Synthesis, structures and physicochemical properties of two two-dimensional coordination polymers based on 3,5-di(1H-benzimidazol-1-yl)pyridine

Two-dimensional coordination polymers [Co(L)(PDA)center dot H2O](n) (1) and [Cd(L)(OBA)center dot 4H(2)O](n) (2) [L = 3,5-di(1H-benzimidazol-1-yl)pyridine, H(2)PDA = 1,3-phenylenediacetic acid, H(2)OBA = 4,4 '-oxybis(benzoic acid)] have been prepared and characterized by IR, elemental analysis, thermal analysis and single-crystal X-ray diffraction. The latter revealed that both complexes have 2D (4,4)-connected layer structures. These layers are linked by O-H center dot center dot center dot O and C-H center dot center dot center dot O hydrogen bonds to form a three-dimensional supramolecular framework, which is reinforced by pi-pi interactions. There is an antiferromagnetic interaction between the adjacent Co(II) centers in complex 1, while complex 2 displays interesting photoluminescence and is also a good photocatalyst for the degradation of methyl orange.