Sequence-DefinedDendrons Dictate Supramolecular CogwheelAssembly of Dendronized Perylene Bisimides

A dendronized perylene bisimide (PBI) that self-organizes into hexagonal arrays of supramolecular double helices with identical single crystal-like order that disregards chirality was recently reported. A cogwheel model of selfassembly that explains this process was proposed. Accessing the highly ordered cogwheel phase required very slow heating and cooling or extended periods of annealing. Analogous PBIs with linear alkyl chains did not exhibit the cogwheel assembly. Here a library of sequence-defined dendrons containing all possible compositions of linear and racemic alkyl chains was employed to construct self-assembling PBIs. Thermal and structural analysis of their assemblies by differential scanning calorimetry (DSC) and fiber X-ray diffraction (XRD) revealed that the incorporation of n-alkyl chains accelerates the formation of the high order cogwheel phase, rendering the previously invisible phase accessible under standard heating and cooling rates. Small changes to the primary structure, as constit...