Design of Conformationally Distorted Donor–Acceptor Dyads Showing Efficient Thermally Activated Delayed Fluorescence
| Autor: | Hartmut Yersin, Thomas Müller, Rafał Czerwieniec, Thomas Hofbeck, Gereon A. Sommer, Larisa Mataranga-Popa, Herbert H. H. Homeier |
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| Jazyk: | angličtina |
| Předmět: |
Materials science
Photoluminescence Band gap Quantum yield 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Photochemistry 01 natural sciences Acceptor Fluorescence Toluene Arrhenius plot 0104 chemical sciences chemistry.chemical_compound Intersystem crossing chemistry General Materials Science Physical and Theoretical Chemistry 0210 nano-technology |
| Zdroj: | The Journal of Physical Chemistry Letters |
| ISSN: | 1948-7185 |
| DOI: | 10.1021/acs.jpclett.8b01511 |
| Popis: | A highly potent donor–acceptor biaryl thermally activated delayed fluorescence (TADF) dye is accessible by a concise two-step sequence employing two-fold Ullmann arylation and a sequentially Pd-catalyzed Masuda borylation–Suzuki arylation (MBSA). Photophysical investigations show efficient TADF at ambient temperature due to the sterical hindrance between the donor and acceptor moieties. The photoluminescence quantum yield amounts to ΦPL= 80% in toluene and 90% in PMMA arising from prompt and delayed fluorescence with decay times of 21 ns and 30 μs, respectively. From an Arrhenius plot, the energy gap ΔE(S1– T1) between the lowest excited singlet S1and triplet T1state was determined to be 980 cm–1(120 meV). A new procedure is proposed that allows us to estimate the intersystem crossing time to ∼102ns. |
| Databáze: | OpenAIRE |
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