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981.
Xu‐Shuang Han Xinqi Luan Hai‐Feng Su Jiao‐Jiao Li Shang‐Fu Yuan Zhen Lei Yong Pei Quan‐Ming Wang 《Angewandte Chemie (International ed. in English)》2020,59(6):2309-2312
An alkynyl‐protected gold nanocluster, Au22(tBuC≡C)18 ( 1 ), has been synthesized and its structure has been determined by single‐crystal X‐ray diffraction. The molecular structure consists of a Au13 cuboctahedron kernel and three [Au3(tBuC≡C)4] trimeric staples. The cluster 1 has strong luminescence in the solid state with a 15 % quantum yield, and it displays interesting thermochromic luminescence as revealed by temperature‐dependent emission spectra. The enhanced room‐temperature emission is characterized as thermally activated delayed fluorescence. 相似文献
982.
Weiwei Yang Kushal Samanta Xintong Wan Tushar Ulhas Thikekar Yang Chao Shunshun Li Ke Du Jun Xu Yan Gao Han Zuilhof Andrew C.‐H. Sue 《Angewandte Chemie (International ed. in English)》2020,59(10):3994-3999
Tiara[5]arenes (T[5]s), a new class of five‐fold symmetric oligophenolic macrocycles that are not accessible from the addition of formaldehyde to phenol, were synthesized for the first time. These pillar[5]arene‐derived structures display both unique conformational freedom, differing from that of pillararenes, with a rich blend of solid‐state conformations and excellent host–guest interactions in solution. Finally we show how this novel macrocyclic scaffold can be functionalized in a variety of ways and used as functional crystalline materials to distinguish uniquely between benzene and cyclohexane. 相似文献
983.
Russian Journal of Organic Chemistry - Successive reactions of pentafluoronitrobenzene with resorcinol, orcinol, and tetrafluororesorcinol in acetonitrile in the presence of triethylamine afforded... 相似文献
984.
Qian Yi Han Haoyue Li Long Qiao Peng Zhao Rongmin Zhang Haiming 《Journal of Thermal Analysis and Calorimetry》2020,142(1):409-423
Journal of Thermal Analysis and Calorimetry - Layered yttrium hydroxides (LYH)- and graphene oxide (GO)-supported layered yttrium hydroxides (GO–LYH) were synthesized by a co-precipitation... 相似文献
985.
Han Bing-yuan Khoroshilov Andrey V. Tyurin Alexander V. Baranchikov Alexander E. Razumov Mikhail I. Ivanova Olga S. Gavrichev Konstantin S. Ivanov Vladimir K. 《Journal of Thermal Analysis and Calorimetry》2020,142(4):1533-1543
Journal of Thermal Analysis and Calorimetry - Thermodynamic properties (heat capacity Cp, entropy S°, enthalpy change ΔH° and reduced Gibbs energy ΔΦ°) of crystalline... 相似文献
986.
Lingheng Kong Xi Han Song Liu Yun Zou Yu Lan Xingwei Li 《Angewandte Chemie (International ed. in English)》2020,59(18):7188-7192
Axial‐to‐central chirality transfer is an important strategy to construct chiral centers, where the axially chiral reagents are mostly limited to atropomerically stable ones. Reported herein is a RhIII‐catalyzed enantioselective spiroannulative synthesis of nitrones. The coupling proceeds via C?H arylation to give an atropomerically metastable biaryl, followed by intramolecular dearomative trapping under oxidative conditions with high degree of chirality transfer. 相似文献
987.
Zhi‐Chao Jiang Yao‐Yu Xiao Lu Yin Li Han Yue Zhao 《Angewandte Chemie (International ed. in English)》2020,59(12):4925-4931
Novel main‐chain liquid crystalline Diels—Alder dynamic networks (LCDANs) were prepared that exhibit unprecedented ease for actuator programming and reprocessing compared to existing liquid crystalline network (LCN) systems. Following cooling from 125 °C, LCDANs are deformed with aligned mesogens self‐locked at room temperature by slowly formed Diels–Alder (DA) bonds, which allows for the formation of solid 3D actuators capable of reversible shape change, and strip walker and wheel‐capable light‐driven locomotion upon either thermally or optically induced order–disorder phase transition. Any actuator can readily be erased at 125 °C and reprogrammed into a new one under ambient conditions. Moreover, LCDANs can be processed directly from melt (for example, fiber drawing) and from solution (for example, casting tubular actuators), which cannot be achieved with LCNs using exchangeable covalent bonds. The combined attributes of LCDANs offer significant progress toward developing easily programmable/processable LCN actuators. 相似文献
988.
Jun‐Chao Liu Wei‐Qiang Liao Peng‐Fei Li Yuan‐Yuan Tang Xiao‐Gang Chen Xian‐Jiang Song Han‐Yue Zhang Yi Zhang Yu‐Meng You Ren‐Gen Xiong 《Angewandte Chemie (International ed. in English)》2020,59(9):3495-3499
Molecular ferroelectrics have attracted considerable interests because of their easy and environmentally friendly processing, low acoustical impedance and mechanical flexibility. Herein, a molecular thermochromic ferroelectric, N,N′‐dimethyl‐1,4‐diazoniabicyclo[2.2.2]octonium tetrachlorocuprate(II) ([DMe‐DABCO]CuCl4) is reported, which shows both excellent ferroelectricity and intriguing thermochromism. [DMe‐DABCO]CuCl4 undergoes a ferroelectric phase transition from Pca21 to Pbcm at a significantly high Curie temperature of 413 K, accompanied by a color change from yellow to red that is due to the remarkable deformation of [CuCl4]2? tetrahedron, where the ferroelectric and paraelectric phases correspond to yellow and red, respectively. Combined with multiple bistable physical properties, [DMe‐DABCO]CuCl4 would be a promising candidate for next‐generation smart devices, and should inspire further exploration of multifunctional molecular ferroelectrics. 相似文献
989.
Langli Luo Yao Nian Shuangbao Wang Zejian Dong Yang He You Han Chongmin Wang 《Angewandte Chemie (International ed. in English)》2020,59(6):2505-2509
By using in situ aberration‐corrected environmental transmission electron microscopy, for the first time at atomic level, the dynamic evolution of the Cu surface is captured during CO oxidation. Under reaction conditions, the Cu surface is activated, typically involving 2–3 atomic layers with the formation of a reversible metastable phase that only exists during catalytic reactions. The distinctive role of CO and O2 in the surface activation is revealed, which features CO exposure to lead to surface roughening and consequently formation of low‐coordinated Cu atoms, while O2 exposure induces a quasi‐crystalline CuOx phase. Supported by DFT calculations, it is shown that crystalline CuOx reversibly transforms into the amorphous phase, acting as an active species to facilitate the interaction of gas reactants and catalyzing CO oxidation. 相似文献
990.
Yi Han Zibo Xue Guangwu Li Yanwei Gu Yong Ni Shaoqiang Dong Chunyan Chi 《Angewandte Chemie (International ed. in English)》2020,59(23):9026-9031
Incorporation of a non‐hexagonal ring into a nanographene framework can lead to new electronic properties. During the attempted synthesis of naphthalene‐bridged double [6]helicene and heptagon‐containing nanographene by the Scholl reaction, an unexpected azulene‐embedded nanographene and its triflyloxylated product were obtained, as confirmed by X‐ray crystallographic analysis and 2D NMR spectroscopy. A 5/7/7/5 ring‐fused substructure containing two formal azulene units is formed, but only one of them shows an azulene‐like electronic structure. The formation of this unique structure is explained by arenium ion mediated 1,2‐phenyl migration and a naphthalene to azulene rearrangement reaction according to an in‐silico study. This report represents the first experimental example of the thermodynamically unfavorable naphthalene to azulene rearrangement and may lead to new azulene‐based molecular materials. 相似文献