Olefination And Core-Extension Of Perylene Diimide Derivatives

As step-and atom-economical procedures,direct activation and functionalization of specific C-H bonds shows great potential in late-stage modification of various functional molecules with complicated organic skeletons.Perylene diimide derivatives(PDIs)are a class of important non-fullerene acceptors.Endowed with high photochemical and thermal stabilities,high fluorescence quantum yield and high electron mobility,the readily modified PDI derivatives have received tremendous research interest in recent years.Chemical modification of PDIs could be achieved through three different pathways:1)alteration of substituents on the amide nitrogen;2)aromatic halogenation at bay-positions and subsequent transformations;3)selective functionalization at ortho-positions on the perylene core.Selective functionalization of the perylene core of PDIs can effectively regulate the LUMO levels of PDI derivatives.More importantly,ortho-substituted-PDIs hold more promise as high-performance functional materials by virtue of the favorable balance between the?-? stacking,energy levels and solubility,which has wider research prospects.However,due to the electron-deficient property of the PDI core and higher reactivity of the bay positions,regioselective functionalization at the ortho positions is challenging.In this paper,a range of ortho-substituted PDI derivatives were designed and synthesized through Ru(II)or Rh(III)catalyzed ortho-C-H activation.Their photoelectric properties,self-assembly and responses of molecular chirality to circular polarized light were explored.This dissertation consists of the following two parts:1.Taking 3,4,9,10-perylene diimide as starting material and using[Ru(p-cymene)Cl2]2 or[Cp*RhCl2]2 as catalyst precursors,a series of 2,5,8,11-tetraalkenyl perylene diimide derivatives were synthesized by regio-and steroselective ortho-C-H alkenylation of PDI with different alkenes.Preliminary investigation of their physical properties and self-assembled morphology shows that ortho-alkenylation of PDIs not only can improve the solubility,but also effectively regulate the LUMO values and increase the intermolecular ?-? interaction.2.Based on the previous work of our group on regioselective Cp*Rh(III)-catalyzed ortho-iodization of PDIs,a series of indole-or benzofuran-fused PDIs were synthesized through Pd(II)-catalyzed C-H/C-Br oxidative couplings,and two benzothiophene-fused PDIs were also synthesized through Pschorr cyclization.These core-annulated molecules have significant bathochromic shift compared with the parent unsubstituted PDIs in the ultraviolet visible spectroscopy.Stable axial chirality of tetra-indole-fused-PDIs have been observed,and different enantiomers show distrinct responses to circularly polarized light.