Bis[5-(pyridin-2-yl)pyrazine-2-carbo­nitrile-κ2 N 4,N 5]silver(I) perchlorate

Fan Zhang; Zhi-Wei Wang; Yong-Li Yang

doi:10.1107/S1600536811046708

. 2011 Nov 12;67(Pt 12):m1749. doi: 10.1107/S1600536811046708

Bis[5-(pyridin-2-yl)pyrazine-2-carbonitrile-κ² N ⁴,N ⁵]silver(I) perchlorate

Fan Zhang ^a,^*, Zhi-Wei Wang ^a, Yong-Li Yang ^a

PMCID: PMC3238656 PMID: 22199547

Abstract

In the mononuclear title complex, [Ag(C₁₀H₆N₄)₂]ClO₄, the Ag^I ion is surrounded by two 5-(pyridin-2-yl)pyrazine-2-carbonitrile ligands, forming a considerably distorted square-planar N₄-coordination geometry, with two short and two long Ag—N distances. Each perchlorate anion links two mononuclear coordination units through C—H⋯O(perchlorate) hydrogen bonding, forming an infinite tape structure along [110]. Intermolecular π–π stacking interactions between adjacent pyridine and pyrazine rings [centroid–centroid distances of 3.777 (3) and 3.879 (2) Å] further assemble the tape motifs into a three-dimensional supramolecular structure.

Related literature

For coordination complexes with cyano, carboxylate, pyridyl and triazole groups, see: Wang et al. (2009 ▶); Manriquez et al. (1991 ▶). For these involving 2,2′-bipyridine derivatives, see: Berghian et al. (2005 ▶); Mathieu et al. (2001 ▶). For comparable structures, see: Biju & Rajasekharan (2008 ▶); Wang et al. (2010 ▶).

Experimental

Crystal data

[Ag(C₁₀H₆N₄)₂]ClO₄
M _r = 571.70
Triclinic,
a = 7.8804 (10) Å
b = 11.3152 (14) Å
c = 12.3317 (14) Å
α = 104.015 (2)°
β = 92.015 (2)°
γ = 101.171 (2)°
V = 1042.8 (2) Å³
Z = 2
Mo Kα radiation
μ = 1.14 mm⁻¹
T = 293 K
0.30 × 0.20 × 0.12 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2007 ▶) T _min = 0.577, T _max = 0.755
7304 measured reflections
5075 independent reflections
3882 reflections with I > 2σ(I)
R _int = 0.021

Refinement

R[F ² > 2σ(F ²)] = 0.034
wR(F ²) = 0.092
S = 1.03
5075 reflections
307 parameters
10 restraints
H-atom parameters constrained
Δρ_max = 0.54 e Å⁻³
Δρ_min = −0.31 e Å⁻³

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: APEX2 and 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: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536811046708/ez2265sup1.cif

e-67-m1749-sup1.cif^{(21.1KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811046708/ez2265Isup2.hkl

e-67-m1749-Isup2.hkl^{(248.5KB, hkl)}

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

Table 1. Selected bond lengths (Å).

Ag1—N1	2.184 (2)
Ag1—N5	2.193 (2)
Ag1—N6	2.683 (2)
Ag1—N2	2.739 (2)

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C15—H15A⋯O2ⁱ	0.93	2.71	3.203 (2)	114
C14—H14A⋯O2ⁱ	0.93	2.54	3.103 (2)	119
C5—H5A⋯O4ⁱⁱ	0.93	2.45	3.193 (3)	137

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

Acknowledgments

The authors are grateful for financial support from the Science and Technology program, Beijing Municipal Education Commission.

supplementary crystallographic information

Comment

Cyano, carboxylate, pyridyl and triazole groups have been widely employed as organic linkers to bond with metal ions to construct subtile metal organic frameworks (MOFs) (Wang et al. 2009; Manriquez et al. 1991). Many 2,2'-bipyridine derivatives together with their various metal complexes have also been synthesized and well characterized (Berghian et al. 2005; Mathieu et al. 2001).

Herein, we present the structure of a new complex [Ag(C₁₀H₆N₄)₂]ClO₄ derived from 5-(2-pyridyl)pyrazine-2-carbonitrile, a similar ligand to the 2,2'-bipyridine featuring a 2-cyanopyrazinyl group bonding to the 2-pyridyl carbon atom (Scheme 1). As shown in Fig. 1, the two ligands around the central Ag^I ion are in an anti-relationship and almost in the same plane, thus the Ag^I ion is surrounded by two 2-pyridyl N atoms and two 2-pyrazinyl N atoms. The Ag1—N1(pyridyl) and Ag1—N5(pyridyl) bonds are 2.184 (2) and 2.193 (2) Å, respectively. Meanwhile, the longer Ag1—N6(pyrazinyl) and Ag1—N2(pyrazinyl) distances are 2.684 (2) Å and 2.739 (3) Å, respectively. The Ag—N bond lengths are similar to those (2.196 (2)–2.685 (2) Å) in the isomorphous mononuclear structure of [Ag(C₁₀H₆N₄)₂]BF₄ reported by us recently (Wang et al., 2010). Also, the longer Ag—N(pyrazinyl) distance is comparable to that in [Ag(dafone)₂]NO₃.H₂O (dafone = 4,5-diazafluoren-9-one) (Biju & Rajasekharan, 2008). If the weak Ag···N contact is included, a planar N4-square coordination geometry is formed. The perchlorate anions function as linkages to link neighboring [Ag(C₁₀H₆N₄)₂]⁺ moieties arranged along the [110] direction into an infinite tape structure through C—H···O interactions (Table 1, Fig. 2). The tapes are stacked along the [110] direction and interconnect via π–π interactions. The Cg1(pyridyl)···Cg1ⁱ(pyridyl) and Cg2(pyridyl)···Cg2ⁱⁱ(pyridyl) distances are 3.777 (3) and 3.879 (2) Å, respectively, while that of Cg3(pyrazinyl)···Cg3ⁱⁱⁱ(pyrazinyl) is 3.626 (2) Å (symmetry codes: I –x + 1, –y + 1, –z + 1; ii –x + 1, –y + 2, –z + 2; iii –x + 1, –y + 2, –z + 1. Cg1, Cg2, Cg3 represent the N1-C1-C2-C3-C4-C5, N5-C11-C12-C13-C14-C15 and N2-C6-C7-N3-C8-C9 rings, respectively). A three-dimensional supramolecular framework is formed (Fig. 3).

Experimental

The ligand 5-(2-pyridyl)-2-cyanopyrazine was obtained commercially. To a clear solution of 3 ml methanol containing the ligand (18.2 mg, 0.1 mmol), AgClO₄ (22 mg, 0.1mmol) was added with stirring at room temperature. 1 ml acetonitrile was subsequently added dropwise to make the solution clear. After filtration the clear solution was kept in air for one week at room temperature to yield colorless rod-like crystals (19.0 mg, 66% yeild).