(Nitrato-κO)bis­[5-(pyridin-2-yl)pyrazine-2-carbonitrile-κ2 N 4,N 5]silver(I)

Fan Zhang; Yong-Li Yang

doi:10.1107/S1600536811049221

. 2011 Nov 30;67(Pt 12):m1863. doi: 10.1107/S1600536811049221

(Nitrato-κO)bis[5-(pyridin-2-yl)pyrazine-2-carbonitrile-κ² N ⁴,N ⁵]silver(I)

Fan Zhang ^a,^*, Yong-Li Yang ^a

PMCID: PMC3238754 PMID: 22199631

Abstract

In the mononuclear title complex, [Ag(NO₃)(C₁₀H₆N₄)₂], two κ² N:N′-chelating 5-(pyridin-2-yl)pyrazine-2-carbonitrile ligands surround the Ag^I atom, forming an N₄O square-pyramidal coordination geometry with one nitrate anion bonding at the apical site. The two heterocyclic rings of the 5-(2-pyridin-2-yl)pyrazine-2-carbonitrile ligand are almost coplanar [dihedral angle = 5.63 (8)°], and the two chelating ligands are in an anti relationship. The mononuclear units are interconnected along [010] through C—H⋯O(nitrate) and C—H⋯N(cyano) interactions, forming an infinite chain. The mononuclear units are stacked along the a axis and interconnected via intermolecular π–π stacking interactions between adjacent pyridine and pyrazine rings [centroid–centroid distances = 3.984 (2) and 3.595 (3) Å], thus forming a three-dimensional supramolecular structure.

Related literature

For coordination complexes with pyridyl-based ligands, see: Dunne et al. (1997 ▶); Wang et al. (2009 ▶). For a related complex with 5-(2-pyridin-2-yl)pyrazine-2-carbonitrile, see: Wang et al. (2010 ▶).

Experimental

Crystal data

[Ag(NO₃)(C₁₀H₆N₄)₂]
M _r = 534.26
Orthorhombic,
a = 14.000 (3) Å
b = 12.133 (2) Å
c = 23.832 (4) Å
V = 4048.4 (13) Å³
Z = 8
Mo Kα radiation
μ = 1.04 mm⁻¹
T = 293 K
0.44 × 0.35 × 0.25 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2007 ▶) T _min = 0.631, T _max = 1.000
27695 measured reflections
5029 independent reflections
3255 reflections with I > 2σ(I)
R _int = 0.037

Refinement

R[F ² > 2σ(F ²)] = 0.034
wR(F ²) = 0.099
S = 1.03
5029 reflections
298 parameters
H-atom parameters constrained
Δρ_max = 0.46 e Å⁻³
Δρ_min = −0.28 e Å⁻³

Data collection: APEX2 (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: 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/S1600536811049221/zq2135sup1.cif

e-67-m1863-sup1.cif^{(22.5KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811049221/zq2135Isup2.hkl

e-67-m1863-Isup2.hkl^{(246.4KB, 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
C19—H19A⋯O1ⁱ	0.93	2.35	3.233 (3)	157
C11—H11A⋯O2ⁱⁱ	0.93	2.54	3.232 (5)	132
C13—H13A⋯N8ⁱⁱⁱ	0.93	2.73	3.319 (3)	122

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

Acknowledgments

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

supplementary crystallographic information

Comment

Pyridyl based ligands have attracted increasing attention because of their versatile linkage behavior and their artificial and controllable synthesis (Dunne et al., 1997; Wang et al., 2009). Recently, we reported a silver(I) complex derived from 5-(2-pyridyl)pyrazine-2-carbonitrile (Wang et al., 2010). To make a further insight into the coordination chemistry of such a ligand featuring a 2-cyanopyrazinyl group at the 2-pyridyl carbon atom (Scheme 1), herein we present the structure of the new complex [Ag(C₁₀H₆N₄)₂(NO₃)].

As shown in Fig. 1, in the mononuclear title complex two κ²N:N chelating 5-(2-pyridyl)pyrazine-2-carbonitrile ligands surround the Ag^I center to form a N4O-pyramidal coordination geometry with one nitrate bonding at the axial site. The Ag—N bond lengths lie within the range of 2.301 (2) - 2.579 (3) Å, with Ag1—N1 and Ag1—N4 slighty shorter than Ag1—N2 and Ag1—N5. These bond distances are comparable to those in [Ag(C₁₀H₆N₄)₂]BF₄ (2.196 (2) - 2.685 (2) Å) reported by us recently (Wang et al. 2010). Furthermore, in the present case, the nitrate binds to the silver center with Ag1—O1 = 2.547 (3) Å. It is worth to note that a second O atom of the nitrate interacts with the silver center as shown by the Ag1—O2 distance of 2.800 (2) Å. Along the b axis, the mononuclear moieties are arranged with two adjacent ones around an inversion center. Indeed, C—H···O(nitrate) and C—H···N(cyano) interactions (Table 1) are found to link the mononuclear units together to form an infinite chain structure along the b axis (Fig. 2). Along the a direction, intermolecular π–π stacking interactions between adjacent pyridyl rings and pyrazinyl rings connect the mononuclear units together, forming a three-dimensional framework (Fig. 3). The distance between Cg1 (N4-N11-C12-C13-C14-C15) and Cg2ⁱ(N5-N16-C17-N6-C18-C19) is 3.984 (2) Å, while that between Cg3 (N1-N5-C6-N7-C8-C9) and Cg4ⁱⁱ(N2-C1-C2-N3-C3-C4) equals to 3.595 (3) Å (symmetry codes: i = –x, –y-1, –z+1; ii = –x+0.5, –y+1, z+1.5).

Experimental

The 5-(2-pyridyl)-2-cyanopyrazine ligand was obtained commercially. The ligand (18.1 mg, 0.1 mmol) and AgNO₃ (17 mg, 0.1mmol) were mixed and dissolved in 3 ml methanol, and then 1 ml acetonitrile was subsequently added to make the solution clear. After stirring at room temperature for 3 hours, the resulted solution was filtrated, and the clear solution was kept in air for about one week at room temperature to yield yellow block-like crystals (21.1.0 mg, 79% yield).