Study On Synthesis,Structure And Properties Of New Complexes Based On An Amide Salen-like Ligand

The interest in studying rare earth complexes stems from their diverse applications due to their fluorescent,magnetic,biological activities and other excellent performances.It is a great challenge to control crystal structures with desired properties because many factors affect the result,such as the coordination geometry of the central metal ions,connection modes of organic ligands,reaction temperature,the ratio of reagents,solvents ratio,pH of anion and solvent system etc.The key point for preparing rare-earth compound with special structure and properties is the designing and synthesis of organic ligand which possesses both good chelating capability and function.Amide-type ligands,as well as their rare earth complexes,have unique structures and excellent fluorescence properties,while Schiff base ligands can be used for the preparation of transition metal complexes.The design and synthesis of new amide salen-like ligands combined with amide and imine group together with their rare earth complexes with unique properties and the study of the correlation between the structure and properties is still a challenge,because the prepare of rare earth complexes based on new Salen-like ligand and their properties plays an important role in the development of molecular materials with potential applications.In this thesis,a salicylamide Salen ligand and their dinuclear and heterometallic complexes were synthesized.The main contents of this research are divided as follows:In the first chapter,we summarized the research progress of rare earth and their luminescent complexes together with the significance of this thesis.In the second chapter,salicylamide Salen-like ligands:2-hydroxy-N-?2-???3-hydroxynaphthalen-2-yl?methylene?amino?ethyl?benzamide?H₂L?was synthesized.Two new dinuclear rare earth complexes[Er₂L₂?NO₃?₄].2CH₃CN and[Yb₂L₂?NO₃?₄].3CH₃CN.CH₃OH and one 3d-4f metal complex[Zn₂Dy₂L₄Cl₄?NO₃?₂].2CH₃CN were prepared and characterized by elemental analysis,infrared spectrum IR and X-ray single crystal diffraction.Crystal analysis indicates that the two rare earth complexes are isomorphous and two rare-earth ions are bridged by two phenoxys of two deprotonated ligand L^2-.In the third chapter,the luminescence and UV-Visible spectra of the two dinuclear rare earth complexes were measured.The luminescence determination indicates that the fully deprotonated phenoxy ligand L^2-can sensitize the characteristic near-infrared emission of Er???and Yb???effectively.