Conjugated Macrocycles for Host-Guest Recognition and Optoelectronic Applications

Since the 1960s, π-conjugated macrocycles have garnered significant interest from both organic and materials chemists due to their aesthetically pleasing molecular architectures, distinctive electronic features, and tunable optical properties. Recent years have witnessed remarkable advancements in the design of synthetic strategies, geometric structure construction, and physicochemical property optimization of π-conjugated macrocycles, thereby fostering their applications and development in supramolecular chemistry and organic electronic materials. In this review, the recent progress of π-conjugated macrocycles, including molecular structure, physicochemical properties, host-guest recognition, and applications in optoelectronic devices, is systematically summarized, aiming to elucidate the structure-performance relationship between molecular structure, aggregation state, and host-guest behavior/device performance. Based on π-orbital alignment, macrocycles are categorized into two primary types: those with radially oriented π-orbitals and those with axially oriented π-orbitals. Their applications in host-guest recognition, organic field-effect transistors (OFETs), organic light-emitting diodes (OLEDs), and organic solar cells (OSCs) are comprehensively discussed to provide valuable insights for the future research and applications of π-conjugated macrocycles.