Synthesis, Crystal Structure, Interaction With Ct-DNA And Antibacterial Activity Studies Of Metal Complexes With Quinolone Drugs

The third quinolone inhibit well the Gram positive and Gram negative microorganisms. The recent research results indicate the inhibitory activity of the metal complex will increase because of the cooperation between the metals and ligands. On the other hand, because they possess numerous coordination sites in the structure of quinolone, can assemble into coordination polymers with potential application in luminescent, electric and magnetic materials.Therefore, much attention has been paid to the metal complexes with quinolone in recent years. But there are few researches on orbifloxacin cipfloxacin and enoxacin. Here in, we selected them as ligands, to synthesize four metal complexes, characterized their crystal structures and properties. In addition, we primary synthesized 6 kinds of rare earth metal complexes and determined their IR spectra and antibacterial activity.Chapter One: The mononuclear complex [Ni(H-Orbi)2(NH3)2](ClO₄)₂ (1) and [Cu(Orbi)(Phen)H₂O]ClO₄ (2) have been synthesized by reaction of orbifloxacin with Ni(ClO₄)₂·6H₂O and Cu(ClO₄)₂·6H₂O under the solvthermal condition, respectively. X-ray single crystal diffraction analysis revealed that complex 1 and 2 belong to monoclinic crystal system with P 21/c and C2/c space group, respectively. Cell parameters for complex 1: a = 19.546(2) A, b = 8.1458(9) A, c = 27.423(3) A;α= 90°,β= 95.482(4)°,γ= 90°; V = 4346.3(9) A3, Z = 4, Dc = 1.654 mg/m3. In complex 1, the central metal Ni(II) coordinates with four oxygen and tow nitrogen atoms forming slightly distorted octahedron structure. The basal plane comprise of three oxygen atoms form two different orbifloxacin molecules and one nitrogen atom from an ammonia molecule and an oxygen atom from another orbifloxacin molecule and an nitrogen atom from ammonia complete the coordination sphere in the apical site. Three-dimensional super-molecular structure of complex 1 is formed by intermolecular hydrogen bonding in the space. Cell parameter for complex 2: a = 21.517(4) A, b = 9.7157(16) A, c =34.309(6) A;α= 90°,β= 105.567(3)°,γ=90°; V = 6909(2) A3, Z = 8, Dc = 1.530 mg/m3. And Complex 2 is five–coordinated and slightly distorted quadrilateral pyramid. The oxygen atom from water molecular occupy the apical position.Two oxygen atoms from the 4-keton and the 3-carboxylate group, and two nitrogen atoms from a 1,10-Phen occupy four equator plane sites. 3-dimension super-molecular structure of the complex is formed by innermolecualr and intermolecular hydrogen bonds in space. The interaction between the complexes and DNA had been studied by UV-Vis spectra and fluorescence spectra, and the combination constants had been obtained. The antibacterial activity of the complexes had been tested. We also tested the antibacterial activity of the complexes.Chapter Two: One-dimensional chain structure of the 1,10-Phen-Cu(II)-Enoxacin coordination polymer [Cu(Enox)(1,10-Phen)]ClO₄·2H₂O(3) is assembled by reaction of Cu (ClO₄)₂·6H₂O, Enoxacin and 1,10-Phen.under solvthermal conditions. It belongs to triclinic crystal system with P -1 space group. Cell parameter: a = 12.662(15) A, b = 15.190(18) A, c = 16.171(19) A;α= 89.916(15)°,β=89.883(17)°,γ= 71.408(18)°; V = 2948(6)A3,Z = 4, Dc =1.572 mg/m3。In complex 3 the central Cu(II) ion is coordinated with two oxygen atoms from a enoxacin molecule and three nitrogen atoms(one is terminal nitrogen in the piperzinyl of another noxacin molecule,others come from a 1,10-Phen). One-dimension chain structure of the coordination polymer is formed in space by the bridge enoxacin. Two-dimension net structure is formed, in space, by theÏ€-Ï€stacking interaction of side rings in 1,10-Phen molecules in adjacent chains. Three-dimensional superstructure of the complex is formed via intermolecular hydrogen bonding. For probing into the action between complexes and the DNA, we studied the UV-Vis absorption spectra and the fluorescence spectra of the complexes 2 binding with ct-DNA and figured out the combination constants between the complexes and the ct-DNA by established method.Chapter Three: The complex [Cu(H-cip)2Cl]Cl·7H₂O(4)is obtained by the reaction of CuCl2 and cipfloxacin under solvthermal condition. The complex 4 belongs to triclinic crystal system with P–1 space group. Cell parameters: a = 9.2954(14) A, b = 9.5317(15)A, c = 22.465(3)A;α= 86.788(8)°,β= 79.981(7)°,γ= 86.520(8)°; V = 1954.3(5)A3, Z = 2, Dc = 1.569 mg/m3. Every Cu(II) ion coordinates with four oxygen atoms and one chlorine ion atom. The geometry around Cu(II) can be described as a distorted quadrilateral pyramid. For probing into the action between complexes and the DNA, we studied the UV-Vis spectra and the fluorescence spectra of the complexes binding with ct-DNA and figured out the combination constants between the complexes and the ct-DNA by constructing method. We also tested the antibacterial activity of the complexes. Chapter Four: Six rare earth metal complexes with orbifloxacin have been synthesized and primary characterized by IR, and their antibacterial activity also been evaluated. The results show that they exhibit similar antibacterial activity to orbifloxacin.