Construction,PSM And Properties Of MOFs Based On Linear Ligands With N Or O Donor Atoms

Metal-organic frameworks（MOFs）or porous coordination polymers（PCPs）have unique chemical and physical properties,such as ultrahigh surface area,tunable structure,and high thermal and chemical stability.So MOFs or PCPs is a challenging and hot research topic in inorganic chemistry.And it has potential application in gas storage,gas separation,enantioselective separation,heterogeneous catalysis,chemical sensing and drug delivery.In this thesis,Mn²⁺,Fe²⁺and Co²⁺about MOFs of different types of structures were constructed based on different nitrogen-containing carboxylic acid linear ligands.Firstly 4,4’-（1,2,5-benzothiadiazole-4,7-diyl）bis-Benzoicacid（H₂L₁）and Mn²⁺was used to constructebased on the earlier work of our group.It likes a rhombus-shaped window of pillar-chain structure.Based on the method of Post-synthetic Modification（PSM）,compounds which is before and after post-synthetic modification were research in the properties of fluorescence.Secondly,Fe²⁺,ethylene glycol with Co²⁺,4-Pyridin-4-yl-Benzoic Acid（pybz）ligand were successfully constructed to be Fe based MOF and Co based MOF respectively.The properties about thermal stability,gas adsorption were research.In detail,the full text was included three chapters:In Chapter 1,some basic concepts related with PSM of MOFs,the difference with the former synthesis and species of PSM.Then we gave brief introduction about potential application of MOFs:chemical fluorescence,gas storage,electrocatalyst and magnetic.At last,it introduced the significance of the selected topic and research progress.In Chapter 2,based on our group,the 4,4’-（1,2,5-benzothiadiazole-4,7-diyl）bis-Benzoic acid（H₂L₁）and Mn²⁺was used to successfully constructe.It likes a rhombus-shaped window of pillar-chain structure.By the PSM of idea-Oxidate Mn²⁺,we study on the pre-modified compound 1 and post-modified compound 2 on the we study on the pre-modified compound 1 and post-modified compound 2 on the properties of fluorescence.It had significance in the chemical sense（oxidative sense,pressure sense and metal ions sense）.The fluorescence intensity which compound 1 in the solvent DMSO;H₂O;DMSO and H₂O mixed solution respectively were decreased.But the fluorescence intensity which compound 1 in the solvent H₂O with oxidant iodine,DMSO and H₂O mixed solution with oxidant iodine respectively were increased.The fluorescence intensity which compound 1 in the solvent DMSO with iodine was the same as the compound 1.With the existence of DMSO which fully dissolved iodine,this demonstrated the effect of oxidation that H₂O and iodine generated made the fluorescence intensity increase.Then based on the theory of electron conservation,the theoretical oxidant iodine was calculated.And we study the sensing process under a serial of gradient concentration of oxidant.Using variable-controlling approach,we also research the relationship between temperature,concentration,time and the fluorescence intensity.Secondly,driven by the idea of synergy,the both（oxidation and metal ion）and the synergy effect of three can make the fluorescence intensity increase by tens to hundreds of times.Compare with single senses（anions;cations;small molecules;solvents;gases and vapors;pH;temperature etc.）,the study has special significance.In Chapter 3,4-Pyridin-4-yl-Benzoic Acid（pybz）ligand with Fe²⁺successfully constructed to be the compound which had a rhombus-shaped window of pillar-chain structure.And another compound-ethylene glycol,Co²⁺and 4-Pyridin-4-yl-Benzoic Acid（pybz）were used to successfully constructed which had like cube features.By studying thermal stability,DSC and calculate the solvent accessible volume of 45.2%of the unitcell（Fe based MOFs）and the solvent accessible volume of 59.1%of the unitcell（Co based MOFs）respectively,the adsorption of 77K-N₂ and 195K-CO₂ for Fe based MOFs and Co based MOFs was researched.