Design,Synthesis And Studying Of Fluorescence Sensing Based On Aromatic Carboxylic Acid Metal-organic Framework Materials

In this paper,we mainly focus on the design,synthesis and fluorescence properties of Luminescent Metal-Organic Frameworks?LMOFs?.Seven novel structures of MOFs are designed and synthesized by using organic ligands containing aromatic carboxylic acids and alkaline earth metals or transition metals under solvothermal or hydrothermal conditions.The fluorescence properties of four LMOFs for the accurate recognition of nitro explosives and metal cations were studied.The main work of this paper is as the follows:1.In this part,we selected[1:1':4',1''-terphengl]-3,3'',5,5''-tetracarboxylic?H₄TPTC?as the organic linkers to synthesize LMOFs with the low toxicity of alkali metal:[Mg?H₂TPTC?₂·2H₂O]_n?1?.A new structure of Complex 2-3 were synthesized bysolvothermalmethodandCo?II?with[1:1':4',1''-terphengl]-3,3'',5,5''-tetracarboxylic ether as the main ligand and a semi-rigid rich electronic ligand of 4,4'-bis?pyridyl?diphenyl ether?BDPDE?as the auxiliary ligand.We explore the luminescence properties of the complex 1-3 through a series of characterization.Complex 1 has good thermal stability,high selectivity and sensitivity to 1,3,5-trinitrophenol?TNP?,and recyclable utilization.The metal center of complex 2 is cobalt,and Co-MOF has few fluorescence properties in the existing reports.Complex 2 not only has strong fluorescence properties,but also has such excellent sensitivity and high selectivity for TNP detection for the first time in the cobalt metal organic framework,which opens up a new way for the design of fluorescent sensing materials in the future.2.In this section,we selected 2'-amino-1,1':4',1''-terphenyl-4,4''-dicarboxylate?H₂ATDC?as the organic linkers to synthesize complex 4 via solvothermal reaction with alkali metal metal ion Mg²⁺.The complex has strong acid resistance,strong alkalinity resistance and recyclability.In this field,the central metals are lanthanides and transition metals.Before this paper,low toxic alkaline earth metals were seldom used as metal centers.This is the first time in this field to synthesize complex with magnesium as metal center and detect TNT with high selectivity and sensitivity.The complex also has high selectivity and sensitivity to Cr³⁺solution.The mechanism of fluorescence quenching is due to electron transfer and energy transfer,not the hydrogen bond between amino group and analyte.3.We selected N,N'-Bis?3,5-discarboxyphenyl?oxalamide?H₄BDPO?as the organic linkers to synthesize three isostructural MOFs with transition metal ion:{[(Zn₂?BDPO?·3H₂O]·H₂O}_n?5??[Co₂?BDPO??DMSO??DMF??CH₃OH?]_n?6?and[Cd₂?BDPO??DMSO?·H₂O]_n?7?.We explore the luminescence properties of the complex 5-6 through a series of characterization.The fluorescence sensing properties of complexes 5 were also studied.It was found that complex 5 not only has high selectivity and sensitivity for TNT,but also has excellent fluorescence sensing properties for Fe?III?.The mechanism of fluorescence quenching is the synergistic effect of electron transfer and energy transfer.Figure[63]table[8]reference[95]...