关键词: 手性组装, 超分子, 光控, 圆偏振发光(CPL)

In recent years, chiral materials based on circularly polarized luminescence (CPL) generated by molecular assembly have developed rapidly. However, the overall CPL signal of organic material systems is still weak and lacks precise modulation means. As a non-contact external stimulus, light stimulation has the advantages of precision and speed. Therefore, in this work, hexathiobenzene (M-1) with photoactive aggregation-induced emission (AIE) properties were used as fluorescent dyes, and chiral amino acids L/D-Lysine hydrochloride (L/D-Lys) were used as chiral templates. Supramolecular L/D-Lys@M-1 components are formed by intermolecular hydrogen bonding in a mixed solvent (N,N-dimethylformamide (DMF)/H₂O). Specifically, 1 mmol/L M-1 and 6 mmol/L L/D-Lys were dissolved in 700 μL DMF. Next, add 300 μL ultra-pure water to the mixture at 60 ℃ and cool the solution to 25 ℃. Due to the formation of L/D-Lys@M-1 co-assembly, the transparent solution gradually becomes an opaque suspension. The photoluminescence spectra, UV absorption spectra and DLS (dynamic light scattering) were used to characterize the structure and photoluminescence properties of the photoluminescence components. It was found that L/D-Lys@M-1 had self-aggregation effect under the photoluminescence, its particle size increased from ca. 700 nm to ca. 1400 nm, and it produced continuously enhanced emission at 450 nm and 550 nm. The chiral properties of ground state and excited state were studied by CD (circular dichroism) and CPL. The Cotton effect was observed at 250 nm and 300 nm under solvent-induced and light-controlled conditions, and the CD intensity of the L/D-Lys@M-1 co-assembly system increased with prolonged illumination time, indicating that the co-assembly system realized chiral transfer and amplification. CPL spectra indicate that, under the solvent effect of poor solvent H₂O, the co-assembly induced CPL signal at 540 nm (M-1 molecule fluorescence emission), luminescent dissymmetry factor (|g_lum|) 0.3×10^-2. This study provides a strategy for CPL construction and dynamic regulation of achiral fluorescence molecules.

Key words: chiral assembly, supramolecular, photocontrol, circularly polarized luminescence (CPL)