Enhanced emission by stacking of crown ether side chains in a 2D covalent organic framework
Liu Yuan1,2, Jun Zhu1, Shaofei Wu1
1Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore, Singapore. chmcc@nus.edu.sg.
Chemical Communications (Cambridge, England)
|January 6, 2022
Summary
This study enhances fluorescence in 2D hydrazone-linking covalent organic frameworks (COFs). Bulky side chains restrict rotation, reducing energy loss and boosting emission 20-fold.
Area of Science:
- Materials Science
- Organic Chemistry
- Photophysics
Background:
- Hydrazone compounds show potential for solid-state emission.
- Most hydrazone-linked covalent organic frameworks (COFs) exhibit poor luminescence.
Purpose of the Study:
- To enhance fluorescence in a 2D hydrazone-linking COF.
- To investigate the effect of side chain engineering on luminescence properties.
Main Methods:
- Synthesized a 2D hydrazone-linking COF with crown ether side chains.
- Characterized the material's structural and photophysical properties.
- Analyzed the impact of side chain stacking on intramolecular rotation and emission.
Main Results:
- Achieved a 20-fold improvement in fluorescence emission.
- Demonstrated that bulky, semi-rigid side chains restrict backbone rotation.
- Reduced non-radiative decay pathways through restricted intramolecular rotation.
Conclusions:
- Side chain engineering is an effective strategy to enhance luminescence in hydrazone-linking COFs.
- Restricting intramolecular rotation via bulky side chains suppresses thermal dissipation.
- Developed a highly emissive 2D COF for potential optoelectronic applications.
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