Synthesis And Properties Of Luminescent Metal Organic Frameworks Based On Pyridine-Substituted Tetraphenylethene

Tetraphenylethylene?TPE?,as a well-known AIE chromophore,has been widely used to prepare light-emitting materials due to its simple synthesis and easy modification.It is a common strategy to introduce carboxylic acid or pyridine coordination groups on TPE as multidentate ligands and chelate with metal ions to build TPE-based luminescent MOFs.TPE-based LMOFs can be used as fluorescent sensors to detect various environmental pollutants and explosives.In this paper,multiple TPE-based LMOFs were designed and synthesized,and their fluorescence and sensing properties were studied.There are three main parts:?1?Tetrastyrenepyridine derivative cation?TMPy PE?was synthesized.The bio-MOF-1 with known structure and MOF constructed from trimesic acid were used as anion skeleton to encapsulate TMPy PE.Two new MOF composites TMPy PE@bio-MOF-1?1?and[Cd₃?BTC?₃?Cl]??TMPy PE???H₂O??2?with high fluorescence quantum yield were synthesized.The structures of the complexes were characterized by nuclear magnetic resonance,powder X-ray diffraction,infrared and thermogravimetry.The fluorescence sensing properties of complex 1 for antibiotics in water were studied.The results show that all kinds of antibiotics can quench complex1 in different degrees,but nitrofuran antibiotics have the most obvious quenching effect.The detection limits of nitrofurazone?NFZ?and nitrofurantoin?NFT?were0.110 and 0.134 ppm,respectively.Due to the preparation simplicity and fluorescence sensitivity towards antibiotics,complex 1 has application potential in sensing antibiotics.?2?Two different chiral LMOFs[Ag₂?TPy PE??L-CSA?₂]?3?and[Ag₂?TPy PE??D-CSA?₂]?4?were constructed with 1,1,2,2-tetrakis?4-?pyridin-4-yl?phenyl?ethane?TPy PE?as the organic ligand and the synthesized chiral silver camphorsulfonate?L/D-CSA-Ag?.The structures of the complexes were characterized by nuclear magnetic resonance,PXRD,infrared and thermogravimetry.The CPL spectra of 3 and 4 are nearly mirror images of each other.nm for 4.In addition,they exhibit interesting enantioselective fluorescence quenching responses to chiral amino acids.The results show that complexes 3 and 4 are promising materials for the recognition of chiral compounds.?3?Using TPy PE as an organic ligand and synthesized chiral silver binaphthol phosphate?S/R-BPA-Ag?with a rigid structure,two different chiral LMOFs[Ag₄?TPy PE?₂?R-BPA?₃]?5?and[Ag₄?TPy PE?₂?S-BPA?₃?C₃H₇NO?₂]?6?were constructed.PXRD,infrared and thermogravimetry were used to characterize the structure of the complexes.In the fluorescence performance test,it was found that complexes 5 and 6 showed circularly polarized fluorescence?CPL?properties that mirror each other.