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Double π‐Extended Undecabenzo[7]helicene
Author(s) -
Chen Ying,
Lin Chaojun,
Luo Zhixing,
Yin Zhibo,
Shi Haonan,
Zhu Yanpeng,
Wang Jiaobing
Publication year - 2021
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.202014621
Subject(s) - helicene , fluorescence , crystallography , absorption (acoustics) , conjugated system , materials science , ultraviolet , circular dichroism , crystal (programming language) , chemistry , dichloromethane , photochemistry , molecule , optics , organic chemistry , polymer , optoelectronics , physics , programming language , solvent , computer science , composite material
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 (|Δ ϵ |=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 .