Multicolor Fluorescence Writing Based on Host-Guest Interactions and Force-Induced Fluorescence-Color Memory

Area of Science:

• Materials Science
• Organic Chemistry
• Solid-State Physics

Background:

• Developing novel methods for multicolor fluorescence writing is crucial for advanced optical materials.
• Pentiptycene derivatives are known for their unique photophysical properties.
• Mechanofluorochromism, the change in fluorescence upon mechanical stress, offers potential for responsive materials.

Purpose of the Study:

• To report a new strategy for multicolor fluorescence writing on thin solid films using mechanical forces.
• To demonstrate the application of a green-fluorescent pentiptycene derivative for creating variable-colored fluorescent exciplexes.
• To investigate the mechanofluorochromic properties and memory effects in solid-state materials.

Main Methods:

• Utilizing a green-fluorescent pentiptycene derivative capable of forming variably colored fluorescent exciplexes.
• Applying mechanical forces (grinding, shearing) to induce crystalline-to-amorphous phase transitions.
• Characterizing fluorescence changes, including color shifts and quenching, upon interaction with guest molecules (anilines, benzoquinone) and mechanical stress.

Main Results:

• Demonstrated multicolor fluorescence writing (yellow to red, black) on thin solid films using mechanical forces.
• Observed mechanofluorochromism and color memory in pristine and guest-adsorbed pentiptycene solids.
• Created fluorescence drawings with five or more colors on glass and paper, which were erasable with air and dichloromethane fumes.

Conclusions:

• Mechanical forces can induce significant changes in fluorescence color and properties in solid films.
• The reported pentiptycene derivative exhibits tunable mechanofluorochromism, enabling multicolor writing and erasable optical data storage.
• This strategy offers a novel pathway for developing advanced responsive materials and fluorescence-based writing technologies.