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991.
Xue Min Ivan A. Popov Fu‐Xing Pan Dr. Lei‐Jiao Li Eduard Matito Prof. Dr. Zhong‐Ming Sun Prof. Dr. Lai‐Sheng Wang Prof. Dr. Alexander I. Boldyrev 《Angewandte Chemie (International ed. in English)》2016,55(18):5531-5535
Antiaromaticity, as introduced in 1965, usually refers to monocyclic systems with 4n π electrons. This concept was extended to all‐metal molecules after the observation of Li3Al4? in the gas phase. However, the solid‐phase counterparts have not been documented to date. Herein, we describe a series of all‐metal antiaromatic anions, [Ln(η4‐Sb4)3]3?(Ln=La, Y, Ho, Er, Lu), which were isolated as the K([2.2.2]crypt) salts and identified by single‐crystal X‐ray diffraction. Based on the results obtained from the chemical bonding analysis, multicenter indices, and the electron‐counting rule, we conclude that the core [Ln(η4‐Sb4)3]3? fragment of the crystal has three locally π‐antiaromatic Sb4 fragments. This complex represents the first locally π‐antiaromatic all‐metal system in the solid state, which is stabilized by interactions of the three π‐antiaromatic units with the central metal atom. 相似文献
992.
Yuntao Zhu Jie Wu Prof. Xing Chen 《Angewandte Chemie (International ed. in English)》2016,55(32):9301-9305
Molecular imaging of glycans has been actively pursued in animal systems for the past decades. However, visualization of plant glycans remains underdeveloped, despite that glycosylation is essential for the life cycle of plants. Metabolic glycan labeling in Arabidopsis thaliana by using N‐azidoacetylglucosamine (GlcNAz) as the chemical reporter is reported. GlcNAz is metabolized through the salvage pathway of N‐acetylglucosamine (GlcNAc) and incorporated into N‐linked glycans, and possibly intracellular O‐GlcNAc. Click‐labeling with fluorescent probes enables visualization of newly synthesized N‐linked glycans. N‐glycosylation in the root tissue was discovered to possess distinct distribution patterns in different developmental zones, suggesting that N‐glycosylation is regulated in a developmental stage‐dependent manner. This work shows the utility of metabolic glycan labeling in elucidating the function of N‐linked glycosylation in plants. 相似文献
993.
Tian Luo Prof. Dr. Jianling Zhang Xiuniang Tan Chengcheng Liu Dr. Tianbin Wu Dr. Wei Li Xinxin Sang Prof. Buxing Han Prof. Zhihong Li Dr. Guang Mo Dr. Xueqing Xing Prof. Zhonghua Wu 《Angewandte Chemie (International ed. in English)》2016,55(43):13533-13537
Herein we propose for the first time the utilization of a metal complex for forming water‐in‐supercritical CO2 (scCO2) microemulsions. The water solubility in the metal‐complex‐stabilized microemulsion is significantly improved compared with the conventional water‐in‐scCO2 microemulsions stabilized by hydrocarbons. Such a microemulsion provides a promising route for the in situ CO2 reduction catalyzed by a metal complex at the water/scCO2 interface. 相似文献
994.
Ivan A. Popov Fu‐Xing Pan Xue‐Rui You Dr. Lei‐Jiao Li Dr. Eduard Matito Chao Liu Prof. Dr. Hua‐Jin Zhai Prof. Dr. Zhong‐Ming Sun Prof. Dr. Alexander I. Boldyrev 《Angewandte Chemie (International ed. in English)》2016,55(49):15344-15346
Gas‐phase clusters are deemed to be σ‐aromatic when they satisfy the 4n+2 rule of aromaticity for delocalized σ electrons and fulfill other requirements known for aromatic systems. While the range of n values was shown to be quite broad when applied to short‐lived clusters found in molecular‐beam experiments, stability of all‐metal cluster‐like fragments isolated in condensed phase was previously shown to be mainly ascribed to two electrons (n=0). In this work, the applicability of this concept is extended towards solid‐state compounds by demonstrating a unique example of a storable compound, which was isolated as a stable [K([2.2.2]crypt)]+ salt, featuring a [Au2Sb16]4? cluster core possessing two all‐metal aromatic AuSb4 fragments with six delocalized σ electrons each (n=1). This discovery pushes the boundaries of the original idea of Kekulé and firmly establishes the usefulness of the σ‐aromaticity concept as a general idea for both small clusters and solid‐state compounds. 相似文献
995.
This paper characterized the observed low frequency acoustic signals generated by rock falls, thunderstorm, and wind turbulence in large rocky landslide. A digital infrasonic recording system was deployed on site to capture real-time low frequency acoustic signals associated with rock falls. An advanced non-stationary signal analysis method, i.e. Empirical Mode Decomposition (EMD), was applied to get insight to the characteristics of the low frequency acoustic signals induced by the hazards. Joint time–frequency distribution spectra technique was used to detect distinctive features of the events. The study shows that the low frequency acoustic signals can be excited by rock falls, thunderstorm and wind turbulence in the field environment, but the signal varies in both time domain and frequency domain with different patterns depending on the physical processes. The results demonstrated that the EMD-based signal processing technique is capable of extracting distinctive features to differentiate acoustic signals in real environment. 相似文献
996.
Design of Enhanced Catalysts by Coupling of Noble Metals (Au,Ag) with Semiconductor SnO2 for Catalytic Reduction of 4‐Nitrophenol 下载免费PDF全文
Mei Lei Wei Wu Shuanglei Yang Xingang Zhang Zhuo Xing Feng Ren Xiangheng Xiao Changzhong Jiang 《Particle & Particle Systems Characterization》2016,33(4):212-220
The reduction of 4‐nitrophenol (Nip) into 4‐aminophenol (Amp) by NaBH4, which is catalyzed by both binary and ternary yolk–shell noble‐metal/SnO2 heterostructures, is reported. The binary heterostructures contain individual Au or Ag nanoparticles (NPs) and the ternary heterostructures contain both Au and Ag NPs. The Au@SnO2 yolk–shell NPs are synthesized via a silica seeds‐mediated hydrothermal method. Subsequently, the Au@SnO2@Ag and Au@SnO2@Au yolk–shell–shell (YSS) NPs are synthesized, whereby SnO2 is located between the Au and Ag NPs. The morphology, composition, and optical properties of the as‐prepared samples are analyzed. For the binary heterostructures, the rate of the reduction reaction increases with decreasing particle size. The catalytic results demonstrate the synergistic effect of Au and Ag in the ternary metal–semiconductor heterostructures, which is beneficial to the catalytic reduction of Nip into Amp. Both the binary and ternary heterostructures exhibit significantly better catalytic performances than the corresponding bare Au and Ag NPs. It is envisaged that the current synthesized strategy will promote further interest in the field of bimetal NP‐based catalysis. 相似文献
997.
Xing Fan Jian Xiao Guang-Zhou Hu Yun-Peng Zhao Shi-Gang Kang Jin-Li Lu Hong-Ru Fan 《Chemical Papers》2016,70(6):848-855
Glycerol, a liquid matrix material for matrix-assisted laser desorption ionization mass spectrometry, was irradiated by a tunable pulsed infrared laser at wavelengths of 2.80 μ.m, 2.94 μ.m, 3.10 μ.m and 3.50 μ.m, covering the OH and CH stretch vibrations. A fast photography system was introduced to analyze the dynamic process of plume propagation induced by laser ablation up to 1000 μ.s of the delay time. Propagation distance of the plume front was measured and the corresponding velocities were calculated; they varied with the wavelength and decreased with the delay time. At the tunable wavelength of the peak of the OH absorption (3.0 μ.m), theoretical calculations indicate that energy deposition from the pulsed laser is in the regime of stress confinement. The mode of energy deposition depends on the wavelength of the OH vibration and its distance from the absorption maxima. However, stages after a 10 μ.s delay at various wavelengths show a certain similarity in the distance of plume propagation, which can be well fitted by a drag model. 相似文献
998.
999.
Benjamin A. Chalmers Hui Xing Sevan Houston Charlotte Clark Sussan Ghassabian Andy Kuo Benjamin Cao Andrea Reitsma Cody‐Ellen P. Murray Jeanette E. Stok Glen M. Boyle Carly J. Pierce Stuart W. Littler David A. Winkler Paul V. Bernhardt Cielo Pasay James J. DeVoss James McCarthy Peter G. Parsons Gimme H. Walter Maree T. Smith Helen M. Cooper Susan K. Nilsson John Tsanaktsidis G. Paul Savage Craig M. Williams 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2016,128(11)
1000.
Xiufeng Shi Bin Xing Binbin Fan Zhaoteng Xue Ruifeng Li 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2016,90(3):545-551
The SBA-16 obtained by different routes of elimination of organic templates were used as the hosts for encapsulation of chiral Ru complex (1S,2S)-DPEN-RuCl2(TPP)2 (1) (DPEN = 1,2-diphenylethylene-diamine, TPP = triphenyl phosphine). The methods for removing templates had distinct effects on the amount of residual template in SBA-16, which made the SBA-16 with different surface and structure properties. 1 encapsulated in SBA-16 extracted with the mixture of pyridine and ethanol showed higher activity and enantioselectivity for acetophenone asymmetric hydrogenation. 相似文献