Details of a Researcher

Asato Eiji

写真a

Title	Professor
Researcher Number(JSPS Kakenhi)	10222580

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Current Affiliation Organization 【 display / non-display 】

Duty University of the Ryukyus Faculty of Science Chemistry, Biology and Marine Science Professor
Concurrently University of the Ryukyus Graduate School of Engineering and Science Marine and Environmental Sciences Professor
Concurrently University of the Ryukyus Graduate School of Engineering and Science Chemistry, Biology and Marine Science Professor

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Academic degree 【 display / non-display 】

Kyushu University - Doctor of Science

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External Career 【 display / non-display 】

2010.06

　

　

University of the Ryukyus, Faculty of Science, Department of Chemistry, Biology, and Marine Science, Analytical and Inorganic Chemistry, Professor

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Research Interests 【 display / non-display 】

Coordination Chemistry

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Research Areas 【 display / non-display 】

Nanotechnology/Materials / Inorganic/coordination chemistry

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Research Theme 【 display / non-display 】

Pharmaceutical and Material Chemistry of Group 15 Elements
Synthesis of Metal-Assembled Complexes with Redox-Active Ligands
Synthesis of Metal-Assembled Complexes with Large Macrocyclic Ligands

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Published Papers 【 display / non-display 】

Structures of Dimer-of-Dimers Type Defect Cubane Tetranuclear Copper(II) Complexes with Novel Dinucleating Ligands

Ryusei Hoshikawa, Ryoji Mitsuhashi, Eiji Asato, Jianqiang Liu, Hiroshi Sakiyama

Molecules 27 ( 2 ) 576 2022.01 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)
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Crystal Structure of S8 Molecule from Thiourea

MIKURIYA Masahiro, TANIGUCHI Kazuki, KOYAMA Yoshiki, WATANABE Hiroaki, YOSHIOKA Daisuke, MITSUHASHI Ryoji, ASATO Eiji

X-ray Structure Analysis Online ( 社団法人日本分析化学会 ) 36 ( 0 ) 1 - 2 2020 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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Sulfur S8 was isolated from a reaction solution of thiourea and bismuth nitrate in N,N-dimethylformamide. The crystal structure was determined by the single-crystal X-ray diffraction method at 90 K. It crystallizes in the orthorhombic space group Fddd with a = 10.3310(8)Å, b = 12.6786(10)Å, c = 24.3519(19)Å, V = 3189.7(4)Å3, Dx = 2.136 g/cm3, and Z = 6. The R1 [I > 2σ(I)] and wR2 (all data) values are 0.0220 and 0.0570, respectively, for all 1864 independent reflections. The S8 molecule has a crown-shaped ring structure with the α-form.
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Synthesis and magnetic properties of a dinuclear manganese(II) complex with two manganese(II) ions of C-2-twisted octahedral geometry

Hiroshi Sakiyama, Masatoshi Kato, Satoshi Sasaki, Moriya Tasaki, Eiji Asato, Masayuki Koikawa

POLYHEDRON ( PERGAMON-ELSEVIER SCIENCE LTD ) 111 32 - 37 2016.06 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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A dinuclar manganese(II) complex [Mn-2(sym-hcp)(2)](BPh4)(2).2acetone.2H(2)O (1) was synthesized with a new dinucleating ligand, 4-chloro-2,6-bis1(2-hydroxyethyl)methylaminomethyllphenol [H(sym-hcp)I, for the purpose of studying the magnetic properties. The single-crystal X-ray analysis revealed a bis-mu-phenolato-dimanganese(II) core structure containing two distorted octahedral manganese(II) ions of C-2 symmetry. The order of the coordination bond lengths is Mn-O(phenolato) < Mn-O(hydroxy) < Mn-N. Magnetic susceptibility data for 1 was fitted well with the parameters 2J = -0.93 cm(-1) and g = 2.03, indicating weak antiferromagnetic interaction. (C) 2016 Elsevier Ltd. All rights reserved.
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Effects of La doping on structural, optical, electronic properties of Sr2Bi2O5 photocatalyst

Yuki Obukuro, Shigenori Matsushima, Kenji Obata, Takuya Suzuki, Masao Arai, Eiji Asato, Yuji Okuyama, Naoki Matsunaga, Go Sakai

JOURNAL OF ALLOYS AND COMPOUNDS ( ELSEVIER SCIENCE SA ) 658 139 - 146 2016.02 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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Single-phase Sr2Bi2O5 was obtained by calcination of the heterobimetallic complex precursor Sr [Bi(DTPA)]center dot 9H(2)O (DTPA is diethylenetriaminepentaacetic acid) at 700 degrees C for 6 h. The effect of La doping on the crystal structure, surface area, morphology, surface chemical state, and absorption properties of Sr2Bi2O5 samples prepared from Sr[Bi(DTPA)]center dot 9H(2)O were investigated. No traces of an impurity phase were detected in samples with a lower La content (3 and 5 mol%), while impurity phases such as Sr2Bi2O5 and SrCO3 were observed in Sr2Bi2O5 samples with larger La contents of 8 and 10 mol%. The Brunauer-Emmett-Teller surface area of Sr2Bi2O5 increased slightly with the content of La. High-resolution transmission electron microscopy revealed clear crystalline planes for both undoped and La-doped Sr2Bi2O5 samples without amorphous phases. Meanwhile, X-ray photoelectron spectroscopy indicated that the valence states of constituent metals were Sr2+, Bi3+, and La3+. The solubility limit of La in the Sr2Bi2O5 crystal phase was determined from Raman scattering measurements. La atoms substituted Bi sites when the doping content was low, while both Bi and Sr sites were substituted with La when the content of La was high. The electronic structure of Sr2Bi2O5 could be modified by La doping, resulting in a red shift of the absorption edge with increasing La content. The band-gap narrowing of Sr2Bi2O5 with La-doping was reproduced in energy-band calculations. The photocatalytic activity of Sr2Bi2O5 under visible-light irradiation for the oxidation of isopropanol was enhanced by doping with La. (C) 2015 Elsevier B.V. All rights reserved.
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Synthesis and Characterization of a Di-µ-oxalato Tetracopper(Ⅱ) Complex with Tetranucleating Macrocyclic Ligand

Miyazato Yuji, Asato Eiji, Ohba Masaaki, Wada Tohru

Bulletin of the Chemical Society of Japan ( 公益社団法人日本化学会 ) 89 ( 4 ) 430 - 436 2016 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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A tetracopper(II) complex containing two oxalate anions in the metal-based host cavity, [Cu4(Lpy)(µ-ox)2](PF6)2·2(2-PrOH), where ox2−: oxalato (C2O42−), was prepared by reacting H2Lpy, a phenol-based tetranucleating macrocyclic ligand with four pyridylmethyl pendant arms, Cu(ClO4)2·6H2O, and sodium oxalate (1:4:2 stoichiometry, respectively) in methanol, followed by exchange of the counteranion with excess of NH4PF6. Single-crystal X-ray diffraction of 1 revealed that two {Cu(II)Cu(II)} units, bridged by a phenolato group of Lpy2−, were connected by two oxalato anions, to construct a rectangular “{CuCu}(µ-ox)2{CuCu}” tetranuclear framework. This rectangular framework was maintained in DMF solution. The magnetic measurement of 1 in the 2–300 K range revealed antiferromagnetic behavior. The antiferromagnetic interaction in this complex occurs between the Cu(II) centers bridged by an oxalate (J = −140 cm−1).
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