1. Benzothiadiazole-derived double aza [5]helicenes: Synthesis, crystal structure and optical properties.
- Author
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Yu, Zhenxing, Shi, Guangjin, Wang, Kun-Peng, Xu, Liang-Zhong, Chen, Shaojin, and Hu, Zhi-Qiang
- Subjects
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CRYSTAL optics , *HELICENES , *MATERIALS science , *POLYCYCLIC aromatic hydrocarbons , *STOKES shift - Abstract
Double helicenes have attracted increasing attention of researchers for their unique structures as well as potential application in material science. Most of the double helicene compounds are all-carbon helicenes, and nitrogen-doped double helicenes are rarely synthesized and studied. As polycyclic aromatic hydrocarbons doped with heteroatoms could show specific optoelectronic properties, it is necessary to develop new strategy for the synthesis of double azahelicenes. In this work, three double aza [5]helicene compounds have been designed and synthesized through Bischler-Napieralski cyclization. These molecules have symmetrical saddle-type conformations and P/M configurations. Moreover, these molecules could exhibit positive solvatochromic properties and have large Stokes shifts in various organic solvents. According to the DFT calculation results, the distributions of HOMOs are mainly over bilateral aromatic rings, while the LUMOs are delocalized over the central benzothiadiazole or benzopyrazine moiety. The calculation results are in consistent with the fluorescent properties of these molecules. This work provides a new strategy for the synthesis of double aza [5]helicene molecules with fluorescent properties. Double aza [5]helicene derivatives have been synthesized. These compounds have symmetrical saddle-type conformations and PM configurations. These double aza [5]helicenes have large Stokes shifts and could exhibit positive solvatochromic properties in solutions. [Display omitted] • Three double aza [5]helicene derivatives have been synthesized. • These double helicene molecules have symmetrical saddle-type conformations and P/M configurations. • These molecules have large Stokes shifts. • These molecules could exhibit positive solvatochromic properties in solutions. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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