Synthesis, structure, cytotoxic activities, and DNA-binding of 1-D copper(II) and zinc(II) coordination polymers

Two 1-D coordination polymers have been synthesized and identified as [Zn(ox)(en)](n)(H2O)(2n) (1) and [Cu-2(dmeo)(N-3)(2)](n) (2), where en represents diaminoethane, ox and dmeo stand for dianions of oxalic acid and N,N'-bis[2-(dimethylamino)ethyl]oxamide, respectively. Polymer 1 was characterized by elemental analysis, molar conductance measurement, IR and electronic spectra, and single-crystal X-ray diffraction. Polymer 1 consists of 1-D chains bridged by oxalate. The Zn-II can be described as a distorted octahedral environment and the Zn-II center dot center dot center dot Zn-II separation through the mu-oxalato-bridge is 5.5420(9) angstrom. Hydrogen bonds assemble the coordination polymers to a 3-D supermolecular structure. The crystal structure of 2 has been reported previously. However, the bioactivities were not studied. The DNA-binding properties and cytotoxic activities of the two coordination polymers are investigated. The results suggest that the two polymers interact with HS-DNA in groove binding with binding affinity following the order of 1 > 2, which is consistent with their anticancer activities.