Flexible interlocked porous frameworks allow quantitative photoisomerization in a crystalline solid

Area of Science:

• Materials Science
• Chemistry
• Crystallography

Background:

• Photochromic molecules are key for stimuli-responsive materials, but solid-state applications face challenges due to limited structural flexibility.
• Achieving quantitative photochemical conversions in solids is difficult because of stress and strain accumulation during reactions.

Purpose of the Study:

• To develop photoresponsive crystalline materials with quantitative and reversible photochemical reactions.
• To overcome the limitations of framework rigidity in solid-state photochromic systems.

Main Methods:

• Designing crystalline porous frameworks with twofold interpenetration using a diarylethene-based ligand.
• Introducing structural flexibility into the porous framework to accommodate photochemical events.
• Utilizing single-crystal-to-single-crystal transformations for photochemical electrocyclization.

Main Results:

• Achieved quantitative and reversible photochemical reactions upon UV and visible light irradiation.
• Demonstrated highly efficient photochemical electrocyclization in a single-crystal-to-single-crystal manner.
• Showcased reversible modulation of CO2 sorption by light irradiation in the flexible framework.

Conclusions:

• Structural flexibility is crucial for enabling quantitative photoisomerization in crystalline porous materials.
• The developed twofold interpenetrated framework offers a viable strategy for advanced solid-state photoresponsive materials.
• This work paves the way for new applications in smart materials and gas storage.