Pyrazine-Based Chiral AIE Electronic Acceptors for Real-Time Monitoring Hierarchical Self-Assembly and Tuning Emissions through Intermolecular Charge-Transfer Effects

Development of chiral aggregation-induced emission (AIE) materials toward hierarchical self-assembly is crucial to reveal the origin and evolution of life. In this work, a pair of chiral AIE enantiomers is fabricated by attaching the typical AIE units to the chiral binaphthyl core via a single bond linkage. The AIE behavior is inherited from the introduced AIE unit while the binaphthyl unit can not only improve the photo-physical properties but also provide the whole molecules with chirality. Moreover, as driven by the dipolar structure and chirality of the AIEgens, the hierarchical self-assembly with different morphologies such as spheres, ribbons or fibers, flowers, and even bigger structures with various sizes can be dynamically monitored with the assembled time, which provided a favorable evidence to study the structural evolution from molecular level to a higher-level structure. On the other hand, these AIEgens can act strong electronic acceptors due to the introduced AIE unit. By complexing them with strong electronic donors, the resulting intermolecular charge transfer can induce remarkable red emissions with the tunable properties which is much different from their individuals. This enabled it as a facile, economic, and flexible approach to develop organic photoelectric materials.