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Updated: Jan 16, 2026

Preparation of a Corannulene-functionalized Hexahelicene by CopperI-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units
Published on: September 18, 2016
Pyrazine-Linked End-Functionalized Helicenes: Impact of π-Extension on Frontier Orbital Localization and Chiroptical
Zheng Zhang1, Zhibo Liu1, Takashi Hirose1
1Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan.
Abstract:
Control of chiroptical responses in π-conjugated molecules is critical for the design of chiral materials. We synthesized terminal π-extended helicenes linked by a pyrazine bridge and investigated their circular dichroism. Extension from naphthalene to tetracene decreased the S0 → S1 dissymmetry factors from 0.027 to nearly zero. TD-DFT calculations and our transition-moment density analysis revealed that frontier orbital localization on the helicene moiety is essential to achieving large g values, clarifying the origin of strong chiroptical activity.
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