Light-emitting properties of donor–acceptor and donor–acceptor–donor dyes in solution, solid, and aggregated states: structure–property relationship of emission behavior
and near-IR emission. In the benzothiadiazole-based dyes, when the phenyl groups in the donor moieties were replaced with methyl groups, the fluorescence quantum yield decreased, indicating that the triphenylamine donor moiety is suitable for emission in the aggregated state. The nonplanar structure of triphenylamine disrupts an ordered packing and produces a less-ordered spherical aggregate, leading
interaction and expanding the absorption spectrum. Typically, when a thiophene ring is fused on the Qx unit in DQxD, a near-infrared dye is realized in simple chromophore DTQD, which displays the maximum absorption wavelength at 716 nm with the threshold over 900 nm. This is probably due to the enhanced charge density on the acceptor moiety and better orbital overlap, as revealed by theoretical calculation
一系列带有各种吸电子基团的对称供体-受体-供体(D–A–D)发色团,例如喹喔啉(Qx),苯并[ g ]喹喔啉(BQ),吩嗪(Pz),苯并[ b ]吩嗪(BP),噻吩并[3,4- b ]吡嗪(TP)和噻吩并[3,4- b ]喹喔啉(TQ),已经过设计和合成。由于吡嗪环中两个亚胺氮的吸电子特性和两个三苯胺中另外两个胺氮的给电子性,可以发现所有发色团的分子内电荷转移(ICT)相互作用。苯环或噻吩环在吡嗪受体单元上融合后,ICT相互作用会增强,导致ICT的红移。此外,噻吩环在扩大ICT相互作用和扩大吸收光谱方面优于苯环。通常,将噻吩环稠合在DQxD的Qx单元上时,可以在简单的生色团DTQD中实现近红外染料,在716 nm处显示最大吸收波长,阈值超过900 nm。如理论计算所揭示的,这可能是由于受体部分上电荷密度的提高和更好的轨道重叠。这些结果表明,在垂直于D–A–D主链的方向上扩展吡嗪受体的共轭可显着改善ICT相互作用。
Red‐Light‐Emitting System Based on Aggregation of Donor–Acceptor Derivatives in Polar Aqueous Media
Glowing together: An efficient red‐light‐emitting system has been created in polar water media based on the aggregation of donor–acceptor molecules. In the THF/water mixture, the emission was quenched when a small volume of water was used, whereas it was recovered and enhanced upon aggregate formation with a large water volume.
A multifunctional luminescent material based on quinoxaline and triphenylamine groups: polymorphism, mechanochromic luminescence, and applications in high-efficiency fluorescent OLEDs
作者:Zhengjie Wen、Tingting Yang、Di Zhang、Zhengqin Wang、Shufan Dong、Huixia Xu、Yanqin Miao、Bo Zhao、Hua Wang
DOI:10.1039/d1tc04285h
日期:2022.3.3
Multifunctionalmaterials with aggregation-induced emission (AIE), mechanochromic luminescence and electroluminescent (EL) features in organic light-emitting devices (OLEDs) are demonstrated to be promising applications in many fields. Herein, we present our work on TQT, using quinoxaline as an acceptor and triphenylamine (TPA) as a donor with a D–A–D symmetrical structure. TQT exhibits high-contrast