A new chain-like cadmium(II) coordination polymer containing chains of water molecules.

The title cadmium(II) polymer, catena-poly[[[bis(4-aminopyridine-kappaN)aquacadmium(II)]-mu-1,4-phenylenediacetato-kappa(4)O,O':O'',O'''] dihydrate], {[Cd(C10H8O4)(C5H6N2)2(H2O)].2H2O}n, comprises one-dimensional wave-like chains, in which the Cd atom is coordinated by 1,4-phenylenediacetate and 4-aminopyridine molecules. The 1,4-phenylenediacetate ligands lie about inversion centres. Extensive hydrogen-bonding interactions between the chains lead to a three-dimensional structure. Free water molecules form chains in the structure.