Perylene Derivatives Functionalized At Peri-Positions

Perylene and its vast amount of derivatives have attracted much interest due to wide applications in organic solar cells,organic field effect transistors and near-infrared absorbing materials.They exhibit not only high thermal and photochemical stability,but also efficient charge carrier mobility.The parent perylene has 12 positions including peri-,bay-and ortho-positions,which can be served as a core for construction of many photoconductive and electronic materials.Much attention has been given to its functional derivatives.However,the functionalization at the peripositions is much less well studied due to the lack of efficient synthetic methods,which hinders the further functionalization and extension.In addition,the perylene is considered as a promising candidate for organic optoelectronic materials,the development of functional derivatives is beneficial to explore its application in electronic devices.In this thesis,we have designed and synthesized a new fully functionalized perylene derivative 4Br-Per and corresponding functional perylene derivatives.In addition,the electronic structure and photophysical properties of the molecules have been investigated.The main contents as follows:1.We have successfully synthesized the fully functionalized perylene derivative 4Br-Per.The synthesis of 4Br-Per was based on the dibromofunctionalized perylene derivatives Per-2Br-1 or Per-2Br-2,which can be obtained by bromination reaction.The compound 4Br-Per showed different absorption,emission spectra and energy levels with the increase of bromine atoms.In addition,the introduction of four bromine atoms at the peripositions can be further prepared of organic conjugated molecules.2.We have designed and synthesized perylene derivatives Per-2SMe-1,Per-2SMe-2 and 4SMe-Per.With the increase of thiomethyl substitutions,the compound 4SMe-Per showed shift of the absorption maxima.We also focused on the charge transport properties and structure-activity relationship by the Scanning Tunnelling Microscope Break Junction(STM-BJ)measurement.The conductance of three single-molecule junctions was low.Such low conductance may be attributed to the twisted structure.3.In this chapter,using known fully functionalized compound 4Br-Per as the building block,we have designed π-extended conjugated molecule via Suzuki-Miyaura cross coupling and oxidative dehydrogenation reactions,in which five-membered rings and seven-membered rings fused to perylene.Theoretical calculations indicated that the molecule may have interesting electronic structures.We proposed a powerful methodology for the construction of the defect-type conjugated based system.