14548-46-0Relevant articles and documents
Rapid formation of nitrogen-doped carbon foams by self-foaming as metal-free catalysts for selective oxidation of aromatic alkanes
Qin, Guo-Xin,Hao, Yan,Wang, Shuai,Dong, Yu-Bin
, (2020)
Porous carbon materials have attracted considerable interest as metal-free catalysts. In this study, we report a nitrogen-doped and nanofiber-based porous carbon foam produced via an efficient and facile self-foaming approach and its subsequent pyrolysis; in this approach, carbon dioxide-rich ethanolamine serves as the foaming agent, N source and polymerization catalyst. Meanwhile resorcinol and formaldehyde are used as carbon sources. Carbon dioxide-rich ethanolamine plays a crucial role in the release of gas as well as initiating polymerization on the interfaces of bubbles, which directs the formation of polymer foam. The N-doped carbon foam can be a highly active metal-free heterogeneous catalyst to promote selective oxidation of the benzyl group to the corresponding phenone. In addition, the carbon foams are easily cast with different morphologies. Notably, the prepared carbon foam is fabricated as a monolithic reactor for the oxidation reaction, which also exhibits good catalytic performances in the scale-up experiment.
Fluorescent pH sensor constructed from a heteroatom-containing luminogen with tunable AIE and ICT characteristics
Yang, Zhiyong,Qin, Wei,Lam, Jacky W. Y.,Chen, Sijie,Sung, Herman H. Y.,Williams, Ian D.,Tang, Ben Zhong
, p. 3725 - 3730 (2013)
A heteroatom-containing organic fluorophore 1-(4-pyridinyl)-1-phenyl-2-(9- carbazolyl)ethene (CP3E) was designed and synthesized. CP 3E exhibits the effect of intramolecular charge transfer (ICT) caused by the donor-acceptor interaction between its carbazole and pyridine units. Whereas it emits faintly in solution, it becomes a strong emitter in the aggregated state, demonstrating the phenomenon of aggregation-induced emission (AIE). Its emission can be reversibly switched between blue and dark states by repeated protonation and deprotonation. Such behaviour enables it to work as a fluorescent pH sensor in both solution and the solid state and as a chemosensor for detecting acidic and basic organic vapors. Analyses by NMR spectroscopy, single-crystal X-ray diffraction and computational calculations suggest that the change in electron affinity of the pyridinyl unit and molecular conformation of CP3E upon protonation and deprotonation is responsible for such sensing processes.
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Fulda
, p. 762 (1899)
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Crook,McElvain
, p. 4006,4009;vgl. H 331 (1930)
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An efficient and practical aerobic oxidation of benzylic methylenes by recyclable: N -hydroxyimide
Wang, Jian,Zhang, Cheng,Ye, Xiao-Qing,Du, Wenting,Zeng, Shenxin,Xu, Jian-Hong,Yin, Hong
, p. 3003 - 3011 (2021/01/28)
An efficient and practical benzylic aerobic oxidation catalyzed by cheap and simple N-hydroxyimide organocatalyst has been achieved with high yields and broad substrate scope. The organocatalyst used can be recycled and reused by simple workup and only minute amount (1 mol% in most cases) of simple iron salt is used as promoter. Phenyl substrates with mild and strong electron-withdrawing group could also be oxygenated in high yields as well as other benzylic methylenes. Influence of substituents, gram-scale application, catalysts decay and general mechanism of this methodology has also been discussed. This journal is
Half-sandwich ruthenium complex containing phenyl benzoxazole structure as well as preparation method and application of half-sandwich ruthenium complex
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Paragraph 0045-0048, (2021/04/14)
The invention relates to a half-sandwich ruthenium complex containing a phenyl benzoxazole structure as well as a preparation method and application of the half-sandwich ruthenium complex. The ruthenium complex has the following structure as shown in the specification. The preparation method comprises the steps of dissolving phenyl benzoxazole, [CymRuCl2] 2 and sodium acetate in methanol at room temperature, heating the system, and continuing to react; and after the reaction is finished, standing, filtering, carrying out reduced pressure pumping on the solvent, carrying out column chromatography separation on the obtained crude product to obtain the red half-sandwich ruthenium complex containing the phenyl benzoxazole structure, and applying the red half-sandwich ruthenium complex to catalysis of oxidation of alkyl pyridine compounds to prepare nitrogen heterocyclic ketone compounds. Compared with the prior art, the preparation method provided by the invention is simple and green, the catalytic oxidation reaction can be carried out under mild conditions, and the catalyst has high stability and is not sensitive to air and water.
Mn(III) active site in hydrotalcite efficiently catalyzes the oxidation of alkylarenes with molecular oxygen
Wang, Anwei,Zhou, WeiYou,Sun, Zhonghua,Zhang, Zhong,Zhang, Zhihui,He, MingYang,Chen, Qun
, (2020/12/07)
Developing efficient heterogeneous catalytic systems based on easily available materials and molecular oxygen for the selective oxidation of alkylarenes is highly desirable. In the present research, NiMn hydrotalcite (Ni2Mn-LDH) has been found as an efficient catalyst in the oxidation of alkylarenes using molecular oxygen as the sole oxidant without any additive. Impressive catalytic performance, excellent stability and recyclability, broad applicable scope and practical potential for the catalytic system have been observed. Mn3+ species was proposed to be the efficient active site, and Ni2+ played an important role in stabilizing the Mn3+ species in the hydrotalcite structure. The kinetic study showed that the aerobic oxidation of diphenylmethane is a first-order reaction over Ni2Mn-LDH with the activation energy (Ea) and pre-exponential factor (A0) being 85.7 kJ mol?1 and 1.8 × 109 min?1, respectively. The Gibbs free energy (ΔG≠) was determined to be -10.4 kJ mol-1 K-1 for the oxidation based on Eyring-Polanyi equation, indicating the reaction is exergonic. The mechanism study indicated that the reaction proceeded through both radical and carbocation intermediates. The two species were then trapped by molecular oxygen and H2O or hydroxyl species, respectively, to yield the corresponding products. The present research might provide information for constructing highly efficient and stable active site for the catalytic aerobic oxidation based on available and economic material.
