“振动诱导发光”(VIE)：二氢吩嗪类衍生物的双荧光发射机理

“Vibration induced emission”(VIE): N,N′-disubstituteddihydrodibenzo[a,c]phenazines dual fluorescent mechanism

N,N′-二取代-二氢二苯并[a,c]吩嗪类化合物一直以来被用作空穴传输材料,我们发现这类化合物还具有独特的光物理学性质,即双荧光发射、大的Stokes位移以及环境响应性荧光光谱性质等.针对其特有的"马鞍形"结构,本课题组通过极性、黏度及温度相关的稳态和超快分辨光谱以及飞秒超快光谱的研究,以及反应势能面的计算模拟的验证,提出了"振动诱导发光"(VIE)的共轭分子发光新机制.利用这一机制,通过调谐分子振动,可以达到调节分子发光波长和强度的目的,为今后设计新型共轭分子宽光谱的发光材料提供了一条全新的思路.

In serendipity, N,N′-disubstituted-dihydrodibenzo[a,c]phenazines was discovered to exhibit intriguing photophysical properties including dual fluorescence, large Stokes shift and responsiveness to ambient conditions（polarity, viscosity, etc.）, which inspired us to take in-depth research into it. Upon investigations on temperature dependent steady-state spectroscopy, nanosecond time-resolved spectroscopy, femtosecond dynamics and computational simulation of the reaction energy surfaces, we verified that the red emission and its extremely large Stokes shift originate from the bending to planarity motion of benzo[a,c]phenazines moiety and coined this novel mechanism as ＂vibration induced emission＂（VIE）. Hence, these phenazines are capable of developing single molecular color tunable materials by affecting the vibration of the molecules, which provides a new paradigm en route to developing versatile materials for photoelectric devices and panel displays.