城戸・笹部研究室M2 増田雄貴君（Yuki Masuda）と笹部久宏准教授のシアノピリジン含有遅延蛍光発光材料群に関する「High Efficiency Sky Blue-to-Green Fluorescent Emitters based on 3-Pyridinecarbonitrile Derivatives」と題する論文が Frontiers in Chemistry (IF: 4.155) に受理されました！
Title: High Efficiency Sky Blue-to-Green Fluorescent Emitters based on 3-Pyridinecarbonitrile Derivatives
By Yuki Masuda, Hisahiro Sasabe*, Hiroki Arai, Natsuki Onuma, and Junji Kido*, Front. Chem. 2019, accepted.
Abstract: The pyridinecarbonitrile derivative is well known as an acceptor unit in fluorescent materials. However, the its use in thermally activated fluorescent emitters (TADF) is significantly limited compared with the benzenecarbonitile counterparts. Very recently, we have developed a series of 4-pyridinecarbonitrile, so-called isonicotinonitrile derivatives, as a highly efficient sky blue-to-green TADF emitters realizing low-drive-voltage OLEDs. In this work, we contributed new design and development for three 3-pyridinecarbonitrile-based TADF emitters named 2AcNN, 2PXZNN, and 5PXZNN. Among these emitters, a sky-blue emitter, 2AcNN showed a maximum external quantum efficiency (EQEmax) of 12% with CIE (0.19, 0.36). While green emitters, 5PXZNN and 2PXZNN realized highly efficient TADF OLEDs with an EQEmax of 16–20%. Introduction of electron-donor moiety into the 2-position of 3-pyridinecarbonitrile contributes a larger overlapping of frontier molecular orbitals (FMOs) and stronger intramolecular charge-transfer (ICT) interaction generating efficient TADF emitters.