Synthesis And Fluorescence Properties Of Coordination Polymers Based On Rare Earth Metals

Rare-earth metal coordination polymer is a new type of functional material.The main frame structure of this kind of material includes two properties about luminescence and porosity,and the host-guest response is sensitive.This material has been widely concerned by scientists domestic and abroad.In recent years,domestic and foreign chemical and materials workers have made remarkable research progress in the field of rare earth metal coordination polymers,which are mainly reflected in biological imaging,drug sustained release,ion sensing,small molecule sensors.The development of fluorescent sensors for the detection and screening of biomolecules has great practical significance.In this paper,we research the changes in the fluorescence properties of the entire system when different rare earth ions are doped into the same coordination polymer,and use this special fluorescence property to study its application in the identification of small biological molecules.We used powder X-ray diffractometer,thermal weight analyzer,fluorescence spectrum,infrared spectrophotometer and other modern detection methods to analyze the structure and fluorescence properties of the three types of rare earth metal coordination polymers.This paper is divided into the following three parts:1.In this experiment,H₂BPDC was used as the organic ligand,Tb³⁺and Eu³⁺were the central ions,and a series of rare earth metal coordination polymers MOF-1-6 were prepared under solvothermal conditions.Tb/Eu-MOF-6 can be used to identify DPA molecules in solution.DPA will change the fluorescence intensity and lifetime of Tb/Eu-MOF-6,and it can achieve the obvious naked-eye recognition effect under ultraviolet light.The fluorescence emission will change from yellow to red,and the fluorescence change achieves a linear relationship.The calculated limit of detection(LOD)was 4.51?M.2.Taking Tb³⁺and Eu³⁺as the central ions and H₃BTC as the organic ligand,a series of rare earth metal coordination polymers MOF-76-1-6with a three-dimensional network structure were prepared under solvothermal conditions.Among them,both Tb-MOF-76-1 and Tb/Eu-MOF-76-6 can show the naked eye recognition effect to AFB1,Tb-MOF-76-1 fluorescence emission changes from green to cyan;Tb/Eu-MOF-76-6 fluorescence emission changes from yellow to white;Tb/Eu-MOF-76-6 is a self-calibration fluorescence sensor that can induce fluorescence signals at 487nm,548nm,and 616nm to be amplified to varying degrees,where at 487nm The fluorescence intensity rises most obviously,and has a linear relationship with the concentration change.After calculation,the limit of detection(LOD)was 6.57?M.3.In this experiment,H₂BDC was used as the organic ligand,doped with different proportions of Tb³⁺and Eu³⁺ions,and a series of rare earth metal coordination polymers MOF-1114-1-6 with the same structure were prepared under solvothermal reaction conditions.Due to the different doping ratios,the fluorescence colors in MOF-1114-1-6 are also different.Our selected Tb/Eu-MOF-1114-6 bimetallic center fluorescence sensor can show a significant fluorescence quenching effect on the biomolecule creatinine and the recognition effect is specific.The fluorescence color changes from yellow to colorless.The quenching efficiency reaches85.51%and varies linearly with concentration,K_SV=27.01 M^-1,and the limit of detection(LOD)is 4.37?M.