Universal Routes to Conjugated Organoboranes and Organoborane Polymers

• Applicant: Professor Dr. Holger Helten
• Subject Area: Inorganic Molecular Chemistry - Synthesis and Characterisation
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 449008594

The incorporation of the vacant p orbital of trivalent, three-coordinate boron into extended conjugated organic systems often leads to materials with intriguing features such as strong luminescence and/or semiconducting behavior. This has enabled applications in organic (opto)electronic devices such as organic field-effect transistors (OFETs), light-emitting diodes (OLEDs), and photovoltaic cells (OPVs), as well as uses as selective sensory materials for certain anions, amines, or other physiologically relevant species. For many applications, polymers bear several advantages over molecular materials, for instance, extended conjugation lengths and improved solution processing properties. Chromophores with sensory ability commonly benefit from pronounced signal amplification when embedded into a macromolecular framework. Nevertheless, the development of conjugated organoboron polymers is still in its infancy and commercial use of these versatile materials is a distant prospect. The reason for this appears to be the lack of generally applicable, efficient synthetic routes to such species. Current syntheses are either poorly efficient and/or produce highly toxic and environmentally harmful by-products. This project aims at the development of highly efficient and sustainable methods for the synthesis of conjugated organoboranes and organoborane polymers to the point where they become generally applicable. Electrophile-initiated routes such as organocatalytic Si/B exchange condensation processes will be explored, which are likely to proceed via highly reactive borocation intermediates. This will provide access to a variety of novel organoborane-based materials with specifically tailored properties and functions.

• DFG Programme: Research Grants