Preparation And Luminescence Properties Of Eu(?)/Tb(?)-4,4'-dicarboxydiphenyl Ether Metal-organic Framework Materials

Metal-organic frameworks(MOFs)are a kind of a porous material composing of organic linkers and metal ions,clusters or chains.With high crystallinity and large surface area,they have obtained in-depth study and extensive applications,such as gas adsorption and separation,catalysis,drug transport and probe sensing.Among them,fluorescent probe has attracted more and more attention due to its low cost and high sensitivity.Herein,ionothermal reactions with V-shaped ligand of 4,4'-dicarboxydiphenyl ether(H2OBA)and Eu3+/Tb3+ constructed a series of lanthanide complexes as fluorescence sensors.The main contents are as follows:1.Three compounds of[Eu(OBA)(H2O)Cl](1),[Tb(OBA)(H2O)Cl](2)and[Eu0.05Tb0.95(OBA)(H2O)Cl](3)were synthesized with[BMI]I as solvent.Through recognizing water or H+,OH-by forming the interactions between the functional oxygen atom in 3 and H+,OH-or H2O,compound 3 as an effective fluorescence sensor realized the water molecules and pH detections.Furthermore,the paper-based fluorescent sensor of 3 achieved the visual pH detection.2.Aiming at regulation the ligand energy,four ligands were selected and four radiometric fluorescent hetero lanthanide MOFs,[(Eu0.0143Tb0.9857)(L)(H2O)Cl](H2L=H2OBA(4),terephthalic acid(H2BDC)(5);4,4'-biphthalic acid(H2BPDC)(6);2,6naphthalene dicarboxylic acid(H2NDC)(7)),were prepared,whose crystal structures are same.Compounds 4-7 emitted fluorescent colors of yellow,yellow-green,light red and red light at ambient temperature.Their fluorescence showed the temperature-dependence in the temperature range of 140-200?.Their performances of temperature sensor were explored and their sensitivities are analyzed.On consideration of the difference in ligand's energy,the mechanism of energy transformation from Tb3+ to Eu3+ were explored.According to the literature processes,other three compounds,[(Eu0.0143Tb0.9857)2(OBA)3(H2O)4]·2H2O(8),[(Eu0.0143Tb0.9857)2(BDC)3(H2O)4](9)and[(Eu0.0143Tb0.9857)2(BPDC)3(HCOOH)2](10),have been prepared and waiting for the validation of the mechanism of temperature sensor.3.For the observation of the effect of guest molecules on fluorescence properties,[PMI]2[Eu(OBA)Cl3](11)and[PMI]1.5[Eu2.5(OBA)4Cl](12)were fabricated with[PMI]Cl as reaction medium and structural template under different ratio of metal ions to ligand.As ionic liquids as guest molecules,the effect of ionic liquid on fluorescence properties of 11-12 was summarized with the comparison of the structure,fluorescence intensity and quantum yield.