Bathochromic effect of trifluoromethyl-substituted 2-naphthalen-1-yl-pyridine ligands in color tuning of iridium complexes
作者:Cheng-Hsien Yang、Chun-Hung Chen、I-Wen Sun
DOI:10.1016/j.poly.2006.02.003
日期:2006.8
A series of trifluoromethyl-substituted 2-naphthalen-1-yl-pyridine ligands and the corresponding iridium complexes have been synthesized and characterized by spectroscopic methods as well as X-ray crystallography. Upon excitation at 470 nm, (4-fnapy)(2)Ir(acac) and (5-fnapY)(2)Ir(acac) emit red photoluminescence at 617 and 613 nm, respectively. Compared to (naPY)(2)Ir(acac), the introduction of trifluoromethyl substituents resulted in a significant bathochromic shift caused by a lowering of the LUMO levels. We propose that the bathochromic effect of the nitrogen atom on the pyrimidine ring should be much weaker than expected from the work of Chi et al. [Inorg. Chem. 44 (2005) 1344]. For a blend with 6 wt% of (5-fnapy)(2)Ir(acac), a brightness of 8600 cd m(-2) at 10.5 V is reached with Commission Internationale de L'Eclairage chromaticity coordinates of x = 0.65 and y = 0.35. (c) 2006 Elsevier Ltd. All rights reserved.
Electronically Divergent Triscyclometalated Iridium(III) 2-(1-naphthyl)pyridine Complexes and Their Application in Three-Component Methoxytrifluoromethylation of Styrene
properties of triscyclometalated homoleptic iridium(III) complexes based on 2-(1-naphthyl)pyridine (npy) ligands is presented. A systematic investigation of ligand substitution patterns showed an influence on the lifetime of the excited state, with slight changes in the absorption and emission spectral features. Specifically, the emission lifetime of a complex of an npy ligand substituted with a strongly
系统研究了基于 2-(1-萘基) 吡啶 (npy) 配体的三环金属化均质铱 (III) 配合物的光物理和电化学性质。配体取代模式的系统研究表明对激发态寿命的影响,吸收和发射光谱特征略有变化。具体而言,被强吸电子三氟甲基取代的 npy 配体的复合物的发射寿命比具有电子非扰动配体的相应复合物的发射寿命长(3.7 μs vs 1.5 μs)。与未取代的 npy (1.4–3.0 μs) 相比,具有正交构型的电子互补配体和配合物显示出略短的激发态寿命。所有配合物都显示出可逆或准可逆的氧化还原偶过程,三氟甲基化配体的配合物显示出最高的基态氧化电位 E1/2 ox [Ir(III)/Ir(IV) = 0.95 V vs. CH2Cl2 中的 SCE]。该研究表明,这些配合物可用作有效的光氧化还原催化剂,正如它们在区域选择性甲氧基三氟甲基化反应中的应用所证明的那样,与原型光氧化还原催化剂三 [2-苯基吡啶基]铱