共查询到20条相似文献,搜索用时 31 毫秒
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Lin Li Yu‐Peng Tian Jia‐Xiang Yang Ping‐Ping Sun Jie‐Ying Wu Hong‐Ping Zhou Sheng‐Yi Zhang Bao‐Kang Jin Xiao‐Juan Xing Chuan‐Kui Wang Ming Li Guang‐Hua Cheng Huo‐Hong Tang Wen‐Hao Huang Xu‐Tang Tao Min‐Hua Jiang 《化学:亚洲杂志》2009,4(5):668-680
Mark us bent! The synthesis, structure, and single‐ and two‐photon spectroscopic properties of a series of pyrimidine‐based (bent‐shaped) molecules are reported. These allow structure‐property relationships and guidelines for both the development and application of TPA compounds to be derived.
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Yann Gloaguen Gilles Alcaraz Dr. Anne‐Frédérique Pécharman Eric Clot Dr. Laure Vendier Dr. Sylviane Sabo‐Etienne Dr. 《Angewandte Chemie (International ed. in English)》2009,48(16):2964-2968
A question of coordination mode : Two new borane compounds are prepared. They act as bifunctional ligands as illustrated by their reaction with ruthenium polyhydrides which leads to the formation of two complexes (see scheme) displaying either a δ‐agostic interaction of a η2‐B? H bond involving a trivalent boron atom or a dihydroborate ligation.
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Masumi Itazaki Dr. Kensuke Ueda Hiroshi Nakazawa Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(18):3313-3316
A variety of tertiary silanes , even those with functional substituents, undergo an unprecedented iron‐catalyzed dehydrogenative coupling (see scheme) in a convenient approach to disilanes, including unsymmetrical disilanes and polymers with Si? Si bonds in the backbone. Consideration of the catalytic reaction pathway revealed the intermediacy of a hydrido(disilyl)iron(IV) complex.
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Mingjian Yuan Xiaodong Yin Haiyan Zheng Canbin Ouyang Zicheng Zuo Huibiao Liu Yuliang Li 《化学:亚洲杂志》2009,4(5):707-713
Bright funnels : A series of dendritic systems, which are capable of funneling energy from the periphery to the core, have been synthesized. The photophysical properties of dendrimers have been determined. Selective excitation of the donor leads to an efficient energy transfer (>90 %) to the acceptor. The approach provides a facile synthesis for the modification of near‐infrared BF2‐Azadipyrromethenes.
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Horst Weiss Dr. Michael F. Bräu Dr. 《Angewandte Chemie (International ed. in English)》2009,48(19):3520-3524
Ordered water : Gypsum has been used for construction for millennia. The structure and water content of calcined gypsum, CaSO4?0.5 H2O, has been under discussion until now: single‐crystal structure analysis (see picture: S yellow, Ca gray, O blue, H red) provides an ordered model that is confirmed by DFT calculations.
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Playing the sax : The enantioselective total syntheses of (?)‐ and (+)‐decarbamoyloxysaxitoxin (doSTX) and (+)‐saxitoxin (STX) are reported. A new methodology was developed for the synthesis of STXs, featuring discriminative reduction of the nitro group and N? O bond in nitroisoxazolidine.
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Richard A. L. Winchester Max Whitby Milo S. P. Shaffer Dr. 《Angewandte Chemie (International ed. in English)》2009,48(20):3616-3621
To Bi or not to Bi? The synthesis of phosphorus nanorods of two differing morphologies is reported, in both the presence and absence of a bismuth catalyst. Not only do these materials represent a new class of elemental nanorods but they also give valuable insight into the complex allotropy of phosphorus.
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Yong Guo Dr. Xiaming Zhao Dr. Dazhi Zhang Dr. Shun‐Ichi Murahashi Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(11):2047-2049
Catalytic convenience : The use of iridium or ruthenium catalysts for C? H bond activation has led to the addition reaction of trifluoromethylated compounds to alkenes (see scheme). This atom‐economical reaction occurs under neutral reaction conditions and without the formation of undesired defluorinated by‐products, even at high temperature.
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Guicun Li Hongrui Peng Yi Wang Yong Qin Zuolin Cui Zhikun Zhang 《Macromolecular rapid communications》2004,25(18):1611-1614
Summary: Polyaniline nanobelts have been synthesized by a self‐assembly process using the chemical oxidative polymerization of aniline in a surfactant gel. The morphologies of polyaniline nanostructures were characterized by field‐emission scanning electron microscopy and transmission electron microscopy. The effects of the concentrations of cetyltrimethylammonium bromide on the morphologies of polyaniline nanostructures have also been investigated.
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Sbastien Bontemps Ghenwa Bouhadir DavidC. Apperley PhilipW. Dyer Karinne Miqueu Didier Bourissou 《化学:亚洲杂志》2009,4(3):428-435
Bridging or pendant? Palladium and rhodium complexes deriving from an ambiphilic phosphine–borane ligand are shown to adopt a bridging P→M? Cl→B coordination mode in the solid state. DFT calculations provide more insight into the Cl→B interaction and suggest the possible interconversion of the bridging and B‐pendant forms in solution.
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Mathias Sprinzl 《Angewandte Chemie (International ed. in English)》2009,48(21):3738-3739
Quality control : The incorporation of a wrong amino acid into a growing polypeptide chain induces a correction step in which the release factor (RF1) hydrolyzes the peptide from the incorrectly matched peptidyl‐tRNA (see picture). The nascent erroneous polypeptide is released from the ribosome and degraded.
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《Angewandte Chemie (International ed. in English)》2009,48(13):2265-2265
“My most exciting discovery to date has been that molecules can have a magnetic memory. The biggest challenge facing scientists is to find renewable and sustainable energy sources…?” This and more about Roberta Sessoli can be found on page 2265.
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Anthony S. R. Chesman David R. Turner Dr. Glen B. Deacon Prof. Stuart R. Batten Assoc. Prof. 《化学:亚洲杂志》2009,4(5):761-769
Additional cyclization : Dicyanonitrosomethanide, [C(CN)2(NO)]? undergoes nucleophilic addition and cyclization of 1,2‐diaminoethane and 1,3‐diaminopropane on the nitrile groups to form imidazolinyl and 1,4,5,6‐tetrahydropyrimidinyl groups, respectively. Ethanolamine has lower reactivity and fails to cyclize.
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Wei Wu Prof. Junjing Gu Jinshuai Song Sason Shaik Prof. Philippe C. Hiberty Prof. 《Angewandte Chemie (International ed. in English)》2009,48(8):1407-1410
Bonded or not bonded? An ab initio valence bond study of [1.1.1]propellane shows that the two bridgehead carbons are linked by a strong and direct σ bond that is neither classically covalent nor classically ionic, but rather a charge‐shift bond, in which the covalent–ionic resonance energy plays the major role. As such, the central bond of [1.1.1]propellane closely resembles the single bond of difluorine.
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Artur Mardyukov Elsa Sanchez‐Garcia Dr. Rachel Crespo‐Otero Wolfram Sander Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(26):4804-4807
That's radical! A photochemical reaction between the phenyl radical and water results in the abstraction of a hydrogen atom from water and the formation of a hydroxyl radical. The hydroxyl radical forms an OH???π hydrogen bond with benzene (see picture) and does not react with benzene thermally under the conditions of matrix isolation.
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EddieL. Myers RonaldT. Raines 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2009,121(13):2280-2280
Im Jahr 1919 berichteten H. Staudinger und J. Meyer über die reduktive Fragmentierung eines Azids zu einem Amin. Auf S. 2395 ff. stellen nun E. L. Myers und R. T. Raines ein ergänzendes Verfahren vor: die Spaltung der anderen N‐N‐Bindung eines Azids unter Bildung einer Diazoverbindung. Weil in beiden Umsetzungen ein Phosphor(III)‐Reagens zur Anwendung kommt, wurde als Hintergrund das Bild The Alchymist, in Search of the Philosopher's Stone, Discovers Phosphorus aus dem Jahr 1771 gewählt, in dem Joseph Wright die Entdeckung des Phosphors durch Hennig Brandt im Jahr 1669 darstellt. (Gestaltung: H. Adam Steinberg)