Syntheses,characterization And Antibacterial Activity Of Metal Complexes Based On 6,6'-dihydroxyl-2,2'-bipyridine Ligands

In this thesis,the work is associated with pyripropanol-based complexes.Using 6,6'-dihydroxyl-2,2'-bipyridine(dhbpH2)as ligand,and pivalic acid(Hpiv)as co-ligand,seven clusters combined with 3d and 3d-4f ions have been synthesized:one Co-cluster(1)and six Fe-Ln-clusters(2-6).All complexes have been characterized by single-crystal,elemental analysis,magnetic susceptibility and antibacterial activity.1.Co-complex was synthesized through the reaction of dhbpH2 and Co? ions,with the formula of {[Co?6(?3-OH)(dhbpH)4(dhbp)2(piv)3]·5CH3CN}(1).Crystal data:Triclinic,P-1,a/A = 13.5335(7),b/A = 15.0440(8),c/A = 23.0909(10),?/°= 83.302(4),?/°=89.004(4),?/° = 69.765(5),V/A3 = 4379.67(40),Z = 2.Dc magnetic susceptibility studies reveal probably antiferromagnetic couplings.Ac magnetic susceptibility measurements shows there is no frequency-dependent out-of-phase(?")signals.2.Six 3 d-4f hetero-metal complexes were synthesized through the reaction of dhbpH2,Ln? and Fe? ions,with the formula of {[Ln?2Fe?8(0)6(OH)2(C2H5O)2(dhbp)4(dhbpH)(piv)6]·4C2H5OH }(Ln = Gd(2),Tb(3),Dy(4),Ho(5),Er(6),Y(7)).The metal core of complexes 2-7 is made up of a distorted quardrangular.Dc magnetic susceptibility studies reveal that there are dominant antiferromagnetic interactions in 2-6.Ac magnetic susceptibility studies show frequency-dependent out-of-phase(?")signals for[Dy?2Fe?8](4),suggesting the single-molecule magnet(SMM)behaviour of 4.3.The antibacterial activity of complexes 1-4 against Gram-negative bacterium(Escherichia coli and Pseudomonas aeruginosa)and Gram-positive bacterium {Bacillus subtilis and Staphylococcus aureus)are investigated.The results shows the weakly antibacterial activities for Gram-negative bacterium,which may be dependent on the composition and thickness of bacterial cell wall.