Switchable trans-cis interconversion of an amphiphilic anthracene trimer
Junji Iwasa1, Kosuke Ono, Makoto Fujita
1Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
Chemical Communications (Cambridge, England)
|September 24, 2009
Summary
Researchers created novel molecules with three anthracene rings. These molecules exist as distinct trans- and cis-forms, with their shape-shifting influenced by solvents and controllable by a simple base stimulus at room temperature.
Area of Science:
- Organic Chemistry
- Supramolecular Chemistry
- Materials Science
Background:
- Atropisomers are stereoisomers that result from hindered rotation around a single bond.
- Controlling the interconversion of atropisomers is crucial for developing responsive materials and molecular switches.
- Anthracene derivatives offer unique photophysical properties and structural rigidity for molecular design.
Purpose of the Study:
- To synthesize and characterize novel anthracene-based compounds with potential for isomer interconversion.
- To investigate the factors influencing the stability and transformation between cis- and trans-atropisomers.
- To explore the use of external stimuli for controlled activation of isomer interconversion.
Main Methods:
- Synthesis of multi-anthracene compounds featuring m-phenylene spacers and hydroxyl groups.
- Isolation and characterization of distinct trans- and cis-atropisomers using spectroscopic techniques (NMR, X-ray crystallography).
- Solvent-dependent studies and kinetic analysis of the interconversion process between atropisomers.
Main Results:
- Successfully synthesized and isolated stable trans- and cis-atropisomers of the anthracene derivative.
- Demonstrated that the interconversion between isomers is sensitive to the polarity and nature of the solvent.
- Showed that the cis-trans isomerization can be triggered and controlled at room temperature using a basic stimulus.
Conclusions:
- The designed anthracene framework allows for the generation of stable, isolable atropisomers.
- Solvent polarity plays a significant role in the equilibrium and kinetics of atropisomer interconversion.
- External stimuli, specifically a base, can effectively activate and control the isomerization process at ambient temperatures, paving the way for molecular switch applications.
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