Synthesis, Structure And Biological Activity Studies Of Polycopper(Ⅱ) Complexes Bridged By μ-N,N′-Di(Substituted)Oxamides

Recent years, owing to its unique characteristics in medicine and material, polynuclearcomplexes have attracted extended interests. Based on this background, we designed ansynthesized two novel dissymmetrical N,N’-bis（substituted）oxamide ligands and a series ofpolycopper（II） complexes, we also have gotten four complex crystals. Their structures have beendetermined by a series of techniques, as well as their biological activities. The detail contentsinclude several aspects as follows:1. Syntheses and structures of two dissymmetrical μ-N,N’-bis（substituted）oxamide ligands.In order to synthesize new complexes, two novel dissymmetrical μ-N,N’-bis-（substituted）oxamideligands, N-benzoato-N′-[3-（diethelamino） propyl]oxamide （H₃bdpox） and N-（2-hydroxyphenyl）-N′-[3-（diethylamino）propyl]oxamide （H₃pdpox） have been synthesized with diethyl oxalate asraw material and characterized by a series of techniques. At the same time, another ligand crystal,N-benzoato-N′-[3-（diethelamino） propyl]oxamide, has been gotten and its crystal structure havebeen determined by X-ray single-crystal diffraction.2. Synthesis and structures of bridging polynuclear complexes. A series of polycopper（II）complexes have been synthesized by choosing dissymmetrical μ-N,N’-bis（substituted）oxamideligands, H₃bhyox and H₃bdpox, as the bridging ligands. Especially, four crystals of thesecomplexes have been gotten and characterized by X-ray single-crystal diffraction, including: twoone-dimension complexes,{[Cu₂（bhyox）（dabt）]·NO₃}_n（1）,{[Cu₂（bhyox）（dabt）]·pic}_n（2） andtwo tetranuclear complexes,[Cu₂（bhyox）（dabt）]₂（ClO₄）₂（3）,[Cu₂（bdpox）（bpy）]₂（ClO₄）₂（4）.3. In vitro cytotoxicities of compounds and their interactions with DNA and BAS. Theinteractions of four polycopper complexes with HS-DNA were investigated by using absorptionand emission spectrometry, electrochemical measurements and viscometry. The results suggestedthat all of the four ploycopper complexes can interact with HS-DNA in the mode of intercalation.The bonding intensities of the four complexes are bigger than the free ligands. The interactions offour polycopper complexes with BAS were also investigated by using absorption and emissionspectrometry. The results exhibit the four complexes can bond to BAS well. At the same time, wealso investigated their in vitro cytotoxic activities against human hepatocellular carcinoma cellsSMMC-7721and human lung adenocarcinoma cells A549by SRB assays, and the results displayall of the four complexes have cytotoxic activities and also are better than the free ligands.According to these results, we conclude that the complexation maybe the major cause of theenhanced effect on the biological activity.