Aggregation-induced emission and the working mechanism of 1-benzoyl and 1-benzyl pyrene derivatives

Abstract

Over the past decade, research studies on solid-state luminescent materials featuring aggregation-induced emission (AIE) have achieved great success. It has been proved that lots of planar ACQ (aggregation-caused quenching) chromophores can be converted to AIE luminogens (AIEgens) by combining with an AIE-active unit such as tetraphenylethene (TPE). In this work, we present a new method to create AIE luminogens just by introducing benzoyl or benzyl to a planar chromophore, pyrene. The generated 1-benzoyl and 1-benzyl pyrene derivatives exhibit weak emission when molecularly dissolved in good solvents but strong emission from pyrene dimers when aggregated in poor solvent or the solid state. Their crystal structure analysis and theoretical calculations are performed to depict the working mechanism of these new AIEgens. The results show that the structural rigidification of these 1-benzoyl pyrene derivatives is the major cause for their AIE effect. This new AIE system along with a clear working mechanism will contribute to the development of AIE-related functional materials and theories.

Stimuli-responsive aggregation-induced fluorescence in a series of biphenyl-based Knoevenagel products: effects of substituent active methylene groups on π–π interactions

“…3(c)]. The presence of stronginteractions between adjacent biphenyl rings leads to RIM (Zhang et al, 2018), resulting in AEE in the solid state as well as in the ethanol-water solvent system.…”

“…2(c)] on changing the solvent system polarity with an increased percentage of water. A plausible cause for this may be the fact that water as a polar solvent has a gradual influence on C-HÁ Á Á interactions of 1b compared with the non-polarinteractions in 1a, leading to a sudden shift caused by the alignment of 1a molecules (Zhang et al, 2018).…”

Rationally Designed Furocarbazoles as Multifunctional Aggregation Induced Emissive Luminogens for the Sensing of Trinitrophenol (TNP) and Cell Imaging

“…Technological demands have generated pronounced interest in the study and development of new luminogens and the scientific community has witnessed a phenomenal escalation in the exploration of efficient AIEgenic materials for various applications including the biomarkers, organic light‐emitting diodes (OLED), and sensors . Although several AIEgens have been constructed based on different structural motifs, the working mechanisms of the AIEgens are highly debatable and mandate extensive research …”

Synthesis and Characterisation of Polyaromatic Chalcones with Electron Donation

“…In this context, pyrene is a well-known polyaromatic hydrocarbon and has also quite interesting properties including high fluorescence [26], high optical contrast [27], and white-light emission [28]. Moreover, various pyrene derivatives exhibit surprising exciplex emission at higher concentrations or solid state [29,30]. In other words, π-stacking or intermolecular interaction of among pyrene rings can change whole photophysical characteristics and this phenomenon promotes an increase or quench at emission.…”