Structure And Property Of Coordination Polymers Based On Semi-rigid 5-((4-carboxypyridin-2-yl)oxy)isophthalic Acid Ligands

Coordination polymers?CP?has a one-dimensional chain,two-dimensional layered or three-dimensional network periodic network structure,which usually refer to metal ions/metal ion clusters as nodes,O and N polydentate organic ligands as linkers,assembled through coordination bonds or other weak chemical forces?such as halogen bonds,hydrogen bonds,Van der Waals forces and?-?forces,etc.?.Among them,porous coordination polymers are also known as metal-organic frameworks?MOFs?.As a new type of porous material,compared with traditional inorganic zeolites and activated carbon,MOFs has a series of advantages such as high porosity and pore surface modification.Therefore,it is used in greenhouse/lower alkane gas storage and selective separation,organic dye adsorption,fluorescent probes,heterogeneous catalysis and magnetism,etc.The development of MOF materials has shown attractive application prospects,and has quickly developed into one of the research hotspots recently in the field of materials chemistry.With the continuous research of MOFs,how to obtain target products with novel structure and specific functionalization is still facing huge challenges.Therefore,in this paper,we use 5-??4-carboxypyridin-2-yl?oxo?isophthalic acid?H₃L?as the ligand for subsequent experiments.Four cases of novel coordination polymers with novel structures were synthesized by hydrothermal/solvothermal method under different temperature conditions.The single crystal structure determination,characterization of basic properties,and its specific fucntions in gas adsorption separation,magnetism,fluorescence sensing,CO₂ catalytic conversion,and organic dye adsorption were investigated sequentially.The full text consists of four chapters:Chapter One:The concept,controllable design and synthesis,potential application value of coordination polymers were briefly introduced.The research status of semi-rigid carboxylic acid nitrogen heterocyclic ligands and the significance of this topic were summarized.Chapter Two:Based on the above-mentioned ligands and similar solvothermal conditions,two metal-organic framework compound[Cu_1.5?L??H₂O?]·2H₂O?1?and[Co₄?L?₂?CH₃CN??OH?₂?H₂O?₄]·3H₂O?2?were successfully synthesized.Among them,1is an example of a metal organic framework compound with high porosity and good water stability,and 2 is an example of a two-dimensional layered compound.Furthermore,the adsorption and selective separation of CO₂ and CH₄ gas,the adsorption of organic dyes,and the CO₂ addition reaction of catalytic conversion of epoxy compounds were studied in detail,and both showed different degrees of antiferromagnetic interaction.Chapter Three:An example of a high porosity?47.1%?MOF,[Zn₂?L??OH??H₂O?]·2DMA?3?,containing a tetranuclear metal cluster secondary building unit?SBU?based on the above-mentioned ligands and metal Zn²⁺ions was synthesized.The different contents of Co²⁺ions were successfully introduced into the MOF by direct method,afforded two isomorphic cobalt-doped MOF materials Co1-MOF 3 and Co2-MOF 3 were successfully synthesized.In addition,we systematically studied the changes of three cases of porous materials in CO₂ and CH₄ gas adsorption capacity,adsorption selectivity,and adsorption process.Chapter Four:This chapter reported a 3D MOF,[Cd₃?L?₂?H₂O?₂]?4?,constructed from the above-mentioned ligands and Cd²⁺d¹⁰ metal ions,which contains two different shapes of one-dimensional channels.At the same time,we have studied in detail the fluorescence quenching effect on Fe³⁺,Cr₂O₇^2-and its quenching mechanism.