Design,Synthesis And Properties Of MOFs Materials Based On Chain Azo Ligand

Coordination polymer is a kind of compound which is composed of metal ions providing empty orbitals and organic ligands providing lone electron pairs as coordination sites.Some novel compounds with holes have potential application value.The key to synthesize novel complexes is to select appropriate metal ions and design organic ligands with different structures.As one of the important branches,metal organic framework materials have been widely used in material separation,drug delivery,energy storage,catalysis,luminescence and adsorption.In this paper,a series of nitrogen-containing chain organic ligands were designed,which used nitrogen-containing ligands and carboxyl ligands to provide coordination sites,and combined with the space orbital self-assembly provided by metal ions to form a new type of complex with potential application value.The adsorption performance of the complex for heavy metal ions was studied This kind of MOFs has great significance in the treatment of industrial pollution and domestic pollution.In this paper,azobenzene-4,4’-dicarboxylic acid（ADB）ligand containing azooxy and carboxylic acid and 4-[4-（pyridin-4-ylmethyl）ligand containing azo and carboxylic acid were synthesized.（Oxy）-phenylazo]-benzoic acid pyridin-4-ylmethyl ester（L1）ligand,3-[4-（pyridin-3-ylmethoxy）-phenylaz-o]-benzoic acid Pyridin-3-ylmethyl ester（L2）ligand,3-[4-（pyridin-4-ylmet-hoxy）-azobenzene oxide]-benzoic acid pyridin-4-ylmethyl ester（L3）ligand The synthesis of the body,centering on the transition metal ions Zn（II）,Co（II）and Cd（II）and the lanthanide metal ion Pr（III）,using a solvothermal synthesis method,nine new complexes were synthesized Position compounds,respectively[Pr₂（ADB）]_n（1）（ADB=azobenzene-4,4’-dicarboxylic acid）,[Zn₂L1₂（4,4’-dpa）₂]_n（2）（4,4’-dpa=4,4’-diphthalic acid）,[Cd₂L1₂-（5-CH₃-H₂BDC）₂]_n（3）（5-CH₃-H₂BDC=5-methyl isophthalic acid）,(Cd₂L1₂（H₂BDC）₂]_n（4）（H₂BDC=isopht-halic acid）,[Co L1₂（4,4’-bdp）₂（H₂O）]_n（5）（4,4’-bdp=4,4’-dicarboxydiphenyl ether）,[Zn L2₂（5-CH₃-H₂BDC）₂]_n（6）（5-CH₃-H₂BDC=5-methyl isophthalic acid）,[Zn L2₂（5-NO₂-H₂BDC）₂]_n（7）（5-NO₂-H₂BDC=5-nitroisop-hthalic acid）,[Zn₂L3-（5-OH-H₂BDC）₂]_n（8）（5-OH-H₂BDC=5-hydroxyisophthalic acid）,(Zn₂L3（H₂BDC）₂]_n（9）（H₂BDC=isophthalic acid）nine new metal-organic framework complexes.Characterized by X-ray single crystal diffraction,X-ray powder diffractometer（XRD）,infrared spectroscopy（IR）,and thermogravimetric analysis（TGA）,etc.and focused on the effect of[Pr₂（ADB）]_n on heavy metal ions Pb²⁺.In the adsorption situation,it was found that when the p H of the solution is 6,the longer the adsorption time and the higher the initial concentration of Pb²⁺,the better the adsorption effect of complex 1 on it.