Design,Synthesis And Properties Of Chiral BINOL-based Circularly Polarized Luminescence Materials

Circular polarized luminescence(CPL)refers to a chiral luminescent system which can emit circular polarized light itself.It can not only characterize the structural information of the excited state of chiral molecules,but also have potential prospects in the fields of bioprobes,3D optical display,optical storage,liquid crystal laser and so on.In the past several years,more research system on CPL materials mainly focused on the chiral rare earth complexes.Due to the high fluorescence quantum efficiency,the easier processing performance,the valuable broadband emission and the easier structural modification,the chiral organic CPL dyes and chiral polymer-based CPL materials have been received much attention in recent years.In this thesis,we chose 1,1-binaphthol(BINOL)as chiral source and synthesized a series of BINOL-based CPL materials.In chapter II,three kinds of chiral BINOL-based polymers were synthesized by polymerization of Pd-catalyzed cross-coupling reaction.The resulting chiral polymers can exhibit strong mirror image Cotton effects.Interestingly,only P2 and P3 with double or triple bond in the main chain can emit CPL signals due to the chirality transfer of the BINOL moiety via the rigid ?-conjugation chain backbone structure system.This work can develop a new strategy on the design of novel polymer-based CPL materials.In chapter ?,two kinds of chiral BINOL-based polymer enantiomers were designed and synthesized by the polymerization of 5,5'-((2,2'-bis(octyloxy)-[1,1'-binaphthalene]-3,3'-diyl)bis(ethyne-2,1-diyl))bis(2-hydroxybenzaldeh yde)monomer(Ml)with alkyl diamine mononmer(M2)via nucleophilic addition-elimination reaction.The resulting chiral polymers can exhibit mirror image Cotton effects either in the absence or in the presence of Zn2+ ion.Almost no fluorescence or CPL emission could be observed for two chiral BINOL-based polymer enantiomers in the absence of Zn2+.Interestingly,the chiral polymers can show strong fluorescence and CPL response signals upon the addition of Zn2+ which can be attributed to Zn2+-coordination fluorescence enhancement effect.This work can develop a new strategy on the design of the novel CPL materials via metal-coordination reaction.In chapter IV,two chiral binaphthyl-based enantiomers containing AIE-active TPE group and O-BOPHY chromophore were designed and synthesized by Sonogashira cross-coupling reaction.Interestingly,the resulting chiral molecule R/S-7 can exhibit emission enlargement response in DCM/hexane mixtures due to the formation aggregarate nanoparticles,but fluorescence quenching in THF/H2O mixtures can be observed,which can be due to ACQ effect.R/S-7 can produce gradual reversal AI-CD(aggregation induced circular dichroism)signals from the solution system to the aggregation state,which can be assigned to axial chirality transfer to self-assembled helical nanowires in aggregation state.In chapter V,two kinds of Zn(?)-containing coordination polymer enantiomers were synthesized by using chiral BINOL-based pyridine derivative ligand.Due to the conjugation structure of chiral BINOL-based ligand,the chiral ligand can exhibit the strong fluorescence emission and CPL signal.Moreover,the resulting coordination polymer can exhibit red-shifted FL emission in poor solvent,and further improve the fluorescence emission and glum.value because the Zn(II)coordination limits the free rotation of the ligand and promots the ligand-metal charge transfer(LMCT)between the pyridine and Zn2+.