Research Projects

Tricoordinated organoboron compounds, characterized by sp²-hybridized boron atoms bearing vacant p-orbitals, have gained prominence in organic materials chemistry due to their strong electron-deficient nature and remarkable optoelectronic tunability. These boron centers enable precise modulation of electronic structures, making them ideal for crafting advanced functional materials. Nevertheless, the inherent air and moisture sensitivity of B-C bonds poses a significant challenge, necessitating the incorporation of structural stabilization strategies. Common approaches include the introduction of sterically demanding substituents, intramolecular π-donor units, or rigidified π-extended backbones such as boron-embedded polycyclic aromatic hydrocarbons. While early generations of boron-based emitters capitalized primarily on the intrinsic Lewis acidity and π-accepting characteristics of boron, their practical applicability in optoelectronic devices was hindered by broad emission profiles. These limitations arise from excessive structural reorganization and vibronic coupling in the excited states, which compromise color purity and efficiency. Transformative advancement came with the introduction of multi-resonance thermally activated delayed fluorescence (MR-TADF) materials, which incorporate alternating electron-deficient boron and electron-rich nitrogen or oxygen atoms within rigid π-conjugated backbones. This architecture leads to spatial separation of the HOMO and LUMO, enabling narrowband emission, high photoluminescence quantum yield (PLQY), and efficient reverse intersystem crossing (RISC). These features make MR-TADF compounds highly promising for next-generation OLED technologies, offering exceptional color purity, efficiency, and exciton utilization. Despite their immense potential, the structural diversity of MR-TADF materials remains limited. Most reported systems contain no more than two boron centers, primarily due to the lack of efficient tandem multi-borylation methodologies. This project aims to address this critical gap by developing innovative synthetic strategies capable of incorporating up to six boron atoms in a single framework. Additionally, seven-membered fused ring systems with modular donor variations will be explored to yield unsymmetrical, full-color emissive materials with enhanced rigidity. The use of heavy atoms will be investigated to boost RISC kinetics and photostability. Furthermore, double-boron cores will be embedded into π-conjugated polymer systems, enabling the fabrication of flexible, solution-processable, and narrowband emissive materials for scalable optoelectronic device applications.