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A new axially-chiral photochemical switch.
Silvia Pieraccini1, Stefano Masiero, Gian Piero Spada
1Alma Mater Studiorum-Università di Bologna, Dipartimento di Chimica Organica A. Mangini, Via San Donato 15, 40127 Bologna, Italy.
Chemical Communications (Cambridge, England)
|April 3, 2003
Summary
Axially chiral bis(azo) derivative 1 exhibits photochemical isomerization. This transformation is observable using circular dichroism and pitch measurements of cholesteric liquid crystal phases.
Area of Science:
- Organic Chemistry
- Photochemistry
- Materials Science
Background:
- Axially chiral molecules offer unique stereochemical properties.
- Azo compounds are known for their photoresponsive behavior.
- Cholesteric liquid crystals exhibit tunable helical structures.
Purpose of the Study:
- To investigate the photochemical isomerization of an axially chiral bis(azo) derivative.
- To correlate molecular changes with macroscopic properties of induced cholesteric phases.
Main Methods:
- Synthesis of the axially chiral bis(azo) derivative.
- Photochemical irradiation experiments.
- Circular dichroism spectroscopy.
- Pitch measurements of cholesteric phases.
Main Results:
- The bis(azo) derivative successfully underwent photochemical isomerization upon irradiation.
- Circular dichroism spectra showed distinct changes corresponding to the isomerization.
- Pitch measurements revealed alterations in the helical structure of the induced cholesteric phases.
Conclusions:
- Photochemical isomerization of the axially chiral bis(azo) derivative is feasible.
- The molecular transformation directly impacts the optical properties of cholesteric phases.
- This work demonstrates a potential for photo-switchable chiral materials.