Conjugated Polymers Bearing Macrocyclic Architectures as Side Chains: Design, Synthesis, and Function.

Conjugated polymers are versatile organic semiconductors combining mechanical flexibility with tunable optoelectronic properties for applications in photovoltaics, light-emitting diodes, and transistors. The incorporation of macrocyclic architectures into conjugated polymers has opened new avenues for property modulation, leveraging the unique topology, ring strain, and host-guest capabilities of cyclic compounds-features inaccessible in linear systems. This Review provides a systematic overview of conjugated polymers incorporating macrocyclic motifs, classifying them into three categories: saturated macrocycles, macrocyclic arenes, and cycloparaphenylenes (CPPs) and their analogs. For each class, we discuss design strategies, synthetic approaches, and emerging functions, with special emphasis on CPP-based systems, where radial conjugation enables unprecedented electronic hybridization with the polymer backbone. Finally, we present an outlook on challenges and opportunities, highlighting the need for scalable synthesis and device integration to realize the full potential of these materials.