The Synthesis And Performance Characterization Of The Rare Earth-β/Polydentate,Carboxylic Acid Complexes

Due to their excellent optical properties,rare earth luminescent functional complexes based on multidentate ligands have been widely used in many frontier fields such as fluorescence sensing,bioimaging,and immunoassays.In this thesis,a series of rare-earth binuclear complexes and one-dimensional rare-earth/transition metal complexes were designed and synthesized using multidentate organic ligands,and the potential applications of the materials as fluorescent probes and electrochemiluminescence（ECL）signal transmitters were explored.The research of this thesis includes the following four aspects:（1）Using bis-β-diketone（L1）as the main ligand and 1,10-phenanthroline derivative（bpz）as the auxiliary ligand to react with rare earth chloride salts step by step,three binuclear rare earth complexes were synthesized by solvent evaporation method[Ln₂（L1）₃（bpz）₂]·2TL{Ln=Eu（1）,Tb（2）,Yb（3）}.From the single crystal diffraction data,it can be seen that complex 1 belongs to the monoclinic system,the space group P2₁/c,and the central metal ion is eight-coordinated.Through the fluorescence spectrum detection of the complex,the complex 1 can be used for the detection of Al³⁺in water with a detection limit of 9.41μM and a Ksv value of 5.099×10⁴ M^-1.Through the anti-interference test,it is found that complex 1 has high sensitivity and low detection limit,and can be used as the fluorescence detection of Al³⁺in aqueous medium,which has potential application prospects.（2）Three water-soluble rare earth complexes{Ln（L2）（H₂O）₂}·3Cl,Ln=Eu（4）,Dy（5）,Sm（6）were synthesized by solvothermal reaction of pyridine carboxylic acid[H₃（L2）Cl₃]and rare earth perchlorate.According to the single crystal diffraction data,the complexes 4-6 belong to the monoclinic system,the space group C2/c,and the central metal ion is octacoordinated.Subsequently,complex 4 was found to have electroluminescent properties,and complex 4 was used as an ECL signal probe combined with a Mg²⁺-driven three-dimensional DNA walker to construct a biosensor for the detection of circulating tumor cell marker let-7a.The experimental results show that the sensor has good stability,and has broad application prospects in clinical diagnosis.（3）Five one-dimensional rare earth complexes[Ln（L3）（DMF）₂（NO₃）]{Ln=Pr（7）,Sm（8）,Eu（9）,Tb（10）,Dy（11）}were synthesized by the reaction of p-benzaldehyde 3-amino-4-methylbenzoic acid（L3）with rare earth nitrate.The complexes were characterized by infrared spectroscopy,powder diffraction,thermogravimetric analysis,ultraviolet-visible absorption and single crystal diffraction.Single-crystal tests show that the complexes are connected by binuclear rare earth cluster units to form a one-dimensional chain structure,but due to the DMF coordination,the material does not show luminescence properties.（4）Two water-soluble transition metal complexes{[Zn（L2）Cl]·NO₃·H₂O}（12）和{[Cd₂（L2）₂Cl₂]·2NO₃·2H₂O}（13）were synthesized by solvothermal reaction of pyridine carboxylic acid[H₃（L2）Cl₃]with transition metal nitrate.The study found that transition metal complexes can interact with biomacromolecules（BSA）,the complexes have strong binding affinity to BSA,and the main mechanism of the interaction between complexes and BSA is static quenching.