Non-symmetric side chain engineering as a design strategy towards novel functional semiconducting polymers

Abstract

Non-symmetric side-chain engineering has emerged as a promising strategy for tuning the mechanical and optoelectronic properties of π-conjugated polymers for applications in organic electronics. Most high-performance donor–acceptor semiconducting polymers, particularly those incorporating lactam-based acceptor units, rely on symmetrically substituted side chains to regulate solubility and solid-state packing. While effective, this design paradigm often restricts side chains to aliphatic motifs and limits opportunities to introduce additional functionality. In contrast, non-symmetric side chain architectures provide a versatile platform to move beyond conventional designs by enabling more functional and adaptive side-chain chemistries. Recent studies demonstrate that non-symmetric motifs can provide enhanced control over polymer self-assembly and structure–property relationships while helping decouple solubility from side chain functionality. In this review, we highlight recent advances in non-symmetric side chain engineering and discuss emerging synthetic strategies, design principles, and applications that illustrate the growing impact of this approach in the field of π-conjugated polymers.