Synthesis And Properties Of Rare Earth Complexes Based On Multipodal Carboxylate Ligands

As a kind of inorganic ions,lanthanide ions have unique electronic structures that make their complexes to possess excellent optical,electrical and magnetic properties.As ligands of lanthanide ions,the flexibility,modifiable skeleton structures,and changeable functional groups of multi topical carboxylate ligands have received great attention.Among them,multi-podal salicylic acid derivatives as “antenna” can transfer energy to lanthanide ions to get luminescence complexes.Especially their europium?III?or terbium?III?complexes have remarkable advantages,such as narrow emission band,better monochromaticity,long lifetime,high quantum yield,etc..Therefore,design and synthesis the europium?III?or terbium?III?complexes based on multi-podal carboxylate ligands to as probe to detect other ions is still in high demand.Based on our previous work,we synthesized a series of multipodal carboxylate ligands and their rare earth complexes,and explored their fluorescence properties.This paper is divided into three chapters:Chapter 1: A brief overview of the recent research progress of rare earth complexes,and the complexes based on multipodal carboxylate ligands.Chapter 2: By modifying the end group of tripodal carboxylate ligands,three Tb?III?complexes with high sensitivity “Off-On-Off” pH fluorescent probes?L^?·Tb,L^?·Tb,L^?·Tb?were synthesized.Due to the push-pull electronic effects of salicylic acid ligands,the fluorescence efficiencies of three Tb?III?complexes were different,L^?·Tb complex was the best one.Therefore,L^?·Tb was successfully applied for pH detection of some patients' urines.Chapter 3: To new ligands?H₃L^?and H₃LV?and their corresponding Eu?III?complexes were synthesized by adding a fluorescent group?5-Dimethylamino-1-napthalenesulfonyl group?to the tripodal salicylic acid ligand.However,the fluorescence spectra of Eu?III?complexes had no their characteristic emission peaks of Eu3+ at 594 nm?5D0?7F1?and 620 nm?5D0?7F2?.Only a broad peak of the fluorescent group?5-Dimethylamino-1-napthalenesulfonyl group?was observed at 440⁶20 nm.In the detection of a series of nitroaromatics,L^?·Eu complex could selectively recognize 2,4,6-trinitrophenol?TNP?,which showed the fluorescence quenching.Therefore,L^?·Eu complex can be used as a fast,efficient and sensitive probe for the selective recognition of TNP over other explosives.