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) ?, b = 6.6599(4) ?,c = 23.5921(16) ? and b = 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 ?), c?h•••? (with h•••? distance of 2.941 ?) and c=o•••? (with o•••? distances of 2.943, 3.702 and 3.743 ?) stacking interactions stabilize the supramolecular structure.