Diaryltriazolium Photoswitch: Reaching a Millisecond Cycloreversion with High Stability and NIR Absorption

Area of Science:

• Organic Chemistry
• Materials Science
• Photochemistry

Background:

• Diarylethene photoswitches offer exceptional thermal stability, limiting their use in applications needing rapid thermal reversibility.
• Existing photoswitches often lack desirable properties like near-infrared absorption or water solubility for biological applications.

Purpose of the Study:

• To develop a novel photoswitch with rapid thermal cycloreversion and near-infrared absorption.
• To create a photoswitch scaffold accessible via modular and efficient synthetic routes.
• To enhance photoswitch properties for potential biological applications.

Main Methods:

• Synthesis of the diaryltriazolium (DAT+) scaffold using click chemistry and alkylation.
• Characterization of the photoswitch's thermal and photochemical properties.
• Evaluation of fatigue resistance and water solubility.

Main Results:

• The diaryltriazolium (DAT+) photoswitch exhibits thermal cycloreversion within milliseconds.
• The closed form of the DAT+ photoswitch absorbs light above 900 nm in the near-infrared region.
• The photoswitch demonstrates excellent fatigue resistance and increased water solubility due to its charge.

Conclusions:

• The developed DAT+ photoswitch overcomes the limitations of traditional diarylethenes by offering rapid thermal reversibility.
• Its near-infrared absorption and water solubility make it a promising candidate for biological applications.
• The modular synthesis provides a versatile platform for further photoswitch development.