Structural Characterization,Spectral Properties And Biological Activity Of N-heterocyclic Ligands And Bi(Ⅲ),Ni(Ⅱ),Zn(Ⅱ) And Co(Ⅱ) Schiff Base Complexes

Schiff base metal complexes have developed rapidly in bioinorganic chemistry,catalysts,medicinal chemistry and materials science due to their structural diversity and some interesting properties.(Due to the structural diversity and some interesting characteristics,Schiff base metal complexes have rapidly developed their applications in bioinorganic chemistry,catalysts,medicinal chemistry and materials science.)At the same time,some Schiff base ligands were combined with certain metal ions(such as Bi(Ⅲ),Zn(Ⅱ),Co(Ⅱ),etc.),and the metal complexes formed were also widely studied in terms of biological activity In this thesis,three Schiff base ligands were synthesized and their interaction mechanisms with metal ions(Bi(Ⅲ),Ni(Ⅱ),Zn(Ⅱ),Co(Ⅱ))were investigated.The main research contents are as follows:1.O-aminoacetophenone oxime was prepared synthetically and three organic ligands were synthesized by reacting it with 4-imidazole formaldehyde,2-pyridinaldehyde and 3-ethoxysalicylaldehyde.HL1:2-(4-imidazolyl)-4-methyl-1,2-quinazoline-N3-oxide;HL2:2-(2-naphthyl)-4-methyl-1,2-quinazoline-N3-oxide;HL3:2-(3-ethoxy-4-phenolic hydroxy)-4-methyl-1,2-quinazoline-N3-oxide.2.The ligands HL1 and HL2 were selected to react with Bi(NO3)3.5H2O and two crystals of Bi(Ⅲ)complexes 1 and 2 were obtained.Characterize the structures of the two Bi(Ⅲ)complexes by means of elemental analysis,X-ray single crystal diffraction and other testing methods.Simultaneously,UV absorption and fluorescence spectra of complexes 1 and 2 were tested and compared with the formed ligands.The antibacterial activity of two Bi(Ⅲ)complexes was discussed.Theoretical studies of complexes 1 and 2 were performed.The structures of the two complexes were optimized by density functional theory(DFT)and the energy and band gap of the highest occupied molecular orbital(HOMO)and the lowest unoccupied molecular orbital(LUMO)were calculated.Ultraviolet data simulation(TD-DFT)was performed on the optimized structure to further explain the effect of electronic transitions on the ultraviolet-visible absorption spectrum.Finally,Hirshfeld surface analysis was used to study the intermolecular interactions of Bi(Ⅲ)complexes 1 and 2.3.Select the ligand HL2 was reacted with Ni(NO3)2.6H2O to obtain the crystal of Ni(Ⅱ)complex 3.The ultraviolet absorption spectrum and antibacterial activity of complex 3 were analyzed and compared with HL2.And the electrochemical properties of complex 3 were studied.In addition,the complex 3 was theoretically studied by DFT calculations,TD-DFT calculations and Hirshfeld surface analysis.4.The crystal of Zn(Ⅱ)complex 4 was obtained by reacting HL1 with Zn(NO3)2·6H2O.Its structure was determined by characterization methods such as elemental analysis,IR and X-ray single crystal diffraction.The ultraviolet absorption spectrum and fluorescence spectrum of complex 4 were analyzed and compared with HL1 and the antibacterial activity was also studied.Finally,the complex 4 was theoretically studied using DFT calculation,TD-DFT calculation and Hirshfeld surface analysis.5.The ligand HL3 was reacted with Co(NO3)2·6H2O to obtain the crystal of Co(Ⅱ)complex 5.The chemical composition and spatial configuration were determined by characterization methods such as elemental analysis,IR and X-ray single crystal diffraction and the electrochemical properties of complex 5 were studied.The coordination mode of complex 5 and the molecular force of the internal structure of the crystal were analyzed.Finally,the complex 5 was theoretically studied using DFT calculation,TD-DFT calculation and Hirshfeld surface analysis.