Dictating Packing and Interactions of Perylene Bisimides within Cyclophane Structures in the Solid State

Crystal packing and chromophore communication are key parameters for the performance and functionality of many applications related to light-energy harvesting and conversion. However, obtaining crystals of flexible and very soluble structures is troublesome. Nevertheless, a crystal structure of a highly flexible perylene-3,4 : 9,10-tetracarboxylic acid bisimide (PBI) cyclophane was obtained and analysed to compare the chromophore arrangement in the solid state with theconfiguration in solution as well as with calculated structures. The crystal structure exhibits an intra- and intermolecular slip-stack arrangement of the heterochiral PBI units, forming a unique one-dimensional pi-stacking supramolecular polymer-like structure. These findings emphasize that the unique solid-state arrangement of the chromophores cannot be easily predicted by elaborate studies in solution or by theoretical calculations. Furthermore, it features the importance of controlling the crystal packing to enable specific applications based on multiexciton generation processes where the spatial dependence and relative orientation of the chromophores are decisive parameters.