Efficient blue and bluish-green iridium phosphors: Fine-tuning emissions of FIrpic by halogen substitution on pyridine-containing ligands
作者:Cong Fan、Liping Zhu、Bei Jiang、Cheng Zhong、Dongge Ma、Jingui Qin、Chuluo Yang
DOI:10.1016/j.orgel.2013.09.026
日期:2013.12
Three new iridium compounds, 4-F-FIrpic, 4-Cl-FIrpic and 4-Br-FIrpic, were designed and synthesized by introducing the F, Cl and Br atoms to the 4-position of pyridine ring in the frame of sky-blue emitter, FIrpic. Adding F atom stabilizes the HOMO level of FIrpic but keeps the LUMO level of FIrpic almost unchanged, which consequently broadens the HOMO-LUMO gap of FIrpic and finely tunes the emission to 465 nm of 4-F-FIrpic from 470 nm of FIrpic. In contrast, introducing of Cl and Br atoms simultaneously lowers the HOMO and LUMO levels of FIrpic, which brings about the squeeze of HOMO-LUMO gap in FIrpic and makes the emissions of 4-Cl-FIrpic and 4-Br-FIrpic red-shift to 475 and 479 nm, respectively. The phosphorescent organic light-emitting devices using the three iridium compounds as dopants were fabricated with the following configuration: ITO/MoO3/TAPC/TCTA: dopants/Tm/LiF/Al. The device based on 4-F-FIrpic showed a blue emission with the Commission Internationale de L'Eclairage coordinate of (0.15, 0.28), and revealed rather high efficiencies, with maximum current efficiency of 29 cd A(-1), power efficiency of 29 lm W-1 and external quantum efficiency of 14.6%. (C) 2013 Elsevier B.V. All rights reserved.
More efficient spin–orbit coupling: adjusting the ligand field strength to the second metal ion in asymmetric binuclear platinum(<scp>ii</scp>) configurations
作者:Zhaoran Hao、Kai Zhang、Kuan Chen、Pu Wang、Zhiyun Lu、Weiguo Zhu、Yu Liu
DOI:10.1039/d0dt00939c
日期:——
binuclear platinum(II) complexes (Pt-1 and Pt-3) bearing bridging ligands of 2-(2,4-difluorophenyl)-5-(pyridin-2-yl)pyridine and 2-(2,4-difluorophenyl)-4-(pyridin-2-yl)pyridine as well as their corresponding mononuclear counterparts (Pt-2, Pt-4, and Pt-5) were synthesized and characterized. Different chelating constructions of the second platinum(II) ions and the bridging ligands in Pt-1 and Pt-3 gave
Regioselective synthesis of 4-functionalized pyridines
作者:Chao Li、Zixi Yan、Bingding Wang、Jiaxing Li、Weiping Lyu、Zhixing Wang、Ning Jiao、Song Song
DOI:10.1016/j.chempr.2023.10.015
日期:2024.2
pyridine derivatives. However, this reaction is still unexplored because of the inert property of pyridine and the challenge in the regioselectivity. Herein, we report an aromatic C-4 selective functionalization of pyridine -oxides with DABCO and TfO as the regioselective controller. The commercial availability of reagents, good tolerance of functional groups, and simple operability made it a promising