Structures And Proterties Of Lanthonide And Zinc Coordination Frameworks With Nitrogen Containing Polycarboxylate Ligands

Metal-organic frameworks?MOFs?have exceptionally high porosities and versatile structural features that allow for their applications in a wide range of areas.Over recent years,chiral recognition,luminescent,temperature sensing and breathing behavior functional complexes have received intense attention.This dissertation aims at designing functional metal organic framework materials.The 4,4?,4??-s-triazine-1,3,5-triyltri-p-aminobenzoic acid and 5,5?-??1R,2R?-cyclohexane-1,2-diamino?isophthalic acid ligands were selected,combining with lanthanide and transition metal generated a series of novel complexes by hydrothermal method,and carried out characterization in detail.Simultaneously,their properties are fuether explored,especially in fluorescence,gas absorption and chiral recognition.The main research results are as follow:1.Solvothermal reactions of lanthanide salts and semirigid tripodal H₃tatab?4,4?,4??-s-triazine-1,3,5-triyltri-p-aminobenzoic acid?ligand generated three rare earth oxygen chain coordination frameworks 1-Eu,1-Tb and 1-Eu_0.015Tb_0.985.These rare earth coordination frameworks were partially or reversibly dehydrated to convert 1'-Eu,1'-Tb and1'-Eu0.015Tb0.985 in air or in a desiccators,respectively.Single-crystal X-ray analyses demonstrate that 1 has the breathing ability to spontaneous release of guests and maintain the same topology.In contrast to as-synthesized 1,the cell volume of 1?is shrunk by 16.4%.Different from linear dicarboxylates coordination frameworks,the breathing mechanism is based on the flexible C-N-C angles of amide bonds in tatab ligand.Interestingly,the breathing co-doped lanthanide MOF 1?-Eu_0.015Tb_0.985 can be applied as a high sensitive ratiometric thermometer in a broad temperature from 90 K to 300 K.The luminescence color of breathing co-doped lanthanide MOF 1?-Eu_0.015Tb_0.985 is blue-shifted and tuned from orange to green with increase of temperature and is quite different from reported related compounds.2.5,5?-??1R,2R?-cyclohexane-1,2-diamino?isophthalic acid?R,R-CHCAIP?which is similar to windmill blade shape is selected as the chiral ligand with the zinc salt to construct two chiral materials:Zn4?R,R-CHCAIP?₂?4-4?-bipy??H2O?₅?5?,Zn_1.5?R,R-CHCAIP??H2O?₂?6?.The structure was analyzed by x-ray single crystal diffraction,and the properties such as thermogravimetry,powder,and fluorescence were measured.The compound 5 shows a wavy two-dimensional layered structure,in which the carboxylate oxygen atoms and zinc ions form band structure,further linked by 4-4?–bipy to construct the wave layers.The structure contains a large number of nitrogen active sites and coordinated water molecules,easily forming hydrogen bonds with small molecules having?-hydroxyl group.This provides a good condition for the chiral recognition of enantiomers.Research indicates that compound 5 is used as a fluorescence sensor to detect and identify three isomers?lactic acid,mandelic acid and tartaric acid?.Among which,the R/S-mandelic acid show the highest enantioselectivity,reaching 2.12,and the LOD?S-mandelic?/LOD?R-mandelic?is 2.17:1.