Hexakis(1-methyl-1H-imidazole-κN 3)cobalt(II) dibromide dihydrate

Rufu Yao

doi:10.1107/S1600536808042906

. 2009 Jan 8;65(Pt 2):m149. doi: 10.1107/S1600536808042906

Hexakis(1-methyl-1H-imidazole-κN ³)cobalt(II) dibromide dihydrate

Rufu Yao ^a,^*

PMCID: PMC2968233 PMID: 21581762

Abstract

The asymmetric unit of the title compound, [Co(C₄H₆N₂)₆]Br₂·2H₂O, contains one-half of the centrosymmetric cation, one Br atom and one water molecule. The Co^II atom, lying on an inversion center, has a distorted octahedral geometry, defined by six N atoms from six 1-methylimidazole ligands. In the crystal structure, intra- and intermolecular O—H⋯Br hydrogen bonds link pairs of uncoordinated water molecules and bromide anions.

Related literature

For general background, see: Lin et al. (2007 ▶); Rogers & Seddon (2003 ▶); Xie et al. (2008 ▶). For a related structure, see: Baca et al. (2005 ▶).

Experimental

Crystal data

[Co(C₄H₆N₂)₆]Br₂·2H₂O
M _r = 747.41
Monoclinic,
a = 8.182 (2) Å
b = 13.573 (2) Å
c = 16.2340 (19) Å
β = 111.12 (4)°
V = 1681.8 (7) Å³
Z = 2
Mo Kα radiation
μ = 2.93 mm⁻¹
T = 298 (2) K
0.40 × 0.30 × 0.30 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2001 ▶) T _min = 0.363, T _max = 0.416
16985 measured reflections
3294 independent reflections
2710 reflections with I > 2σ(I)
R _int = 0.071

Refinement

R[F ² > 2σ(F ²)] = 0.037
wR(F ²) = 0.103
S = 1.04
3294 reflections
187 parameters
H-atom parameters constrained
Δρ_max = 0.86 e Å⁻³
Δρ_min = −0.36 e Å⁻³

Data collection: SMART (Bruker, 2001 ▶); cell refinement: SAINT (Bruker, 2001 ▶); 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 I, global. DOI: 10.1107/S1600536808042906/hk2594sup1.cif

e-65-0m149-sup1.cif^{(19.5KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808042906/hk2594Isup2.hkl

e-65-0m149-Isup2.hkl^{(161.6KB, hkl)}

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

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

Co1—N3	2.174 (2)
Co1—N5	2.182 (2)
Co1—N1	2.207 (2)

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N3ⁱ—Co1—N3	180.0
N3—Co1—N5	88.07 (8)
N3—Co1—N5ⁱ	91.93 (8)
N5—Co1—N5ⁱ	180.0
N3ⁱ—Co1—N1	87.52 (8)
N3—Co1—N1	92.48 (8)
N5—Co1—N1	89.43 (8)
N5ⁱ—Co1—N1	90.57 (8)
N1ⁱ—Co1—N1	180.00 (11)

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Symmetry code: (i) Inline graphic .

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1W—H1WA⋯Br1ⁱⁱ	0.85	2.57	3.371 (3)	157
O1W—H1WB⋯Br1	0.86	2.51	3.338 (3)	164

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Symmetry code: (ii) Inline graphic .

Acknowledgments

This work was supported by the National Natural Science Foundation of China (grant No. 20871039).

supplementary crystallographic information

Comment

Ionothermal synthesis of novel organic-inorganic hybrid materials are not accessible by traditional hydro- or solvothermal reactions (Rogers & Seddon, 2003, Xie et al., 2008, Lin et al., 2007). We report herein the crystal structure of the title compound.

The asymmetric unit of the title compound (Fig. 1) contains one-half of the centrosymmetric cation, one Br atom and one water molecule. The Co^II atom lying on the inversion center of the centrosymmetric cation has a distorted octahedral geometry (Table 1). It is coordinated by six N atoms from six 1-methylimidazole ligands, where N3, N3ⁱ, N5 and N5ⁱ atoms comprise the equatorial plane, and the other two N atoms, N1 and N1ⁱ, occupy the axial positions [symmetry code: (i) 1 - x, 2 - y, 1 - z]. The Co-N bonds [average value = 2.1877 (2) Å] are longer than the Ni-N bonds [average value = 2.065 Å] in the reported Ni complex with the same ligand (Baca et al., 2005).

In the crystal structure, intra- and intermolecular O-H···Br hydrogen bonds (Table 2) link the pairs of uncoordinated water and bromide anions (Fig. 2), in which they may be effective in the stabilization of the structure.

Experimental

C_O(NO₃)₂.6H₂O (0.9 g) and N-methyl imidazole (0.5 g) were placed in a Teflon-line stainless-steel autoclave (25 ml) mixed with 1-ethyl-3-methyl- imidazolium (EMIBr)(1.0 g). The mixtures were heated at 423 K for 3 d, followed by cooling slowly to room temperature. The red block crystals were collected.