18992-85-3Relevant articles and documents
A simple strategy to achieve efficient thermally activated delayed fluorescent emitters via enhancing electron donating ability of donors
Li, Ganggang,Li, Jiafang,Li, Kai,Liu, He,Liu, Zhiwen,Wang, Zhiming,Yang, Chuluo,Zhan, Qun,Zhang, Bing,Zhou, Changjiang
, (2020)
Simultaneously achieving both effective reverse intersystem crossing (RISC) process and high values of radiative decay rate (kr)/photoluminescent quantum yield (PLQY) are critical for efficient thermally activated delayed fluorescent (TADF) emitters. The separation of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) through typical molecular geometry tuning method guarantees a small ΔEST but results in disfavored oscillator strength for fluorescent decay. Herein, a simple method is provided to facilitate the reverse intersystem crossing (RISC) of TADF emitters via enhancing electron donating property of donors rather than twisting the donor-acceptor configuration. Three molecules, namely Me-Cz, Me-MOC and Me-DOC, are designed and synthesized. The introduction of methoxy group enhances the electron-donating ability of carbazole. The stabilized charge transfer state features a reduced splitting energy between the first singlet and triplet excited state, thus activating TADF process. Consequently, the molecules Me-DOC and Me-MOC achieve good external quantum efficiency of 18.6% and 12.4% in electroluminescent devices.
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Cadogan et al.
, p. 847 (1975)
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Aerobic Dehydrogenation of N-Heterocycles with Grubbs Catalyst: Its Application to Assisted-Tandem Catalysis to Construct N-Containing Fused Heteroarenes
Kawauchi, Daichi,Noda, Kenta,Komatsu, Yoshiyuki,Yoshida, Kei,Ueda, Hirofumi,Tokuyama, Hidetoshi
, p. 15793 - 15798 (2020/10/12)
An aerobic dehydrogenation of nitrogen-containing heterocycles catalyzed by Grubbs catalyst is developed. The reaction is applicable to various nitrogen-containing heterocycles. The exceptionally high functional group compatibility of this method was confirmed by the oxidation of an unprotected dihydroindolactam V to indolactam V. Furthermore, by taking advantage of the oxygen-mediated structural change of the Grubbs catalyst, we integrated ring-closing metathesis and subsequent aerobic dehydrogenation to develop the novel assisted-tandem catalysis using molecular oxygen as a chemical trigger. The utility of the assisted-tandem catalysis was demonstrated by the concise synthesis of N-containing fused heteroarenes including a natural antibiotic, pyocyanine.
NEW POLYMERIZABLE LIQUID CRYSTAL HAVING A CARBAZOLE CORE
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Page/Page column 23, (2021/01/23)
The invention relates to novel anisotropic compounds of formula (I) as well as to liquid crystalline mixtures, films and electro-optical devices comprising the compound.