Breaking Classic Heavy‐Atom Effect to Achieve Heavy‐Atom‐Induced Dramatic Emission Enhancement of Silole‐Based AIEgens with Through‐Bond and Through‐Space Conjugation
Zuping Xiong, Zhenni Wang, Longxiang Liu, Mengyi Jiang, Xiaoxiao Zhang, Qiaozhi Zhu, Hui Feng, Zhaosheng Qian
Abstract
Abstract Classic heavy‐atom effect is well known on traditional luminophores, but its usability for newly developed AIEgens with through‐bond and through‐space conjugation leaves a question open. Herein, an interesting heavy‐atom‐induced emission enhancement against classic heavy‐atom effect is reported by examining unique photophysical behaviors of aggregation‐induced emission (AIE)‐active silole compounds both experimentally and theoretically. It is revealed that heavy atoms exert an insignificant impact on the fluorescence of AIEgens due to their through‐space conjugation nature, and weak intermolecular interactions and heavy‐atom‐caused vibration restriction collaboratively contribute to the emission enhancement of these AIEgens via restricting intramolecular motions. The breaking of classic heavy‐atom effect on silole‐based AIEgens not only proves its usability scope only on through‐bond conjugated dyes, it also provides an effective and simple strategy to dramatically improve the emission efficiency of AIEgens.