Carborane photochromism: a fatigue resistant carborane switch

Area of Science:

• Materials Science
• Photochemistry
• Supramolecular Chemistry

Background:

• Dithienylethenes are photochromic compounds known for their reversible color changes upon light irradiation.
• Carborane clusters offer unique structural and electronic properties, potentially enhancing material performance.
• Developing photochromic materials with high fatigue resistance and distinct switching behaviors is crucial for advanced applications.

Purpose of the Study:

• To synthesize and characterize a novel dithienylethene molecule incorporating carborane clusters.
• To investigate the photochromic properties, including color change and fatigue resistance, under alternating UV and visible light irradiation.
• To explore the switching behavior of fluorescence in both solid and solution states.

Main Methods:

• Synthesis of a dithienylethene derivative functionalized with carborane clusters.
• Photoirradiation experiments using alternating ultraviolet (UV) and visible light.
• Spectroscopic analysis (UV-Vis absorption, fluorescence spectroscopy) to monitor color and fluorescence changes.
• Fatigue resistance testing through repeated irradiation cycles.

Main Results:

• The synthesized dithienylethene-carborane molecule demonstrated significant fatigue resistance.
• High-contrast visual color changes were observed upon alternating UV and visible light irradiation.
• The fluorescence of the material could be reversibly switched on and off in the solid state.
• Switching of fluorescence was not observed in the solution state.

Conclusions:

• The integration of carborane clusters into dithienylethene molecules leads to robust photochromic materials.
• The observed solid-state switchable fluorescence and high fatigue resistance are promising for applications in optical memory and sensors.
• The distinct behavior in solid versus solution states highlights the importance of molecular environment in photochromic switching.