Chromic and Fluorescence-Responsive Metal-Organic Frameworks Afforded by N-Amination Modification

Area of Science:

• Materials Science
• Chemistry

Background:

• Sensory materials detecting gases and vapors are crucial for various applications.
• Metal-organic frameworks (MOFs) offer tunable properties for sensing.

Purpose of the Study:

• To report the postsynthetic preparation of novel sensory MOFs with multiple responsive properties.
• To explore their chromic and fluorescence responses to specific analytes.

Main Methods:

• Postsynthetic N-amination of a Zr(IV) MOF to create N-aminobipyridinium groups.
• Grafting polycyclic aromatic hydrocarbons onto the N-amino groups.
• Characterization of chromic and fluorescence responses.

Main Results:

• The modified MOF (Zr-bpy-A) exhibits chromic behavior towards ammonia, amines, and formaldehyde.
• Grafting aromatic hydrocarbons induces variable-color fluorescence and high-contrast responses.
• A fluorescence response to HCl was also observed due to unquaternized bipyridyl groups.

Conclusions:

• The novel MOFs demonstrate versatile sensing capabilities for multiple analytes.
• These materials show promise for applications in chemical sensing, switching, and anti-fake marking.
• Demonstrated utility via test paper and writing ink applications.