Design,Synthesis And Properties Of Carbazolebased Framework Structure Molecules

Macrocyclic are widely used in the fields of molecular recognition,molecular complexation,host and guest chemistry,supramolecular chemistry,self-assembly of micro-nanomaterials and other fields due to their unique chemical structure and special chemical properties.Since Charles Pedersen first obtained artificially synthesized macrocyclic crown ethers in 1967,macrocyclic have attracted the attention of a large number of chemists and biologists.Cyclic Aromatic hydrocarbons,calixarene,cucurbituril,Pillararenes,and various cyclophanes have been synthesized and reported,this has greatly enhanced scientists’understanding of all aspects of macrocyclic chemistry and the use of macrocyclic in molecular recognition,self-assembly processes and electro-optical applications.Carbazole units have been widely used in the framework of macrocyclic due to their strong luminescence and supra molecular behavior.In this paper,Friedel-Crafts（F-C）reaction occurred at position 9 of fluorene,and Grid based on carbazolium were constructed by SP²-SP³-carbon-carbon coupling.The first part is the construction and photoelectric properties of carbazole-based framework molecule（L,Cis-Grid,Trans-Grid,Th-Grid）.The structure of the compound was determined by NMR and MADLI-TOF-MS.At the same time,the absorption spectrum,emission spectrum,fluorescence life in CH₂Cl₂solution state and CV curve of them were studied.In the second part,carbazole-based framework molecule are applied to the detection of halogen anions（F^-、Cl^-、Br^-、I^-）.UV,PL and ¹H NMR showed that the four compounds had good binding capacity and selectivity to I^-.Compared with the other three compounds,Cis-Grid had the best binding capacity for I^-,with the complexation constant reaching K=（2.422±0.902）×10⁴,which may be attributed to better cavity size and shape matching and multiple hydrogen bond interaction.In the last part,carbazole-based framework molecule are applied to the detection of nitro explosives（NB,4-NT,DNT,TNT）.The fluorescence emission spectrum shows that the quenching constant of nitro explosives for each compound satisfies TNT>DNT>NB≈4-NT,which is consistent with the difference between the molecular and nitro explosive LUMO energy levels（TNT>DNT>NB≈4-NT）.By analyzing the quenching effect of the same nitro explosive on the four molecules,we can conclude that the matching of the size and shape of the cavity also has a certain effect on the quenching effect.