Crystal structure of a Co(II) coordination polymer with a dipyridyl ligand: catena-poly[[bis-(nitrato-κ(2)O,O')cobalt(II)]-μ-N-(pyridin-2-ylmeth-yl)pyridine-3-amine-κ(3)N,N':N''].

The asymmetric unit of the title compound, [Co(NO(3))(2)L] (n) , L = N-(pyridine-2-ylmeth-yl)pyridine-3-amine (C(11)H(11)N(3)), contains one Co(II) centre, two nitrate anions and one L ligand in which the C(py)-C-N-C(py) moiety adopts a trans conformation with a torsion angle of -173.1†(3)†à . The coordination geometry of the Co(II) atom is a distorted penta-gonal bipyramid. One amine N atom from the L ligand and four O atoms from two η(2)-nitrato ligands form the basal plane and two pyridyl N atoms from two symmetry-related L ligands occupy the apical positions [N-Co-N = 171.86†(11)°]. The displacement of the central Co(II) atom from the basal plane (r.m.s. deviation = 0.085†à ) is 0.1491†(12)†à . Each bidentate nitrate group is bonded asymmetrically to the cobalt atom in an chelating fashion. The Co(II) ions are linked by the L ligands to form a zigzag chain propagating along the c-axis direction. Within the zigzag chain, C-H⋯O hydrogen bonds between the ligands and the nitrate anions are observed. Adjacent zigzag chains are connected via inter-molecular π-π stacking inter-actions [centroid-to-centroid distance = 3.844†(2)†à ] between the pyridine rings together with N/C-H⋯O hydrogen bonds.