A coordination polymer of Mn (III) with pyridine-2, 3-dicarboxylic acid and 4,4-bipyridine

The polymeric compound, {(C10H9N2)[Mn(C7H3NO4)2].(C10H8N2).6H2O}n, was prepared by the reaction of manganese (II) nitrate with pyridine-2,3-dicarboxylic acid, (py-2,3-dcH2) and 4,4'-bipyridine (4,4'-bipy) in a 1:2:4 molar ratio. The crystal system of the complex is monoclinic with space group P21/n and four molecules per unit cell. The unit cell parameters are: a = 22.2099(15) Å, b = 6.6599(4) Å, c = 23.5921(16) Å and 9 = 104.014(3)°. The final R value was 0.04 based on 8960 reflections. The central atom is attached to two (py-2,3-dc)2– ligands through their N and O atoms in a planar square arrangement and two O atoms from bridging carboxylate groups, forming polymeric chains. So, the anionic complex features six-coordinate Mn (III) with a distorted octahedral geometry. In the crystal structure, a wide range of non-covalent interactions consisting of hydrogen bonding (of the types O>H···O, O>H···N and C>H···O), ion pairing, and @–@ (centroid-centroid distances of 3.607 and 3.721 Å), C>H···@ (with H···@ distance of 2.941 Å) and C=O···@ (with O···@ distances of 2.943, 3.702 and 3.743 Å) stacking interactions stabilize the supramolecular structure.