Chiral V‐shaped Pyrenes: Hexagonal Packing, Superhelix, and Amplified Chiroptical Performance

Abstract

Here, we designed symmetric and dissymmetric chiral V‐shaped pyrenes by linking achiral pyrenes to trans‐1,2‐cyclohexane diamine scaffolds with varied spacers to investigate their circular dichroism (CD) and circularly polarized excimer emission (CPEE). In molecular solution, the symmetric V‐shaped molecules (P1, P2, P3) displayed spacer‐dependent CD and CPEE originating from the intramolecular excimers while the dissymmetric V‐shaped B was silent in CD and CPEE. Upon self‐assembly, the chiral V‐shaped conformation guided a helical hexagonal packing. Notably, P1 self‐assembled into delicate superhelices with optimum chiroptical activities and the largest gCD for pyrene derivatives to date. The dissymmetric B formed two distinct hexagonal aggregates as twists and rectangular nanotubes with greatly amplified CPEE. This work demonstrates unprecedented hexagonal superhelices from chiral V‐shaped scaffolds and provides a deep insight into the relationship between molecular conformation, supramolecular architectures, and their chiroptical performance.