Synthesis And Fluorescence Properties Of Flexible Schiff Base Rare Earth Complexes

Lanthanide ions have a unique 4f electronic layer structure,the study of lanthanide ions has gained great recognition owing to their fascinating photoluminescence and magntism.Lanthanide metal coordination has received a lot of attention.we described two types of fifteen lanthanide（III）complexes achieved by using N,N′-bis（salicylidene）-hexane-1,4-diamine withβ-diketonate ligands2-thenoyltrifluoroacetone and dibenzoy-lmethane which adopt the solution diffusion method,the structure and luminescent properties have been tested and analyzed.The results were as follows:A series of lanthanide-based self-assembling complexes constructed from H₂L base and TTA ligands have been synthesized by the same method.They are one dimensional complexes{[Ln（H₂L）（tta）₂（OAc）]·0.5H₂O}_n[Ln=Nd（1）,Sm（2）,Eu（3）,Gd（4）,Tb（5）,Dy（6）,Yb（7）];H₂L=N,N′-bis（salicylidene）hexane-1,4-diamine,TTA=2-thenoyltrifluor-oacetone).Complexes 2 and 3 exhibit Sm（III）and Eu（III）ion-based luminescence not only in the solid state but also in solution.Complexes 1and 7 exhibit Nd（III）and Yb（III）ion-based near-infrared luminescence properties.the lifetimes of luminescence were also tested and calculated in the same way.The magnetic analysis reveals that complex 3 exhibits field-induced single-molecule magnet behavior with an energy barrier.Complexes 8–15[Ln（H₂L）（DBM）₃（CH₃OH）][Ln=Nd（8）,Sm（9）,Eu（10）,Gd（11）,Tb（12）,Dy（13）,Yb（14）,Er（15）]were synthesized by the H₂L and DBM（DBM=dibenzoylmethane）.The luminescence of complexes 9 exhibited luminescence Sm（III）ion with ligands,The luminescence of complexes 10 exhibited characteristic luminescence Eu（III）ion.It was found that the complexes 8,14 and 15 showing near-infrared luminescence properties.Under the 2000Oe,Magnetic studies show complex 13 is a SMM.