Self‐Assembled Helical Arrays for the Stabilization of the Triplet State
| Autor: | Goudappagouda, Retheesh Krishnan, Rajesh G. Gonnade, Divya S. Mohana Kumari, Sukumaran Santhosh Babu, G. V. Pavan Kumar, Aakash D. Nidhankar, Shailendra K. Chaubey, Rashmi Ashwathama Nayak |
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| Rok vydání: | 2020 |
| Předmět: |
Physics::General Physics
Materials science 010405 organic chemistry Carbazole Quantum yield General Chemistry 010402 general chemistry 01 natural sciences Fluorescence Catalysis 0104 chemical sciences Crystal chemistry.chemical_compound Intersystem crossing chemistry Chemical physics Molecule Triplet state Phosphorescence |
| Zdroj: | Angewandte Chemie International Edition. 59:13079-13085 |
| ISSN: | 1521-3773 1433-7851 |
| Popis: | Room-temperature phosphorescence of metal and heavy atom-free organic molecules has emerged as an area of great potential in recent years. A rational design played a critical role in controlling the molecular ordering to impart efficient intersystem crossing and stabilize the triplet state to achieve room-temperature ultralong phosphorescence. However, in most cases, the strategies to strengthen phosphorescence efficiency have resulted in a reduced lifetime, and the available nearly degenerate singlet-triplet energy levels impart a natural competition between delayed fluorescence and phosphorescence, with the former one having the advantage. Herein, an organic helical assembly supports the exhibition of an ultralong phosphorescence lifetime. In contrary to other molecules, 3,6-phenylmethanone functionalized 9-hexylcarbazole exhibits a remarkable improvement in phosphorescence lifetime (>4.1 s) and quantum yield (11 %) owing to an efficient molecular packing in the crystal state. A right-handed helical molecular array act as a trap and exhibits triplet exciton migration to support the exceptionally longer phosphorescence lifetime. |
| Databáze: | OpenAIRE |
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