Diaqua­bis­[5-(pyrazin-2-yl-κN 1)-3-(pyridin-4-yl)-1H-1,2,4-triazol-1-ido-κN 1]cobalt(II) methanol disolvate

Yan Bi; Na Wu; Jing Chen

doi:10.1107/S160053681201495X

. 2012 Apr 18;68(Pt 5):m600. doi: 10.1107/S160053681201495X

Diaquabis[5-(pyrazin-2-yl-κN ¹)-3-(pyridin-4-yl)-1H-1,2,4-triazol-1-ido-κN ¹]cobalt(II) methanol disolvate

Yan Bi ^a, Na Wu ^a, Jing Chen ^a,^*

PMCID: PMC3344341 PMID: 22590107

Abstract

The Co^II ion in the title mononuclear compound, [Co(C₁₁H₇N₆)₂(H₂O)₂]·2CH₃OH, is located on an inversion center and is six-coordinated in a distorted octahedral geometry defined by four N atoms from two deprotonated 5-(pyrazin-2-yl-κN)-3-(pyridin-4-yl)-1H-1,2,4-triazol-1-ide (ppt) ligands and two water molecules. In the crystal, the complex molecules and lattice methanol molecules are linked via O—H⋯N and O—H⋯O hydrogen bonds, generating a two-dimensional supramolecular network parallel to (001). π–π interactions between the triazole and pyrazine rings and between the pyridine rings are present [centroid–centroid distances = 3.686 (3) and 3.929 (4) Å, respectively].

Related literature

For coordination complexes based on N-involved polydentate ligands, see: Guo et al. (2010 ▶); Ha (2011 ▶); Sun et al. (2011 ▶); Tang et al. (2011 ▶); Yang et al. (2010 ▶). For related structures based on 5-(pyrazin-2-yl)-3-(pyridin-4-yl)-1H-1,2,4-triazole, see: Liu et al. (2009 ▶).

Experimental

Crystal data

[Co(C₁₁H₇N₆)₂(H₂O)₂]·2CH₄O
M _r = 605.50
Monoclinic,
a = 11.462 (9) Å
b = 7.121 (5) Å
c = 16.116 (12) Å
β = 95.418 (14)°
V = 1309.6 (17) Å³
Z = 2
Mo Kα radiation
μ = 0.71 mm⁻¹
T = 296 K
0.36 × 0.22 × 0.10 mm

Data collection

Bruker APEX CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2001 ▶) T _min = 0.783, T _max = 0.932
6377 measured reflections
2307 independent reflections
1685 reflections with I > 2σ(I)
R _int = 0.039

Refinement

R[F ² > 2σ(F ²)] = 0.040
wR(F ²) = 0.104
S = 1.03
2307 reflections
189 parameters
H-atom parameters constrained
Δρ_max = 0.22 e Å⁻³
Δρ_min = −0.31 e Å⁻³

Data collection: SMART (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: DIAMOND (Brandenburg, 1999 ▶); software used to prepare material for publication: SHELXTL (Sheldrick, 2008 ▶).

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S160053681201495X/hy2533sup1.cif

e-68-0m600-sup1.cif^{(19KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S160053681201495X/hy2533Isup2.hkl

e-68-0m600-Isup2.hkl^{(113.4KB, 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
O2—H2⋯N6ⁱ	0.82	1.97	2.760 (4)	163
O1—H1B⋯N5ⁱⁱ	0.85	1.94	2.785 (3)	176
O1—H1A⋯O2ⁱⁱⁱ	0.85	1.81	2.660 (3)	173

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

Acknowledgments

This work was supported financially by Tianjin Normal University (No. 52XQ1104).

supplementary crystallographic information

Comment

The selection of organic ligands is generally considered as the critical factor for constructing metallosupramolecular complexes. In this connection, nitrogen-involved polydentate ligands have attracted special attentions because of their preference and reliability for coordinating to transition metal ions in versatile fashions (Guo et al., 2010; Ha, 2011; Sun et al., 2011; Tang et al., 2011; Yang et al., 2010). For example, 5-(pyrazin-2-yl)-3-(pyridin-4-yl)-1H-1,2,4-triazole (Hppt) has been recently used to prepare two Cu(II) complexes with the observation of unique structural transformations (Liu et al., 2009). Herein, the reaction of Hppt with Co(NO₃)₂.6H₂O produces the title mononuclear complex.

The asymmetric unit of the title complex consists of a Co^II ion that lies on an inversion center, one deprotonated ppt anion, one water ligand and one lattice methanol molecule. As shown in Fig. 1, the Co^II ion takes a distorted octahedral geometry, coordinating to four N atoms from two ppt ligands [Co—N = 2.076 (2) and 2.130 (2) Å] in the equatorial plane and to two axial water ligands [Co—O = 2.087 (2) Å]. The deprotonated ppt ligand adopts a chelating mode through both the pyrazinyl and triazolyl N donors.

As shown in Fig. 2, the lattice methanol molecule is bonded to the water ligand via O1—H1A···O2ⁱⁱⁱ and the uncoordinated pyridyl group of the ppt ligand via O2—H2···N6ⁱ hydrogen bonds [symmetry codes: (i) x, -1+y, z; (iii) -1+x, y, z], linking the adjacent mononuclear complexes into a two-dimensional network. O1—H1B···N5ⁱⁱ hydrogen bond [symmetry code: (ii) -x, 1-y, -z] between the coordinated water and triazole ring is also observed to reinforce this two-dimensional network. In addition, aromatic stacking interactions between the triazolyl (N3—N5, C5, C6) and pyrazinyl (N1, N2, C1—C4) rings as well as between the parallel pyridyl groups (N6, C7—C11) are also found within this supramolecular layer, with centroid–centroid distances and dihedral angles of 3.686 (3)/3.929 (4) Å and 4.2/0.0°.

Experimental

A CH₃OH solution (3 ml) of Hppt (11.2 mg, 0.05 mmol) was carefully layered onto an aqueous solution (5 ml) of Co(NO₃)₂.6H₂O (29.1 mg, 0.1 mmol) in a straight glass tube. After evaporating the solvents slowly for ca 1 week, yellow block single crystals suitable for X-ray diffraction analysis were obtained in ca 40% yield. Analysis, calculated for C₂₄H₂₆CoN₁₂O₄: C 47.61, H 4.33, N 27.76%; found: C 48.02, H 4.19, N 27.89%.