Synthesis And Optical Property Studies Of Aminocorannulene Derivatives

Corannulene,C₂₀H₁₀,was firstly synthesized by W.E.Barth and L.G.Lawton in1966,which has been more than 50 years.The unique structural and electronic properties of corannulene attracted the attention of many research groups,while the low overall yield and lengthy synthesis limited the further studies of corannulene and its derivatives.A milestone event occurred in 2012.Siegel’s group developed a kilogram-scale synthesis scheme,which has provided ready access to future studies of corannulene derivatives.In this thesis,a general three-stage strategy was conceived to prepare corannulene derivatives suitable for biological evaluation.Stage 1:Identify a class of readily-prepared fluorescent corannulenes,compatible with Stage 2:The preparation of fluorescent water-soluble derivatives.These would then allow pursuit Stage 3:A general approach to preparing membrane-permeant corannulene derivatives.This thesis employed mono-bromocorannulene（2）and 1,6-dibromo-2,5-dimethylcorannulene（3）as crucial intermediate to yield mono-and di-aminocorannulenes by Buchwald-Hitwig C-N bond cross-coupling reaction.The D-π-A system corannulene derivative was generated by the equivalent controlling of diphenylamine.The optical properties of aminocorannulenes were studied.Evaluation of their luminescence leads to five discoveries.1)The emission spectra of the amino-edge modified corannulenes produce a relatively large red shift,and those of the di-aminocorannulenes are significant.2)The Stokes shift of the mono-and di-aminocorannulenes are generally larger than those of the parent hydrocarbons.3)Primary amine substituted corannulenes increased the quantum yields more than the secondary amines.4)Both 2,5-dimethylcorannulene and amino-corannulenes showed higher quantum yields in tetrahydrofuran.5)4a-4j and 5a-5d are also fluorescent in solid-state.5a exhibits yellow-orange fluorescence in dichloromethane solution（552nm）but orange-red fluorescence（615 nm）as a solid.This has implications for materials applications,to develop aggregation-based sensors,and to construct corannulene-based electronics.This thesis completes the first two stages of the design of corannulene derivatives suitable for biological evaluation.Here we reported ethylenediamine substituted corannulenes（4j and 5e）is simultaneously water-soluble and brightly fluorescent.The freely soluble and brightly fluorescent in water sets the stage for identifying cell-permeant derivatives,which will allow a broad study of the biological activity of corannulenes.In summary,the novel aminocorannulenes provide a library data for the systematic study of fluorescence properties,and provide a new modification scheme for adjusting the fluorescence properties,and developed a water-soluble corannulene which exhibit fluorescence both in organic solvents and water.This research provides a new direction for the development of corannulene derivatives as fluorescent probes for detecting the changes in organisms or the environment,and expands the application range of it.