九州大学博士研究員の劉冠廷博士と笹部久宏准教授の多重共鳴型熱活性化遅延蛍光材料群の簡便合成に関する「Facile synthesis of multi-resonance ultra-pure-green TADF emitters based on bridged diarylamine derivatives for efficient OLEDs with narrow emission」と題する論文が英国化学会（Royal Society of Chemistry）の Top10% 高被引用論文に選出されました！本研究は山形大学片桐研究室との共同研究です。

Title: Facile synthesis of multi-resonance ultra-pure-green TADF emitters based on bridged diarylamine derivatives for efficient OLEDs with narrow emission
By Guanting Liu, Hisahiro Sasabe*, Kengo Kumada, Amane Matsunaga, Hiroshi Katagiri and Junji Kido*, J. Mater. Chem. C 2021, 9, 8308.

Abstract: High color-purity emission with a minimum full width at half maximum (FWHM) is critical for high-resolution displays. Despite the increasing demand for narrow-band emission materials with multi-resonance-induced thermally activated delayed fluorescence (MR-TADF), their development remains challenging from the viewpoint of synthetic chemistry. In this study, we developed a novel one-pot borylation method that does not require the use of hazardous tert-BuLi, and for which the starting materials are not limited to aromatic fluorides and carbazole-based materials. We achieved this by making simple modifications to a boron-nitrogen skeleton. By inserting carbon and oxygen into the skeleton, we created two types of highly efficient green-emitting MR-TADF emitters, namely DMAc-BN and PXZ-BN. This design enabled the suppression of aggregation-induced quenching, which was one of the major challenges faced by MR-TADF emitters developed in the past. OLEDs using our DMAc-BN and PXZ-BN emitters exhibited external quantum efficiencies of 20.3% and 23.3%, respectively, with FWHM values of 49 and 47 nm, respectively. PXZ-BN exhibited pure green emission with CIE coordinates of (0.22, 0.67).

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