城戸・笹部・千葉研究室D3 劉冠廷（Mr. Guanting Liu）さんと笹部久宏准教授の分子軌道制御による高効率・高色純度青・緑色多重共鳴型 TADF 型発光材料群に関する論文が Wiely の Chem. Eur. J (IF: 5.020) の Front Cover に選出されました。

本研究は、JSPS 科研費（基盤研究B, 20H02807）、NEDO 官民による若手研究者発掘支援事業 (21502128-0)、JST センター・オブ・イノベーションプログラム（COI) の助成を受けたものです。

Title: Nonbonding/Bonding Molecular Orbital Regulation of Nitrogen–Boron–Oxygen-embedded Blue/Green Multiresonant TADF Emitters with High Efficiency and Color Purity
By Guanting Liu, Hisahiro Sasabe*, Kengo Kumada, Hiroki Arai, and Junji Kido*, Chem. Eur. J, 2022, accepted.

Abstract: In this study, we synthesized and characterized multiresonant thermally activated delayed fluorescent (TADF) materials embedded with nitrogen–boron–oxygen (N–B–O), exhibiting color- tunability between blue and green, namely NBO, m-DiNBO, and p-DiNBO. The three emitter materials showed a high photoluminescence quantum yield (PLQY) and a state-of-the-art narrow full width at half maximum (FWHM) of 96%/25 nm, 87%/17 nm, and 99%/19 nm, respectively. For m-DiNBO and p-DiNBO, the emission color could be tuned from blue to green by regulating the nonbonding/bonding molecular orbital characters. Owing to the expanded planar molecular structure, m-DiNBO and p-DiNBO showed high horizontal dipole ratio (Q) of 88% and 92%, respectively. OLEDs were prepared with NBO, m-DiNBO, and p-DiNBO, exhibiting high external quantum efficiencies of 16.8%, 24.2%, and 21.6%, respectively. NBO and m-DiNBO exhibited pure-blue emission with CIE coordinates of (0.137, 0.142) and (0.126, 0.098), respectively. p-DiNBO showed pure-green emission with a CIE coordinate of (0.258, 0.665).

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