PMID: 24454019

Abstract

The title dinuclear complex, [Fe₂Br₄(C₁₃H₉N₄)₂], which lies on an inversion center, features two approximately planar bis(pyridin-2-yl)pyrazole (bpypz⁻) ligands [maximum deviation = 0.082 (3) Å] and four bromide ions. Each Fe^III ion is octahedrally coordinated by four N atoms of two bpypz⁻ ligands and two Br ions. π–π stacking interactions [centroid–centroid distances = 3.7004 (17)–4.0123 (18) Å] are observed between pyridyl and pyrazole rings, and between pyridyl and pyridyl rings of adjacent complex molecules.

Related literature

For metal complexes of 3,5-bis(pyridin-2-yl)pyrazole, see: Yoneda, Adachi, Hayami et al. (2006 ▶); Yoneda, Adachi, Nishio et al. (2006 ▶); Ishikawa et al. (2010 ▶); Mishima et al. (2011 ▶); Washizaki et al. (2012 ▶). graphic file with name e-69-0m574-scheme1.jpg

Experimental

Crystal data

[Fe₂(C₁₃H₉N₄)₂Br₄]
M _r = 873.79
Monoclinic,
a = 18.180 (4) Å
b = 14.857 (3) Å
c = 10.530 (3) Å
β = 94.646 (3)°
V = 2834.7 (10) Å³
Z = 4
Mo Kα radiation
μ = 6.71 mm⁻¹
T = 110 K
0.10 × 0.10 × 0.10 mm

Data collection

Rigaku Saturn724 diffractometer
Absorption correction: multi-scan (REQAB; Rigaku, 1998 ▶) T _min = 0.408, T _max = 0.511
16288 measured reflections
3246 independent reflections
2730 reflections with I > 2σ(I)
R _int = 0.031

Refinement

R[F ² > 2σ(F ²)] = 0.023
wR(F ²) = 0.060
S = 1.05
3246 reflections
181 parameters
H-atom parameters constrained
Δρ_max = 0.70 e Å⁻³
Δρ_min = −0.46 e Å⁻³

Data collection: CrystalClear (Rigaku, 2008 ▶); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: CrystalStructure (Rigaku, 2010 ▶); software used to prepare material for publication: CrystalStructure.

Supplementary Material

Crystal structure: contains datablock(s) General, I. DOI: 10.1107/S1600536813026573/is5304sup1.cif

e-69-0m574-sup1.cif^{(31.3KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536813026573/is5304Isup2.hkl

e-69-0m574-Isup2.hkl^{(159.3KB, hkl)}

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

Table 1. Selected bond lengths (Å).

Br1—Fe1	2.5119 (6)
Br2—Fe1	2.4652 (6)
Fe1—N1	2.1882 (19)
Fe1—N2	2.070 (2)
Fe1—N3ⁱ	2.0683 (19)
Fe1—N4ⁱ	2.183 (2)

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Symmetry code: (i) Inline graphic .

Acknowledgments

This work was supported by the fund Grant-in-Aids for Science Research (No. 25410078) from the Ministry of Education, Culture, Sports, Science and Technology of Japan.

supplementary crystallographic information

1. Comment

3,5-Bis(pyridin-2-yl)pyrazole[Hbpypz] is a versatile ligand in the construction of a series of mononuclear, dinuclear and polynuclear complexes (Yoneda, Adachi, Hayami et al., 2006; Yoneda, Adachi, Nishio et al., 2006; Ishikawa et al., 2010). The dinuclear complexes show the structure where two bpypz^- ions are bridging two metal ions with the axial coordination sites. This kind of dinuclear complexes with transition metal ions were reported previously (Mishima et al., 2011; Washizaki et al., 2012). We have succeeded in synthesizing the title compound that contains iron(III) ion for the first time. To the best of our knowledge, similar compounds with the only iron(II) ions in it (Yoneda, Adachi, Hayami et al., 2006; Yoneda, Adachi, Nishio et al., 2006). In the dinuclear complex, four N donors from two deprotonated tetrahedral bridging bpypz^- ligands make an equatorial plane (Table 1). The iron(III) ions are six-coordinated and the axial positions are occupied by bromide ions. From the Mössbauer measurement, the valence of all iron ions is trivalent. There are π–π stacking interactions between pyridyl and pyrazole rings and between pyridyl and pyridyl rings [centroid-centroid distances 3.7004 (17) Å, 4.0123 (18) Å and 4.0022 (18) Å] to form a three-dimensional structure.

2. Experimental

A methanolic solution of FeBr₃ (5 ml, 5 mmolL^-1) was transferred to a glass tube, and methanolic solution of Hbpypz (5 ml, 5 mmolL^-1) was poured into the glass tube without mixing the solutions. Black crystals began to form at ambient temperature within one week (yield 58%). Element analysis: calcd (%) for C₂₆H₁₈Fe₂N₈Br₄: C 35.74, H 2.08, N 12.83; found; C 35.97, H 2.26, N 12.67.