Helical Nanographenes Bearing Pentagon‐Heptagon Pairs by Stepwise Dehydrocyclization

The incorporation of pentagon‐heptagon pairs into helical nanographenes lacks a facile synthetic route, and the impact of these pairs on chiroptical properties remains unclear. In this study, a method for the stepwise construction of pentagon‐heptagon pairs in helical nanographenes by the dehydrogen...

Full description

Saved in:
Bibliographic Details
Published in:Angewandte Chemie 2024-05, Vol.136 (20), p.n/a
Main Authors: Ju, Yang‐Yang, Luo, Huan, Li, Ze‐Jia, Zheng, Bing‐Hui, Xing, Jiang‐Feng, Chen, Xuan‐Wen, Huang, Ling‐Xi, Nie, Guo‐Hui, Zhang, Bin, Liu, Junzhi, Tan, Yuan‐Zhi
Format: Article
Language:English
Subjects:
Chiral resolution
Chiroptical properties
Circular polarization
Dehydrogenation
Enantiomers
Helicenes
Isomerization
Luminescence
Nanographenes
Oxidation
Pentagon-heptagon pairs
Synthesis
Citations: Items that this one cites
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The incorporation of pentagon‐heptagon pairs into helical nanographenes lacks a facile synthetic route, and the impact of these pairs on chiroptical properties remains unclear. In this study, a method for the stepwise construction of pentagon‐heptagon pairs in helical nanographenes by the dehydrogenation of [6]helicene units was developed. Three helical nanographenes containing pentagon‐heptagon pairs were synthesized and characterized using this approach. A wide variation in the molecular geometries and photophysical properties of these helical nanographenes was observed, with changes in the helical length of these structures and the introduction of the pentagon‐heptagon pairs. The embedded pentagon‐heptagon pairs reduced the oxidation potential of the synthesized helical nanographenes. The high isomerization energy barriers enabled the chiral resolution of the helicene enantiomers. Chiroptical investigations revealed remarkably enhanced circularly polarized luminescence and luminescence dissymmetry factors with an increasing number of the pentagon‐heptagon pairs. The controlled dehydrogenation of [6]helicene units provides a facile and feasible method for the synthesis of helical nanographenes containing pentagon‐heptagon pairs. The presence of pentagon‐heptagon pairs has proven to be quite effective in modulating the electrochemical and photophysical properties of the resulting nanographenes, including enhanced circularly polarized luminescence.
ISSN:0044-8249
1521-3757
DOI:10.1002/ange.202402621