Research Initiation Award - Beyond Traditional Dynamic Linkages: Reinforcing Chemical Stability and Complexity in Next-generation Covalent Organic Frameworks

Research Initiation Awards provide support for junior and mid-career faculty at Historically Black Colleges and Universities who are building new research programs or redirecting and rebuilding existing research programs. It is expected that the award helps to further the faculty member's research capability and effectiveness, improve research and teaching at the home institution, and involves undergraduate students in research experiences.

The award to Clark Atlanta University has potential to broaden impacts in several areas. The proposed study intends to develop and characterize new crystalline porous materials that are important in solid state chemistry. The research will provide a multidisciplinary platform for undergraduate students to explore cutting-edge materials science and collaborate with researchers at national laboratories.

The proposed work intends to develop next-generation covalent organic frameworks (COFs) that obviate the common reliance upon traditional dynamic linkages such as boron and nitrogen-based linkages. COFs are 2D and 3D crystalline porous materials entirely composed of lightweight organic elements. Due to their unique structural features such as high crystallinity, ultralow density, large surface areas, versatile synthesis, and predesignable structures, COFs have been at the forefront of porous material chemistry in the past decade and garnered enormous attention in widespread areas.

However, the inherent chemical instability and inadequate structural complexity are hindering the fullest exploration of COFs. To this end, the work aims to develop the next-generation COFs beyond traditional dynamic linkages by using reactions with limited reversibility, i.e., nucleophilic aromatic substitution and aldol condensation. A series of as-yet-undiscovered aryl ether-linked COFs and unsubstituted sp2 carbon-conjugated COFs will be produced via conventional solvothermal and mechanochemical synthesis.

Besides experimental synthesis, the work will unveil the underlying mechanism of new COF formation through multipronged approaches, including exchange reactions in model analogs, computational simulation, and kinetic studies coupled with in situ characterizations. Lastly, the research will advance the use of next-generation COFs in heterogeneous catalysis and elucidate hitherto poorly understood structure-catalysis correlations, which will guide the synthesis and enhancement of COFs for catalysis and beyond.

This project challenges the convention of COF chemistry and will produce a series of robust well-ordered porous materials with peculiar properties, thus opening numerous possibilities in widespread applications even in harsh operating environments, which are off-limits of current COF systems.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.