Synthesis And Circularly Polarized Luminescence Of Binaphthyl-based Chiral Luminescent Materials

Circularly polarized luminescence(CPL)is the differential emission of left-and right-circularly polarized light from chiral luminescent systems,which plays a pivotal role in studying the chiral feature of the emitting excited states.CPL have received increasing attention due to its potential application in organic light-emitting diodes(OLEDs),3D display,optical data storage,optical spintronic communication and chiral recognition sensors.In this dissertation,chiral 1,1'-binaphthol(BINOL)was chosen as the chiral source to construct CPL materials.In order to achieve high luminescence dissymmetry factors(glum),mechanism of chirality transferring from chiral BINOL to achiral chromophore has been studied by different structural modification of chiral BINOL skeleton.Furthermore,application of CPL materials in OLEDs has been explored.The main works of this dissertation are as follows:1.Three pairs of chiral binaphthyl-based conjugated polymers enantiomers incorporating boron dipyrromethene(BODIPY)chromophore in the main chain backbone were designed and synthesized by Pd-catalyzed Sonogashira cross coupling reaction.All of these chiral polymers can exhibit strong Cotton effects and CPL signals in THF solutions.The absorption dissymmetry factors(gabs)and glum can be regulated by tuning the dihedral angles of binaphthyl arising from different substitutions of BINOL hydroxyls.The chiral polymers can exhibit the gradual increase of both gabs and glum as the decrease of dihedral angles of the chiral binaphthyl moiety.Theoretical calculations confirmed the experimental results.2.We designed and synthesized the chiral binaphthyl sulphonates as well as achiral bipyrene-based pyridinium.They can self-assemble into chiral supramolecular assemblies through electrostatic and ?-? interactions in MeOH-H2O(50:50 v/v)solutions.FTIR,UV-vis absorption and fluorescent emission spectra were used to characterize chiral supramolecular assemblies.Chiral s.upramolecular assemblies can exhibit strong CD and CPL signals at their absorption and emission wavelength,and the glum values can be up to 0.079.The morphology of chiral supramolecular assemblies was observed by scanning electron microscope(SEM)as helical nanorods,which can support the optical properties of the chiral supramolecular assemblies.3.Chiral dipyrrin zimc(?)coordination polymers and monomers can be synthesized by coordination reactions of chiral binaphthyl-based dipyrrin ligands and Zn2+.These chiral zinc(?)complexes were characterized by X-ray photoelectron spectroscopy(XPS),UV-vis absorption and fluorescent emission spectra.Compared with the monomers,the chiral coordination polymers can exhibit enhanced chiroptical signals according to CD and CPL spectra of these complexes.The glum values can reach as high as 9 × 10-3 for the chiral coordination polymers.The chiral amplification can be attributed to the rigid backbone structure of chiral coordination polymers.4.Two pairs of thermally activated delayed fluorescenc'(TADF)active chiral luminogens were synthesized by introducing D-A groups to chiral BINOL skeletons.These luminogens can exhibit AIE properties in THF-H2O mixtures and TADF emission in doped-film states.However,only the luminogens with fixed conjugation structure can emit CPL signals.The CPL active luminogens were chosen as emitting layers for circularly polarized organic light-emitting diodes(CP-OLEDs),which can display high luminance,moderate efficiency and circularly polarized electroluminescence(CP-EL)signals with gEL=-0.9 × 10-3/+1.0 ×10-3.