LAUSR

Abstract Perylene‐3,4,9,10‐tetracarboxylic acid diimides (PDIs) have recently gained considerable interest for water‐based biosensing applications. PDIs have been studied intensively in the bulk state, but their physical properties in aqueous solution in interplay with side‐chain polarity are, however, poorly understood. Therefore, three perylene diimide based derivatives were synthesized to study the relationship between side‐chain polarity and their self‐assembly characteristics in water. The polarity of the side chains was found to dictate the size and morphology of the formed aggregates. Side‐chain polarity rendered the self‐assembly and photophysical properties of the PDIs—both important for imminent water‐based applications—and these were revealed to be especially responsive to changes in solvent composition.