In:
New Journal of Chemistry, Royal Society of Chemistry (RSC), Vol. 47, No. 15 ( 2023), p. 7182-7188
Abstract:
Employing a 2-phenylfuro[2,3- b ]quinoxaline (FQ) scaffold as a fluorophore, and phenyl, biphenyl, anthracene, and benzothiadiazole units as π-linkers, the four compounds Ph-dFQ, bPh-dFQ, ADN-dFQ and Bth-dFQ were respectively constructed, along with BIZ-FQ with a benzimidazole unit, to screen suitable blue emitters. When the linker was changed from phenyl to biphenyl, benzothiadiazole, or anthracene, the torsion angle between the FQ and linker increased from 29.7° to up to 80.0° due to their steric interaction. Owing to the large bulk and π-conjugation length of the anthracene linker, the torsion angle of 80.0° was predicted from theoretical calculations for ADN-dFQ, and as a result, multiple-wavelength emission is possible. ADN-dFQ and Bth-dFQ provided green emission due to clear charge-transfer emission but low fluorescence efficiency because the large torsion angles would prompt more energy dissipation from the S 1 state and weaken its transition probabilities. Furthermore, despite the weak electron-donating capability of the phenyl, biphenyl and anthracene π-linkers, a charge-transfer state could be clearly formed with the electron-deficient FQ unit, and as a result, sky-blue to green emissions were observed for the three compounds Ph-dFQ, bPh-dFQ and ADN-dFQ. In addition, it was found that the five compounds could form an exciplex with 2-methyl-9,10-di(2-naphthyl)anthracene (MADN), and thus, when the five compounds were doped into a MADN host, the corresponding OLEDs mainly presented a green emission (∼496 nm) from the exciplex.
Type of Medium:
Online Resource
ISSN:
1144-0546
,
1369-9261
Language:
English
Publisher:
Royal Society of Chemistry (RSC)
Publication Date:
2023
detail.hit.zdb_id:
1472933-7
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