Co-assembly And Circularly Polarized Luminescence Property Of Glutamic Acid And Tetraphenylethylene Derivates

Due to the unique characteristics of optical rotation and circular dichroism,circularly polarized luminescent(CPL)materials have attracted much attentions and they have been widely applied in chiral optoelectronic devices.Supramolecular self-assembly provides an efficient and convenient "bottom-up"strategy for construction of optoelectronic devices.Meanwhile,the development of chiral supramolecular systems is meaningful for construction of circularly polarized luminescent materials.Glutamic acid is a natural chiral molecule.Through appropriate modification,glutamic acid derivates show excellent self-assembly performance.In this paper,stearic acid modified glutamic acid(LGG/DGG)and pyridine-functionalized tetraphenylethylene(PTPE)with aggregation-induced emission(AIE)property were designed.The assembly properties of LGG/DGG and PTPE in various solvents and circularly polarized luminescence were studied.System 1:LGG/DGG can form organic gel in chloroform.Because of the strong hydrogen-bonding interaction between pyridine moieties and carboxyl groups,DGG and PTPE can co-assemble into cogels with strong CPL emission.Meanwhile,regulating the stoichiometric ratio of PTPE and DGG is an efficient way to invert the handedness of CPL and the ground-state supramolecular chirality.System 2:DGG exhibits hierarchical assembly property in n-hexane.As time prolongs,the assembly morphology turned from random aggregations to nanofibers.Through fluorescence and circular dichroism(CD)spectra,the hierarchical assembly behavior of DGG was studied by the co-assembly of DGG and PTPE.As time prolongs,the emission color turned from green to cyan,which indicated the hierarchical assembly can be real-time monitored by observing the change of emission color.Furthermore,the circular dichroism of co-assemblies was enhanced as time prolongs and exhibited intense CPL emission.Chiral supramolecular co-assembly based on natural amino acid derivates and AIE agents provides a new methodology for constructing chiral optoelectronic devices and has potential application prospect.