Syntheses And Characterization Of Novel MOFs By Lanthanide Post-synthetic Modification

It is well known that rare earth metal organic framework compounds with unique physical and chemical properties are a class of highly efficient fluorescent probe materials,which are widely used in heavy metal ions,organic small molecules,explosives and temperature detection.However,for various synthesis conditions,such as p H,solvents,metal ions and ligands,it is hard to modulate the structure and properties of Ln-MOFs.In this work,through the post-synthetic method,we have built a series of fluorescent Ln-MOFs based on different MOFs hosts.We also evaluated the potential of these materials as sensors for the detection of bio-markers of virus,explosives and temperature.The following studies have been carried out:（1）Tb³⁺-post synthetic modification of UiO-66 type MOF as a ratiometric fluorescent sensor for trinitrophenol（TNP）and anthrax biomarke（DPA）In this work,a Tb³⁺-MOF(Tb³⁺@UiO-66-PC)was synthesized based on phenoxy and carboxyl bifunctionalized Ui O-66 type MOFs through lanthanide post-synthetic modification.This compound exhibits the dual-emission of organic ligands and Tb³⁺,and can be exploited as the bifunctional sensors for the probe of TNP and anthrax biomarker DPA with low detection limits of 10 n M and 0.9μM.（2）Tb³⁺post-synthetic modification of mixed-ligand UiO-67 type MOF as ratiometric sensor for anthrax biomarkerIn this work,two linear dicarboxylic acids of similar length,4-（4-carboxyphenyl）-1-naphthoic acid（H₂cpna）and 2,2’-bipyridine-5,5’-dicarboxylic acid（H₂bpydc）were integrated together into a UiO-67 type MOF（named UiO-67-mix）.For the presence of lanthanide-affinity group 2,2’-bipyridine,Tb³⁺ions were incorporated into UiO-67-mix by PSM.The generated Tb³⁺@Ui O-67-mix presents two emitting centers,a high blue emission originated from H₂cpna and green emission from Tb³⁺.Tb³⁺@UiO-67-mix can be developed as a ratiometric nanosensor for the“turn-on”sensing of Dipicolinic acid（DPA）with low detection limits of 3.4μM.（3）Eu³⁺/Tb³⁺post-synthetic modification of MOF-253 as the Ratiometric ThermometerIn this work,A MOF-253 type MOF has been successfully synthesized based on a lanthanide-affinity pyridin-4（1H）-one decorated dicarboxylate ligand.Based on the post-synthetic modification method,Eu³⁺and Tb³⁺were incorporated to afford dual-emission lanthanide organic/inorganic hybrid.This compound can be developed as the ratiometric thermometer from 347 K to 487 K.