- A new benzothienoindole-based bipolar host material for efficient green phosphorescent organic light-emitting diodes with extremely small efficiency roll-off
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In this contribution, two new hole-transport units, 10H-benzo[4,5]thieno[3,2-b]indole (BTI) and 10H-benzofuro[3,2-b]indole (BFI), were developed to design and synthesize bipolar host materials namely 10-(3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)-10H-benzo[4,5]thieno[3,2-b]indole.(mBTITrz) and 10-(3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)-10H-benzofuro[3,2-b]indole.(mBFITrz), for phosphorescent organic light-emitting diodes (PHOLEDs). The effect of heteroatoms in the hole-transport unit on the physicochemical and electroluminescence properties of the hosts were investigated in detail. Interestingly, the phosphorescence of the compounds was highly dependent on the hole-transport unit, because it originated from their local excited state (3LE), which was attributed to the interrupted strong electronic communication between donor and acceptor units by meta-mode of conjugation on the phenyl linker. Consequently, the mBTITrz showed high triplet energy (ET) of ~2.88 eV compared to its counterpart mBFITrz (ET ~ 2.65 eV). Both compounds displayed marked thermal stability with high thermal decomposition temperatures of above 410 °C and glass-transition temperatures of above 103 °C. In addition, the single carrier device studies revealed a bipolar charge transporting character for the compounds. Furthermore, the compounds were evaluated as bipolar hosts for green PHOLEDs by employing Ir(ppy)3 dopant. The mBTITrz-hosted device demonstrated much better performance than did the mBFITrz-hosted device, with a maximum external quantum efficiency of 21.3% and maximum current efficiency of 76.0 cd/A. Notably, the mBTITrz-based device exhibited excellent efficacy stability with uncompromised efficiency roll-off at 1000 cd/m2 and an extremely low efficiency roll-off of 3.2% at 5000 cd/m2 and 9.0% at 10,000 cd/m2.
- Konidena, Rajendra Kumar,Lee, Kyung hyung,Lee, Jun Yeob,Hong, Wan Pyo
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- Synthesis and molecular properties of methoxy-substituted diindolo[3,2-: B:2′,3′- h] carbazoles for organic electronics obtained by a consecutive twofold Suzuki and twofold Cadogan reaction
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A set of methoxy-substituted diindolo[3,2-b:2′,3′-h]carbazoles has been synthesized by twofold Suzuki-Miyaura, Cadogan and N-alkylation reactions starting from N-hexyl-2,7-dibromo-3,6-dinitro carbazole. Microwave accelerated reactions ensure a rapid strai
- Srour, Hassan,Doan, Thu-Hong,Silva, Elisabeth Da,Whitby, Richard J.,Witulski, Bernhard
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- Triggering Thermally Activated Delayed Fluorescence by Managing the Heteroatom in Donor Scaffolds: Intriguing Photophysical and Electroluminescence Properties
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Establishment of the structure–property relationships of thermally activated delayed fluorescence (TADF) materials has become a significant quest for the scientific community. Herein, two new donors, 10H-benzofuro[3,2-b]indole (BFI) and 10H-benzo[4,5]thie
- Konidena, Rajendra Kumar,Lee, Kyung Hyung,Lee, Jun Yeob,Hong, Wan Pyo
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- Visible light mediated desilylative C(sp2)-C(sp2) cross-coupling reactions of arylsilanes with aryldiazonium salts under Au(i)/Au(iii) catalysis
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Desilylative C(sp2)-C(sp2) cross-coupling reactions of arylsilanes with aryldiazonium salts under Au(i)/photoredox catalysis have been reported. The addition of Cu-salts as catalysts was found to be crucial for the success of this tr
- Chakrabarty, Indradweep,Akram, Manjur O.,Biswas, Suprakash,Patil, Nitin T.
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supporting information
p. 7223 - 7226
(2018/07/03)
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- Eco-friendly solvents for palladium-catalyzed desulfitative C-H bond arylation of heteroarenes
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Herein, we report the Pd-catalyzed regioselective direct arylation of heteroarenes in which benzenesulfonyl chlorides are used as coupling partners through a desulfitative cross-coupling that can be performed in diethyl carbonate (DEC) or cyclopentyl methyl ether (CPME) as green and renewable solvents or even in neat conditions instead of dioxane or dimethylacetamide (DMA). Under these solvent conditions, the reaction proceeds with a wide range of heteroarenes. C2- or C5-arylated products were obtained with furan and pyrrole derivatives. Benzofuran was also arylated regioselectively at the C2-position, whereas the reaction proceeds selectively at the C3- or C4-positions if thiophenes and benzothiophenes are used. Moreover, in some cases, especially with 1-methylindole, solvent-free conditions afforded better regioselectivities and/or yields than the reaction performed in the presence of solvents.
- Hfaiedh, Anoir,Yuan, Kedong,Ben Ammar, Hamed,Ben Hassine, Bechir,Soulé, Jean-Fran?ois,Doucet, Henri
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p. 1794 - 1804
(2015/06/02)
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- Rapid synthesis of fused N-heterocycles by transition-metal-free electrophilic amination of arene C-H bonds
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We disclose an efficient and operationally simple protocol for the preparation of fused N-heterocycles starting from readily available 2-nitrobiaryls and PhMgBr under mild conditions. More than two dozen N-heterocycles, including two bioactive natural products, have been synthesized using this method. A stepwise electrophilic aromatic cyclization mechanism was proposed by DFT calculations. Controlled fusion: A transition-metal-free, low-temperature, and regioselective intramolecular amination of aromatic C(sp2)-H bonds provides fused N-heterocycles. This reaction is operationally simple and scalable (1-10 mmol) and the scope of substrates is wide (see scheme). Density functional calculations indicate that a stepwise electrophilic aromatic cyclization mechanism may be operative.
- Gao, Hongyin,Xu, Qing-Long,Yousufuddin, Muhammed,Ess, Daniel H.,Kuerti, Laszlo
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supporting information
p. 2701 - 2705
(2014/03/21)
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- Hetero polycyclic biocidal compounds, their synthesis and intermediates therefor,formulations containing them and their use in medicine
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Heterotetracyclic aromatic compounds having biocidal activity containing two hetero atoms selected from oxygen, sulphur and nitrogen and that are substituted by an aminoalkanol group of formula, , ArCH2NHR, , or a monomethyl or monoethyl ether
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- PALLADIUM-CATALYZED ARYLATION OF FURAN, THIOPHENE, BENZOFURAN AND BENZOTHIOPHENE
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Treatment of ?-electron sufficient aromatic heterocycles such as furan, thiophene, benzofuran and benzothiophene with aryl bromides in the presence of tetrakis(triphenyphosphine)palladium gave the corresponding 2-aryl aromatic heterocycles.
- Ohta, Akihiro,Akita, Yasuo,Ohkuwa, Teruya,Chiba, Mari,Fukunaga, Ryuichi,et al.
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p. 1951 - 1958
(2007/10/02)
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