Poly[[trans-diaquabis(mu(2)-biphenyl-2,2'-dicarboxylato)bis(mu(2)-4,4'-bipyridine)dicobalt(II)] biphenyl-2,2'-dicarboxylic acid disolvate].

In the title compound, {[Co(2)(C(14)H(8)O(4))(2)(C(10)H(8)N(2))(2)(H(2)O)(2)].2C(14)H(10)O(4)}(n), each Co(II) ion is six-coordinate in a slightly distorted octahedral geometry. Both Co(II) ions are located on twofold axes. One is surrounded by two O atoms from two biphenyl-2,2'-dicarboxylate (dpa) dianions, two N atoms from two 4,4'-bipyridine (bpy) ligands and two water molecules, while the second is surrounded by four O atoms from two dpa dianions and two N atoms from two bpy ligands. The coordinated dpa dianion functions as a kappa(3)-bridge between the two Co(II) ions. One carboxylate group of a dpa dianion bridges two adjacent Co(II) ions, and one O atom of the other carboxylate group also chelates to a Co(II) ion. The Co(II) ions are bridged by dpa dianions and bpy ligands to form a chiral sheet. There are several strong intermolecular hydrogen bonds between the H(2)dpa solvent molecule and the chiral sheet, which result in a sandwich structure.