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Surface-induced selection during in situ photoswitching at the solid/liquid interface
Sara Bonacchi1, Mohamed El Garah, Artur Ciesielski
1Nanochemistry Laboratory, ISIS & icFRC, Université de Strasbourg & CNRS, 8 allée Gaspard Monge, 67000 Strasbourg (France).
Angewandte Chemie (International Ed. in English)
|March 3, 2015
Summary
This study used scanning tunneling microscopy to observe diarylethene photoswitch isomers interconverting on a graphite surface. A thermodynamic model explained the surface
Area of Science:
- Surface Science
- Supramolecular Chemistry
- Photochemistry
Background:
- Diarylethene molecules are photoswitchable, changing between open and closed forms upon light irradiation.
- Self-assembly of molecules on surfaces is crucial for creating functional nanomaterials.
- Understanding solid/liquid interfaces is key to controlling molecular behavior.
Purpose of the Study:
- To investigate the in situ reversible interconversion of diarylethene photoswitch isomers at the solid/liquid interface.
- To analyze the formation and accumulation of by-product isomers under UV irradiation.
- To develop a thermodynamic model for surface-induced isomeric selection.
Main Methods:
- Submolecularly resolved scanning tunneling microscopy (STM) at the solid/liquid interface.
- In situ monitoring of molecular transformations under UV light.
- Application of a thermodynamic model for quantitative analysis.
Main Results:
- Observed reversible interconversion between open and closed diarylethene isomers on a graphite surface.
- Identified irreversible formation of a by-product isomer upon prolonged UV irradiation.
- Demonstrated preferential physisorption of the by-product isomer, leading to surface accumulation.
- Provided a quantitative description of surface-induced selection of one isomeric form using a thermodynamic model.
Conclusions:
- The study provides the first submolecularly resolved STM insights into diarylethene photoswitch behavior at a solid/liquid interface.
- Surface interactions and thermodynamic principles govern the isomeric selection and stability of photoswitch molecules.
- The findings offer a foundation for designing light-responsive molecular systems with controlled isomeric states.
