Metastable Chiral Azobenzenes Stabilized in a Double Racemate
Self‐assembly of chiral organic chromophores garners huge significance owing to the abundance of supramolecular chirality found in natural systems. We report an interdigitated molecular organization involving axially chiral twisted octabrominated perylenediimide (OBPDI) transferring chiral sense to achiral aromatic moieties. The two‐component crystalline architectures of OBPDI and electron rich aromatic units were facilitated through π‐hole•••π based donor‐acceptor interactions and the charge transfer characteristics in the ground and excited states of OBPDI cocrystals were established through spectroscopic and theoretical techniques. The OBPDI cocrystals entailed a remarkable homochiral segregation of P and M enantiomers of both the molecular entities in the same crystal system to render twisted double racemic architectures. Synergistically engendered cavities with stored chiral information of twisted OBPDI stabilized higher energy P/M enantiomers of trans‐azobenzene through non‐covalent interactions.
Source:: Angewandte Chemie Int. edition