Merging Pyrrole with Boron into Versatile Di(2-pyrryl)borane Building Blocks: π-Extension, Polymerization, and
Daniel Göbel1, Andreas Helbig1, Alexandra Friedrich1
1Julius-Maximilians-Universität Würzburg, Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Am Hubland, 97074, Würzburg, Germany.
Angewandte Chemie (International Ed. in English)
|November 17, 2025
Summary
Researchers developed a new synthesis for pyrrole-based conjugated boranes, enabling their use in organic electronics. These novel materials exhibit enhanced optical properties like intense fluorescence and aggregation-induced emission, expanding their application potential.
Area of Science:
- Organic Chemistry
- Materials Science
- Photophysics
Background:
- Conjugated di(hetaryl)boranes are key in organic optoelectronics.
- Pyrrole-boron combinations are known in BODIPY dyes but tricoordinate boron-pyrrole synergy is underexplored.
- Synthetic challenges limited pyrrole-boron compound development.
Purpose of the Study:
- To develop a high-yield synthesis for di(2-pyrryl)boranes.
- To explore the application of these new boranes as building blocks.
- To investigate the photophysical properties of these novel conjugated boranes.
Main Methods:
- Gram-scale synthesis of di(2-pyrryl)boranes, including NH derivatives.
- Application as building blocks for extended conjugated systems, polymers, and metal complexes.
- Crystallography, UV-Vis absorption, fluorescence spectroscopy, and time-dependent DFT calculations.
Main Results:
- Successful high-yield, gram-scale synthesis of two di(2-pyrryl)boranes.
- Demonstrated versatility in creating π-extended tetrahetarene boranes, polymers, and a Zr(IV) complex.
- New boranes exhibit bathochromically shifted absorption, intense fluorescence, solvatochromism, AIEE, and solid-state emission, attributed to TICT states.
Conclusions:
- Di(2-pyrryl)boranes are valuable building blocks for advanced optoelectronic materials.
- The developed synthetic route overcomes previous limitations.
- These compounds offer tunable photophysical properties for diverse applications.
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