Design,Synthesis And Structure Of D/f Polycarboxylic Acid Complexes And Study On Fluorescence Sensing Effect Of Nitro Compounds

Polycarboxylic acid complexes are a class of typical hybrid materials.Compared with the previous optical materials,these complexes have good MOFs structures,stability and relatively large specific surface area,therefore,in the field of fluorescence sensing and molecular recognition and other fields have a wide range of applications.At the same time,polycarboxylic acid ligands are one of the important organic ligands.Among them,the rigid polycarboxylic acid ligand has a good coordination point,a larger conjugated system,and better coplanarity,can be coordinated in different directions with the metal,and caused widespread attention.In this paper,a series of polycarboxylic acid ligands were used to react with metal,and nine complexes were successfully obtained and characterized by various characterization methods.The main work includes three parts as follows:1.Based on the ligand 1,3,5-triazine-2,4,6-triamine hexaacetic acid(H₆TTHA),three metal organic complexes 1-3 were obtained,and complex 4 was obtained by reacting the metalZn²⁺withtheligand(E)-4',4'''-(1,2-diphenylethene-1,2-diyl)bis([1,1'-biphenyl]-3,5-dicarboxylic acid),which all synthesized by hydrothermal synthesis.Complexes 1-3 possess photovoltage characteristic,which could be applied as extended p-type semiconductors.Complexes 1 and 2 have good fluorescence properties and have high sensitivity and selectivity to nitroaromatic compounds and can be used as a quenching type fluorescent probe for the detection of nitroaromatic compounds.2.Three UOFs 5-7 have been designed and synthesized under hydrothermal reaction conditions based on a series of aromatic polycarboxylate ligands,2,3-pyrazino[1,10]phenanthroline-2,3-dicarboxylicacid(H₂L₁),2,6-bis(2-pyrazinyl)pyridine-4-benzoic acid(HL₂),1,2,4,5-Benzenetetracarboxylic acid(H₄L₃).Complexes 5 and 6 were layered structures and complex 7 was three-dimensional network structure.Complexes 5 and 6 have good fluorescence properties for the nitroaromatic,and both two complexes show fluorescence quenching behavior.In addition,complex 6 shows fluorescence enhanced behavioron the aldehyde small molecules.3.Two novel three-dimensional complexes 8 and 9 were synthesized by different solvents under the conditions of hydrothermal,based on the ligand tetrakis(4-benzoic acid)ethylene(H₄TBE)and transition metal Cd²⁺.Complex 8 shows the fluorescence quenching behavior on the nitroaromatic compounds and showed fluorescence enhanced behavior on aldehyde small molecules.What's more,the experimental results of dye absorption and separation show that the anionic framework 8 displays the remarkable advantages for selective adsorption towards cationic MB dye.