Synthesis and Self‐Assembly of Perylene Imide‐Containing Hydrophilic Polymers in Water

New advances in synthetic strategies have greatly expanded the structural diversity of perylene imides (PIs), increasing the tunability of their molecular properties and assemblies in organic solvents. More recent studies also show molecular assemblies in aqueous media when the hydrophobic perylene core is functionalized with hydrophilic groups, allowing their use not only in optoelectronics or catalysis, but also in biological applications. However, PIs are usually too hydrophobic to be used in water, and their molecular assemblies usually result in ill-defined nanostructures with a significant loss of their emissive properties. Therefore, a powerful and promising strategy to enhance PI solubility in water is to incorporate them into hydrophilic polymer chains. Compared to small hydrophilic groups, the length and architecture of the polymer can be controlled and adapted to modulate the nanostructure morphology while preserving the perylene's properties in water. This review summarizes the current literature on the self-assembly in water of PI-based hydrophilic polymers, with a focus on their synthesis and the different parameters that influence the self-assembly and properties of the materials.