Synthesis And Property Study Of Carbazole-based Macrocycles With Sulfonamide Linkages

The development of classic supramolecular chemistry has resulted in four generations of macrocyclic host molecules,including crown ethers,cyclodextrins,calixarenes,and cucurbiturils.The macrocyclic host molecules are always research focuses of supramolecular chemistry because they can selectively bind some guest molecules to produce a specific function.The synthesis and development of new types of macrocyclic host molecules are of great significance to the field of supramolecular chemistry and materials science.At the same time,the development of macrocyclic molecules with novel structures and multifunctional applications is an important task in the field of supramolecular chemistry.In this dissertation,a novel type of carbazolbased sulfonamide macrocycles was synthesized and the host-guest properties of the macrocycle with four carbazole units were studied.In the first part of this thesis,we synthesized a novel type of carbazole-based macrocycles via both one-pot synthesis and fragment coupling strategy.The carbazole motifs with excellent photoelectric properties were incorporated into the macrocyclic backbones and the sulfonamide bonds with hydrogen bonding sites were used as linkages.If precursors with aliphatic chains of N atoms of the carbazole motifs were used,cyclo[4]sulfonamidecarbazole and cyclo[6]sulfonamidecarbazole could be isolated via one-pot synthesis.While in the case of the precursors with amphiphilic N substituents we got cyclo[4]sulfonamidecarbazole,cyclo[6]sulfonamidecarbazole and cyclo[8]sulfonamidecarbazole in a single step.By applying a fragment coupling strategy we improved the synthetic efficiency of cyclo[4]sulfonamidecarbazole with aliphatic chains on N atoms.At the same time we also got giant cyclo[8]sulfonamidecarbazole.To our surprise we discovered that the cyclization efficiency for non-high dilution condition was higher than that for high dilution condition.The expansion of substituents on N atoms improved the solubility of the macrocycle in organic solvent.A macrocycle with both sulfonamide and amide linkages was also synthesized,which greatly expanded diversity of the macrocycles.In total,nine macrocycles were synthesized and conveniently separated via column chromatography at gram scale.In the second part of this thesis,based on the analysis of the electron distribution and the host-guest binding sites on the macrocycle skeleton,we screened a lot of potential guest molecules via NMR and UV-vis spectroscopy.Finally,we found that all of cyclo[4]sulfonamidecarbazole,cyclo[6]sulfonamidecarbazole and cyclo[8]sulfonamidecarbazole can selectively recognize terephthalate anions.UV-vis absorption spectroscopy studies have shown that macrocyclic hosts do not selfaggregation in DMSO.2D NOESY study revealed that the guest molecule is closer to the aminocarbazole moiety in the complex.Job's plot and titration studies based UVvis absorption spectra reveal a 1:1 stoichiometry and high association constants of the complex in DMSO.The studies based the UV-vis absorption spectra of the hydroxide ion and the host macrocycle confirms that the macrocyclic host interacts with the guest through hydrogen bonding.Fluorescence spectroscopy studies showed that the hostguest complexation significantly enhanced the fluorescence emission intensity.Comparing the host-guest binding constants measured by UV-vis absorption titration spectra and fluorescence titration spectra,it was found that the binding ability of three carbazol-based sulfonamide macrocycles to guest m was similar due to the increase of flexibility.The novel host macrocyclic compounds have potential applications in molecular probes,drug delivery and etc.