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排序方式: 共有659条查询结果,搜索用时 78 毫秒
651.
Kajiwara T Katagiri K Hasegawa M Ishii A Ferbinteanu M Takaishi S Ito T Yamashita M Iki N 《Inorganic chemistry》2006,45(13):4880-4882
Dinuclear and cubane-shaped lanthanide cluster complexes containing EuIII)and TbIII were synthesized by step-by-step construction using p-tert-butylsulfonylcalix[4]arene as a cluster-forming ligand. The sulfonylcalixarene adopts a pinched-cone conformation in the dinuclear complexes and a cone conformation in the cubane complexes. Because the calixarene has a large pi-conjugate system expanding over the entire molecule, it behaves as a good antenna chromophore for UV and near-UV light, and a slight conformational change of the calixarene (from cone to pinched-cone and vice versa) has an effect on the energy levels of excited S1 and T1 states. As a result, selectivity is observed in the luminescent properties of dinuclear and cubane-shaped systems of EuIII and TbIII. 相似文献
652.
Oxovanadium complex bearing 3-hydroxypicolinic acid (H2hpic), that is, VO(Hhpic)2, successfully catalyzes a highly selective oxidation of benzylamines to the corresponding N-(benzylidene)benzylamines under atmospheric molecular oxygen. In addition, the use of imidazolium-type ionic liquids as solvent makes it possible to attain recycling of the catalyst. 相似文献
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Prof. Dr. Toshikazu Takata Prof. Dr. Koji Yamamoto Kazuki Higuchi Dr. Masahiro Ogawa Ayumi Kawasaki Shunya Mizuno Hikaru Iwasaki Masaki Nagashima Prof. Dr. Yoshihiro Hayashi Prof. Dr. Susumu Kawauchi Prof. Dr. Kazuko Nakazono Prof. Dr. Yasuhito Koyama 《Angewandte Chemie (International ed. in English)》2023,62(24):e202303494
Post-synthesis modification of polymers streamlines the synthesis of functionalized polymers, but is often incomplete due to the negative polymer effects. Developing efficient polymer reactions in artificial systems thus represents a long-standing objective in the fields of polymer and material science. Here, we show unprecedented macrocycle-metal-complex-catalyzed systems for efficient polymer reaction that result in 100 % transformation of the main chain functional groups presumably via a processive mode reaction. The complete polymer reactions were confirmed in not only intramolecular reaction (hydroamination) but also intermolecular reaction (hydrosilylation) by using Pd- and Pt-macrocycle-catalyzed systems. The most fascinating feature of the both reactions is that higher-molecular-weight polymers reach completion faster. Various studies suggested that the reactions occur in the catalyst cavity via the formation of a supramolecular complex between the macrocycle catalyst and polymer substrate like pseudorotaxane, which should be of characteristic of the efficient polymer reactions progressing in a processive mode. 相似文献
656.
Hao K. Shen Kiyoshi Morishita Dr. P. K. Hashim Prof. Dr. Kou Okuro Daiki Kashiwagi Ayumi Kimura Dr. Haruaki Yanagisawa Prof. Dr. Masahide Kikkawa Prof. Dr. Tatsuya Niwa Prof. Dr. Hideki Taguchi Prof. Dr. Takuzo Aida 《Angewandte Chemie (International ed. in English)》2023,62(31):e202304894
Herein, we report an ATP-responsive nanoparticle (GroELNP) whose surface is fully covered with the biomolecular machine “chaperonin protein GroEL”. GroELNP was synthesized by DNA hybridization between a gold NP with DNA strands on its surface and GroEL carrying complementary DNA strands at its apical domains. The unique structure of GroELNP was visualized by transmission electron microscopy including under cryogenic conditions. The immobilized GroEL units retain their machine-like function and enable GroELNP to capture denatured green fluorescent protein and release it in response to ATP. Interestingly, the ATPase activity of GroELNP per GroEL was 4.8 and 4.0 times greater than those of precursor cysGroEL and its DNA-functionalized analogue, respectively. Finally, we confirmed that GroELNP could be iteratively extended to double-layered NP. 相似文献
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M. Kodama 《Crystal Research and Technology》1994,29(3):397-401
Undoped MBE-GaSb films were grown on undoped GaSb (100) substrates and the influence of carbon contamination on the etched GaSb substrate on the grown film were investigated. It was found that carbon contamination of the etched GaSb substrate was dependent on the chemical treatment method and produced stacking faults in the subsequent MBE growth of the GaSb film. Carbon contamination on the etched GaSb substrate degraded the quality of the GaSb film and affected ohmic characteristics between the film and the substrate. Substrate surface free of carbon contamination and thereby exhibitting no influence on the electrical transport through the film and the substrate could be reproducibly obtained by performing an oxide etch-off chemical treatment on the GaSb substrate. 相似文献
659.