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排序方式: 共有343条查询结果,搜索用时 15 毫秒
41.
Dr. Yoji Horii Prof. Dr. Keiichi Katoh Prof. Dr. Yuji Miyazaki Dr. Marko Damjanović Tetsu Sato Prof. Dr. Liviu Ungur Prof. Dr. Liviu F. Chibotaru Prof. Dr. Brian K. Breedlove Prof. Dr. Motohiro Nakano Prof. Dr. Wolfgang Wernsdorfer Prof. Dr. Masahiro Yamashita 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(36):8076-8082
Gd3+ complexes have been shown to undergo unusual slow magnetic relaxation processes similar to those of single-molecule magnets (SMMs), even though Gd3+ does not exhibit strong magnetic anisotropy. To reveal the origin of the slow magnetic relaxation of Gd3+ complexes, we have investigated the magnetic properties and heat capacities of two Gd3+-phthalocyaninato triple-decker complexes, one of which has intramolecular Gd3+–Gd3+ interactions and the other does not. It was found that the Gd3+–Gd3+ interactions accelerate the magnetic relaxation processes. In addition, magnetically diluted samples, prepared by doping a small amount of the Gd3+ complexes into a large amount of diamagnetic Y3+ complexes, underwent dual magnetic relaxation processes. A detailed dynamic magnetic analysis revealed that the coexistence of spin–lattice relaxation and phonon-bottleneck processes is the origin of the dual magnetic relaxation processes. 相似文献
42.
Emily J. Hopkins Dr. Yurii Prots Dr. Ulrich Burkhardt Dr. Yves Watier Dr. Zhiwei Hu Dr. Chang‐Yang Kuo Dr. Jen‐Che Chiang Dr. Tun‐Wen Pi Dr. Arata Tanaka Prof. Liu Hao Tjeng Dr. Martin Valldor 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(21):7938-7943
Through a solid‐state reaction, a practically phase pure powder of Ba3V2S4O3 was obtained. The crystal structure was confirmed by X‐ray single‐crystal and synchrotron X‐ray powder diffraction (P63, a=10.1620(2), c=5.93212(1) Å). X‐ray absorption spectroscopy, in conjunction with multiplet calculations, clearly describes the vanadium in charge‐disproportionated VIIIS6 and VVSO3 coordinations. The compound is shown to be a strongly correlated Mott insulator, which contradicts previous predictions. Magnetic and specific heat measurements suggest dominant antiferromagnetic spin interactions concomitant with a weak residual ferromagnetic component, and that intrinsic geometric frustration prevents long‐range order from evolving. 相似文献
43.
The glass-forming region in the system P---S---Ag was determined and density, thermal expansion, dc conductivity and the transport number of Ag ions were measured for P2S5---Ag2S glasses found in the P---S---Ag system. The results for the transport number measurement show that P2S5---Ag2S glasses are purely ionic conductors owing to the Ag ion migration, like most of the As2S3---Ag2S and GeS2---GeS---Ag2S glasses reported previously. Glass structure and ionic conduction processes in As2S3---Ag2S, GeS2---GeS---Ag2S and P2S5---Ag2S glasses are discussed, based on their ionic conductivity and density data. The structural concept of -Ag2S was applied to these glasses, which suggests that the Ag ions in the glasses are distributed in the available Ag ion sites in the non-conducting framework composed of both S anions and As, Ge or P cations. In each system the ionic conductivity increases linearly with increasing Ag+/total cation (%) in glass composition, the determining factor being the activation energy for ionic conduction alone. Thus, the activation energy in these glasses depends predominantly upon the molar ratio of Ag ions to total cation in the glass, irrespective of the kind of system. Small differences in the activation energy among the three systems can be interpreted as arising from differences in the field strength of As, Ge and P cations. 相似文献
44.
Applications of microelectromechanical systems (MEMS) technology are widespread in both industrial and research fields providing
miniaturized smart tools. In this review, we focus on MEMS applications aiming at manipulations and characterization of biomaterials
at the single molecule level. Four topics are discussed in detail to show the advantages and impact of MEMS tools for biomolecular
manipulations. They include the microthermodevice for rapid temperature alternation in real-time microscopic observation,
a microchannel with microelectrodes for isolating and immobilizing a DNA molecule, and microtweezers to manipulate a bundle
of DNA molecules directly for analyzing its conductivity. The feasibilities of each device have been shown by conducting specific
biological experiments. Therefore, the development of MEMS devices for single molecule analysis holds promise to overcome
the disadvantages of the conventional technique for biological experiments and acts as a powerful strategy in molecular biology.
Figure Towards single bio molecular handling and characterization by MEMS 相似文献
45.
46.
Otsuki J Imai A Sato K Li DM Hosoda M Owa M Akasaka T Yoshikawa I Araki K Suenobu T Fukuzumi S 《Chemistry (Weinheim an der Bergstrasse, Germany)》2008,14(9):2709-2718
A star-shaped Ru/Os tetranuclear complex, in which a central Os unit is linked to three peripheral Ru units by 4,4'-azobis(2,2'-bipyridine) (azobpy) bridging ligands, was prepared to examine the unique photodynamics regulated by its redox state. The Ru/Os tetranuclear complex exhibits Ru-based luminescence at 77 K, whereas the three-electron reduction (one for each azobpy) of the Ru/Os complex results in luminescence from the Os unit. The photoexcited state of the Ru/Os complex rapidly decays into low energy metal-to-ligand charge-transfer states, in which the excited electron is localized in the azobpy ligand in the form of azobpy(.-). Upon the one-electron reduction of the azobpy ligands, the above-mentioned low-energy states become unavailable to the photoexcited complex. As a result, an energy transfer from the Ru-based excited state to the Os-based excited state becomes possible. Ultrafast transient absorption measurements revealed that the energy transfer process consists of two steps; intramolecular electron transfer from the terminal bipyridine ligand (bpy(.-)) to form azobpy(2-) followed by a metal-to-metal electron transfer. Thus, the Ru/Os tetranuclear complex collects light energy into the central Os unit depending on the redox state of the bridging ligands, qualifying as a switchable antenna. 相似文献
47.
Kang JH Asai D Kim JH Mori T Toita R Tomiyama T Asami Y Oishi J Sato YT Niidome T Jun B Nakashima H Katayama Y 《Journal of the American Chemical Society》2008,130(45):14906-14907
We succeeded in cancer cell specific gene expression by using a polyplex responsive to protein kinase Calpha, which is activated in various types of cancer cells. 相似文献
48.
Sonomi Arata Dr. Yuna Kim Prof. Norihisa Hoshino Dr. Keishiro Tahara Dr. Kiyonori Takahashi Dr. Tomofumi Kadoya Tomonori Inoue Prof. Takayoshi Nakamura Prof. Tomoyuki Akutagawa Prof. Jun-ichi Yamada Prof. Kazuya Kubo 《欧洲无机化学杂志》2023,26(12):e202300017
Unsymmetrical gold(III)-dithiolene complexes are potential candidates for molecular materials that exhibit thermal structural phase transitions. In this study, unsymmetrical ppy-gold(III) (ppy−=C-deprotonated-2-phenylpyridine(−)) complexes [AuC5] and [AuC6] coordinated by dithiolene ligands containing tetrathiafulvalene (TTF) skeletons with pentylthio (2-{bis(pentylthio)-1,3-dithiol-2-ylidene}-1,3-dithiol-4,5-dithiolate(2−)) and hexylthio groups (2-{bis(hexylthio)-1,3-dithiol-2-ylidene}-1,3-dithiol-4,5-dithiolate(2−)) were synthesized. Both complexes exhibited a large absorption band at approximately 508 nm, owing to intramolecular ligand-to-ligand charge transfer. One-dimensional columnar structures with head-to-tail molecular arrangements around the metal ions were constructed in the crystals. The flexible alkylthio groups were intercalated into crystalline spaces between dithiolene ligands in the columns. [AuC5] exhibits a simple phase transition at 198 °C between crystalline and isotropic phases irreversibly. The crystalline phase of [AuC6] observed at 25 °C melted at 148 °C. Another crystalline phase grew above 148 °C with a very slow crystallization rate from the liquid phase and was completely transformed into an isotropic phase at 200 °C. 相似文献
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