Shape-Persistent Tetraphenylethylene Macrocycle: Highly Efficient Synthesis and Circularly Polarized Luminescence.

Circularly polarized luminescence (CPL) is an emerging field with significant applications in molecular electronics, optical materials, and chiroptical sensing. Achieving efficient CPL emission in organic systems remains a major challenge, particularly in the development of materials with high fluorescence quantum yields (Φ) and large luminescence dissymmetry factors (g). Herein, we report the efficient synthesis of shape-persistent tetraphenylethylene macrocycles and investigate its potential as a CPL material. Chiral side chains were introduced to induce chiroptical properties. The macrocycles and their properties were characterized using NMR, MALDI-TOF MS, FT-IR, TGA, DSC, UV-Vis spectroscopy, SEM, fluorescence spectroscopy, ECD, and CPL. A significant fluorescence enhancement was observed upon aggregation, demonstrating a typical aggregation-induced emission (AIE) behavior. Moreover, one of the macrocycles in the solid state displayed distinct CPL emission with a high g of 2 × 10 and a Φ value reaching 60%, and exhibited aggregation-induced circularly polarized luminescence (AICPL). These findings highlight the advantage of using a macrocycle with a noncollapsible backbone for the design of organic systems with CPL property, offering promising applications in chiroptical materials.