{Bis[4-(2-pyrid­yl)pyrimidin-2-yl] sulfide}dibromidocobalt(II)

Cai-Yun Li; Xiao-Lan Tong; Tong-Liang Hu

doi:10.1107/S1600536808015821

. 2008 Jun 7;64(Pt 7):m856. doi: 10.1107/S1600536808015821

{Bis[4-(2-pyridyl)pyrimidin-2-yl] sulfide}dibromidocobalt(II)

Cai-Yun Li ^a, Xiao-Lan Tong ^b, Tong-Liang Hu ^b,^*

PMCID: PMC2961816 PMID: 21202733

Abstract

The title compound, [CoBr₂(C₁₈H₁₂N₆S)], is a mononuclear complex in which a twofold rotation axis passes through the Co and S atoms. The Co^II center is six-coordinated by four N atoms from one bis[4-(2-pyridyl)pyrimidin-2-yl] sulfide (L) ligand and two bromide anions, forming an octahedral coordination geometry, where the four donor N atoms are located in the equatorial plane and the Br atoms occupy the axial positions. The sum of the bond angles around the Co atom in the equatorial plane is 360.5°, with the four N atoms and the central Co atom almost coplanar. In the crystal structure, the mononuclear units are linked by π–π stacking interactions (the interplanar distances are 3.469 and 3.533 Å, and the corresponding centroid–centroid distances are 3.791 and 3.896 Å) into a three-dimensional supramolecular network.

Related literature

For related literature, see: de Faria et al. (2007 ▶); Teles et al. (2006 ▶); Li & Bu (2008 ▶); Bridson & Walker (1970 ▶).

Experimental

Crystal data

[CoBr₂(C₁₈H₁₂N₆S)]
M _r = 563.15
Monoclinic,
a = 15.191 (5) Å
b = 10.350 (4) Å
c = 13.338 (5) Å
β = 112.312 (5)°
V = 1940.0 (12) Å³
Z = 4
Mo Kα radiation
μ = 5.13 mm⁻¹
T = 294 (2) K
0.20 × 0.18 × 0.14 mm

Data collection

Bruker SMART 1000 CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 1998 ▶) T _min = 0.375, T _max = 0.489
5288 measured reflections
1970 independent reflections
1456 reflections with I > 2σ(I)
R _int = 0.036

Refinement

R[F ² > 2σ(F ²)] = 0.028
wR(F ²) = 0.061
S = 1.04
1970 reflections
128 parameters
H-atom parameters constrained
Δρ_max = 0.39 e Å⁻³
Δρ_min = −0.36 e Å⁻³

Data collection: SMART (Bruker, 1998 ▶); cell refinement: SAINT (Bruker, 1998 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808015821/bq2083sup1.cif

e-64-0m856-sup1.cif^{(16.5KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808015821/bq2083Isup2.hkl

e-64-0m856-Isup2.hkl^{(94.1KB, hkl)}

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

Table 1. Selected geometric parameters (Å, °).

Br1—Co1	2.6178 (10)
Co1—N2	2.099 (2)
Co1—N1	2.125 (2)

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N2ⁱ—Co1—N2	96.18 (13)
N2—Co1—N1	78.04 (9)
N1—Co1—N1ⁱ	108.24 (13)
N2—Co1—Br1	86.87 (7)
N1—Co1—Br1	92.90 (7)

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors thank Nankai University for supporting this work.

supplementary crystallographic information

Comment

Semirigid thioether ligands containing heterocycle with N-donors are gradually used in constructing coordination architectures with novel topologies and useful functions in recent years (de Faria et al., 2007; Teles et al., 2006). The pyridine and pyrimidine groups as normal heterocycle were used to incorporate with different mercapto units to form a series of bi- and multi-dentate ligands, which can adopt different conformations according to the different geometric requirements of metal centers when forming metal complexes (Li & Bu, 2008). Herein, we synthesized a semirigid thioether ligand bis[4-(pyridin-2-yl)pyrimidin-2-yl]sulfide (L) as well as its Co^II complex, [Co(C₁₈H₁₂N₆S)Br₂] (I), and report the crystal structure of this complex.

In the molecule of (I), (Fig. 1), the bond lengths and angles are generally within normal ranges (Bridson & Walker, 1970). The Co^II center is six-coordinated by four N atoms from one L ligand and two bromine ions, forming an octahedral coordination geometry. The bond angles N1—Co1—N2, N2—Co1—N2A, N2A—Co1—N1A and N1A—Co1—N1 are 78.04 (9), 96.18 (1), 78.04 (9) and 108.24 (1)°, respectively. The sum of these angles is 360.5 (2)°, suggesting that N1, N2, N1A, N2A and Co1 are almost in a plane. In the crystal structure of (I), the mononuclear units are interconnected by two π···π stacking interactions between the rings (N1/C1-C5) and (N2/N3/C6-C9) forming a three-dimensional supramolecular network.

Experimental

The ligand bis[4-(pyridin-2-yl)pyrimidin-2-yl]sulfide (L) was synthesized according to the following method. Some amount of potassium 4-(pyridin-2-yl)pyrimine-2-thiolate was dissolved in the distilled water, and the dense hydrochloric acid was added drop by drop with slowly stirring. A lot of yellow precipitate appeared and then gradually disappear when the dense hydrochloric acid was continuously added. After complete disappearance of the yellow precipitate, the potassium hydroxide solution was added to the mixture until another kind of precipitate was obtained largely. The crude product was filtered and washed with the distilled water three times, and recrystallized with the mixture of chloroform and hexane (v/v=1:1), yield: 60%. The title coordination complex, (I), was synthesized according to the following method. A buffer layer of chloroform/methanol (v/v=2:1, 5 ml) was carefully layered over a chloroform solution (4 mL) of L (6.8 mg, 0.02 mmol). Then a solution of CoBr₂ (4.4 mg, 0.02 mmol) in methanol (4 ml) was layered on the buffer layer. Red block crystals suitable for X-ray analysis were collected after five weeks, yield: 30%.