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Preparation of a Corannulene-functionalized Hexahelicene by Copper(I)-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units
Published on: September 18, 2016
Synthesis, structural analysis, and properties of [8]circulenes
Chieh-Ning Feng1, Ming-Yu Kuo, Yao-Ting Wu
1Department of Chemistry, National Cheng Kung University, No. 1 Ta-Hsueh Rd., 70101 Tainan, Taiwan.
Angewandte Chemie (International Ed. in English)
|June 25, 2013
Summary
Newly synthesized [8]circulenes exhibit a unique saddle shape and radialene character. These compounds show dynamic behavior similar to cyclooctatetraene, despite their highly symmetrical structure.
Area of Science:
- Organic Chemistry
- Supramolecular Chemistry
- Materials Science
Background:
- Large annulenes, or circulenes, are of interest due to their unique electronic and structural properties.
- Previous synthetic methods for circulenes have been limited, hindering detailed structural and dynamic studies.
Purpose of the Study:
- To develop an efficient synthesis of [8]circulenes.
- To characterize the structure and dynamic behavior of these novel compounds.
Main Methods:
- Palladium-catalyzed annulation reactions of tetraiodotetraphenylenes with alkynes.
- X-ray crystallography for structural determination.
- Variable-temperature Nuclear Magnetic Resonance (NMR) spectroscopy for dynamic behavior analysis.
Main Results:
- [8]Circulenes were successfully synthesized via Pd-catalyzed annulation.
- X-ray crystallography revealed a saddle-shaped structure with [8]radialene character.
- Variable-temperature NMR studies indicated interesting dynamic properties, with a tub-shaped eight-membered ring exhibiting near-equal bond lengths and angles.
Conclusions:
- Pd-catalyzed annulation provides an accessible route to [8]circulenes.
- The unique structural and dynamic properties of [8]circulenes warrant further investigation for potential applications in molecular electronics or materials science.
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