Negatively Curved Heptagon-Containing Carbon π-Scaffolds

• Applicant: Professor Dr. Frank Würthner
• Subject Area: Organic Molecular Chemistry - Synthesis and Characterisation
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 441793214

Frameworks of sp2-hybridized carbon provide the basis for some of the most exciting molecules employed in organic materials. Accordingly, great interest surrounds the property manipulation of these structures, for which the inclusion of curvature has emerged as a key approach. Specifically, intense current efforts focus on the challenging synthesis and study of saddle-shaped, negatively curved carbon scaffolds which bear a structural relationship to elusive "Schwarzite" carbon allotropes. In this project, structures bearing seven-membered rings and negatively curved structures will be synthesized by a borylation-mediated vinylnaphthyl π-extension approach. The electronic properties of these compounds will be fully characterized and in particular their optical and solid-state properties will be thoroughly studied. Our target structures will focus on exceptional features attainable with negatively-curved PAHs, including persistent chirality, host-guest chemistry, and structural relationships to unseen carbon allotropes (e.g. Schwarzites). Furthermore, imide-substituted variations will be synthesized to exploit these unique warped scaffolds in n-type semiconductor applications (i.e. OPV and OFET devices). Lastly, our flexible synthesis will be used to construct large and unprecedented heptagon-containing carbon ribbons and nanobelts. We anticipate these results to greatly improve the understanding of negatively-curved PAHs and their use as functional organic materials as well as lay groundwork for the bottom-up synthesis of Schwarzites.

• DFG Programme: Research Grants