Heteropolyaromatic Covalent Organic Frameworks via One-Pot Multicomponent Reactions

Area of Science:

• Materials Science
• Organic Chemistry
• Supramolecular Chemistry

Background:

• Multicomponent reactions (MCRs) are versatile for synthesizing stable covalent organic frameworks (COFs).
• The Povarov reaction, a type of MCR, typically yields 2,4-phenylquinoline structures.
• Existing COFs often utilize imine linkages or specific isomer frameworks.

Purpose of the Study:

• To develop new structural isomers of COFs using multicomponent domino reactions.
• To synthesize unprecedented 2,3-phenylquinoline-based COFs.
• To investigate the impact of COF structure on gas sorption and separation properties.

Main Methods:

• A novel domino reaction involving epoxystyrene was employed to generate 2,3-phenylquinoline COFs.
• Scholl reactions were utilized to create extended aromatic linkages in some COFs.
• Synthesized COFs were characterized and their benzene/cyclohexane sorption and separation capabilities were evaluated.

Main Results:

• The study successfully synthesized novel 2,3-phenylquinoline COFs, representing structural isomers to previously known Povarov-derived COFs.
• Two thermally and chemically stable MCR-COFs and two heteropolyaromatic COFs were created.
• The positioning of pendant phenyl groups in the 2,3-phenylquinoline COFs significantly enhanced benzene over cyclohexane sorption and separation.

Conclusions:

• This work establishes a new pathway for constructing heteropolyaromatic COFs via MCRs.
• The developed 2,3-phenylquinoline COFs demonstrate promising performance for industrially relevant gas separations.
• Structural isomerism in COFs can be strategically exploited to tune material properties for specific applications.