catena-Poly[[[dibromidocadmium]-µ(2)-1,1'-(butane-1,4-di-yl)bis-(pyridinium-4-carboxyl-ate)] monohydrate].

In the title compound, {[CdBr(2)(C(16)H(16)N(2)O(4))]·H(2)O}(n), the Cd(II) ion is six-coordinated by a Br(2)O(4) donor set, with four O atoms from two bridging 1,1'-(butane-1,4-di-yl)bis-(pyridinium-4-carboxyl-ate) ligands. The ligands link the Cd(II) ions into a zigzag chain extending along [0[Formula: see text]1]. O-H⋯O and O-H⋯Br hydrogen bonds involving the uncoordinated water mol-ecules connect the chains.

(5,5'-Dicarboxy-biphenyl-2,2'-dicarboxyl-ato-κO,O)bis-(1,10-phenanthroline-κN,N')cobalt(II) dihydrate.

In the title compound, [Co(C(16)H(8)O(8))(C(12)H(8)N(2))(2)]·2H(2)O, the Co atom located on a twofold rotation axis. It is six-coordinated by two O atoms from one 5,5'-dicarboxy-biphenyl-2,2'-dicarboxyl-ate anion and four N atoms from two 1,10-phenanthroline mol-ecules in a distorted octa-hedral environment. The crystal packing is stabilized by O-H⋯O hydrogen bonds.

(5,5'-Dicarboxy-biphenyl-2,2'-dicarboxyl-ato-κO,O)bis-(1,10-phenanthroline-κN,N')zinc(II) dihydrate.

In the title compound, [Zn(C(16)H(8)O(8))(C(12)H(8)N(2))(2)]·2H(2)O, the Zn(II) atom is located on a twofold rotation axis and is six-coordinated by two O atoms from a 5,5'-dicarboxy-biphenyl-2,2'-dicarboxyl-ate ligand and four N atoms from two 1,10-phenanthroline mol-ecules in a distorted octa-hedral geometry. The crystal structure involves O-H⋯O hydrogen bonds.