Synthesis Of 3,4-ethylenedioxythienyl Metal-Organic Framework And Its Application In Fluorescence Sensing

Metal-organic frameworks are highly regular and infinitely structured porous framework structures formed by rigid organic groups and single metal nodes or metal cluster secondary building units connected by coordination bonds under self-assembly conditions.Due to their high crystallinity,large specific surface area,regular and diverse pores,designable structure and functionalized framework,metal organic frameworks have great potential application value in the fields of gas storage,adsorption and separation,catalysis,ion exchange,drug loading,and sensing,especially the luminescent metal organic frameworks with fluorescence performance has shown great application value in the field of chemical sensors.Luminescent metal organic frameworks can achieve rapid,highly sensitive and selective detection of target molecules through a variety of fluorescence response signals such as fluorescence quenching,fluorescence enhancement or new emission peaks and strong host-guest interactions.To realize the detection of specific target molecules,a reasonable design of the luminescent metal organic frameworks is required.By rationally designing organic ligands,we synthesized a luminescent metal-organic framework that can selectively detect nitroarylamines,and introduced functional groups to the organic ligands to realize the selection of high-energy nitrogen-containing heterocyclic compounds.The specific content is as follows:(1)Using 3,4-ethylenedioxythiophene as the electron-donating group,the conjugated aryl group was modified by C-H activation reaction,and a large dipole moment organic ligand was designed and synthesized,and its dipole moment was 8.82 D.The luminescent metal organic frameworks was further synthesized by solvothermal method.Utilizing the strong dipole-dipole interaction with p-nitroaniline,the fluorescence of the metal organic framework is quenched through electron transfer and energy transfer,and the detection of p-nitroaniline is realized.(2)The functional groups hydroxyl and phenyl were modified on the vinyl side chain of 3,4-ethylenedioxythiophene,and two organic ligands with different coordination sites were synthesized,and two luminescent metal-organic frameworks were further synthesized by solvothermal method.Fluorescence tests show that both luminescent metal-organic frameworks have fluorescence responses to high-energy nitrogen-containing heterocyclic compounds.This should be attributed to the more negative lowest unoccupied molecular orbital energy level of high-energy nitrogencontaining heterocyclic compounds,which is more conducive to electron transfer.