Tailoring Helical Ends of π-Extended [6]Heterohelicenes to Control Optical, and Electrochemical Features

Abstract

The inherent helical chirality and improved π-stacking capabilities endow helicenes with fascinating photophysical characteristics when decorated with lateral π-extensions. Here, we report the synthesis and physicochemical characterization of expanded hetero[6]helicenes fused with thiadiazole and selendiazole rings at the helical ends. Comparing these hetero-helicenes revealed the impact of the heteroatom-embedded aromatic rings on the excited state and redox features. A small structural variation of the terminal rings from thiadiazole to selendiazole caused a striking change in the heterohelical nanographenes.