Volume 42, Issue 22 pp. 2811-2817
Concise Report

On-surface Synthesis of Multiple Non-benzenoid Carbohelicenes Fused with Fluorene Unit(s)

Wei Xiong

Wei Xiong

Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming, Yunnan, 650093 China

These authors contribute equally to this work.

Search for more papers by this author
Xi Geng

Xi Geng

Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming, Yunnan, 650093 China

These authors contribute equally to this work.

Search for more papers by this author
Jianchen Lu

Corresponding Author

Jianchen Lu

Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming, Yunnan, 650093 China

These authors contribute equally to this work.

E-mail: [email protected]; [email protected]; [email protected]Search for more papers by this author
Gefei Niu

Gefei Niu

Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming, Yunnan, 650093 China

Search for more papers by this author
Boyu Fu

Boyu Fu

Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming, Yunnan, 650093 China

Search for more papers by this author
Yi Zhang

Yi Zhang

Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming, Yunnan, 650093 China

Search for more papers by this author
Shicheng Li

Shicheng Li

Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming, Yunnan, 650093 China

Search for more papers by this author
Yuhang Yang

Yuhang Yang

Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming, Yunnan, 650093 China

Search for more papers by this author
Nianqiang Li

Nianqiang Li

Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming, Yunnan, 650093 China

Search for more papers by this author
Lei Gao

Corresponding Author

Lei Gao

Faculty of Science, Kunming University of Science and Technology, Kunming, Yunnan, 650093 China

E-mail: [email protected]; [email protected]; [email protected]Search for more papers by this author
Jinming Cai

Corresponding Author

Jinming Cai

Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming, Yunnan, 650093 China

Southwest United Graduate School, Kunming, Yunnan, 650093 China

E-mail: [email protected]; [email protected]; [email protected]Search for more papers by this author
First published: 17 July 2024
Citations: 1

Comprehensive Summary

Carbohelicenes have garnered considerable attention for their inherent chirality and structural flexibility. Increasing multi-helicity and incorporating non-six-membered rings to substitute benzenoid rings within helicenes are effective strategies for introducing unique photoelectric properties. Despite the disclosure of numerous helicenes, the inaccessible precursors and the lack of synthetic routes pose a challenge in achieving desired helicene structures fused with non-benzenoid rings. Herein, we report the synthesis of multiple non-benzenoid carbohelicenes fused with fluorene unit(s) through intramolecular cyclodehydrogenation of 9,10-di(naphthalen-1- yl)anthracene on Au(111) surface. Two potential cyclodehydrogenation manners between naphthyl and anthracene lead to the formation of fluorene-fused [5]helicene and [4]helicene moiety. Consequently, a total of four stable products were observed. The atomic topographies of products are characterized by bond-resolving scanning tunneling microscopy. The chiral helicity of targeted products can be switched by tip manipulation. Density-functional-theory calculations unveils the reaction pathway of four products. The comparative analysis of their respective energy barriers exhibits a correlation with the experimentally determined yields. Furthermore, we synthesize the polymer chains incorporating non-benzenoid carbohelicenes via the Ullmann reaction of 2,6-dibromo-9,10-di(1-naphthyl)anthracene precursors. Our work proposes a synthetic methodology for several novel helicene-like structures fused with fluorene units and the polymer bearing helicene subunits, thus highlighting the immense potential of these compounds in the application fields of luminescent electronic devices.

image

The full text of this article hosted at iucr.org is unavailable due to technical difficulties.