Crystal structure of a looped-chain CoII coordination polymer: catena-polybis­(nitrato-κO)cobalt(II)bis­μ-bis­(pyridin-3-ylmeth­yl)sulfane-κ2N:N′

摘要

The asymmetric unit of the title compound, [Co(NO3)2(C12H12N2S)2]n, contains a bis­(pyridin-3-ylmeth­yl)sulfane (L) ligand, an NO3 ⁻ 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—H⋯π (H⋯ring centroid = 2.89 Å) inter­actions between one pair of corresponding L ligands and C—H⋯O 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 π–π stacking inter­actions [centroid-to-centroid distance = 3.8859 (14) Å] and C—H⋯π hydrogen bonds (H⋯ring centroid = 2.65 Å), leading to the formation of layers parallel to (101). These layers are further connected through C—H⋯O hydrogen bonds between the layers, resulting in the formation of a three-dimensional supra­molecular architecture.