A Bis-Perylene Diimide Macrocycle Chiroptical Switch

Helical assemblies of organic dyes are ubiquitous chiral organic materials, with valuable properties including chiroptical switching due to the dynamic nature of supramolecular chirality. Herein, we report a novel chiral bis-perylene diimide macrocycle, which acts as a discrete molecular model for a chiral supramolecular assembly. Point chirality is installed through amino acid-derived imide groups which, upon macrocyclization, is translated into helical chirality in the perylene diimide dimer. In solution, the macrocycle's chiroptical properties are switchable, with both the sign (+/-) and amplitude (on/off) of the signal tuned using solvent and molecular recognition stimuli respectively. The chiral structure-property relationships identified from this macrocycle are important for the design of high fidelity supramolecular chiroptical switches.