Abstract

Here, pyridopyrazino[2,3-b]indole based D–A assembly was designed and synthesized with modulation of various electron-donating/withdrawing substituent and characterized by various spectroscopic methods. Pyridopyrazino[2,3-b]indole derivatives show inbuilt intramolecular charge transfer (ICT) transition which established D–A building in molecules and induces blue-green emission in the solution state. However, solid-state emission characteristics explore the emission property of some molecules towards aggregation-induced emission (AIE) effect which leads to the formation of emissive nano aggregates in THF/H₂O mixture. Alteration of substituent on pyridopyrazino[2,3-b]indole segment effectively tune electrochemical property and resulting LUMO energy level was found to be comparable with reported electron transporting/n-type materials. These properties and good thermal stability indicate that molecules have the potential to be used as solid-state emitter and n-type materials in optoelectronic devices.

Graphical Abstract

Pyridopyrazino[2,3-b]indole derivatives possess inbuilt intramolecular charge-transfer to reveal donor-acceptor assembly within a molecule. Opto-electrochemical properties of it greatly influenced by an inductive and mesomeric effect caused by a substituted group. Strong solid-state emission owned by some molecule display AIE phenomenon. Additionally, LUMO value of derivatives exhibits electron-transporting ability hence could be used in organic electronics.

中文翻译：

---

吡啶并吡嗪并[2,3-b]吲哚衍生物的光电化学

摘要

在这里，基于吡啶并吡嗪并[2,3- b ]吲哚的D-A组装物的设计和合成是通过调制各种给电子/吸电子取代基并通过各种光谱学方法进行表征的。吡喃并吡嗪并[2,3- b ]吲哚衍生物显示出内在的分子内电荷转移（ICT）转变，该转变在分子中建立了D–A分子并在溶液状态下诱导了蓝绿色发射。然而，固态发射特性探索了一些分子对聚集诱导发射（AIE）效应的发射特性，这导致在THF / H ₂ O混合物中形成纳米发射聚集体。吡啶并吡嗪并[2,3- b]上取代基的变化吲哚链段有效地调节了电化学性质，发现产生的LUMO能级与报道的电子传输/ n型材料相当。这些特性和良好的热稳定性表明分子有潜力在光电器件中用作固态发射器和n型材料。

图形概要

吡喃并吡嗪并[2,3- b ]吲哚衍生物具有内在的分子内电荷转移能力，可揭示分子内的供体-受体组装。它的光电化学性质极大地受取代基引起的感应和介观效应的影响。一些分子拥有的强固态发射会显示AIE现象。另外，衍生物的LUMO值表现出电子传输能力，因此可以用于有机电子学中。