Triptycene-Based Luminescent Materials in Homoconjugated Charge-Transfer Systems: Synthesis, Electronic Structures, AIE Activity, and Highly Tunable Emissions

We
have developed a new family of luminescent materials featuring
through-space charge transfer from electron donors to acceptors that
are electronically separated by triptycene. Most of these molecules
are highly fluorescent, and modulation of their emissions was achieved
by tuning the electron-accepting strength in a range from the weak
triptycene acceptor over triarylborane (BMes) to strongly accepting
naphthalimide (Npa) moieties. Pz–Pz shows an aggregation-induced
emission in aggregates and in the solid state coupled with a highly
red-shifted broad emission (ca. 160 nm) of the excimer,
indicating that phenothiazine (Pz) also plays a vital role in the
emission responses as an electron donor. This work may help develop
new approaches to photophysical mechanism based on the rigid, homoconjugated,
and structurally unusual 3D triptycene scaffold.

本团队研制出一种新型发光材料系列，该系列材料通过三联苯结构实现电子供体至受体的跨空间电荷转移。其中大部分分子均展现出极高的荧光特性，其发射特性通过调节电子接受强度得以调控，范围从弱三联苯受体（BMes）至强接受体萘酰亚胺（Npa）。Pz–Pz在聚集体及固态状态下表现出聚集诱导发射，并伴随有激发态分子（ca. 160 nm）的显著红移宽发射，这表明苯并噻二唑（Pz）在发射响应中亦扮演着至关重要的角色。本研究有望为基于刚性、同共轭且结构独特的3D三联苯骨架的光物理机制研究开辟新的途径。