Syntheses, Structures and Luminescent Properties of Three new Zinc(II) Complexes Constructed from Dicarboxylate and N-donor Coligands

Three new metal coordination polymers, [Zn(oba)(bim)](n) (1), [Zn(oba)(2,2'-bipy)](n) (2) and [Zn(oba)(pbim)](n) (3) [H(2)oba = 2-(4-carboxyphenoxy)benzoic acid, bim = benzimidazole,2,2'-bipy = 2,2'-bipyridine and pbim = 2-(4-Pyridyl)benzimidazole], were synthesized and structurally characterized by elemental analysis, IR and X-ray diffraction. Compound 1 is a two-dimensional supramolecular framework, which is connected by one-dimensional chains through hydrogen bonding interactions. In compound 2, an alternate arrangement of the right- and left-handed helical chains through interchained pi-pi stacking interactions, formed a two-dimensional supramolecular framework. Compound 3 exhibited a 2D -> 3D interdigital architecture with side arms. In compounds 1, 2 and 3, the oba(2-) ligands act as bridging ligands exhibiting three coordination modes to link metal ions; i.e., bis-monodentate, bidentate chelating and monodentate modes. The luminescent properties of 1, 2 and 3, were also investigated.