Bis[5-(2-pyrid-yl)pyrazine-2-carbonitrile]-silver(I) tetra-fluorido-borate

Bis[5-(pyridin-2-yl)pyrazine-2-carbo-nitrile-κ(2)N(4),N(5)](trifluoro-acetato-κO)silver(I)

In the asymmetric unit of the title compound, [Ag(C₁₀H₆N₄)₂(CF₃CO₂)], there two mononuclear but slightly different complex units. In each, two κ²N:N-chelating 5-(pyridin-2-yl)pyrazine-2-carbonitrile ligands surround the Ag^I atom, giving an N₄O square-pyramidal coordination geometry with one trifluoro­acetate O atom at the apex. The difference between the two lies in the Ag—N bond lengths: in one complex, three normal [range 2.272 (5)–2.552 (5) Å] and one long [2.706 (4) Å] and in the second, two normal [2.254 (5) and 2.290 (5) Å] and two long [2.647 (5) and 2.675 (5) Å] are present. Short inter­molecular F⋯F contacts [2.586 (4) Å] and weak π–π stacking inter­actions [minimum ring centroid separation 3.836 (5) Å] between pyridyl and pyrazinyl rings connect the complex units, forming columns which extend along the b-axis direction.

Bis[5-(pyridin-2-yl)pyrazine-2-carbonitrile-κ2N4,N5]silver hexafluoridophosphate

In the mononuclear title complex, [Ag(C₁₀H₆N₄)₂]PF₆, two κ²N,N′-chelating 5-(pyridin-2-yl)pyrazine-2-carbonitrile ligands surround the Ag^I atom, forming a distorted N₄ tetra­hedral coordination geometry. The mononuclear units are inter­connected through π–π inter­actions [centroid–centroid distances = 3.801 (2) and 3.979 (3) Å] and the hexa­fluoridophosphate anions are embedded within the inter­stices. C N⋯π inter­actions [N⋯centroid = 3.519 (2) Å] and C—H.⋯N hydrogen-bonding inter­actions also occur.

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

In the mononuclear title complex, [Ag(NO(3))(C(10)H(6)N(4))(2)], two κ(2)N:N'-chelating 5-(pyridin-2-yl)pyrazine-2-carbonitrile ligands surround the Ag(I) atom, forming an N(4)O 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 inter-connected along [010] through C-H⋯O(nitrate) and C-H⋯N(cyano) inter-actions, forming an infinite chain. The mononuclear units are stacked along the a axis and inter-connected via inter-molecular π-π stacking inter-actions between adjacent pyridine and pyrazine rings [centroid-centroid distances = 3.984 (2) and 3.595 (3) Å], thus forming a three-dimensional supra-molecular structure.

Bis[5-(pyridin-2-yl)pyrazine-2-carbo-nitrile-κN,N]silver(I) perchlorate

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.