Bis[5-(2-pyrid­yl)pyrazine-2-carbonitrile]­silver(I) tetra­fluorido­borate

Zi-Jia Wang; Fan Zhang; Chong-Qing Wan

doi:10.1107/S1600536810035178

. 2010 Sep 8;66(Pt 10):m1232–m1233. doi: 10.1107/S1600536810035178

Bis[5-(2-pyridyl)pyrazine-2-carbonitrile]silver(I) tetrafluoridoborate

Zi-Jia Wang ^a, Fan Zhang ^a, Chong-Qing Wan ^a,^*

PMCID: PMC2983161 PMID: 21587386

Abstract

In the title mononuclear complex, [Ag(C₁₀H₆N₄)₂]BF₄, the Ag^I atom adopts a square-planar N₄coordination geometry and is surrounded by two 5-(2-pyridyl)pyrazine-2-carbonitrile ligands. The tetrafluoridoborate anions link the mononuclear cations through intermolecular C—H⋯F hydrogen-bonding interactions, forming an infinite tape structure along [110]. Other weak interactions occur: π–π stacking with centroid–centroid distances of 3.820 (2) and 3.898 (1) Å between pyridyl rings and 3.610 (2) and 3.926 (2) Å between pyrazinyl rings as well as F⋯π contacts involving the tetrafluoridoborate anions and pyrazine rings [F⋯centroid = 2.999 (3) Å]; these combine with the hydrogen-bonding interactions to link the mononuclear cations into a three-dimensional supramolecular architecture.

Related literature

For coordination complexes with 2,2′-bipyridine, see: Casini et al. (2006 ▶); Li et al. (2010 ▶); Wang et al. (2009 ▶). For other related structures involving 2,2′-bipyridine derivatives, see: Berghian et al. (2005 ▶); Mathieu et al. (2001 ▶). For the coordination chemistry of multidentate N-containing ligands, see: Peedikakkal & Vittal (2010 ▶). For properties of pyridine-based ligands, see: Casini et al. (2006 ▶). For comparison Ag—N(pyrazinyl) distances, see: Biju & Rajasekharan (2008 ▶). For C—H⋯F interactions, see: Denis et al. (2004 ▶). For a comparable BF₄ anion–pyrazinyl interaction, see: Wan et al. (2008 ▶).

Experimental

Crystal data

[Ag(C₁₀H₆N₄)₂]BF₄
M _r = 559.06
Triclinic,
a = 7.8144 (12) Å
b = 11.2492 (16) Å
c = 12.2697 (18) Å
α = 104.168 (3)°
β = 90.789 (2)°
γ = 101.429 (3)°
V = 1022.8 (3) Å³
Z = 2
Mo Kα radiation
μ = 1.05 mm⁻¹
T = 293 K
0.45 × 0.40 × 0.30 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2007 ▶) T _min = 0.615, T _max = 0.783
7178 measured reflections
4986 independent reflections
3929 reflections with I > 2σ(I)
R _int = 0.017

Refinement

R[F ² > 2σ(F ²)] = 0.038
wR(F ²) = 0.111
S = 1.04
4986 reflections
307 parameters
H-atom parameters constrained
Δρ_max = 0.95 e Å⁻³
Δρ_min = −0.73 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 datablocks I, global. DOI: 10.1107/S1600536810035178/bg2359sup1.cif

e-66-m1232-sup1.cif^{(20.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810035178/bg2359Isup2.hkl

e-66-m1232-Isup2.hkl^{(244.2KB, 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
C5—H5a⋯F3ⁱ	0.93	2.49	3.398 (3)	167
C13—H13a⋯F2	0.93	2.43	3.015 (5)	121
C11—H11a⋯F4ⁱⁱ	0.93	2.39	3.132 (4)	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

During the past decades, coordination chemistry based on multidentate N-containing ligands has been widely developed and received intense interests (Peedikakkal et al., 2010). 2,2'-bipyridine is a popular member of the pyridine-based family and attracts a great of attentions because of the potential medicinal applications (Casini et al., 2006) and the fascinating framework structures (Li et al., 2010; Wang et al., 2009) of its divers metal complexes. 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 the new complex [Ag(C₁₀H₆N₄)₂]BF₄ derived from 5-(2-pyridyl)-2-cyanopyrazine ligand, a similar ligand to the 2,2'-bipyridine featuring a 2-cyanopyrazinyl group at the 2-pyridyl carbon atom (Scheme 1). In the mononuclear title complex, the two ligands surrounding the center Ag(I) ion are in an anti-relationship and almost in the same plane, thus each of them chelates the Ag(I) ion through one 2-pyridyl N atom and one 4-pyrazinyl N atom, leading to a square planar N4- coordination geometry. As shown in Fig.1, the Ag1—N1(pyridyl) and Ag1—N3(pyridyl) bonds equal to 2.196 (2) and 2.203 (2) Å, respectively, which are considerably shorter than the other two Ag—N(pyrazinyl) bonds with the distances of 2.659 (2) Å (Ag1—N4) and 2.685 (2) Å (Ag1—N2), respectively. The longer Ag—N(pyrazinyl) distance is comparable to that in [Ag(dafone)₂]NO₃.H₂O (dafone = 4,5-diazafluoren-9-one) (Biju et al., 2008). For the tetrafluoridoborate anions, each one links two neighbor [Ag(C₁₀H₆N₄)₂]⁺ cationic moieties arranged along the [110] direction through C—H···F (Denis et al., 2004) hydrogen bonding (C13···F2 3.015 (1) Å, C13—H13a···F2 120.8°; C11ⁱ···F4 3.132 (2) Å, C11ⁱ—H11aⁱ···F4 137.2°, i x-1, y-1, z), forming an infinite tape structure (Fig. 2). The tape arrays are arranged along [110] direction in a shoulder to shoulder mode and stack along [-110] direction via π-π and F(BF₄^-)···π(pyrazinyl) interactions (Fig. 3). The close centroid(pyridyl)···centroid(pyridyl)distances are 3.820 (2) and 3.898 (1) Å, while that of centroid(pyrazinyl)···centroid(pyrazinyl) are 3.610 (2) and 3.926 (2) Å. For the anion-π interaction, F4(BF₄^-)···centroid(pyrazinyl) distance is 2.999 (3) Å, comparable to that 3.097 (1) Å found in Cu[(2-C₄H₃N₂)₂C(OH)₂]₂(BF₄^-)₂ (Wan, et al., 2008).

Experimental

The ligand 5-(2-pyridyl)-2-cyanopyrazine was obtained commercially.The ligand (0.182 g, 0.1 mmol) was dissolved in a mixture of methanol, 2 ml, and acetonitrile, 2 ml was added to AgBF₄ (0.194g, 0.1mmol), with constantly stirring. After four hours, the clear solution was filtered and kept in air for one week at room temperature to yield colorless rod-like crystals (274 mg, 72% yeild).