Research On Luminescent MOF And Sensing Properties Based On Semi-rigid C And N Center Multidentate Ligands

The photoluminescent MOF material is a metal-organic framework material with a specific structure MOF of inorganic metal ions,metal clusters and organic ligands connected by coordination bonds.The photoluminescent MOF material has a controllable structure,fast time response,and good thermal stability.So it has specific applicability in ions recognition,Nitroaromatic compounds(NACs)recognition,inorganic or organic small molecules recognition,pH response and other aspects.In the first part of this thesis,the nitrogen-containing carboxylic acid ligand with triphenylamines and bifunctional groups are selected 4,4'-((4-(1H-1,2,4-triazol-1-yl)phenyl)azanediyl)dibenzoic acid(H₂TPT),adding the metal salt Pb(NO₃)₂to synthesize a 2D coordination polymer[Pb(TPT)4]_n(1)by solvothermal method.MOF1 can quickly detect Cr₂O₇^2-and S^2-in water,showing strong fluorescence sensitivity and selectivity.MOF 1 has rapid response to 4-NBA.In the second part of the thesis,triphenylamine nitrogen-containing ligand tris(4-(pyridin-4-yl)phenyl)amine(TPPY)and flexible tetrapyridines ligand((2,2-bis(phenoxymethyl)propane-1,3-diyl)bis(oxy))dibenzene(TPOM)combined with 2,3-dihydrothieno[3,4-b][1,4]dioxine-5,7-dicarboxylic acid(H₂thpe),and Cd(NO₃)₂·4H₂O,two coordination polymers[Cd(TPPY)₃(thpe)₂]_n(2)and{[Cd₂(TPOM)₄(thpe)₄]·(H₂O)₂}_n(3)were synthesized by solvothermal method.MOFs2-3 all have a 3D structure and all contain pores.Both have shown excellent performance in the sensing direction of small molecules.We did a fluorescence sensing experiment on MOFs 2-3.The fluorescence of MOF 2 remains stable in the pH range of 3-14.The fluorescence of MOF 3 remains stable in the pH range of 5-13.MOFs 2-3have fast response to Cr₂O₇^2-in solution.They have strong fluorescence sensitivity and selectivity.MOF 3 has good fluorescence sensitivity to ClO^-and NB.MOFs 2-3have relatively good performance in fluorescence sensing,and have potential application value.They are used in small molecule sensing experiments and ion fluorescence sensing.