trans-Diaqua­bis­[2,5-bis­(pyridin-2-yl)-1,3,4-thia­diazole]cobalt(II) bis­(tetra­fluoridoborate)

Fouad Bentiss; Frédéric Capet; Michel Lagrenée; Mohamed Saadi; Lahcen El Ammari

doi:10.1107/S1600536811020125

. 2011 Jun 4;67(Pt 7):m834–m835. doi: 10.1107/S1600536811020125

trans-Diaquabis[2,5-bis(pyridin-2-yl)-1,3,4-thiadiazole]cobalt(II) bis(tetrafluoridoborate)

Fouad Bentiss ^a,^*, Frédéric Capet ^b,^c, Michel Lagrenée ^b,^c, Mohamed Saadi ^d, Lahcen El Ammari ^d

PMCID: PMC3151744 PMID: 21836842

Abstract

The bidentate 1,3,4-thiadiazole ligand substituted by two 2-pyridyl rings (denoted L) has been found to produce the new monomeric title complex, [Co(C₁₂H₈N₄S)₂(H₂O)₂](BF₄)₂. The thiadiazole and pyridyl rings surrounding the Co atom are almost coplanar [dihedral angle = 4.35 (7)°]. The mean plane defined by these heterocyclic moieties makes a dihedral angle of 18.72 (6)° with the non-coordinated pyridyl ring. The Co²⁺ cation, located at a crystallographic center of symmetry, is bonded to two ligands and two water molecules in a trans configuration in an octahedral environment. The tetrafluoridoborate ions can be regarded as free anions in the crystal lattice. Nevertheless, they are involved in an infinite two-dimensional network along the [010] and [101] directions of O—H⋯F hydrogen bonds.

Related literature

For background to compounds with the same ligand, see: Bentiss et al. (2002 ▶, 2004 ▶); Zheng et al. (2006 ▶). For an improved synthesis of the ligand, see: Lebrini et al. (2005 ▶).

Experimental

Crystal data

[Co(C₁₂H₈N₄S)₂(H₂O)₂](BF₄)₂
M _r = 749.15
Monoclinic,
a = 10.8319 (2) Å
b = 11.0623 (2) Å
c = 13.2120 (3) Å
β = 101.114 (1)°
V = 1553.45 (5) Å³
Z = 2
Mo Kα radiation
μ = 0.77 mm⁻¹
T = 100 K
0.39 × 0.30 × 0.19 mm

Data collection

Bruker X8 APEXII diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.757, T _max = 0.863
32328 measured reflections
3055 independent reflections
2877 reflections with I > 2σ(I)
R _int = 0.023

Refinement

R[F ² > 2σ(F ²)] = 0.025
wR(F ²) = 0.064
S = 1.04
3055 reflections
214 parameters
H-atom parameters constrained
Δρ_max = 0.54 e Å⁻³
Δρ_min = −0.36 e Å⁻³

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT (Bruker, 2005 ▶); data reduction: SAINT; 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 datablock(s) I, global. DOI: 10.1107/S1600536811020125/im2290sup1.cif

e-67-0m834-sup1.cif^{(25.9KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811020125/im2290Isup2.hkl

e-67-0m834-Isup2.hkl^{(149.9KB, 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
O1—H1W⋯F1ⁱ	0.86	1.88	2.7014 (16)	161
O1—H2W⋯F4	0.86	1.94	2.7927 (16)	172

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Symmetry code: (i) Inline graphic .

supplementary crystallographic information

Comment

2,5-bis(2-pyridyl)-1,3,4-thiadiazole can be used to produce molecular architectures with transition metals in association with anionic co-ligands. In the resulting di- and mononuclear complexes, a variety of coordination modes have been observed, of which the dinuclear (N`N``, N2, N``) bridging, the dinuclear (N`N``, N2, N``)2 double bridging and the monoclear (N`,N`)2 coordination mode are the most common and the most important ones (Scheme 1). In the latter case, the trans-configuration is exclusively observed for octahedral complexes.

The structures of monomeric complexes of the neutral 2,5-bis(2-pyridyl)-1,3, 4-thiadiazole derivative with divalent Zn (tetrachloride and perchlorate), Co (nitrate and perchlorate), Ni (perchlorate) and Cu (nitrate and perchlorate) have been previously reported (Bentiss et al.,2002, 2004; Zheng et al. 2006). We report here the synthesis and the single-crystal structure of the new monomeric cobalt complex formed by 2,5-bis(2-pyridyl)-1,3, 4-thiadiazole with tetrafluoroborates as counter ions.

The complex cation shows an almost regular octahedral environment of cobalt cation which is located at a crystallographic center of symmetry. Cobalt therefore is linked to two ligands and two water molecules as shown in Fig.1. As a matter of fact, the cobalt coordination sphere is achieved by interaction with the nitrogen atom of a single pyridyl ring and with the adjacent nitrogen of the azine group with Co—N distances in the range of 2.082 (2)— 2.173 (2) Å. Moreover, the water molecules are found in axial positions at distances of Co—O 2.128 (2) Å and all N—Co—O angles being close to 90 °.

The dihedral angle between thiadiazole and the coordinating pyridyl ring is 4.35 (7)°. The mean plane defined by the two preceding heterocyclic moieties forms a dihedral angle with the non-coordinating pyridine ring (N4-C8-C9-C10-C11-C12) of 18.72 (6)°. The counter ion, BF₄^-, is involved in an infinite two-dimensional network of hydrogen bonds (Table 1).

Experimental

2,5-Bis(2-pyridyl)-1,3,4-thiadiazole ligand (noted L) was synthesized as described previously by Lebrini et al., 2005. Co(BF₄)₂ × 6 H₂O (1.5 mmol, 0.51 g) in 8 ml of water was added to (0.42 mmol, 0.1 g) of L (bptd ligand) dissolved in 8 ml of ethanol. The solution was filtered and after 24 h, the orange compound crystallized at room temperature. Crystals were washed with water and dried under vacuum. Yield: 54%. Anal. Calc. for C₁₂H₁₀BCo_0.5F₄N₄OS: C, 38.44; H, 2.67; N, 14.95; S, 8.56; F, 20.29%. Found: C, 38.56; H, 2.72; N, 14.88; S, 8.51; F, 20.36%.