Aggregation-Induced Emission and Aggregation-Promoted Photo-oxidation in Thiophene-Substituted Tetraphenylethylene Derivative

Aggregation-induced emission combined with aggregation-promoted photo-oxidation has been reported only in two works quite recently. In fact, this phenomenon is not commonly observed for AIE-active molecules. In this work, a new tetraphenylethylene derivative (TPE-4T) with aggregation-induced emission (AIE) and aggregation-promoted photo-oxidation was synthesized and investigated. The pristine TPE-4T film exhibits strong bluish-green emission, which turns to quite weak yellow emission after UV irradiation. Interestingly, after solvent treatment, the weakly fluorescent intermediate will become bright-yellow emitting. Moreover, the morphology of the TPE-4T film could be regulated by UV irradiation. The wettability of the TPE-4T microcrystalline surface is drastically changed from hydrophobic to hydrophilic. This work contributes a new member to the aggregation induced photo-oxidation family and enriches the photo-oxidation study of tetraphenylethylene derivatives.