Yasuyuki Yamada 교수

Microstructural properties and their influence on Jc have been studied in detail on Ag-sheathed (Bi,Pb)2Sr2Ca2Cu3Ox tapes prepared by the powder-in-tube method. The present study centres on two important factors for the achievement of high Jc values: (1) The liquid phase reaction during the (2223) phase formation at 847 degrees C for the composition Bi1.72Pb0.34Sr1.83Ca1.97Cu3.13Ox leads to better connectivity between the (2223) platelets, thus considerably improving Jc (77 K, 0 T): single phase

Firmly tied: A four-fold rotaxane was prepared from a porphyrin unit with four alkylammonium chains and a phthalocyanine unit with four peripheral crown ethers. In a dinuclear Cu2+ complex of the four-fold rotaxane, the Cu2+–porphyrin and the Cu2+–phthalocyanine moieties were stacked efficiently on one another to afford spin–spin communication. The spin states were switched reversibly (see picture). Detailed facts of importance to specialist readers are published as ”Supporting Information”. Suc

We report the preparation and crystal structure of a triply stacked metal complex array in which a Cu-phthalocyanine is sandwiched between different Cu-porphyrins. The discrete heterogeneous assembly was prepared through formation of a fourfold rotaxane from a tetradactyl porphyrin with alkylammonium moieties and a phthalocyanine bearing four crown ethers and the subsequent formation of an ionic complex between the fourfold rotaxane and a tetraanionic porphyrin. The tetraanionic porphyrin, Cu-TP

Back and forth. Redox potential sensors that consist of a flavin unit, a bora-3a,4a-diaza-s-indacene (BODIPY) moiety, and a L-proline linker are presented. While reduced forms of these fluorescent sensors are almost nonfluorescent, their oxidized forms exhibit bright emissions under control of the redox status of the flavin unit. It is also shown that these changes are reversible in aqueous solutions and living cells, as illustrated in the figure. Supporting information for this article is avail

Phase relationship in the [(K 1/2 Bi 1/2 ) 1- y (Na 1/2 Bi 1/2 ) y ](Ti 1- x B x )O 3 system with B=Zr, Fe 1/2 Nb 1/2 , Zn 1/3 Nb 2/3 or Mg 1/3 Nb 2/3 has been investigated by dielectric measurement and X-ray diffractometry. All of the bi-binary systems were solid-soluble throughout the entire composition range. With increasing y and x , ferroelectric Curie point decreased and the ε - T curve became flat. Composition dependence of the transition temperature was examined by varying x or y . Phase

Development of supramolecular methods to further activate a highly reactive intermediate is a fascinating strategy to create novel potent catalysts for activation of inert chemicals. Herein, a supramolecular approach to enhance the oxidizing ability of a high-valent oxo species of a nitrido-bridged iron porphyrinoid dimer that is a known potent molecular catalyst for light alkane oxidation is reported. For this purpose, a nitrido-bridged dinuclear iron complex of porphyrin-phthalocyanine heterod

To generate integrated organized molecular properties, multiple molecular components are required to be assembled into the molecular system with sequential and spatial accuracy in accordance with the design of the molecular assembly. Herein, we present a novel programmable synthesis of a cofacially stacked porphyrin array via repetitive construction of a peptide duplex. We designed and synthesized a novel porphyrin having two artificial amino acid moieties at the trans meso-positions. The amino

μ-Nitrido- and μ-carbido-bridged iron phthalocyanine dimers, when used as cathode-active materials for rechargeable lithium batteries, showed four stable redox waves in cyclic voltammetry studies in solution and a stable discharge capacity of approximately 60 mAh g^-1 after 200 cycles. These results indicate that μ-heteroatom-bridged iron phthalocyanine dimers are good platforms for designing novel phthalocyanine-based electrode-active materials.

A stacked assembly composed of a porphyrin and two phthalocyanines was prepared through fourfold rotaxane formation. Two phthalocyanine molecules, bearing four 24-crown-8 units, were assembled onto a porphyrin template incorporating four sidechains with two dialkylammonium ions each through pseudorotaxane formation between crown ether units and ammonium ions. The Staudinger phosphite reaction, as the stoppering reaction, resulted in the formation of the stacked heterotrimer composed of a porphyr

Catalytic CH₄oxidation using a μ-nitrido-bridged iron porphyrinoid dimer was successfully activated by supramolecular complexation.

We present a novel strategy to synthesize multi-molecular arrays in a programmable way by stepwise elongation based on repetition of two-fold rotaxane formation and construction of threads. A cofacially triply stacked porphyrin array was obtained via the repetitive two-fold rotaxane formation.

Preparation of an accurate assembly of phthalocyanines is rather difficult because of the high aggregation property of phthalocyanines. In this study, a novel discrete phthalocyanine dimer was prepared in which the relative configuration of each component was tightly and accurately fixed in an H-aggregate form by a rigid U-shaped linker. Electrochemical measurements showed that there were strong intramolecular electronic interactions between the two phthalocyanines.