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Updated: Nov 22, 2025

Preparation of a Corannulene-functionalized Hexahelicene by CopperI-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units
Published on: September 18, 2016
Double π-Extended Undecabenzo[7]helicene
Ying Chen1, Chaojun Lin1, Zhixing Luo1
1School of Chemistry, Sun Yat-Sen University, Guangzhou, 510275, China.
Abstract:
This work reports the first double π-extended undecabenzo[7]helicene 1, which is a large chiral nanographene, composed of 65 fused rings and 186 conjugated carbon atoms. The molecular identity of 1 has been confirmed by single crystal X-ray diffraction. A wine coloured solution of 1 in dichloromethane absorbs light from ultraviolet to the near infrared, featuring an extremely large molar absorption coefficient of 844 000 M-1 cm-1 at 573 nm. Optically pure 1 shows a record high electronic circular dichroism intensity in the visible spectral range (|Δϵ|=1375 M-1 cm-1 at 430 nm) known for any discrete polycyclic aromatic hydrocarbon. These unusual photophysical properties of 1 contrast sharply with those of a mono-undecabenzo[7]helicene derivative 2.
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