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961.
Structure‐Triggered High Quantum Yield Luminescence and Switchable Dielectric Properties in Manganese(II) Based Hybrid Compounds
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Zhong‐Xia Wang Peng‐Fei Li Wei‐Qiang Liao Yuanyuan Tang Prof. Heng‐Yun Ye Prof. Yi Zhang 《化学:亚洲杂志》2016,11(7):981-985
Two new manganese(II) based organic–inorganic hybrid compounds, C11H21Cl3MnN2 ( 1 ) and C11H22Cl4MnN2 ( 2 ), with prominent photoluminescence and dielectric properties were synthesized by solvent modulation. Compound 1 with novel trigonal bipyramidal geometry exhibits bright red luminescence with a lifetime of 2.47 ms and high quantum yield of 35.8 %. Compound 2 with tetrahedral geometry displays intense long‐lived (1.54 ms) green light emission with higher quantum yield of 92.3 %, accompanied by reversible solid‐state phase transition at 170 K and a distinct switchable dielectric property. The better performance of 2 results from the structure, including a discrete organic cation moiety and inorganic metal anion framework, which gives the cations large freedom of motion. 相似文献
962.
Electrocatalytic Generation of Amidyl Radicals for Olefin Hydroamidation: Use of Solvent Effects to Enable Anilide Oxidation
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Lin Zhu Peng Xiong Zhong‐Yi Mao Yong‐Heng Wang Prof. Dr. Xiaomei Yan Prof. Dr. Xin Lu Prof. Dr. Hai‐Chao Xu 《Angewandte Chemie (International ed. in English)》2016,55(6):2226-2229
Oxidative generation of synthetically important amidyl radicals from N?H amides is an appealing and yet challenging task. Previous methods require a stoichiometric amount of a strong oxidant and/or a costly noble‐metal catalyst. We report herein the first electrocatalytic method that employs ferrocene (Fc), a cheap organometallic reagent, as the redox catalyst to produce amidyl radicals from N‐aryl amides. Based on this radical‐generating method, an efficient intramolecular olefin hydroamidation reaction has been developed. 相似文献
963.
Colloidal GaAs quantum wires with diameters of 5-11 nm and narrow diameter distributions (standard deviation = 12-21% of the mean diameter) are grown by two methods based on the solution-liquid-solid (SLS) mechanism. Resolved excitonic absorption features arising from GaAs quantum wires are detected, allowing extraction of the size-dependent effective band gaps of the wires. The results allow the first systematic comparison of the size dependences of the effective band gaps in corresponding sets of semiconductor quantum wires and quantum wells. The GaAs quantum wire and well band gaps scale according to the prediction of a simple effective-mass-approximation, particle-in-a-box (EMA-PIB) model, which estimates the kinetic confinement energies of electron-hole pairs in quantum nanostructures of different shapes and confinement dimensionalities. 相似文献
964.
NIU Wenxue LIU Zheyi LIU Jing LAI Can ZHANG Tingting ZHAO Heng WANG Guosheng WANG Fangjun 《高等学校化学研究》2023,39(2):260-265
High-resolution liquid chromatography separation is essential to in-depth proteomic profiling of complex biological samples. Herein, we established an ion-pair reversed-phase×reversed-phase two-dimensional liquid chromatography (IPRP×RP 2DLC) strategy for comprehensive proteomic analysis. Both RPLC separation dimensions were performed at low pH, with trifluoroacetic acid(TFA) and formic acid(FA) as mobile phase addictive, respectively. As the good separation resolution offered by ion-pairing effect of TFA, the fractionation efficiency was greatly improved with 74.0% peptides identified in just one fraction. Comparing with conventional high pH RP fractionation, the overall separation rate of IPRP was about 1.6 times that of high-pH RP, which increased the number of identified peptides by 21%. Further, 2169 proteins and 8540 peptides were confidently identified from crude serum sample by our IPRP×RP 2DLC strategy, exhibiting great potential in clinical proteomics in the future. 相似文献
965.
Prof. Xingwei Li Heng Song Prof. Songjie Yu Dr. Ruijie Mi Dr. Xiao-Xi Li 《Angewandte Chemie (International ed. in English)》2023,62(37):e202305669
The incorporation of fluorine atoms in organics improves their bioactivity and lipophilicity. Catalytic functionalization of gem-difluorodienes represents one of the most straightforward approaches to access fluorinated alkenes. In contrast to the regular 1,3-dienes that undergo diverse asymmetric di/hydrofunctionalizations, the regio- and enantioselective oxyamination of gem-difluorodienes remains untouched. Herein, we report asymmetric 1,4-oxyamination of gem-difluorodiene by chiral rhodium-catalyzed three-component coupling with readily available carboxylic acid and dioxazolone, affording gem-difluorinated 1,4-amino alcohol derivatives. Our asymmetric protocol exhibits high 1,4-regio- and enantioselectivity with utility in the late-stage modification of pharmaceuticals and natural products. Stoichiometric experiments provide evidences for the π-allylrhodium pathway. Related oxyamination was also realized when trifluoroethanol was used as an oxygen nucleophile. 相似文献
966.
A hydride generation-atomic fluorescence spectrometry (AFS) method was developed for the detection of arsenic (As) and lead (Pb) in chromite by alkali fusing and acid dissolving. The sample was fused by Na2O2 and acidification dissolved by HCl. As was quantified by AFS with 10% (V/V) HCl as the carrier flow agent, and KBH4(15 g/L) as reducing agent. Pb was quantified by AFS with 1% (V/V) HCl as the carrier flow agent, and KBH4(20 g/L)-KOH(10 g/L)-K3[Fe(CN)6] (15 g/L) as reducing agent. Under the optimum conditions, the correlation coefficient (R2) was 1.0000 in the range of 0.5-10 μg/L, the limit of detection (LOD) was 0.05 μg/g with the relative standard deviations (RSDs) of 1.4%-6.0% and the recoveries of 96.2%-116.7% for As. And the R2 was 0.9998 in the range of 1.25-25 μg/L, the LOD was 0.2 μg/g with the RSDs of 1.5%-3.7% and the recoveries of 95.9%-112.2% for Pb. In addition, the method was validated by certified reference sample analysis and multi-laboratory test, which meets the requirements for the standardized quantitative analysis of trace As and Pb in chromite. © 2023, Youke Publishing Co.,Ltd. All rights reserved. 相似文献
967.
Zheng H Ma D Bao X Hu JZ Kwak JH Wang Y Peden CH 《Journal of the American Chemical Society》2008,130(12):3722-3723
The use of an ultrahigh magnetic field spectrometer and 95Mo isotope enrichment facilitate the direct observation of the local structure of Mo species on Mo/zeolite catalysts by 95Mo NMR. Top trace: The experimental 95Mo NMR spectrum of 6Mo/HZSM-5. Bottom traces: The simulated overall spectrum (orange), the spectral component corresponding to MoO3 (purple), and the component corresponding to the exchanged Mo species (green). The exchanged Mo species proved to be the active center for the methane dehydroaromatization (MDA) reaction. 相似文献
968.
Yi‐Zheng Li Ying‐Ming Pan Xiao‐Yan Huang Heng‐Shan Wang 《Helvetica chimica acta》2008,91(12):2284-2291
Two new withanolides, namely (20S,22R)‐15α‐acetoxy‐5α‐chloro‐6β,14β‐dihydroxy‐1‐oxowitha‐2,24‐dienolide ( 1 ) and (22R)‐5β,6β : 14α,17 : 14β,26‐triepoxy‐2α‐ethoxy‐13,20,22‐trihydroxy‐1,15‐dioxo‐16α,24‐cyclo‐13,14‐secoergosta‐18,27‐dioic acid 18→20,27→22‐dilactone ( 2 ), along with six known compounds, physagulin B ( 3 ), withangulatin A ( 4 ), physalin I ( 5 ), withaminimin ( 6 ), physagulin J ( 7 ), and ergosta‐5,25‐diene‐3β,24ξ‐diol ( 8 ), were isolated from the whole plant of Physalis alkekengi var. francheti. Their structures were elucidated on the basis of spectroscopic analyses. 相似文献
969.
本文合成了一系列3-烷基/对烷氧基苯基-3-羟基-联茚满烯二酮新化合物,并通过1H NMR, IR, MS 和元素分析数据进行了结构表征,其中化合物1,5,6的结构通过单晶X-Ray衍射进行了确证。分别用固体紫外光谱和电子自旋共振光谱研究了化合物的光致变色性能和光致自由基性质,结果表明:该类化合物在200W高压水银灯光源照射下产生光致变色现象,同时具有光致自由基性质。本文还根据分子结构和及分子内的作用力讨论了性质与结构之间的关系。 相似文献
970.
Qian Sun~a Wei Dong Zhang~ 《中国化学快报》2008,19(4):447-449
A new phenolic compound was isolated from the ethanol extract of the bulbs of Crinum asiaticum L.var.sinicum Baker.Its structure was defined as 1-(2-hydroxy-4-hydroxymethyl)phenyl-6-O-caffeoyl-β-D-gluco-pyranoside on the basis of spectroscopic evidences. 相似文献