Construction of boronate ester based single-layered covalent organic frameworks
Lei Yu1, Zhi-Bo Li2, Dong Wang1
1Key Laboratory of Molecular Nanostructure and Nanotechnology and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences (CAS), Beijing 100190, P. R. China. wangd@iccas.ac.cn and Graduate University of CAS, Beijing, P. R. China.
Chemical Communications (Cambridge, England)
|November 9, 2016
Summary
Researchers created single-layered covalent organic frameworks (sCOFs) on graphite. The self-sorting process allows tuning of framework structures for dynamic covalent chemistry applications.
Area of Science:
- Materials Science
- Supramolecular Chemistry
- Surface Chemistry
Background:
- Covalent organic frameworks (COFs) are crystalline porous polymers with tunable properties.
- Fabrication of COFs, particularly single-layered COFs (sCOFs), often requires controlled conditions.
- On-surface synthesis offers a platform for creating ordered nanostructures.
Purpose of the Study:
- To develop a method for fabricating boronate ester based single-layered covalent organic frameworks (sCOFs) on graphite.
- To investigate the self-sorting behavior of precursors during on-surface dynamic covalent chemistry.
- To control the phase separation and resulting nanostructures by adjusting precursor ratios.
Main Methods:
- On-surface synthesis of sCOFs on a graphite substrate under ambient atmosphere.
- Utilizing boronate ester linkages for framework formation.
- Systematic variation of the molecular ratio between two precursors to study phase separation.
- Characterization of the resulting nanostructures and their phase behavior.
Main Results:
- Successful fabrication of boronate ester based sCOFs with large domain areas and uniform pore sizes on graphite.
- Demonstration of tunable phase separation, yielding boronate ester based sCOFs, boroxine based sCOFs, and other nanostructures.
- Observation of a self-sorting process driven by dynamic covalent chemistry, controlled by precursor molecular ratios.
- Capability to tune the formation of different nanostructures through precursor stoichiometry.
Conclusions:
- On-surface dynamic covalent chemistry provides a versatile route for fabricating tailored single-layered covalent organic frameworks.
- The molecular ratio of precursors is a critical parameter for controlling self-sorting and phase separation in on-surface COF synthesis.
- This work enables the rational design and synthesis of specific nanostructures for potential applications in surface chemistry and materials science.
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