Synthesis,Magnetism And Luminescence Of Rare Earth Metal Organic Complexes

In recent years,the study of functional rare earth organic complexes have been one of the hot points,and researches on single-molecule magnet?SMM?and luminescence have been the important issue in this field.This thesis summarizes the research results of rare earth organic complexes reported in recent years in monomolecular magnets and luminescence,and summarizes the research progress of8-hydroxyquinoline and?-diketone ligands.Taking advantage of above results,fourteen complexes based on 8-hydroxyquinoline Schiff Base derivatives and?-diketones coligands were synthesized.The complexes have been characterized by X-ray single crystal diffraction,EA,X-ray power diffraction,TG,IR,UV,and the magnetic and fluorescent properties of some complexes have been investigated.The main contributions in this dissertation are as below:1.Two kinds of 2-methyl-8-hydroxyquinoline derivative ligands were synthesized by 2-methyl-8-hydroxyquinoline,methyl picolinate and methyl pyrazinecarboxylate as materials.HL1=N-?methylene-8-hydroxyquinoline?-pyridyl hydrazone;H₂L2=N-?methylene-8-hydroxyquinoline?-pyrazinyl hydrazone.2.Five kinds of rare earth complexes Nd₃?tfa?₄?L5?₂?CH₃COO?₃?1??Eu₂?tfa?₄?L3?₂?2??Nd₃?tfa?₄?L4?₂?CH₃COO?₃?3??Yb₂?tfa?₄?L5?₂?4??Yb₂?tfa?₄?L3?₂?5??Htfa=trifluoroacetylacetonate?withtheligands4-Xanilino2-methyl-8-hydroxyquinoline Schiff base and trifluoroacetylacetonate as materials.Complexes 1 and 3 are trinuclear structures and complexes 2,4 and 5 are dual-nuclear structures.3.Two kinds of rare-earth complexes[Dy₄?acac?₄?L1?₄]?5CH₃CN?5CH₂Cl₂?6?and Dy?TFA?₂?L1??14??Hacac=acetylacetone,HTFA=2-thiophene trifluoroacetone?were synthesized using the ligand N-?methylene-8-hydroxyquinoline?-pyridyl hydrazone and the?-diketone salts of dysprosium.Complex 6 is a tetranuclear structure and the coordination configuration is a hexagonal bipyramid configuration.Complex 14 is a mononuclear structure and the coordination configuration is a tridecahedral configuration.Each Dy³⁺ion metal center is eight-coordinated in 6 and14.4.With N-?methylene-8-hydroxyquinoline?-pyrazinyl hydrazone as ligand and rare earth 1,3-diphenyl-1,3-propanedione salt as materials,seven kinds of complexes[Nd₂?dbm?₂?L2?₂?CH₃OH?₂]·3CH₃OH?7?,[Tb₂?dbm?₂?L2?₂DMF)₂]·2CH₃OH·H₂O?8?,[Eu₂?dbm?₂?L2?₂?CH₃OH?₂]·3CH₃OH?9?,[Y₂?dbm?₂?L2?₂DMF₂]·2H₂O?10?,[Yb₂?dbm?₂?L2?₂DMF₂]·2CH₃OH?11?,[Er₂?dbm?₂?L2?₂DMF₂]·2CH₃OH·H₂O?12?and[Dy₂?dbm?₂?L2?₂?CH₃OH?₂]·2DMF·CH₃OH?13??Hdbm=1,3-diphenyl-1,3-propanedione?were synthesized.Complexes 7-13 has a dual-nuclear building block in which 7 and 9 are nine-coordinated and in 8,10-13,each Ln³⁺is eight-coordinate.The ac magnetic susceptibility test showed that the complex 13exhibited a typical single-molecule magnet behavior.The relaxation energy barrier Ea/k _B=2.44 K,and the pre-exponential factor?₀=1.8×10^-77 s.