Solution-Mediated Photoreversible Switch Between 2D and 3D Hydrogen-Bonded Organic Frameworks

Area of Science:

• Materials Science
• Supramolecular Chemistry
• Crystallography

Background:

• Photoresponsive crystalline porous materials offer tunable properties through light-induced structural changes.
• Achieving reversible topological transformations in these materials remains a significant challenge.

Purpose of the Study:

• To develop a novel photoresponsive material with light-driven reversible structural transformation.
• To explore the potential of this material for applications like anti-counterfeiting.

Main Methods:

• Self-assembly of a 3D hydrogen-bonded organic framework (HOF) using photochromic diarylethene (DAE) and tetrakis(4-amidiniumphenyl)methane (TAM).
• Utilizing charge-assisted hydrogen bonds for framework construction.
• Employing alternating UV and visible light irradiation to control DAE photoisomerization and induce reversible 3D-2D structural switching via solution-mediated processes.
• Incorporating lanthanide complexes to investigate photochromic fluorescence resonance energy transfer (FRET).

Main Results:

• A 3D hydrogen-bonded organic framework (HOF-OF) was successfully synthesized.
• Reversible switching between 3D and 2D HOF structures was achieved through light-controlled DAE photoisomerization and solution-mediated recrystallization.
• The material demonstrated a reversible luminescence on/off switch via DAE photoisomerization-controlled FRET between lanthanide and DAE moieties.

Conclusions:

• The developed HOF-OF exhibits light-driven reversible structural transformation between 3D and 2D states.
• The material shows potential for intelligent anti-counterfeiting applications due to its reversible luminescence switching.