Design And Luminescent Applications Of Lanthanide MOFs Based On Benzene Tricarboxylic Acids

Metal-organic frameworks (MOFs), employed as a novel porous material, have become more and more attractive during the past decades. Because of their unique luminescent mechanism, various channel strcture and diverse topologies which come from the combination of metal ions and organic linkers, MOFs can be applied in fileds like lighting, fluorescence detection, temperature sensor, imaging, gas storage and separation. Comparing with traditional inorganic luminescent material and organic small molecules, MOFs have abundant and tunable luminescent properties, which made MOFs as one of the most promising materials in the future. Among different types of MOFs, LnMOFs have the rich luminescence centers due to the combination of lanthanide metal ions and various organic ligands, thus can be functionalized for particular applications like ions dectection, light emitting and temperature sensing.Based on the organic linker H3TATAB and lanthanide nitrate, we designed an isomorphic lanthanide metal-organic frameworks LnTATAB. Among these MOFs, TbTATAB provides appealing function for sensing mercury ions. The ligand H3TATAB can transfer its energy to Tb3+, while in the presence of mercury ions the energy transfer process is prevented, leading to the quench of fluorescence of TbTATAB. The TbTATAB showed a good water stable property with the high sensing Ksv calculated to be 4817 M-1. The responding time of the sensor was less than 2 minutes, indicating it to be a rapid and efficiency sensor.By encapsulating blue emitting dye C460 into the MOF TbTATAB, we designed the dye-encapsulated MOF for due-emitting temperature sensing. The TbTATAB(?)C460 is isostructural to the parent MOF TbTATAB. The material showed temperature sensing property in low temperature (50～300 K) with high relative sensitivity 3.33% K-1 and good repeatability. By changing the dye concentration in MOFs, TbTATAB(?)C460 realized ratiometric temperature sensing property in physiological temperature (25～75℃). The max relative sensitivity is 1.88 K-1.Besides LnTATAB, we synthesized another MOF LnBPT:based on the H3BPT ligand. Mixed due-lanthanide MOFs Euo.os9Tbo.94iBPT for equal amount of red light and green light output under 340nm excitation. By encapsulating 0.05 mmol blue-emitting dye C460 into Eu0.059Tb0.94iBPT, the material can emit ideal white light with CIE (0.323,0.340) and the quantum efficiency of the material is 43.43% which is higher than most LnMOFs white-emitting powder.