The number and type of new supramolecular polymer (SMP) systems have increased rapidly in recent years. Some of the key challenges faced for these novel systems include gaining full control over the mode of self-assembly, the creation of novel architectures and exploring functionality. Here we provide a critical overview of approaches related to perylene-based SMPs and discuss progress to exert control over these potentially important SMPs through chemical modification of the imide substituents. Imide substitutions affect self-assembly behaviour orthogonally to the intrinsic optoelectronic properties of the perylene core, making for a valuable approach to tune SMP properties. Several recent approaches are therefore highlighted, with a focus on controlling 1) morphology, 2) H-or J-aggregation, and 3) mechanism of growth and degree of aggregation using thermodynamic and kinetic control. Areas of potential future exploration and application of these functional SMPs are also explored.

Thionation of a model perylene diimide has a significant impact on its self-assembly behaviour. This approach provides a facile route to simultaneously exert control over the mechanism, morphology and functionality of self-assembled PDI materials.

Aggregates of perylene diimides are prized for their stability, efficiency and versatility in a range of optoelectronic applications. Structural control can be achieved via the supramolecular polymerization of perylene diimides, where the morphology and function of aggregates is modulated by rational design of the perylene diimide monomers. This review examines how chemical substitution at the imide position of perylene diimides (which does not affect the parent chromophore's electronic structure) can be used to tune the morphology, H‐ or J‐ aggregation and mode of growth of perylene diimide supramolecular polymers. It also appraises the current state of the art for controlling the degree of aggregation in isodesmic, cooperative and anti‐cooperative systems, and pinpoints the most promising routes and future challenges to achieving greater morphological control of these supramolecular constructs. Read more in the Review by C. F. J. Faul et al. on page 11 ff.