- Meso-substituted boron-dipyrromethene compounds: synthesis, tunable solid-state emission, and application in blue-driven LEDs
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In this work, we depict the synthesis and characterization of a series of meso-substituted boron-dipyrromethene (BODIPY) compounds. Their optical and electrochemical properties were investigated systematically. All these compounds exhibited intense absorption bands in the ultraviolet (UV) and visible regions, which arise from the π–π* transitions based on their BODIPY core segments. By comparing electron-withdrawing substituents and electron-donating substituents, we found that these compounds exhibited some similar photophysical properties but exhibited different fluorescence in the solid state. All compounds were highly emissive in dichloromethane at room temperature (λem = 512–523 nm, ΦPL > 0.9). When these compounds were applied in blue-driven light-emitting diodes (LEDs) as light-emitting materials, the devices showed luminescence efficiency ranging from 1.09 to 34.13 lm/W. Their luminescence and electrochemical properties could be used for understanding the structure–property relationship of BODIPY compounds and developing functional fluorescent materials.
- Liu, Hao,Su, Huan,Chen, Zhiyuan,Zhu, Senqiang,Liu, Rui,Zhu, Hongjun
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p. 1697 - 1705
(2021/07/10)
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- A 2 - (3, 5 - double - trifluoromethyl - phenyl) -2 - methyl - propionic acid preparation method
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The invention provides a 2 - (3, 5 - double - trifluoromethyl - phenyl) - 2 - methyl - propionic acid preparation method. In particular, the use of 3, 5 - trifluoro - methyl-bromobenzene as raw materials, through Grignard - sediment reaction, Suzuki coupling reaction, to obtain 2 - (3, 5 - double - trifluoromethyl - phenyl) - 2 - methyl - propionic acid. The method of short synthetic route, raw materials are easy and the cost is low, mild reaction conditions, easy purification of products, and have high yield, is suitable for industrial mass production.
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Paragraph 0089-0091
(2019/07/08)
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- Synthesis and characterization of perfluorinated phenyl-substituted Ir(iii) complex for pure green emission
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A new deep green-emitting material, a 3,5-bis(trifluoromethyl)phenylene-substituted iridium(iii) complex, fac-tris[2-(3′,5′-bis(trifluoromethyl)biphenyl-3-yl)pyridine]iridium (Ir(mtfppy)3), was synthesized. Introducing bulky 3,5-bis(trifluoromethyl)phenylene to the metaposition of pyridyl-phenyl results in blue-shifted narrow emission compared to that of Ir(ppy)3. The organic light-emitting diode (OLED) based on Ir(mtfppy)3 shows a maximum external quantum efficiency (EQE) of 23.2% with the CIE coordinates of (0.26, 0.63) without strong microcavity effect.
- Kim, Myeong-Jong,Yoo, Seung-Jun,Hwang, Jaeyoung,Park, Sung-Jin,Kang, Jae-Wook,Kim, Yun-Hi,Kim, Jang-Joo,Kwon, Soon-Ki
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supporting information
p. 3107 - 3111
(2017/03/30)
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- NOVEL METHOD FOR PREPARING FLUORINATED PYROMELLITIC DIANHYDRIDE
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The present invention relates to a method for preparing fluorinated pyromellitic dianhydrides represented by the chemical formula 1. The method includes the steps of: (1) preparing the compound of the chemical formula 2 by bromiation of the pyromellitic d
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Paragraph 0089; 0093-0095
(2016/11/17)
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- An easy route to (hetero)arylboronic acids
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An unprecedented spontaneous reactivity between diazonium salts and diboronic acid has been unveiled, leading to a versatile arylboronic acid synthesis directly from (hetero)arylamines. This fast reaction (35 min overall) tolerates a wide range of functional groups and is carried out under very mild conditions. The radical nature of the reaction mechanism has been investigated.
- Erb, William,Hellal, Akila,Albini, Mathieu,Rouden, Jacques,Blanchet, Jerome
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supporting information
p. 6608 - 6612
(2014/06/09)
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- Vaulted biaryls in catalysis: A structure-activity relationship guided tour of the immanent domain of the VANOL ligand
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The active site in the BOROX catalyst is a chiral polyborate anion (boroxinate) that is assembled in situ from three equivalents of B(OPh) 3 and one of the VANOL ligand by a molecule of substrate. The substrates are bound to the boroxinate by Hbonds to oxygen atoms O1-O3. The effects of introducing substituents at each position of the naphthalene core of the VANOL ligand are systematically investigated in an aziridination reaction. Substituents in the 4,4′- and 8,8′-positions have a negative effect on catalyst performance, whereas, substituents in the 7- and 7′-positions have the biggest impact in a positive direction. VANOL destination: The active site in the BOROX catalyst is a chiral polyborate anion (boroxinate; see figure) that is assembled in situ from three equivalents of B(OPh)3 and one of the VANOL ligand by a molecule of substrate. The effects of introducing substituents at each position of the naphthalene core of the VANOL ligand are systematically investigated in an aziridination reaction. Copyright
- Guan, Yong,Ding, Zhensheng,Wulff, William D.
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supporting information
p. 15565 - 15571
(2013/11/19)
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- Organotrifluoroborate hydrolysis: Boronic acid release mechanism and an acid-base paradox in cross-coupling
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The hydrolysis of potassium organotrifluoroborate (RBF3K) reagents to the corresponding boronic acids (RB(OH)2) has been studied in the context of their application in Suzuki-Miyaura coupling. The "slow release" strategy in such SM couplings is only viable if there is an appropriate gearing of the hydrolysis rate of the RBF3K reagent with the rate of catalytic turnover. In such cases, the boronic acid RB(OH)2 does not substantially accumulate, thereby minimizing side reactions such as oxidative homocoupling and protodeboronation. The study reveals that the hydrolysis rates (THF, H2O, Cs2CO 3, 55 °C) depend on a number of variables, resulting in complex solvolytic profiles with some RBF3K reagents. For example, those based on p-F-phenyl, naphthyl, furyl, and benzyl moieties are found to require acid catalysis for efficient hydrolysis. This acid-base paradox assures their slow hydrolysis under basic Suzuki-Miyaura coupling conditions. However, partial phase-splitting of the THF/H2O induced by the Cs2CO 3, resulting in a lower pH in the bulk medium, causes the reaction vessel shape, material, size, and stirring rate to have a profound impact on the hydrolysis profile. In contrast, reagents bearing, for example, isopropyl, β-styryl, and anisyl moieties undergo efficient "direct" hydrolysis, resulting in fast release of the boronic acid while reagents bearing, for example, alkynyl or nitrophenyl moieties, hydrolyze extremely slowly. Analysis of B-F bond lengths (DFT) in the intermediate difluoroborane, or the Swain-Lupton resonance parameter (R) of the R group in RBF3K, allows an a priori evaluation of whether an RBF3K reagent will likely engender "fast", "slow", or "very slow" hydrolysis. An exception to this correlation was found with vinyl-BF 3K, this reagent being sufficiently hydrophilic to partition substantially into the predominantly aqueous minor biphase, where it is rapidly hydrolyzed.
- Lennox, Alastair J. J.,Lloyd-Jones, Guy C.
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supporting information; experimental part
p. 7431 - 7441
(2012/06/16)
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- Substituent effects on aryltrifluoroborate solvolysis in water: Implications for Suzuki-Miyaura coupling and the design of stable 18F-labeled aryltrifluoroborates for use in PET imaging
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(Chemical Equation Presented) Whereas electron withdrawing substituents retard the rate of aryltrifluoroborate solvolysis, electron-donating groups enhance it. Herein is presented a Hammett analysis of the solvolytic lability of aryltrifluoroborates where log(Ksolv) values correlate to a values with a ρ value of approximately -1. This work provides a predictable rubric for tuning the reactivity of boron for several uses including 18F-labeled PET reagents and has mechanistic implications for ArBF3-enhanced ligandless metal-mediated cross coupling reactions with aryltrifluoroborates.
- Ting, Richard,Harwig, Curtis W.,Lo, Justin,Li, Ying,Adam, Michael J.,Ruth, Thomas J.,Petrin, David M.
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p. 4662 - 4670
(2008/09/20)
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- One-pot synthesis of arylboronic acids and aryl trifluoroborates by Ir-catalyzed borylation of arenes
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(Chemical Equation Presented) The synthesis of arylboronic acids and aryl trifluoroborates in a one-pot sequence by Ir-calalyzed borylation of arenes is reported. To prepare the arylboronic acids, the Ir-catalyzed borylation is followed by oxidative cleavage of the boronic ester with NaIO4. To prepare the aryltrifluoroborate, the Ir-catalyzed borylation is followed by displacement of pinacol by KHF2. These two-step sequences give products that are more reactive toward subsequent chemistry than the initially formed pinacol boronates.
- Murphy, Jaclyn M.,Tzschucke, C. Christoph,Hartwig, John F.
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p. 757 - 760
(2007/10/03)
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