Circularly Polarized Luminescence in Macrocycles and Cages: Design, Preparation, and Application

Circularly polarized luminescence (CPL)-active materials have attracted increasing attention due to their widespread applications in three-dimensional displays, optical sensors, and photoelectric devices. Chiral macrocycles and cages can be synthesized with precise structures, extensive functions, and excellent chiroptical properties, making them promising candidates for CPL-active materials. Designing novel CPL-active materials based on macrocycles and cages is a promising avenue to reveal their fundamental principles and expand their practical applications as chiral functional materials. This review summarizes strategies for designing CPL materials based on chiral macrocycles and cages, including both noncovalent interactions (coordination bonds, electrostatic interactions, CH···π interactions, hydrogen bonds, and charge transfer interactions) and covalent bonds. In addition, significant applications of macrocycle- and cage-based CPL materials in displays, sensors, and switches are discussed. Finally, the existing opportunities and challenges in developing novel macrocycle- and cage-based CPL materials are highlighted, with the aim of providing general guidelines for the development of the next generation of chiral macrocycle- and cage-based CPL materials.