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Updated: Jan 1, 2026
Isolating Free Carbenes, their Mixed Dimers and Organic Radicals
Published on: April 19, 2019
cis alkenes stabilized by intramolecular sulphurπ interactions
Xiaolei Zhao1, Wei Zheng, Yi Zhang
1State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P. R. China. whuang@nju.edu.cn.
Researchers synthesized alkenes with bistable isomers on a thiophene/azoheteroaryl framework. These compounds exhibit reversible photoisomerization, stabilized by unique intramolecular sulfur-pi interactions.
Area of Science:
- Organic Chemistry
- Photochemistry
- Materials Science
Background:
- Alkenes are fundamental organic molecules with diverse applications.
- Photochromic materials capable of reversible isomerization are crucial for advanced technologies.
- Azoheteroaryl compounds offer unique electronic and structural properties.
Purpose of the Study:
- To synthesize novel alkenes featuring a thiophene/azoheteroaryl backbone.
- To investigate the visible light and heat-induced reversible cis-trans isomerization of these alkenes.
- To elucidate the stabilizing interactions of the cis isomers.
Main Methods:
- Synthesis of alkenes with a thiophene/azoheteroaryl core.
- UV-Vis spectroscopy to monitor isomerization.
- Proton Nuclear Magnetic Resonance (1H NMR) spectroscopy to confirm structural changes.
- Computational chemistry to investigate intramolecular interactions.
Main Results:
- Successful synthesis of alkenes with bistable isomers.
- Demonstration of reversible cis ⇌ trans isomerization upon exposure to visible light and heat.
- Spectroscopic evidence (UV-Vis, 1H NMR) confirming the isomerization process.
- Theoretical calculations supporting the role of intramolecular sulfur-pi (Sπ) interactions in stabilizing cis alkenes.
Conclusions:
- The synthesized thiophene/azoheteroaryl alkenes exhibit photo- and thermal-responsive bistable isomerization.
- Intramolecular sulfur-pi (Sπ) interactions are key to the stabilization of the cis alkene isomers.
- These findings contribute to the development of novel photochromic materials.
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