| Autor: |
Ona Adomėnienė, Regimantas Komskis, Povilas Adomėnas, Saulius Juršėnas, Paulius Baronas, E. Tankelevičiu̅tė |
| Rok vydání: |
2021 |
| Předmět: |
|
| Zdroj: |
The Journal of Physical Chemistry Letters. 12:6827-6833 |
| ISSN: |
1948-7185 |
| DOI: |
10.1021/acs.jpclett.1c01569 |
| Popis: |
Singlet-Triplet energy exchange is an area of active research due to its role in optoelectronic devices and photodynamic therapy. Large spin-orbit coupling (SOC) is difficult to achieve in simple hydrocarbon structures limiting the intersystem crossing (ISC) rates. A new approach to enhance the spin-orbit coupling via helical molecular orbitals is investigated in oligoyne-bridged bifluorenes. Transient absorption studies showed a singlet-to-triplet ISC rate of up to 6 ns-1 resulting in 0.84 triplet yield. Density functional calculations revealed a direct relation between high ISC and large SOC values mediated by helical molecular orbitals. Calculations and spectroscopic data also suggested that El-Sayed forbidden ISC occurs as a direct transition between 1ππ* and 3ππ*, which becomes allowed due to a symmetry-breaking interaction leading to mixing between orthogonal π-systems in the oligoyne fragment. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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