Metal-organic Framework And Their Properties Of Based On 5,8-Dicarboxynaphthalene-2-sulfonate

Metal-Organic Frameworks（MOFs）,also known as Coordination Polymers（CPs）,are a relatively new class of three-dimensional periodic structures formed by coordination bonds between multidentate organic ligands and metal ions.The possibility that MOFs can tune their chemical properties by changing organic linkers or metal atoms leads to their high adsorption capacity and better selectivity.Therefore,it excels in gas adsorption and separation,heavy metal ion removal,organic dye adsorption,etc.In addition,MOFs also play an important role in fluorescence sensing,catalysis and other fields,and their application prospects are very broad.In this work,the rigid carboxylic acid ligand of 5,8-dicarboxylate naphthalene-2-sulfonate（NaH₂DPNS）is selected as the organic linker to construct the target complex with metal ions.Five complexes were synthesized by a simple solvothermal method:{[Eu₂（DPNS）₂（H₂O）₄]·4H₂O}_n（DPNS-Eu）,{[Gd₂（DPNS）₂（H₂O）₄]·4H₂O}_n（DPNS-Gd）,{[Sm₂（DPNS）₂（H₂O）₄]·4H₂O}_n（DPNS-Sm）,{[（Zn₅（μ-OH）₄）（DPNS）₂（H₂O）₂]}_n（DPNS-Zn-1）and{[Zn₃（DPNS）₂L₃]·4H₂O}_n（DPNS-Zn-2）.The single crystal structure of the complex was obtained by single crystal X-ray diffractometer,and some basic characterizations were carried out.The focus is the application of the DPNS-Eu in dye adsorption,fluorescence detection,catalysis,and the application of the DPNS-Zn-1 in sensing.This thesis is specifically expanded from the following four parts:1.The development process of MOFs,synthesis methods,types and application fields.The main work obtained in the topic of this thesis are briefly described.2.Three isostructural lanthanide MOFs DPNS-Ln（Ln=Eu,Gd,Sm）were synthesized by using NaH₂DPNS ligands and lanthanide metal ions,and a series of characterizations were carried out.Due to the excellent luminescence properties of DPNS-Ln,its luminescence properties were investigated.The DPNS-Eu showed strong red light under UV light,so it can be selectively detected small organic molecules nitrobenzene（NB）and nitrofuran antibiotics（NFAs）.Its high selectivity for NFA was demonstrated by various anti-interfering ions and small molecules.The mechanism of NB and NFAs quenching the luminescence of DPNS-Eu was studied in detail.3.The application of DPNS-Eu for removing residual Congo red dye（CR）in water was studied.The adsorption mechanism was investigated by a series of characterizations such as Zeta potential,FT-IR,XPS,etc.,and it was found that electrostatic attraction,π-πstacking interaction and hydrogen bonding were considered to play important roles in the adsorption of CR on DPNS-Eu.The experiment found that the maximum adsorption amount of CR on DPNS-Eu can reach 1322.9 mg/g,which is larger than that reported in the general literature,and the removal rate of CR could reach 84.39%after 5 cycles.So DPNS-Eu was a potential adsorbent.In addition,the application of DPNS-Eu in epoxide-catalyzed reactions was also explored.4.Two new MOFs materials（DPNS-Zn-1 and DPNS-Zn-2）were synthesized,and a series of structural characterizations were carried out.And the application of DPNS-Zn-1 in pesticide detection was studied.The study found that its detection limit for 2,6-dichloro-4-nitroaniline（DCN）can reach 5.50×10^-6 M,so it has the potential for selective detection.