Construction And Performance Of Porous Metal Organic Framework Based On Triazine Polycarboxylic Acid Ligand

In recent years,metal-organic frameworks?MOFs?based on triazine polycarboxylic acid ligands have shown important application value in many realms,such as fluorescence sensing,gas adsorption and separation,organic pollutants adsorption and removal,photoelectric performance,drug delivery,etc.,due to its advantages of designability,adjustability and rich topological structure.In this paper,19 MOFs with novel structural arrangements and interesting topology were designed and constructed by using the highly symmetrical triazine tricarboxylic acid ligand H3TATAB,triazine hexacarboxylic acid ligand H₆TDPAT,and the flexible triazine hexacarboxylic acid ligand H6TTHA,and their formation conditions,connection modes and structures were systematically explored,and the relationship between basic structures and properties was explored.It mainly carried out the following research work:1.Four actinide metal-organic frameworks?An-MOFs?were constructed by using the ligands H3TATAB,H₆TDPAT and H6TTHA with?UO2?2+and Th4+,respectively.This is the first time to successfully construct uranyl?thorium?crystal skeleton compounds using the triazine polycarboxylic acid ligands H3TATAB,H₆TDPAT and H6TTHA,which enriches the application of larger size conjugated triazine polycarboxylic acid ligands in the construction of uranyl?thorium?crystal skeleton compounds.The results of adsorption experiments on iodine show that complexes 1-4 have good adsorption performance for iodine in cyclohexane solution.Especially,the adsorption capacity of complexes 2?Th-TATAB?to iodine in cyclohexane solution can reach about 750 mg·g-1,the removal efficiency of iodine in cyclohexane solution?0.01 mol·L-1?can reach 90%in 3 hours,which far exceeded that of reported[Zn2?tptc?-?apy?2-x?H2O?x].H2O?80%,48 h?and MIL-101-NH2?90%,30 h?.Complexes 1 and 3 exhibit selective adsorption behavior for cationic dyes through ion exchange.In addition,complex 3 as an adsorbent,shows excellent performance in extracting uranium from aqueous solution,and is not affected by other interfering metal ions.This work is the first application of uranyl-organic frameworks?UOFs?as an adsorbent to extract actinides from water.2.Twelve lanthanide metal-organic frameworks?Ln-MOFs?were constructed with H3TATAB and H₆TDPAT with Ln3+respectively.Compared with the research on fluorescence performance,Ln-MOFs have relatively few studies on the adsorption performance.Here we choose complex 5?Eu-TATAB?to focus on expanding its research on the adsorption performance of as iodine and dyes.The experimental results show that complex 5 has a good adsorption performance for iodine in cyclohexane solution,and shows selective adsorption behavior for cationic dyes.3.Three metal-organic frameworks were constructed by using H₆TDPAT and transition metal ions.The structure analysis shows that the frameworks of the three complexes contain three different polyhedral cages:cubic octahedron?Cub-Oh?,truncated tetrahedron?T-Td?and truncated octahedron?T-Oh?.The experimental results of iodine adsorption show that the three complexes have excellent adsorption properties for iodine in cyclohexane solution.In addition,in terms of fluorescence properties,the complex 17,which has a strong blue emission center of its own,has been explored on the function expansion of white emission regulation.19 MOFs based on triazine polycarboxylic acid ligands list as follows:???Note:H₃TATAB=2,4,6-tris?4-carboxylphenylamino?-1,3,5-triazine;H₆TDPAT=2,4,6-tris?3,5-dicarboxylphenylamino?-1,3,5-triazine;H₅TDPAT*= 2,4-di?3,5-dicarboxylphenylamino?-6-tris?4-carboxylphenylamino?-1,3,5-triazine;H₆TTHA=1,3,5-triazine-2,4,6-triamine hexaacetic acid;...