Synthesis And Properties Of Metal-Organic Frameworks Based On 5,5’-(Naphthalene-2,6-Diyl) Diisophthalic Acid

Metal-organic frameworks（MOFs）have the characteristics of diverse structures and adjustable pores,and the physical properties can be fine-tuned trough organic ligands and metal ions,which have attracted widespread attention.In this thesis,four novel lanthanide MOFs and one Zn MOF were synthesized by hydrothermal/solvothermal method base on 5,5’-（naphthalene-2,6-diyl）diisophthalic acid（H₄NDDP）ligand,and their structures,magnetism,fluorescence recognition,conduction and other physical properties were studied in detail.The main results are as follows:1.A series of three-dimensional lanthanide metal-organic frameworks（Ln-MOFs）（1-4）were prepared by hydrothermal/solvothermal through reactions between lanthanide ions（Eu^Ⅲ,Gd^Ⅲ,Tb^Ⅲ,Dy^Ⅲ）and H₄NDDP.Single crystal structure analysis shows that Ln-MOFs 1-4 are all three-dimensional structures crystallizing in the P（?）space group.According to the topology analysis,they are new topology connected by4,4-8 connect.Fluorescence tests show that the ligand sensitizes the fluorescence of Eu^Ⅲion through the antenna effect so that Ln-MOFs 1 has the characteristic emission of Eu^Ⅲ.Ln-MOF 1 is a fluorescence sensor for phosphate with detection limit of 0.10μM by ratiometric fluorescence,and it also a fluorescence sensor for salicylaldehyde by fluorescence quench effect with detection limit of 0.057 ppm.In addition,the proton conductivity of Ln-MOFs 1-4 were investigated,the best conductivity of Ln-MOF 1reaches 2.42×10^-3 S cm^-1 at 70°C and 98%RH,which indicates that Ln-MOFs 1-4have rich hydrogen-bonding.2.By solvothermal method,a Zn-MOF（5）was prepared by reaction of transition metal ion Zn²⁺with H₄NDDP.Single crystal structure analysis shows that MOF 5 is a three-dimensional neutral MOF crystallized in monoclinic crystal system C2/m space group.The fluorescence tests indicated that MOF 5 is a fluorescence sensor for Fe³⁺by fluorescence quench effect with a detection limit of 0.18μM,and also a fluorescence sensor for Al³⁺by fluorescence enhancement effect with a detection limit of 0.055μM.In addition,the proton conductivity of MOF 5 is 6.19×10^-3 S cm^-1 at 60℃and 98%RH.