Visible-Light-Driven Fluorescence Turn-on Photoswitches With Near Quantitative Photocyclization Yield

Area of Science:

• Materials Science
• Organic Chemistry
• Photochemistry

Background:

• Photoswitchable fluorescent materials are crucial for information encryption and anti-counterfeiting.
• UV light triggers isomerization but causes photobleaching and poor fatigue resistance.
• Visible-light-driven photoswitches are needed but face challenges in achieving high cyclization yields.

Purpose of the Study:

• To develop visible-light-driven fluorescent photoswitches with high performance.
• To investigate dimethoxyphenyl functionalized diarylethene isomers for fluorescence switching.
• To explore applications in advanced security and data storage.

Main Methods:

• Synthesis of dimethoxyphenyl functionalized diarylethene isomers (o-DMPB, p-DMPB, m-DMPB).
• Irradiation with 405 nm visible light to induce isomerization and fluorescence changes.
• Evaluation of conversion yields, thermal stability, photostability, and fatigue resistance.

Main Results:

• o-DMPB and p-DMPB isomers showed near-quantitative conversion yields (up to 94%) under visible light.
• The electron-donating character of dimethoxyphenyl groups facilitated high visible-light-driven conversion.
• m-DMPB isomer exhibited a lower ring-closing yield (22%) under visible light.
• All synthesized photoswitches demonstrated good thermal stability, photostability, and fatigue resistance.

Conclusions:

• Visible-light-driven fluorescent photoswitches based on dimethoxyphenyl functionalized diarylethenes were successfully developed.
• High conversion yields and excellent stability were achieved, addressing limitations of UV-triggered systems.
• o-DMPB shows significant potential for anti-counterfeiting, information encryption, and photorewritable patterns.