Construction And Regulation Of Circularly Polarized Luminescence System Based On Cyclohexanediamine Or Tartaric Acid Framework

In recent years,optical materials with circular polarized luminescence(CPL)have attracted extensive research interest due to their potential applications in 3D display,information storage,asymmetric catalysis and other fields.To date,generating circularly polarized luminescence materials is simple enough,but controllable modulation of CPL remains a challenge because of much uncertainty.In the field of chemistry,the properties of molecules and supramolecules are of concern to us all.Chirality derives from the chirality of molecules themselves on the molecular dimension,while at the supramolecular scale,chirality generally comes from the assembly of the building blocks.In this paper,pyrene acrylic acid derivatives or tartaric acid derivatives were designed and synthesized.By changing the external environmental conditions,the former realized the reversal of circular polarization luminescence signal because of the variation of monomer and excimer which could be regulated by violet light.The inversion or ON/OFF of CPL signal of the latter was also carried out for the excitation wavelength could modulate the excimer state and ESIPT state emission.The main achievements including the following two aspects:1)CHPA which has two pyrene acrylic acid groups was designed and synthesized.It was found that it has strong photo-responsibility in the molecular state.Under the irradiation of the UV light,the signal of the circularly polarized luminescence was inversion and the |glum| could reach to 1.46 × 10-2.The experiment results not only give a new method to modulate the chirality of small molecules in molecular state but also provide a new way for the amplification of circularly polarized fluorescence.2)A series of tartaric acid-derived acylhydrazones was designed and synthesized.It was found that TAP could form white gels and the fluorescence emission of the gel was at 518 nm under high energy excited,while the fluorescence emission was at 467 nm under the excitation wavelength of low energy.In addition,the direction of the circularly polarized luminescence(CPL)signal was reversed due to the change of excitation wavelength,but the morphology of the molecular assembly remained during this process.Similar phenomena also discovered in the TAHP assemblies,the fluorescence emission at about 500 nm when was excited by high energy excitation wavelength,and the emission at 435 nm when excited by low energy excitation.However,the CPL signal of TAHP assemblies showed ON/OFF.This system showed an interesting phenomenon of excitation wavelength dependence of various properties of chiral molecules after self-assembly,and its causes are studied in detail.This study also provided us with a simple and non-damaging method to control the direction of the chiral supramolecular circularly polarized luminescence signal.