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Dynamic Chirality in Perylene Diimide Nanoribbons

Presented By: Si Tong (Ally) Bao

Abstract:
Here we present a comprehensive study on the control of dynamic axial chirality in perylene diimide (PDI)-based nanoribbons. Chiral substituents at the imide positions induce helicity in PDI-based dimers (chPDI[2]), enabling the remote modulation of flexible [4]helicene subunits. Extending this principle, we synthesize defect-free, ultralong chiral cove-edged graphene nanoribbons (chPDI[n]s), achieving precise control of helicity and extraordinary circular dichroic responses through post-functionalization with chiral side chains. The iterative synthesis and polymerization-cyclization strategies yield ribbons with lengths up to 30 nm while maintaining structural integrity. Furthermore, we demonstrate that the chiral PDI dimer, chPDI[2], can function as a PDI-based chiral molecular redox switch, with high-intensity, broadband chiroptical switching across ultraviolet to near-infrared regions. Its contorted molecular structure facilitates ionic diffusion, enabling stable, reversible multistate chiral switching in solid-state films. These findings not only advance the understanding of chirality in extended π-systems but also establish new benchmarks for dynamic, tunable chiral materials with potential applications in nonlinear optics, magnetochirality, asymmetric catalysis, and chiral-induced spin selectivity.