[μ-1,2-Bis(4-pyridyl)ethane-κ2 N:N′]bis[(4′-phenyl-2,2′:6′,2′′-terpyridine-κ3 N,N′,N′′)silver(I)] bis(trifluoromethanesulfonate)

In the title compound, [Ag2(C12H12N2)(C21H15N3)2](CF3SO3)2, the AgI atom is coordinated by three N atoms of one 4′-phenyl-2,2′:6′,2′′-terpyridine (phtpy) ligand and one pyridyl N atom of the 1,2-bis(4-pyridyl)ethane (bpe) ligand, displaying a distorted square-planar geometry. Two AgI atoms are bridged by one trans-bpe ligand, generating a dinuclear cation. The dinuclear cation is located on a centre of inversion, which is in the middle of the ethylene fragment of the bpe ligand. In the crystal, the pyridyl rings of neighboring dinuclear units are stacked by π–π interactions with centroid–centroid distances of 3.667 (2) and 3.835 (2) Å. The F and O atoms of the CF3SO3 − anions are involved in intermolecular C—H⋯F and C—H⋯O hydrogen-bonding interactions, respectively, with –CH groups from the phtpy ligands.

In the title compound, [Ag 2 (C 12 H 12 N 2 )(C 21 H 15 N 3 ) 2 ]-(CF 3 SO 3 ) 2 , the Ag I atom is coordinated by three N atoms of one 4 0 -phenyl-2,2 0 :6 0 ,2 00 -terpyridine (phtpy) ligand and one pyridyl N atom of the 1,2-bis(4-pyridyl)ethane (bpe) ligand, displaying a distorted square-planar geometry. Two Ag I atoms are bridged by one trans-bpe ligand, generating a dinuclear cation. The dinuclear cation is located on a centre of inversion, which is in the middle of the ethylene fragment of the bpe ligand. In the crystal, the pyridyl rings of neighboring dinuclear units are stacked byinteractions with centroid-centroid distances of 3.667 (2) and 3.835 (2) Å . The F and O atoms of the CF 3 SO 3 À anions are involved in intermolecular C-HÁ Á ÁF and C-HÁ Á ÁO hydrogen-bonding interactions, respectively, with -CH groups from the phtpy ligands.

silver(I)]
bis(trifluoromethanesulfonate) Y. Ma, B. Liu and C. Xue Comment 4'-Phenyl-2,2':6',2"-terpyridine (phtpy) is an excellent chelating ligand and arising from its good coordinating abilities with a broad variety of transition metal ions, such as Cu I , Ag I , Mn II , Ni II , Cu II , Zn II and Ru II metal ions, it has recently been the focus of several investigations (Chen et al., 2005;Constable et al., 1990;Hou & Li, 2005;Rao et al., 1997;Shi et al., 2007;Tu et al., 2004;Xie et al., 2008). Some of the reported complexes exhibit interesting photoluminescent and magnetic properties. We report here the synthesis and crystal structure of a new Ag I complex incorporating both phtpy and 1,2-bis(4-pyridy)ethane (bpe) as ligands.
In the title compound, [Ag 2 (C 12 H 12 N 2 )(C 21 H 15 N 3 ) 2 ] (CF 3 SO 3 ) 2 , the asymmetric unit is composed of one Ag atom, one phtpy ligand, one half bpe ligand and one CF 3 SO 3 anion, as shown in Fig. 1. The Ag I centre is four-coordinated by three N atoms of one phtpy ligand and one pyridyl N atom of the bpe ligand, resulting in a distorted square-planar geometry. The sum of the angles about the Ag I centre is 385.02°. The bpe ligand exhibits a trans-mode at the ethylene unit (C24/C27/C27 ii /C24 ii , symmetry code, ii = 2-x, 1-y, 1-z) and bridges the two Ag I centres to generate a dinuclear structure, which is located on a center of inversion in the middle of the ethylene group of the bpe ligand. In the solid state, the phtpy ligands are π-stacking with phtpy units from neighboring complexes so as to form stacks along the a-axis of the cell. Alternating phtpy units in the stacks have opposite orientation with one phtpy unit of each dinuclear complex being part of one stack, while the other phtpy unit is part of the next neighboring stack. The interdigitating π-stacked columns thus form layers of connected stacks that stretch perpendicular to the c-axis of the unit cell. Closest entroid-to-centroid distances within the stacks are of 3.835 (2) Å and 3.667 (2) Å for the distances of the N3 pyridyl and the N1 iii and N2 i pyridyl rings, respectively ( Fig. 2). (Symmetry operators: i = 1-x, -y, 1-z, iii = 2-x, -y, 1-z). In addition, the F1 and O1 atoms of CF 3 SO 3 anions are involved in intermolecular C-H···F and C-H···O hydrogen bonding interactions, respectively, with -CH groups from the phtpy ligands ( Fig. 3).

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.
Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > 2sigma(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.