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Kaneda-Nakashima, Kazuko*; Shirakami, Yoshifumi*; Kadonaga, Yuichiro*; Watabe, Tadashi*; Oe, Kazuhiro*; Yin, X.*; Haba, Hiromitsu*; Shirasaki, Kenji*; Kikunaga, Hidetoshi*; Tsukada, Kazuaki; et al.
International Journal of Molecular Sciences (Internet), 25(2), p.933_1 - 933_14, 2024/01
Tabata, Chihiro; Watanabe, Hirohito*; Shirasaki, Kenji*; Sunaga, Ayaki*; Fukuda, Takamitsu*; Li, D.*; Yamamura, Tomoo*
Journal of Molecular Structure, 1277, p.134870_1 - 134870_8, 2023/04
Times Cited Count:0 Percentile:0(Chemistry, Physical)Neutral and cationic U(IV) sandwiched phthalocyanine (Pc) complexes were prepared. The neutral species, UPc, was obtained by the reaction of UCl] and phthalonitrile, and the [UPc][BF] crystals were grown by electrolysis. The structures of the complexes were determined crystallographically. A U(IV) ion has two electrons, which carry a magnetic moment localized at the U sites, making the complex magnetically active. The magnetic susceptibility measurement of UPc revealed that the system was paramagnetic with local magnetic moments down to 2 K, but these magnetic moments were suppressed, possibly by a ligand field effect. The paramagnetism was also confirmed by the magnetization curve without hysteresis. The cationic complex, [UPc][BF]] crystalized in a tetragonal structure with the space group , in which the UPc molecules stacked along the tetragonal -axis. The structure was similar to that of [LnPc][BF]], but with distinct disorder in the stacking plane. The stabilities of the crystal and molecular structures and the electronic configurations of UPc and [UPc][BF]] were evaluated via the calculations that included the multiconfigurational nature of the actinide element.
Tabata, Chihiro; Shirasaki, Kenji*; Sakai, Hironori; Sunaga, Ayaki*; Li, D.*; Konaka, Mariko*; Yamamura, Tomoo*
CrystEngComm (Internet), 24(19), p.3637 - 3648, 2022/05
Times Cited Count:2 Percentile:53.04(Chemistry, Multidisciplinary)Shirasaki, Kenji*; Tabata, Chihiro*; Sunaga, Ayaki*; Sakai, Hironori; Li, D.*; Konaka, Mariko*; Yamamura, Tomoo*
Journal of Nuclear Materials, 563, p.153608_1 - 153608_11, 2022/05
Times Cited Count:2 Percentile:56.43(Materials Science, Multidisciplinary)We focused on the direct synthesis of (U, )O solid solution (=Th, Np) by extending our recent progress in hydrothermal synthesis with additives. The homogeneity of the (U, )O ( = Th, Np) systems prepared by supercritical hydrothermal reactions was investigated through crystallographic analysis based on Vegard's law, and the Na nuclear magnetic resonance (NMR) measurement of (U, Np, Na)O solid solutions. Our experimental and analytical results revealed that (i) an optimal additive is ammonium carbonate and starting uranium valence is IV in the case of (U, Th)O, and (ii) an optimal additive is ethanol and starting uranium valence is VI in the case of (U, Np)O, for producing the homogeneous solid solutions by hydrothermal synthesis.
Tabata, Chihiro*; Shirasaki, Kenji*; Sunaga, Ayaki*; Sakai, Hironori; Li, D.*; Konaka, Mariko*; Yamamura, Tomoo*
CrystEngComm (Internet), 23(48), p.8660 - 8672, 2021/12
Times Cited Count:5 Percentile:66.03(Chemistry, Multidisciplinary)The hydrothermal synthesis of pure uranium dioxide under supercritical water (SCW) conditions was investigated. The nonstoichiometry, crystallite size and morphology of the UO particles were investigated. The SCW hydrothermal synthesis may be a promising method for producing homogeneous UO and its solid solutions with well-defined nonstoichiometries (), shapes, and sizes.
Tanaka, Keita*; Hirano, Kosuke*; Yamaguchi, Atsushi*; Muramatsu, Haruka*; Hayashi, Tasuku*; Yuasa, Naoki*; Nakamura, Keisuke; Takimoto, Misaki; Haba, Hiromitsu*; Shirasaki, Kenji*; et al.
no journal, ,
Haga, Yoshinori; Yamamoto, Etsuji; Nakamura, Ai*; Honda, Fuminori*; Aoki, Dai*; Matsumoto, Yuji*; Yamamura, Tomoo*; Shirasaki, Kenji*; Yamagami, Hiroshi*
no journal, ,
Haga, Yoshinori; Yamamoto, Etsuji; Matsumoto, Yuji*; Shirasaki, Kenji*
no journal, ,
Haga, Yoshinori; Yamamoto, Etsuji; Nakamura, Ai*; Honda, Fuminori*; Aoki, Dai*; Matsumoto, Yuji*; Yamamura, Tomoo*; Shirasaki, Kenji*; Yamagami, Hiroshi*; Sumida, Kazuki
no journal, ,
no abstracts in English