Design,Synthesis And Properties Of Chiral Organic-Based Circularly Polarized Luminescence Materials

Circularly polarized luminescence(CPL)is a special chiroptical property originating from chiral fluorescence system.Recently,there has been increasing interest in the design and development of novel CPL materials,which can be regarded as an effective tool to investigate structural information of the excited state of chiral fluorescent molecules,and its potential applications for chemical sensors,3D optical display,optical storage,liquid crystal laser,and so on.Early research on CPL materials was mainly focused on chiral rare earth complexes.Nowdays,more efforts on CPL materials have been devoted to common chiral organic dyes,chiral conjugated fluorescence polymers,and chiral supramolecular self-assembly systems because of their high emission quantum yields,easy processing,tunable emission wavelengths,easy structure modification,and so on.In this dissertation,we decsribed the design and synthesis of CPL materials based on chiral organic molecule and chiral polymers.The second chapter reported the synthesis of four chiral monomers with different connections based on chiral source 1,2-hexamethylene diamine,then four chiral fluorescence polymers were synthesized via the Pd-catalyzed Sonogashira coupling reaction.Menanwhile,this work studied the CD and CPL properties of theses chiral fluorescence polymers in THF solution.The results demonstrate that the polymers with conjugated double bond can exhibit the mirror-image CD and CPL signals,however,the CD and CPL signals of the polymer without conjugated double bond were silent.These results indicate that the structure of the conjugated double bond is favorable for the chiral transfer,resulting the optical activity of the polymers with conjugated structure.The third chapter reported the design and synthesis of BINOL(1,1’-binaphthyl-2,2’-diol)-based polymers via the Pd-catalyzed Sonogashira coupling reaction,and the CD and CPL properties of the polymers in different solvents and aggregate state.The polymers show obvious CD and CPL signals with stable gabs and glum in the different states which is originated from the chiral transfer of BINOL,the results show that the chiral properties of conjugated polymers could be influenced slightly by the solvent microenvironment。The fourth chapter reported the synthesis of perylene diimide incorporating chiral amino acid.And the optical activity and the morphologies of the chiral PDI-based molecules were studied in chloroform and methanol solution.The chiral molecules did not show any CD and CPL signals in chloroform,however,they could exhibit strong CD effects and CPL signals in aggregate state.We further investigated the morphologies of the chiral PDI-based molecules,they can exhibit optical activity in aggregation which was due to the special stacking 3D flower-like structure originated from nanorobs via intermolecular π-π interactions.The fifth chapter reported that the chiral 1,8-naphthalimide-based pyrene fluorophore enantiomers which incorporated D/L-alanine moieties were synthesized via the Pd-catalyzed Sonogashira coupling reaction.We studied the CD and CPL activity,and the morphologies of the chiral molecules in THF solution and aggregation.The CD and CPL signals of the compounds in THF solution were silent which could be assigned to the limited chiral transfer,however,they can exhibit strong mirror-image CD effects and CPL signals in the aggregate which was attributed to the formation of self-assembly helical nanofibers via intermolecular π-π interactions.