| New type of functional material,Metal-Organic Frameworks(MOFs)has becoming a hot research topic in multiple subjects and interdisciplinary,such as chemistry,materials science,biology,medicine and so on.This is due to a large selection of inorganic and organic modules for assembly,functional modification of organic functional groups,oriented design and tailoring of framework,which making MOFs show rich characteristics and immeasurable application prospects.Reasonable selection of organic ligands in MOFs plays a guiding role in the construction of targeted framework.Literatures review has found that 2,4,6-tri(pyridin-4-yl)-1,3,5-trazine(TPT)has been extensively studied by researchers,due to its tridentate rigid plane,triazine electron deficient center,and large ? conjugated system.In this paper,TPT was selected as the dominant organic ligand,application function orientation strategy,three types MOFs and seven new complexes have been constructed,which based on the characteristics of the ligand itself.All these structures have been deeply analyzed to explore the role of supramolecular interactions in framework.In addition,the gas adsorption and separation performance of these MOFs were explored.The specific research contents are as follows:The first chapter:summarizes the whole paper,introduces the research background of MOFs,briefly summarizes the research status and development trend of the related topics,and on this basis,expounds the significance of this paper and the main development achieved.The second chapter:TPT as a rigid organic ligand was selected to react with terephthalic acid and Zn2+/Ni2+ ions to give three new MOFs materials of 1a,1b and 1c,and its characterization,analysis and performance of the three structures were studied.compounds la and lb exhibit completely different water stability.The Zn/Ni bimetallic compound 1c was successfully synthesized by adjusting the synthesis conditions,and hierarchically pore MOFs were constructed by hydrolytic and etching the SBUs of Zn part in lc to form structural defects.In addition,the distribution of hierarchically pores can be adjusted by adjusting the bimetallic ratio,synthesis conditions and water etching treatment time.The third chapter:in the construction system of flexible MOFs,based on the TPT large ? conjugated system and the variable supramolecular ?-? interaction,and introduce the flexible ligand of 4,4'-diazene-1,2-diyldibenzoate acid as the second dynamic mechanism at the meantime,to constructed the flexible framework 2a with breathing behavior.Analysis of single crystal structures show that under the stimulation of external temperature and solvent,the structure of target framework 2a can be resolved into six states.C2/C3 light hydrocarbons can be sectionally selectively separated based on the flexibility of 2a.In addition,the in situ PXRD test characterized the change of framework during the adsorption process,and the results were analyzed.The fourth chapter:based on the electron-deficiency of TPT triazine center,two cage-based MOFs 3a and 3b were successfully constructed by introducing aromatic electron-rich coronene into the MOFs assembly process.Structural analysis shows that coronene as a part of the main framework with TPT formed "TPT-coronene-coronene-TPT"of D-A system in the cage.The results show that in the process of MOFs assembly,the supramolecular interaction of donor and acceptor with coordination are of equal importance,and we think that both of them are synergistic.In the gas selective adsorption separation test,3a and 3b showed good CH4 selectivity.The fifth chapter:the research work is summarized and prospected.Based on pyridine triazine ligand,we successfully designed and constructed three systems of MOFs materials,obtianed the actual products and characterized their structural properties.New ideas were proposed for the construction of flexible MOFs and hierarchically pore MOFs,and the structure-activity relationship of supramolecular interaction in framework assembly was explored. |
PDF Full Text Request