Crystal structure of a looped-chain Co^IIcoordination polymer:catena-poly[[bis(nitrato-κO)cobalt(II)]bis[μ-bis(pyridin-3-ylmethyl)sulfane-κ²N:N′]]

Abstract

The asymmetric unit of the title compound, [Co(NO 3 ) 2 (C 12 H 12 N 2 S) 2 ] n , contains a bis(pyridin-3-ylmethyl)sulfane (L) ligand, an NO 3 À anion and half a Co II cation, which lies on an inversion centre. The Co II cation is six-coordinated, being bound to four pyridine N atoms from four symmetry-related L ligands. The remaining coordination sites are occupied by two O atoms from two symmetry-related nitrate anions in a monodentate manner. Thus, the Co II centre adopts a distorted octahedral geometry. Two symmetry-related L ligands are connected by two symmetry-related Co II cations, forming a 20-membered cyclic dimer, in which the Co II atoms are separated by 10.2922 (7) Å . The cyclic dimers are connected to each other by sharing Co II atoms, giving rise to the formation of an infinite looped chain propagating along the [101] direction. Intermolecular C-HÁ Á Á (HÁ Á Áring centroid = 2.89 Å ) interactions between one pair of corresponding L ligands and C-HÁ Á ÁO hydrogen bonds between the L ligands and the nitrate anions occur in the looped chain. In the crystal, adjacent looped chains are connected by intermolecular -stacking interactions [centroid-tocentroid distance = 3.8859 (14) Å ] and C-HÁ Á Á hydrogen bonds (HÁ Á Áring centroid = 2.65 Å ), leading to the formation of layers parallel to (101). These layers are further connected through C-HÁ Á ÁO hydrogen bonds between the layers, resulting in the formation of a three-dimensional supramolecular architecture.