Abnormally aggregation-induced emissions observed from hydrogen- and silyl-substituted siloles

Abstract Silacyclopentadienes (siloles) are currently of great interest because of their intriguing aggregation-induced emission (AIE) characteristics. In this work, abnormally AIE phenomena were observed from silyl- and hydrogen-substituted siloles respectively. We propose silyl-substituent and hydrogen atom effects to explain this via both experiments and theoretical calculations. It was discovered that trimethylsilyl substituents destroyed the p-interactions with the silole core and resulted in the non-fluorescence. Additionally, 1-chloro-1-H-2,3,4,5-tetraphenylsilole featuring strong fluorescences in both solid and solution states with high fluorescence quantum yields represents a new potential photoelectric material. This work not only reports the silole with strong fluorescences in both solid and solution states for the first time but also contributs to enrich the AIE research of siloles. Graphical Abstract