Zhang’s comment on his Aggregate paper entitled “Kinetic and thermodynamic control of tetraphenylethene aggregation-induced emission behaviors”[1]:
Tetraphenylethene (TPE) is a classic example of an Aggregation-Induced Emission (AIE) system. In good solvents, it doesn’t display any photoluminescence. However, in poor solvents, it exhibits sky-blue fluorescence emission. During the experiment, we noticed subtle changes in TPE’s AIE emission wavelength and peak maximum and spectral shape over time. By synthesizing various derivatives, we discerned this phenomenon is prevalent during AIE sample preparation. Organic molecules, when aggregating rapidly, might be locked into a kinetically metastable state that remains stable at room temperature. But this kinetic stability can transition to a thermodynamically stable aggregated state when heated or when exposed to good solvents. Depending on the molecular structure, these kinetically aggregated species and thermodynamically aggregated species display vastly different luminescent phenomena. This topic underscores that the physical properties of organic aggregates are highly sensitive to their surroundings and offers crucial theoretical insights for precision synthesis of an AIE system.
REFERENCES
X. Nie, W. Huang, D. Zhou, T. Wang, X. Wang, B. Chen, X. Zhang, G. Zhang, Aggregate 2022 , 3 , e165. https://doi.org/10.1002/agt2.165
CONFLICT OF INTEREST
The author declares that there is no conflict of interest.