Syntheses, characterizations and crystal structures of four zinc(II) and cadmium(II) complexes constructed by ligand bearing poly-coordination atoms

Treatment of 3-(4-carboxyphenylhydrazono)pentane-2,4-dione (HL) with transition metal ions afforded four novel complexes, [Zn(L)(μ2-OOCCH3)(H2O)]n (1), [Zn(L)2(MeOH)4] (2), {[Cd4(η2-L)4(μ2-η2-L)4(H2O)4(MeOH)2]·MeOH} (3) and [Cd(η2-L)(μ2-η2-OOCCH3)(H2O)2]n (4). Their crystal structures have been characterized by single-crystal X-ray crystallography. In polymer 1, the acetate anions bridge the Zn(II) ions forming an infinite one-dimensional (1-D) chain with L− units acting as monodentate ligands in the side chain. In mononuclear complex 2, two L− ligands act as monodentate fashion to coordinate to the Zn(II) ion. In its solid-state structure, [Zn(L)2(MeOH)4] groups are joined together by hydrogen bonds forming a three-dimensional (3-D) supramolecular network. In tetranuclear complex 3, four Cd(II) ions are linked by four μ2-η2-L− ligands, and chelated by another four L− ligands, respectively. In polymer 4, the acetate anions bridge the Cd(II) ions leading to a 1-D chain containing chelating L− units in the side chain.