Synthesis,structure, anticancer activities,and DNA-binding properties of a 1-D polymeric copper(II) complex alternately bridged by oxamide and terephthalate

A 1-D polymeric copper(II) complex alternately bridged by N,N′-bis(N-hydroxyethylaminopropyl)oxamide (heap^2?) and terephthalate (tpa^2?), [Cu₂(heap)(tpa)] _n , has been synthesized and characterized by single-crystal X-ray diffraction. The crystal structure reveals that the asymmetric unit of the copper(II) polymer is half a dinuclear copper(II) complex, [Cu₂(heap)(tpa)], in which Cu(II) is located in a square-pyramidal coordination environment. Separations of Cu(II) through heap^2? and tpa^2? bridges are 5.2459(6) and 11.1375(6)?Å, respectively. The complex chains, accompanied with glide planes parallel to the a0c plane, can be classified to two groups according to their extending direction. Hydrogen bonds occur between a complex chain and any adjacent ones in the other orientation. Consequently, a 3-D supramolecular network is completed. The polymeric copper(II) complex exhibits potent anticancer activities against human hepatocellular carcinoma cell SMMC-7721 and human lung adenocarcinoma cell A549 tested by sulforhodamine B assays. The interactions of the polymeric copper(II) complex with herring sperm DNA (HS-DNA) are investigated by using electronic absorption titration, fluorescence titration, electrochemical titration, and viscometry measurements. The results suggest that the polymeric copper(II) complex interacts with HS-DNA via intercalation with intrinsic binding constant of 1.8?×?10^6?(mol?L^?1)^?1.