The Studies On Construction,Characterizations And Properties Of Multifunctional Coordination Polymers With Bioactivities

The design and construction of metal-organic coordination polymers is of current interest in the fields of supramolecular chemistry and crystal engineering. A major reason for this interest is the promise of being able to generate new materials with intriguing architectures and potential applications in optical, electronic, magnetic, adsorption, gas storage, ion exchange, biology activity and supramolecular chemical drugs. How to obtain materials with prospective structures and function is the prime importance in crystal engineering. It demonstrates that using some specific assembly strategy and choosing suitable building blocks should be the key in constructing target materials. In this paper, with the aim of obtaining novel materials with beautiful architecture and excellent physical, biological properties, we selected multi-functional ligands (N-containing imidazolic ligands, di-or polycarboxylate ligands and flavonoids of natural bioactive ingredients) as building blocks to construct coordination polymers under the intervention of various transition metal ions and auxiliary ligands guided by assembly principle of coordination polymer crystal engineering. The coordination behavior of the ligand completely, the role of solvent and metal ions have been discussed.Under different reaction condition, seven coordination polymers have been synthesized. They are listed as follows:[Cu2(bcm)2(CH3OH)2]·2CH3OH (1),[Cu2(bcm)2(CH3CH2OH)2]·2CH3CH2OH (2),{[Zn(bbi)3(NO3)]Br·2H2O}n (3),[Zn(oxa)(bbi)]n (4),[Mn(fma)2(bbi)2(H2O)2]n (5),[Cd2(bpdc)2(bbi)2]n (6),{[Cog(cit)4(bbi)6(H20)10]·7H20}n (7). These polymers have been characterized by X-ray single crystal diffraction analysis, elemental analysis, thermal analysis and fluorescence spectroscopy to investigate the spectroscopy characters and properties. The results revealed that the conformation of the ligands play an important role in the structure of complexes. The coordination of2is similar to that of1except that ethanol molecules are coordinated instead of methanol molecules. And there-dimensional network structures of1and2are formed through p-p interactions. Compounds3,4and7all exhibit2D layer structures, in which3displays a3-fold interpenetration framework containing2D networks with (6,3) topology and4is a2D structure with (4,4) topology. Compound7contains a2D44grid-like layer with (44.62) topology composed of octanuclear cobalt clusters. Two high-dimensional compounds (3D) with a microporous network containing1D flower-like metal-organic motifs interlinked by bbi ligands for6, and a3-fold interpenetrating network with66-dia topology by considering the manganese ion as a four-connected node for5, are observed. The biological activities of the title compounds have been studied. The results indicate that3-7exhibit certain antimicrobial activities and7exhibits weaker radical-scavenging activities than that of bbi ligand.Furthermore, three kinds of Cu(II), Zn(II), Fe(IlI) complexes of Quercetagetin (Que) were synthesized and characterized by IR spectra, UV spectra and elemental analysis etc. The free radical (DPPH·, O2-·,·OH) scavenging activities of the complexes were investigated in this paper. Then, the mechanism of the interaction between the free ligand and complexes with calf thymus DNA(CT-DNA) were investigated by using means of UV spectra. The results showed that free radical’scavenging activities of the complexes on DPPH·, O2-· and·OH were obviously stronger than that of the quercetagetin. In addition results of spectroscopic measurements suggested that the three complexes bound to DNA via an intercalative mode and calculated DNA-binding action decreased in the order Que-Fe>Que-Cu>Que-Zn>Que. The new metallic complexes of quercetagetin add new contents for coordination chemistry. The well bioactivity of the complexes afford an applied foundation on the medicine.