Synthesis,adsorption And Fluorescence Properties Of Cu/Zn-MOFs

As a new type of inorganic-organic hybrid porous materials,Metal-Organic Frameworks(MOFs)have the characteristics of adjustable pore size,high specific surface area and structural diversity etc.Consequently,MOFs material is considered by many researchers as a kind of adsorption material with great application potential.Compared with traditional adsorbent materials,MOFs materials have the characteristics of devisable structure and pore size,high specific surface area and low density,open metal sites and Lewis base sites and periodic super microporous structure.Therefore,they are far superior to traditional adsorbents in terms of adsorption performance.Devisable structures and channels are usually achieved by changing the number of connections of metal clusters and the length,angle and torsion angle of organic ligands.The provision of metal sites and Lewis base sites in MOFs materials provides the possibility of efficient catalysis.At present,MOFs materials with novel structure can be synthesized by means of secondary structural unit method,supramolecular building block method,mixed metal method and mixed ligand method.Nowadays,with the efforts of numerous researchers,MOFs materials no longer stay in the initial stage of exploring the structure and properties,but are developing rapidly towards the direction of molecular devices and functional materials.According to the hard-soft acid-base theory,the structure of MOFs materials constructed by the coordination of nitrogen-containing azole ligands with metal copper is relatively stable.In order to explore the relationship between structure and properties,compound 1 and compound 2 were synthesized under solvothermal conditions by using organic ligand HPTZ and copper and indium as metal sources using mixed metal strategy.Crystallographic analysis showed that compound 1 is a two-dimensional interpenetrated structure with sql topology,consisting of Cu(?)-paddlewheel and Cu₄I₄,two inorganic secondary structural units and two linked organic ligands.Due to the synergistic effect of the Cu₄I₄ metal cluster in the structure and the organic ligand benzene ring on iodine adsorption,compound 1 exhibits excellent iodine adsorption performance in solution.Compound 2 is composed of HPTZ,CuI and In(NO)₃.6H₂O.Due to its open metal site,Lewis acid site and stable pore channel,compound 2 can adsorb N₂.A 3,6-connected compound 3 was successfully synthesized by stepwise synthesis from organic ligand H₃NTB and Zn(NO)₃.6H₂O.Since compound 3 has a more sensitive fluorescence response,we explored its fluorescence detection properties to metal ions and explosives,and the results showed that compound 3 has a better fluorescence response to low concentration of toxic and harmful metal ions.