- Molecular engineering of “A-D-D-A” dual-emitting-cores emitters with thermally activated delayed fluorescence and aggregation-induced emission characteristics
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Endowing thermally activated delayed fluorescence (TADF) emitter with aggregation-induced emission (AIE) peculiarity is of great significance for realizing more promising commercial applications. Herein, two new dual-emitting-cores emitters with a structu
- Sun, Yibai,Sun, Yueming,Tang, Jinan,Tang, Qifeng
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- 3,3'-Bicarbazolyl-containing oxirane and its reaction products as new glass-forming electroactive materials
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Low-molar-mass oxiranyl-substituted 3,3'-bicarbazolyl derivatives were synthesized by the reaction of 3,3'-bicarbazolyl-containing oxirane with dimercapto compounds as linking agents. The cationic ring opening polymerization of oxirane monomers was performed using ytterbium (III) trifluoromethanesulfonate [Yb(OTf)3] as a cationic initiator to obtain polyether. The full characterization of the compounds by mass spectrometry, IR, 1H NMR, and 13C NMR is presented. All the compounds represent amorphous materials with glass transition temperatures ranging from 28C to 112C and with 5%-weight-loss temperatures exceeding 308C. The electron photoemission spectra of the materials were recorded, and the ionization potentials of ca. 5.5eV were established. Time-of-flight hole drift mobilities of the amorphous films of some synthesized compounds exceed 10-5cm2/Vs at high electric fields.
- Vaitkeviciene,Grazulevicius,Jankauskas
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p. 241/[573]-253/[585]
(2008)
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- An effective thermally activated delayed fluorescence host material for highly efficient blue phosphorescent organic light-emitting diodes with low doping concentration
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A thermally activated delayed fluorescence (TADF) material BCz-2SO has been designed and synthesized as host for blue phosphorescent organic light-emitting diodes (OLEDs). Photophysical studies and theoretical calculations show that the molecule has a small singlet-triplet energy gap (ΔEST) of 0.345 eV, which is beneficial to the reverse energy transferring between the singlet and triplet state. Thanks to the TADF property, the triplet energy can be transmitted to the singlet state through reverse intersystem crossing (RISC), and then transmitted to the guest through the Fo?rster energy transfer (FET) to achieve 100% utilization of energy. Thus, the triplet–triplet annihilation (TTA) of the blue phosphor can be avoided by the extremely low doping concentration of 1%. By using BCz-2SO as the host of FIrpic, the solution-processed blue phosphorescent device achieves the maximum current efficiency (CE), power efficiency (PE), external quantum efficiency (EQE) and highest brightness of 16.38 cd A?1, 9.04 lm W?1, 7.8% and 16,537 cd m-2, respectively. It demonstrates that one can employ the solution-processed method to prepare the high performance phosphorescent OLEDs using the TADF host material we have developed.
- Liu, Yan,Pan, Jie,Chen, Feng,Gao, Kun,Zhu, Aiyun,Wang, Ruoxian,Yue, Xuan,Ban, Xinxin
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- 3,3-Bicarbazole-Based Host Molecules for Solution-Processed Phosphorescent OLEDs
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Solution-processed organic light-emitting diodes (OLEDs) are attractive due to their low-cost, large area displays, and lighting features. Small molecules as well as polymers can be used as host materials within the solution-processed emitting layer. Herein, we report two 3,3-bicarbazole-based host small molecules, which possess a structural isomer relationship. 9,9-Di-4-n-butylphenyl-9H,9H-3,3-bicarbazole (BCz-nBuPh) and 9,9-di-4-t-butylphenyl-9H,9H-3,3-bicarbazole (BCz-tBuPh) exhibited similar optical properties within solutions but different photoluminescence within films. A solution-processed green phosphorescent OLED with the BCz-tBuPh host exhibited a high maximum current efficiency and power efficiency of 43.1 cd/A and 40.0 lm/W, respectively, compared to the device with the BCz-nBuPh host.
- Kim, Jungwoon,Lee, Suhan,Lee, Jaemin,Lim, Eunhee,Jung, Byung Jun
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- A thermally cross-linkable hole-transporting small-molecule for efficient solution-processed organic light emitting diodes
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Fabrication of multilayered organic light-emitting diodes (OLEDs) through solution process involves several challenges, especially in preventing dissolution of prior layers during subsequent coating. To overcome, extensive efforts had been made in developing cross-linkable materials. In this work, a thermally cross-linkable hole-transporting material, (9,9′-bis(4-vinylbenzyl)-9H,9′H-3,3′-bicarbazole) (VyPyMCz), is synthesized, characterized and successfully applied to multilayered OLEDs via solution-process. After cross-linking, the hole-transporting material forms robust, smooth and solvent-resistant network, enabling a subsequent spin-coating without deteriorating its film integrity. The measured energy level suggests that VyPyMCz facilitates the injection of hole and effectively blocks electron to realize high efficiency, especially at high luminance. At 1000 cd m?2 for example, the power efficiency of a studied red device is increased from 7.5 to 11.9 lm W?1, an increment of 58%, and the maximum brightness improved from 7724 to 13,560 cd m?2, an increment of 75%, as this electron confining, hole transporting material is incorporated. Remarkably, VyPyMCz also works for a high band gap (2.90 eV) with a high triplet energy (2.80 eV) blue emitter containing OLED device, the power efficiency is increased from 6.6 to 11.8 lm W?1, an increment of 78%, and the maximum luminance enhanced from 5260 to 6857 cd m?2, an increment of 30%, because of its higher triplet energy (2.87 eV).
- Dubey, Deepak Kumar,Swayamprabha, Sujith Sudheendran,Kumar Yadav, Rohit Ashok,Tavgeniene, Daiva,Volyniuk, Dmytro,Grigalevicius, Saulius,Jou, Jwo-Huei
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- Oxidative Coupling of Carbazoles: A Substituent-Governed Regioselectivity Profile
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Oxidative C-C coupling of carbazoles possessing various substituents is demonstrated in the presence of organic (metal-free) recyclable oxidants, such as DDQ or CA/H+, for accessing bicarbazole regioisomers. Differently substituted carbazoles are examined to showcase regioselective discrimination (3,3′-versus 1,3′-bicarbazoles) and preferences based on sterics and electronics in oxidative coupling. Finally, a mechanism that involves the carbazole radical cation has been traced (evidenced) and proposed on the basis of the UV-vis-NIR absorption and EPR spectroscopy results. This study underlines the strategic chemical preparation of a series of bicarbazoles in an efficient manner.
- Mallick, Sudesh,Maddala, Sudhakar,Kollimalayan, Kalidass,Venkatakrishnan, Parthasarathy
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- Synthesis of new bicarbazole-linked triazoles as non-cytotoxic reactive oxygen species (ROS) inhibitors
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Carbazole analogs 3 and 4 and a new library of bicarbazole-linked triazoles 6–11 were prepared via new synthetic methodology. Metal-catalyzed oxidative coupling reaction was utilized for the synthesis of bicarbazole acetylene 4 and different metals (Znsu
- Iqbal, Shazia,Khan, Maria A.,Ansari, Zulqarnain,Jabeen, Almas,Faheem, Aisha,Fazal-Ur-Rehman, Saba,Basha, Fatima Z.
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supporting information
p. 2330 - 2341
(2019/07/05)
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- Low temperature curable hole transporting materials and OLED comprising the same
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The invention refers to low temperature curing herein and hole transporting material selected from an organic light emitting device, more specifically hole transport core and cover dozing,, alkoxy styrene-based curable functionality including curing the organic layer hole transport hole is cured at a low temperature and having a curable composition having improved efficiency and lower drive voltages is an electron transporting layer are disclosed. Hole transporting material is herein of the existing method of the invention is curable at a lower temperature than 180 °C hereinafter having hole transporting material as well as good curing possible impact from a, such low temperature curing composition comprising organic hole transport material cured at a low temperature curing the number of organic light-emitting layer by thermal diffusion for avoiding unnecessary sample pore conditions thermal modified so that improved efficiency and lower drive voltage Gd oxide or number of organic light-emitting pivotably.
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Paragraph 0153 - 0156
(2018/03/01)
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- MATERIAL FOR ORGANIC ELECTROLUMINESCENCE DEVICE AND APPLICATION THEREOF, ORGANIC ELECTROLUMINESCENCE DEVICE AND APPLICATION THEREOF
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The object of the invention is to provide an organic EL (electroluminescence) material, which is suitable for production by printing method due to excellent solvent solubility, and may perform high efficiency illumination due to high triplet energy. Further, an organic EL device using the organic EL material, a display device, and an illuminator is provided. The invention achieves the object of the invention by providing an organic EL material including a compound having specific carbazole backbone, an ink for organic EL device including the organic EL material, and an organic EL device. Further, a display device and an illuminator including the organic EL device are provided.
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Paragraph 0090-0092
(2018/02/08)
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- Curing temperature reduction and performance improvement of solution-processable hole-transporting materials for phosphorescent OLEDs by manipulation of cross-linking functionalities and core structures
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Three new thermally cross-linkable hole-transporting materials (HTMs) with a bicarbazole (BCz) core and vinylbenzyl or alkoxystyrene-based cross-linking functionalities viz.BCzMS, BCzBOS and MeO-BCzBOS have been synthesized, characterized and applied to solution-processed green phosphorescent organic light-emitting diodes (PhOLEDs) by achieving cross-linking at different temperatures. The thermal curing behavior and structure-property relationships of our new thermally cross-linkable HTMs were systematically investigated by changing styrene-based cross-linking functionalities and a record low thermal curing temperature (150 °C, solvent resistance > 95%) for thermally cross-linkable HTMs for solution-processed PhOLEDs was achieved by introducing flexible butoxystyrene functionalities to the HTMs. First, the effect of the curing temperature on the performance of devices was studied by fabricating green PhOLEDs using the new materials as HTMs cured at different temperatures and it was found that lower temperature cured devices performed better than those processed at higher temperatures. Taking 150 °C as the best curing temperature, the devices employing BCzBOS (having butoxystyrene functionalities) showed an increase in the current and power efficiencies, respectively of 136% and 137% (at a luminance of 1000 cd m-2) as compared to the control device with no HTM. Furthermore, modification of the HTM core structure by introducing methoxy groups at the 6,6'-position of the bicarbazole core of BCzBOS (MeO-BCzBOS) resulted in further increases in the current and power efficiencies of 157% and 176% (at a luminance of 1000 cd m-2), respectively, as compared to the control device incorporating no HTM.
- Ameen, Shahid,Lee, Jaemin,Han, Hyun,Suh, Min Chul,Lee, Changjin
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p. 33212 - 33220
(2016/05/09)
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- Light-emitting element material and light-emitting element
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Disclosed is a light-emitting device material which comprises a compound having a specific structure of a carbazole skeleton and can realize a light-emitting device having high light-emitting efficiency and durability. Also disclosed is a light-emitting device comprising the light-emitting device material.
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Page/Page column 52
(2016/11/17)
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- Iterative double cyclization reaction by SRN1 mechanism. A theoretical interpretation of the regiochemical outcome of diazaheterocycles
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In this report, we present a synthetic and mechanistic study of novel iterative double cyclization intramolecular SRN1 reactions from diamides bearing two aryl iodide moieties. This cyclization affords aromatic diazaheterocyclic compounds in good yields. Two synthetic strategies were employed for their preparation: intramolecular SRN1 and Homolytic Aromatic Substitution. The mechanism is non-trivial and we propose that radicals are intermediates. The regiochemistry was studied using computational calculations, employing the DFT method and the B3LYP functional. It was found that the distribution of products depends on the cyclization activation energies, proportion of neutral conformers, and the type of the electron transfer reaction.
- Peisino, Lucas E.,Camargo Solorzano, Gloria P.,Budén, María E.,Pierini
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p. 36374 - 36384
(2015/05/05)
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- New [...] derivative, and the host material consisting of the organic electroluminescence element using the same
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PROBLEM TO BE SOLVED: To provide a new bicarbazolyl derivative useful for providing organic electroluminescent elements enabling own low-voltage driving and having high efficiency, to provide a host material comprising the same and such an organic EL (
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Paragraph 0123
(2016/12/16)
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- HOST MATERIALS FOR PHOSPHORESCENT OLEDS
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Novel aryl silicon and aryl germanium host materials are described. These compounds improve OLED device performance when used as hosts in the emissive layer of the OLED.
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(2013/03/26)
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- Synthesis of carbazoles by intramolecular arylation of diarylamide anions
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(Chemical Equation Presented) The synthesis of a series of substituted 9H-carbazoles by the photostimulated SRN1 substitution reaction with diarylamines as starting substrate was performed. The diarylamines were obtained by two approaches, the Pd-catalyzed reactions (Buchwald-Hartwig) or Cu-catalyzed reactions of 2-haloanilines with aryl halides, or 2-bromoiodobenzene with anilines, with moderate to very good isolated yields (45-89%). Through an intramolecular C-C bond formation of diarylamines by the SRN1 mechanism, carbazoles were achieved. These reactions proceeded synthetically in very good to excellent yields (81-99%) in liquid ammonia and DMSO. The reaction of N-(2-bromophenyl)-2-phenylbenzenamine gave 1-phenyl-9H-carbazole (38%) and the isomer 9H-tribenz[b,d,f]azepine (58%). By using this methodology, 9Hcarbazoles, substituted 9H-carbazoles, benzocarbazoles, and even 3,3′-bi(9H-carbazole) were obtained by a double SRN1 reaction with benzidine.
- Buden, Maria E.,Vaillard, Victoria A.,Martin, Sandra E.,Rossi, Roberto A.
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experimental part
p. 4490 - 4498
(2009/09/26)
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- SPECTROPHOTOMETRIC, VOLTAMMETRIC, AND QUANTUM-CHEMICAL INVESTIGATION OF CARBAZOLE OXIDATION
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A spectrophotometric, voltammetric, and quantum-chemical investigation has suggested a scheme of the mechanism of carbazole oxidation in acid medium to dimeric diquinonediimine products, including two one-electron steps and the formation of radical cation intermediates.The electrooxidation of carbazole on a rotating disk electrode proceeds under conditions of mixed control and is a one-electron process.
- Pankratov, A. N.,Stepanov, A. N.,Grebenyukova, L. V.
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p. 164 - 168
(2007/10/02)
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