Structure,Properties And Theoretical Calculation Of Aromatic Aldehyde And Pyridine Ring Ligands And Their Cu(?),Cd(?),Bi(?)Complexes

Among various nitrogen heterocyclic compounds,quinazoline and its derivatives have attracted much attention because of their unique antibacterial and anti-inflammatory activities.At present,a series of quinazoline derivatives have been obtained by introducing various active groups into quinazoline fragments,which have a wide range of applications in the area of biology,pesticide and medicine.In recent years,quinazoline-type metal complexes have developed rapidly,among which the complexes containing some specific metal ions(such as Cu²⁺,Cd²⁺,Bi³⁺)possessed excellent antibacterial activity.It has potential application value as well as in the field of luminescent materials,industrial catalysis,etc.In this thesis,four quinazoline metal complexes were designed and synthesized,and their interaction mechanisms with Cu(?),Cd(?),and Bi(?)were discussed,respectively.The major research details were listed follows:1.O-aminoacetophenone oxime was synthesized,and then it was reacted with3-nitrobenzaldehyde,pyridine-2-carbaldehyde and 3-pyridinecarbaldehyde to prepare three ligands,respectively.L¹:2-(3-nitrophenyl)-4-methyl-1,2-quinazoline-N³-oxide;L²:2-(2-pyridyl)-4-methyl-1,2-quinazoline-N³-oxide;L³:2-(3-pyridyl)-4-methyl-1,2-quinazoline-N³-oxide.In addition,two containing coumarin acylhydrazone ligands,L⁴ and L⁵ were synthesized,and the structure were verified by ¹H NMR.2.L¹ was reacted with Cu(NO₃)₂·3H₂O to obtain clear black striped crystal of Cu(?)complex 1,and the structure was confirmed by IR and X-ray crystallography.The UV-visible absorption and fluorescence spectra of 1 were tested to compare with the L¹,the antibacterial activities of all compounds were also explored.Moreover,the optimize structure of 1 was calculated by density functional theory(DFT)and the energy of HOMO and LUMO as well as gap value were calculated.The time-dependent density functional theory(TD-DFT)was performed on the optimized structure to investigate the electronic transition.The atomic charges distribution and electrostatic potential(ESP)diagrams showed that the chemical reaction sites in 1.Finally,the Crystal Explorer17 program was carried out to quantitatively analyze the weak interaction in the Cu(?)complex.3.L² was reacted with Cd(NO₃)₂·4H₂O and Bi Cl₃ to obtain the complexes 2 and 3,the structures were characterized by IR and X-ray single crystal diffraction.The spectroscopy method and antibacterial activity of both complexes were tested and compared with L².Moreover,the optimal structure of 2 and 3 was obtained by DFT,and the energy of the HOMO and LUMO as well as gap value were calculated.The TD-DFT was performed on the optimized structure to explore electronic transition.The atomic charges distribution and ESP diagrams showed that the chemical reaction sites in both complexes.Finally,the Crystal Explorer17 program were carried out to quantitatively analyze the intermolecular interaction in Cd(?)and Bi(?)complexes.4.L³ was reacted with Bi Cl₃ to obtain crystal of Bi(?)complex 4.Its structure was characterized by IR and X-ray crystallography.The UV-visible spectrum,fluorescence spectrum and antibacterial activity of 4 were analyzed and compared with L³.The theoretical calculation of complex 4 was carried out through DFT,TD-DFT calculation,ESP and the Hirshfeld surface analysis.In addition,the Zn(?),Ni(?)/Co(?)and Cd(?)/Cu(?)complexes of L⁴ and L⁵ were obtained,and the properties of these complexes were tested by spectroscopy method.