Three cobalt (II)hexanedioate complexes [Co(H 2 O) 4 (H 2 L)]n 1 (H 2 L=hexanedioic acid), Co(imidazole) 4 (H 2 L)]n 2 and [Co(pyridine) 2 (H 2 O) 4 ][H 2 L] 3 are synthesized and structurally characterized to study the effect of N-donor substituents coordinated to the metal center on the polymeric network. Complex 1 is an extended linear polymer; Co(H 2 O) 4 units are linked by the monodendate carboxylate from either end of the extended deprotonated hexanedioic acid. There are intra- and interchain H-bonding interactions between the coordinated water molecules and the end carboxylate O atoms, the uncoordinated O atom creates two dimensional hydrogen bonding pattern. Complex 2 also is a linear polymer; Co(imidazole) 4 units are linked by monodentate dibasic acid at the either end but with S shaped conformation of the hexanedioic acid, not as fully extended as in 1. The effect of bulkier N-donor substitution is seen in the distortion of the octahedral coordination polyhedron of Co(II). The noncordinated carboxylate oxygen makes one intra and one interchain H-bonding interaction with the imidazole N-H group making a two-dimensional H-bonded network as in 1. In 3 with the two strong N-donor pyridines coordinated to the metal center, the hexanedioate is out of the coordination sphere and acts as a counter ion. The Co(pyridine) 2 (H 2 O) 4 units are linked by H-bonding in both the dimensions by extensively folded adipate dianion forming a sheet structure parallel to ab plane. According to our knowledge this is the first example showing a strong H-bonding network in which a tetraaquaCo(II) center forms an eight-membered ring with bidendate H-bonding interactions. None of the coordination polymeric structures form any channels in their molecular packing, even to include a small entity as a water molecule.