In:
New Journal of Chemistry, Royal Society of Chemistry (RSC), Vol. 46, No. 31 ( 2022), p. 15168-15174
Abstract:
In a variety of skeletal structures of delayed fluorescence molecular materials, the donor–acceptor–donor (D–A–D) type has been widely considered for improving the efficiency of the reverse intersystem crossing (RISC) process. Herein, three new D–A–D molecules (PTZ-MPS, TPA-MPS and PCz-MPS) bearing 9,9-dimethylthioxanthene-S,S-sulfur dioxide (MPS) as the electron acceptor group are designed and investigated using theoretical calculations. PTZ-MPS shows the feature of the high-lying reverse intersystem crossing process, which is conducive to improving the exciton utilization of organic light-emitting diodes (OLEDs). PTZ-MPS has a much smaller singlet–triplet energy splitting (Δ E S 1 T 3 = 0.03 eV) than TPA-MPS (Δ E S 1 T 3 = 0.32 eV) and PCz-MPS (Δ E S 1 T 3 = 0.59 eV). However, it has a much larger spin–orbital coupling (SOC) strength (〈S 1 | Ĥ SOC |T 3 〉 = 1.013 cm −1 ) than TPA-MPS (〈S 1 | Ĥ SOC |T 3 〉 = 0.311 cm −1 ) and PCz-MPS (〈S 1 | Ĥ SOC |T 3 〉 = 0.354 cm −1 ), which makes it easy to induce a sufficient RISC from the T n state to the S 1 state. The Δ E ST and SOC are the two most important factors in determining TADF molecules. Therefore, PTZ-MPS is expected to be a potential high-lying excited state delayed fluorescence material candidate, and our work demonstrates that high-performance TADF materials can also be obtained successfully by designing rational molecules.
Type of Medium:
Online Resource
ISSN:
1144-0546
,
1369-9261
Language:
English
Publisher:
Royal Society of Chemistry (RSC)
Publication Date:
2022
detail.hit.zdb_id:
1472933-7
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