Synthesis Of Metal-Organic Frameworks Based On Ligand Design And Fluorescence Detection Study

In the fields of fine chemicals and pharmaceutical,water plays an important role in the rate and yield of chemical reaction in solvent system,thus water content in the reaction solvent becomes a key indicator.Like water,amino acids are foundational substances as well,they serve as the basic components of protein in life.And are involved in many physiological processes in organisms.Therefore,the quantitative detection of amino acids is of great significance for disease diagnosis and physiological regulation.In the study of fluorescence probe,Metal-Organic Frameworks(MOFs)show potential applications in the fluorescence detection of trace substances,because of its rich luminescent sites,flexible design and diverse topological structure.Based on the previous research on the fluorescence detection of MOFs,three kinds of MOFs probes with excellent optical properties have been prepared via reasonable design in this paper,and are applied to the detection of trace amino acids and water.Choosing H2DCPB as the organic ligand,three dimensional crystals LnDCPB(Ln=Tb,Eu)are prepared by solvothermal method.The material has good water stability and thermal stability.Organic ligands H2DCPB can transfer energy to Eu3+ions effectively,and there is interaction between the liand and Asp.EuDCPB shows the ratiometric detection pattern,and the detection lmit reachs 27.6 ?M.And the probe EuDCPB shows good selectivity,which is not interfered by other common ions and amino acids.Taking H4HFDA and H2HFBA containing trifluoromethyl group as organic ligands,the crystals LnHFDA and LnHFBA(Ln=Tb,Eu)are hydrothermal synthesized with rare earth ions as metal precursor.These prepared MOFs have good water stabiliy.The specific hydrophobic interaction between hydrophobic amino acids Trp and trifluoromethyl groups on organic ligands can be established.TbHFDA has quenching fluorescence response to hydrophobic Trp,and the detection limit is 6.65?M.the probe shows high selectivity for Trp and is not interfered by other amino acid molecules.This experimental design provides a new idea for the detection of amino acids and other small biomolecules.Rrystals Mn-sdc-1 and Mn-sdc-2 with reversible phase transformation property are selected.Mn-sdc-1 has a close packed structure with smaller pores,while Mn-sdc-2 has larger one-dimensional channels.Dye R6G whose molecular size between the two is selected.The dye is firstly introduced into Mn-sdc-2 by immersion.By pahse transition process,R6G@Mn-sdc-1 is obtained from R6G@Mn-sdc-2.The dye R6G is firmly bound in the smaller pores of Mn-sdc-1.The prepared R6G@Mn-sdc-1 can be transformed back to R6GMn-sdc-2 in the presence of trace water,and the bound dye is easy to release.And the fluorescence intensity of the released dye is related to the water content in the solution.This makes R6G@Mn-sdc-1 a turn-on fluorescence probe based on phase transformation property for trace water.The probe has the potential to be applied to the detection of trace water in various organic solvents.