Restriction of Flip-flop Motion as a Mechanism for Aggregation-Induced Emission
| Autor: | Peng Li, Yanliang Zhao, Panwang Zhou, Ke-Li Han |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Physics
Motion (geometry) 02 engineering and technology Conical intersection 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences law.invention law Chemical physics Intramolecular force Excited state General Materials Science Physical and Theoretical Chemistry Bright state Aggregation-induced emission 0210 nano-technology Mechanism (sociology) Flip-flop |
| Zdroj: | The Journal of Physical Chemistry Letters. 10:6929-6935 |
| ISSN: | 1948-7185 |
| DOI: | 10.1021/acs.jpclett.9b02922 |
| Popis: | Although the restriction of intramolecular motion (RIM) has been accepted as a general working mechanism for the aggregation-induced emission (AIE) phenomenon, some new mechanisms, such as suppression of Kasha's rule (SOKR), has also been proposed to explain the AIE of boron difluorohydrazone (BODIHY) derivatives. However, the understanding of the relation and difference between RIM and SOKR mechanisms is limited. To address this issue, we performed a theoretical study on the excited state decay of a series of BODIHY derivatives. Surprisingly, we found that the first excited state of BODIHY derivatives is a bright state and contradicts with the SOKR mechanism. Importantly, we proposed a new mechanism, termed as restriction of flip-flop motion, to explain the AIE of BODIHY derivatives. This mechanism involves the formation of an umbrella-like minimal energy conical intersection through flip-flop motion, which is easily accessible in low-viscosity solvents and will be restricted in high-viscosity solvents. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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