Emissive Single-Crystalline Boroxine-Linked Colloidal Covalent Organic Frameworks
Austin M Evans, Ioannina Castano, Alexandra Brumberg
1Center for Nanoscale Materials , Argonne National Laboratory , Lemont , Illinois 60439 , United States.
Journal of the American Chemical Society
|November 20, 2019
Summary
Researchers synthesized single-crystalline two-dimensional (2D) covalent organic frameworks (COFs) using a colloidal method. These novel 2D COFs exhibit enhanced light emission due to chromophore interactions between sheets.
Area of Science:
- Polymer Chemistry
- Materials Science
- Nanotechnology
Background:
- Synthesizing periodic two-dimensional (2D) polymers and characterizing their optoelectronic properties are key challenges.
- Previous work demonstrated single-crystal 2D covalent organic frameworks (COFs) via colloidal suspensions.
Purpose of the Study:
- Expand colloidal synthesis to new 2D COFs using dehydrative trimerization.
- Investigate the optoelectronic properties of these novel colloidal 2D COFs.
- Establish colloidal COFs as a platform for precise functional material assembly.
Main Methods:
- Dehydrative trimerization of polyboronic acids to form boroxine-linked colloids.
- Colloidal stabilization of 2D and 3D COFs.
- Structural analysis using synchrotron X-ray diffraction and TEM.
- Optoelectronic characterization via solution fluorescence and excitation-emission matrix spectroscopy.
Main Results:
- Successfully synthesized single-crystalline boroxine-linked colloidal 2D and 3D COFs.
- Demonstrated enhanced fluorescence emission from COF crystallites compared to monomers.
- Attributed enhanced emission to through-space chromophore communication between COF sheets.
Conclusions:
- Colloidal synthesis provides a viable route to single-crystalline 2D COFs.
- Colloidal COFs exhibit unique, enhanced optoelectronic properties.
- These findings pave the way for designing advanced materials with tunable properties.
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