- A solution-processable triphenylamine-fluorene host for exciplex based white phosphorescent organic light-emitting diodes
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A novel triphenylamine-fluorene oligomer with macro-spirocyclic structure was designed and prepared as a host for exciplex based white phosphorescent organic light-emitting diodes (white PhOLEDs), in which only iridium(iii)bis(4,6-(difluorophenyl)pyridina
- Fan, Zhaokang,Li, Nengquan,Quan, Yiwu,Chen, Qingmin,Ye, Shanghui,Fan, Quli,Huang, Wei,Xu, Hui
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- Selective Electrochemical Oxygenation of Alkylarenes to Carbonyls
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An efficient electrochemical method for benzylic C(sp3)-H bond oxidation has been developed. A variety of methylarenes, methylheteroarenes, and benzylic (hetero)methylenes could be converted into the desired aryl aldehydes and aryl ketones in moderate to excellent yields in an undivided cell, using O2 as the oxygen source and lutidinium perchlorate as an electrolyte. On the basis of cyclic voltammetry studies, 18O labeling experiments, and radical trapping experiments, a possible single-electron transfer mechanism has been proposed for the electrooxidation reaction.
- Li, Xue,Bai, Fang,Liu, Chaogan,Ma, Xiaowei,Gu, Chengzhi,Dai, Bin
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supporting information
p. 7445 - 7449
(2021/10/02)
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- The Origin of Catalytic Benzylic C?H Oxidation over a Redox-Active Metal–Organic Framework
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Selective oxidation of benzylic C?H compounds to ketones is important for the production of a wide range of fine chemicals, and is often achieved using toxic or precious metal catalysts. Herein, we report the efficient oxidation of benzylic C?H groups in a broad range of substrates under mild conditions over a robust metal–organic framework material, MFM-170, incorporating redox-active [Cu2II(O2CR)4] paddlewheel nodes. A comprehensive investigation employing electron paramagnetic resonance (EPR) spectroscopy and synchrotron X-ray diffraction has identified the critical role of the paddlewheel moiety in activating the oxidant tBuOOH (tert-butyl hydroperoxide) via partial reduction to [CuIICuI(O2CR)4] species.
- Carter, Joseph H.,Day, Sarah J.,Han, Xue,Kang, Xinchen,Kimberley, Louis,Li, Jiangnan,McInnes, Eric J. L.,Schr?der, Martin,Sheveleva, Alena M.,Smith, Gemma L.,Tang, Chiu C.,Tuna, Floriana,Yang, Sihai
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supporting information
p. 15243 - 15247
(2021/06/08)
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- Amphiphilic ligands for Cu-catalyzed aerobic oxidation to synthesize 9-fluorenones in water
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A series of amphiphilic PEG-functionalized nitrogen ligands were developed for the highly efficient copper-catalyzed aerobic oxidation of 9-fluorenes, with molecular oxygen as the sole oxidant in neat water. A broad range of functional groups are well tolerated and thus offer the opportunity for further functionalization.
- Li, Longjia,Liu, Zibo,Tang, Shanyu,Li, Jiao,Ren, Xuanhe,Yang, Guanyu,Li, Heng,Yuan, Bingxin
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- Method for synthesizing fluorenone ketone compound through molecular oxygen oxidation in water phase
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Aiming at the technical problems that in the prior art a method for synthesizing a fluorenone ketone compound has organic solvent pollution and byproducts can be generated, the invention provides a method for synthesizing a fluorenone ketone compound through molecular oxygen oxidation in a water phase. The method comprises the following steps: by taking a fluorenone compound as a substrate, dispersing into an alkali solution, and at 40-120 DEG C, in the presence of oxygen, and with a water-soluble transition metal compound as a catalyst, stirring to carry out reactions, thereby obtaining the fluorenone ketone compound. By adopting the method, molecular oxygen is adopted as an oxidant, and water is adopted as a solvent, so that an organic solvent is avoided, and the problem that multiple byproducts are generated because of peroxidation can be avoided.
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Paragraph 0062-0065
(2019/08/20)
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- Sodium copper chlorophyllin catalyzed chemoselective oxidation of benzylic alcohols and diarylmethanes in water
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We report the highly efficient and chemoselective oxidation of benzylic alcohols catalyzed by sodium copper chlorophyllin in water, producing corresponding arylcarbonyl compounds. Importantly, the catalytic system exhibits a wide substrate scope and high functional group tolerance. Moreover, secondary alcohols and even diarylmethanes were smoothly oxidized to the desired aryl ketones with excellent yields.
- Liu, Shi-juan,Zhang, Miao,Lu, Rong,Li, Xiu-ying,Che, Guang-bo
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- Immobilization of Keggin polyoxovanadoniobate in crystalline solids to produce effective heterogeneous catalysts towards selective oxidation of benzyl-alkanes
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Two ionic organic-inorganic hybrid compounds, [CuII(C2N2H8)2]4[CuII(C2N2H8)2(H2O)2]2[PNb12O40VVVIVO2]·(OH)2·11H2O (1) and [CoIII(C2N2H8)3]2[CoIII(C2N2H8)2(H2O)2]0.5[H2.5PNb12O40 VVVIVO2]·20H2O (2), based on P-centered dicapped polyoxoniobates and organometallic cations were isolated and structurally characterized by routine techniques. The trivalent cobalt complex-containing compound exhibits a looser arrangement compared with its divalent copper complex-containing counterpart, with a space volume of 34.9% for the former and 17.0% for the latter. The two compounds were proved to be effective in facilitating the oxidation of benzyl-alkanes to ketone products in a heterogeneous manner, evidencing the feasiblity of the strategy of self-immobilization of catalytically active, readily soluble PNb12O40(VO)2 species in crystalline solids.
- Hu, Jufang,Dong, Jing,Huang, Xianqiang,Chi, Yingnan,Lin, Zhengguo,Li, Jikun,Yang, Song,Ma, Hongwei,Hu, Changwen
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p. 8245 - 8251
(2017/07/10)
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- Four alkoxohexavanadate-based pd-polyoxovanadates as robust heterogeneous catalysts for oxidation of benzyl-alkanes
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Four alkoxohexavanadate-based Pd-POVs [Pd(dpa)(acac)]2[V6O13(OMe)6] (1), [Pd(dpa)(acac)]2[V6O11(OMe)8] (2), [Pd(dpa)(acac)]2[V6O11(OMe)8]·H2O (3), and [Pd(DMAP)2(acac)]2[V6O11(OMe)8]·H2O (4) (POV = polyoxovanadate; dpa = 2,2′-dipyridine amine; DMAP = 4-dimethylaminopyridine; acac = acetylacetone anion) have been synthesized and fully characterized by single crystal X-ray diffraction and powder X-ray diffraction analyses, Fourier transform infrared spectroscopy, element analyses, and X-ray photoelectron spectroscopy. In 1-4, Pd complexes and hexavanadate anions are assembled through electrostatic interactions. Interestingly, the [V6O11(OMe)8]2- cores in 2 and 3 are a pair of isomers that can be isolated by controlling crystallization temperature. Moreover, to the best of our knowledge, the {V6} core in 3 represents a new octamethoxyhexavanadates cluster. It is notable that compounds 1-4 exhibit excellent heterogeneous catalytic performance in the oxidation of benzyl-alkanes with t-butylhydroperoxide as oxidant. Among them, the catalytic activity of 1 (conv. and selec. up to 99%, respectively) outperforms others and can be reused without losing its activity.
- Li, Ji-Kun,Huang, Xian-Qiang,Yang, Song,Ma, Hong-Wei,Chi, Ying-Nan,Hu, Chang-Wen
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supporting information
p. 1454 - 1461
(2015/04/21)
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- Tuning HOMO-LUMO levels: Trends leading to the design of 9-fluorenone scaffolds with predictable electronic and optoelectronic properties
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Highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) tuning is an important consideration in the development of organic-based semiconducting materials. A study of the specific effects and overall trends for the HOMO-LUMO tuning of a diverse series of 9-fluorenones by means of extended conjugation and substituent effects is described. Trends were explored in a range of compounds, beginning with structures having highly electron-withdrawing substituents and progressing to structures having highly electron-donating substituents. Compounds with an incremental increase in conjugation were also examined. Electrochemical and optical measurements were used to calculate the HOMO-LUMO levels and HOMO-LUMO bandgap (HLG) for each structure. Results from both methods were compared and correlated with the differences in molecular structure. Increasing the electron-donating character of the substituents was observed to decrease the HLG and increase the energy levels of the HOMO and the LUMO, whereas an increase in the electron-withdrawing character produced the opposite results. Increasing conjugation decreased the HLG, increased the HOMO energy level, but decreased the LUMO energy level. Spectroscopic evidence of substituent influence on the carbonyl suggests that substituents directly impact the HLG by influencing the availability of nonbonding electrons within the carbonyl, which impacts the probability of an nπ* transition. The data presented not only elaborate on the HOMO-LUMO tuning of 9-fluorenone systems but also enable the consideration of 9-fluorenones as analogous models for HOMO-LUMO tuning in other more complex polyaromatic systems such as bifluorenylidenes. These trends may provide insight into developing materials with specifically tuned HLGs and HOMO-LUMO levels for a variety of applications. Copyright
- Eakins, Galen L.,Alford, Joshua S.,Tiegs, Brandon J.,Breyfogle, Bryan E.,Stearman, Chad J.
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experimental part
p. 1119 - 1128
(2012/03/22)
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- C-9 fluorenyl substituted anthracenes: A promising new family of blue luminescent materials
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Syntheses, optical, and electrochemical properties of novel C-9 fluorenyl substituted anthracenes linked by a tetrahedral sp3-hybridized carbon atom are reported for blue light emitting materials. Remarkably, an unoptimized organic light-emitting diode based on 1-fold fluorene-functionalized anthracene 3 exhibits a radiance of 4100 cd/m2 at 12 V and a maximum EL efficiency of 1.36 cd/A with color purity CIE x, y (0.157, 0.082), which is very close to the National Television System Committee standard blue.
- Wang, Jing,Wan, Wen,Jiang, Haizhen,Gao, Yan,Jiang, Xueyin,Lin, Huaping,Zhao, Weiming,Hao, Jian
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supporting information; experimental part
p. 3874 - 3877
(2010/11/18)
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- New dispiro compounds: Synthesis and properties
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We report the synthesis and structural characterization of two dispiro compounds. These two positional isomers have been designed and synthesized through an efficient method. Because of the rigidity and orthogonality of the spiro bridge, both molecules ex
- Portel, Cyril,Rault-Berthelot, Joelle,Barriere, Frederic,Slawin, Alexandra M. Z.
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p. 373 - 376
(2008/09/20)
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- The superbase-mediated pairwise substitution of the 2,2′- and 6,6′-positions in a biphenyl derivative
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The superbasic mixture of butyllithium and potassium tertbutoxide is powerful enough to enable the double proton abstraction from one ortho and one ortho′ position of 4,4′-di-tert-butylbiphenyl. In this way, a series of functionalized derivatives becomes readily accessible, among them 4,4′-di-tert-butylbiphenyldiyl-2,2′-dicarboxylic acid (2a) and 4,4′-ditert-butylbiphenyl-2,2′-diol (2d). The latter compound can be subjected again to a superbase-promoted double metalation, thus giving rise to 2,2′,6,6′-tetrasubstituted biphenyl derivatives. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
- Schlosser, Manfred,Mangano, Guiseppe,Leroux, Frederic
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p. 1014 - 1017
(2007/10/03)
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- Efficient method for the synthesis of hetarenoindanones based on 3-arylhetarenes and their conversion into hetarenoindenes
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A series of hetarenoindanones have been prepared by direct double metalation of the appropriate 3-phenylhetarene with butyllithium in the presence of TMEDA followed by treatment of the resulting dilithium compound with ethyl N ,N-dimethylcarbamate. All hetarenoindanones were reduced according to Wolff-Kishner by hydrazine in the presence of KOH to the corresponding hetarenoindenes.
- Kashulin, Igor A.,Nifant'ev, Ilya E.
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p. 5476 - 5479
(2007/10/03)
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- Versatile and Convenient Lattice Hosts derived from Singly Bridged Triarylmethane Frameworks, X-Ray Crystal Structures of Three Inclusion Compounds
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A new family of host molecules, based on the singly bridged triarylmethanol and triarylacetic acid frameworks, is described.These hosts form crystalline inclusions with a variety of uncharged organic molecules ranging from protic dipolar to apolar compounds (130 different species).The formation and stoicheiometry depend in a systematic manner on structural parameters of the host, such as the nature of the functional group and the substituents, and on the substituent positions.The crystal structures of three inclusion compounds have been studied by X-ray diffraction.They reveal the building principles of the new inclusion family.In the crystals of 1a*benzene (8:3), the benzene is interstitially entrapped by H-bonded tetramer clusters of 1a.Crystals of 1a*dioxane (4:3) are built of H-bonded 2:1 host-guest complexes including interstitial molecules of dioxane.In the case of 4c*EtOH (1:1), the building principle is formation of 2:2 host-guest clusters via a twelve-membered H-bonded ring.
- Weber, Edwin,Doerpinghaus, Norbert,Csoeregh, Ingeborg
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p. 2167 - 2177
(2007/10/02)
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