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Journal Articles

Coexistence of magnetoelectric and antiferroelectric-like orders in Mn$$_{3}$$Ta$$_{2}$$O$$_{8}$$

Kimura, Kenta*; Yagi, Naoki*; Hasegawa, Shunsuke*; Hagihara, Masato; Miyake, Atsushi*; Tokunaga, Masashi*; Cao, H.*; Masuda, Takatsugu*; Kimura, Tsuyoshi*

Inorganic Chemistry, 60(20), p.15078 - 15084, 2021/10

Journal Articles

Density functional theory study on the $$^{193}$$Ir M$"o$ssbauer spectroscopic parameters of Vaska's complexes and their oxidative adducts

Kaneko, Masashi; Nakashima, Satoru*

Inorganic Chemistry, 60(17), p.12740 - 12752, 2021/09

 Times Cited Count:0

In the present study, density functional theory (DFT) calculation was applied to Vaska's complexes of formula ${it trans}$-[IrCl(CO)(PPh$$_{3}$$)$$_{2}$$], and their oxidative adducts with small molecules (YZ) including H$$_{2}$$, i.e., ${it trans}$-[IrCl(YZ)(CO))(PPh$$_{3}$$)$$_{2}$$], to successfully correlate the electronic states of the complexes with the corresponding $$^{193}$$Ir M$"o$ssbauer spectroscopic parameters. After confirming the reproducibility of the DFT methods for elucidating the equilibrium structures and $$^{193}$$Ir M$"o$ssbauer isomer shifts of the octahedral Ir complexes, the isomer shifts and quadrupole splitting values of Vaska's complexes and their oxidative adducts were calculated. A bond critical point analysis revealed that the tendency in the isomer shifts was correlated with the strength of the covalent interaction in the coordination bonds. In an electric field gradient (EFG) analysis of the oxidative adducts, the sign of the principal axis was found to be positive for the complex with YZ = Cl$$_{2}$$ and negative for the complex with YZ = H$$_{2}$$. This reversal of the sign of the EFG principal axis was caused by the difference in the electron density distribution for the coordination bonds between Ir and YZ, according to a density of states analysis.

Journal Articles

Programmable synthesis of silver wheels

Kwon, H.*; Pietrasiak, E.*; Ohara, Takashi; Nakao, Akiko*; Chae, B.*; Hwang, C.-C.*; Jung, D.*; Hwang, I.-C.*; Ko, Y. H.*; Kim, K.*; et al.

Inorganic Chemistry, 60(9), p.6403 - 6409, 2021/05

 Times Cited Count:0 Percentile:0.01(Chemistry, Inorganic & Nuclear)

Journal Articles

Observation of dihydrogen bonds in high-pressure phases of ammonia borane by X-ray and neutron diffraction measurements

Nakano, Satoshi*; Sano, Asami; Hattori, Takanori; Machida, Shinichi*; Komatsu, Kazuki*; Fujihisa, Hiroshi*; Yamawaki, Hiroshi*; Goto, Yoshito*; Kikegawa, Takumi*

Inorganic Chemistry, 60(5), p.3065 - 3073, 2021/03

 Times Cited Count:0 Percentile:0.01(Chemistry, Inorganic & Nuclear)

X-ray and neutron diffraction analyses of ammonia borane were conducted at ambient and high pressures. The H-H distance in dihydrogen bonds was shorter than twice the van der Waals radius (2.4 ${AA}$). The half of the dihydrogen bonds were broken on phase transition from AP to the first high pressure phase (HP1) at approximately 1.2 GPa as revealed by an increase in the H-H distances. On further pressure increase, all of the H-H distances became shorter than 2.4 ${AA}$ again, implying the pressure-induced reformation of the dihydrogen bonds. Furthermore, the HP1 transformed to the second one with the structure of $$P2_1$$ (Z = 2) at about 11 GPa. In this phase transition, the inclination of the molecule axis became larger and the number of types of dihydrogen bonds increased from 6 to 11. Just before the third transition at 18.9 GPa, the shortest dihydrogen bond decreased to 1.65 ${AA}$. The present study experimentally first confirmed the breakage and reformation of the dihydrogen bonds by the structural change under pressure.

Journal Articles

Effect of oxygen-donor charge on adjacent nitrogen-donor interactions in Eu$$^{3+}$$ complexes of mixed N,O-donor ligands demonstrated on a 10-fold [Eu(TPAMEN)]$$^{3+}$$ chelate complex

Schnaars, K.; Kaneko, Masashi; Fujisawa, Kiyoshi*

Inorganic Chemistry, 60(4), p.2477 - 2491, 2021/02

 Times Cited Count:2 Percentile:0.01(Chemistry, Inorganic & Nuclear)

To reduce high-level radiotoxic waste generated by nuclear power plants, highly selective separation agents for minor actinides are mandatory. The mixed N,O-donor ligand ${it N,N,N',N'}$-tetrakis[(6-carboxypyridin-2-yl)methyl]ethylenediamine (H$$_{4}$$TPAEN) has shown good performance as a masking agent in Am$$^{3+}$$/Eu$$^{3+}$$ separation studies. In this work, we examine whether a decrease in O-donor basicity can promote the M$$^{3+}$$-N$$_{am}$$ interactions. Therefore, we replace the deprotonated "charged" carboxylic acid groups of TPAEN$$^{4-}$$ by neutral amide groups and introduce ${it N,N,N',N'}$-tetrakis[(6-${it N",N"}$-diethylcarbamoylpyridin-2-yl)methyl]ethylenediamine (TPAMEN) as a new ligand. TPAMEN was crystallized with Eu(OTf)$$_{3}$$ and Eu(NO$$_{3}$$)$$_{3}$$ 6H$$_{2}$$O to form positively charged 1:1 [Eu(TPAMEN)]$$^{3+}$$ complexes in the solid state. Alterations in the M-O/N bond distances are compared to [Eu(TPAEN)]$$^{-}$$ and investigated by DFT calculations to expose the differences in charge/energy density distributions at europium(III) and the donor functionalities of the TPAEN$$^{4-}$$ and TPAMEN. On the basis of estimations of the bond orders, atomic charges spin populations, and density of states in the Eu and potential Am and Cm complexes, the specific contributions of the donor-metal interaction are analyzed. The prediction of complex formation energy differences for the [M(TPAEN)]$$^{-}$$ and [M(TPAMEN)]$$^{3+}$$ (M$$^{3+}$$ = Eu$$^{3+}$$, Am$$^{3+}$$) complexes provide an outlook on the potential performance of TPAMEN in Am$$^{3+}$$/Eu$$^{3+}$$ separation.

Journal Articles

Precious metal separations

Narita, Hirokazu*; Kasuya, Ryo*; Suzuki, Tomoya*; Motokawa, Ryuhei; Tanaka, Mikiya*

Encyclopedia of Inorganic and Bioinorganic Chemistry (Internet), 28 Pages, 2020/12

Journal Articles

Role of the hydroxo group in the coordination of citric acid to trivalent americium

Tamain, C.*; Bonato, L.*; Aupiais, J.*; Dumas, T.*; Guillaumont, D.*; Barkleit, A.*; Berthon, C.*; Solari, P. L.*; Ikeda, Atsushi; Guilbard, P.*; et al.

European Journal of Inorganic Chemistry, 2020(14), p.1331 - 1344, 2020/04

 Times Cited Count:0 Percentile:0.01(Chemistry, Inorganic & Nuclear)

The molecular characterization based on multi-technique approach has led to major highlights on revealing the coordination environment of americium (Am) surrounded by citric acid (H$$_{3}$$CitH). The structure of the different complexes at pH 1 and 3 are described. These characterizations are made possible by the comparison of the americium-citric acid system with the americium-tricarballylic acid (one analogue of the citric acid without the alpha-hydroxo group).

Journal Articles

Density Functional Theory (DFT)-based bonding analysis correlates ligand field strength with $$^{99}$$Ru M$"o$ssbauer parameters of ruthenium-nitrosyl complexes

Kaneko, Masashi; Kato, Akane*; Nakashima, Satoru*; Kitatsuji, Yoshihiro

Inorganic Chemistry, 58(20), p.14024 - 14033, 2019/10

 Times Cited Count:7 Percentile:62.61(Chemistry, Inorganic & Nuclear)

We applied density functional theory calculations to ruthenium-nitrosyl complexes, which are known to exist in high-level radioactive waste, to give a theoretical correlation between $$^{99}$$Ru M$"o$ssbauer spectroscopic parameters ($$delta$$ and $$Delta$$$$E_{rm Q}$$) and ligand field strength ($$Delta$$$$_{rm o}$$) for the first time. The structures of the series of complexes, [Ru(NO)L$$_{5}$$] (L = Br$$^{-}$$, Cl$$^{-}$$, NH$$_{3}$$, CN$$^{-}$$), were modeled based on the corresponding single-crystal X-ray coordinates. The comparisons of the geometries and total energies between the different spin states suggested that the singlet spin state of [Ru(II)(NO$$^{+}$$)L$$_{5}$$] complexes were the most stable. The calculated results of both the $$delta$$ and $$Delta$$$$E_{rm Q}$$ values reproduced the experimental results by reported previously and increased in the order of L = Br$$^{-}$$, Cl$$^{-}$$, NH$$_{3}$$, CN$$^{-}$$. Finally, we estimated the ligand field strength ($$Delta$$$$_{rm o}$$) based on molecular orbitals, assuming C$$_{rm 4v}$$ symmetry and showed the increase of $$Delta$$$$_{rm o}$$ values in that order, being consistent with well-known spectrochemical series of ligands. The increase attributes to the strengthening of the abilities of $$sigma$$-donor and $$pi$$-acceptor of the L-ligands to the Ru atom, resulting in the increase of the $$delta$$ values.

Journal Articles

Proton chelating ligands drive improved chemical separations for rhodium

Narita, Hirokazu*; Nicolson, R. M.*; Motokawa, Ryuhei; Ito, Fumiyuki*; Morisaku, Kazuko*; Goto, Midori*; Tanaka, Mikiya*; Heller, W. T.*; Shiwaku, Hideaki; Yaita, Tsuyoshi; et al.

Inorganic Chemistry, 58(13), p.8720 - 8734, 2019/07

 Times Cited Count:6 Percentile:55.42(Chemistry, Inorganic & Nuclear)

Journal Articles

Ion hydration and association in an aqueous calcium chloride solution in the GPa range

Yamaguchi, Toshio*; Nishino, Masaaki*; Yoshida, Koji*; Takumi, Masaharu*; Nagata, Kiyofumi*; Hattori, Takanori

European Journal of Inorganic Chemistry, 2019(8), p.1170 - 1177, 2019/02

 Times Cited Count:6 Percentile:62.61(Chemistry, Inorganic & Nuclear)

Neutron diffraction measurements of an aqueous 2 mol dm$$^{-3}$$ CaCl$$_2$$ solutions in D$$_{2}$$O have been made at 1 GPa, 298 K as well as 0.1 MPa, 298 K. The experimental structure factors are subjected to Empirical Potential Structure Refinement (EPSR) modeling to reveal the ion hydration and association and solvent water at the atomic level. About seven water molecules surround Ca$$^{2+}$$ at the Ca-O and Ca-D distances of 2.44 ${AA}$ and 3.70 ${AA}$, respectively, at both pressures, suggesting no significant pressure effect on the cation hydration. On the other hand, the Cl$$^{-}$$ ion shows a drastic change in water oxygen coordination from 7 at 0.1 MPa to 14 at 1 GPa, accompanied by shortening of Cl-O distance from 3.18 ${AA}$ to 3.15 ${AA}$. However, the number of water hydrogen atoms around Cl$$^{-}$$ does not change significantly as 6.0 $$sim$$ 6.7 with shortening Cl-D distance from 2.22 to 2.18 ${AA}$ on compression. The pressure effect on the solvent water structure is also drastic as an increase in water oxygen atoms of 4.7 at the O-O distance of 2.79 ${AA}$ at 0.1 MPa to 10.3 at 2.85 ${AA}$ at 1 GPa. The number of water hydrogen atoms, however, does not change as 1.2 at the O-D distance of 1.74 ${AA}$ for both pressures, demonstrating the presence of the O$$cdots$$D hydrogen bonds which are significantly bent at 1 GPa at 298 K. This change of hydrogen bonds in water with pressure probably causes the drastic increase in water oxygen atoms around Cl$$^{-}$$.

Journal Articles

Theoretical elucidation of Am(III)/Cm(III) separation mechanism with diamide-type ligands using relativistic density functional theory calculation

Kaneko, Masashi; Suzuki, Hideya; Matsumura, Tatsuro

Inorganic Chemistry, 57(23), p.14513 - 14523, 2018/12

 Times Cited Count:10 Percentile:70.56(Chemistry, Inorganic & Nuclear)

We elucidated the separation mechanism between Am(III) and Cm(III) ions by using two different types of diamide ligands, diglycolamide (DGA) and alkylated diamide amine (ADAAM), by means of the density functional theory technique and electron density analysis. The molecular geometries and formation reactions of the metal-ligand complexes were modeled by using [M(DGA)$$_{3}$$]$$^{3+}$$ and [M(ADAAM)(NO$$_{3}$$)$$_{3}$$(H$$_{2}$$O)]. We successfully reproduced Cm(III) selectivity over Am(III) with DGA and Am(III) selectivity over Cm(III) with ADAAM. Furthermore, we analyzed the bonding properties between the metal ion and the diamide-type ligands by using model complexes, [M(DGA)$$_{3}$$]$$^{3+}$$ and [M(ADAAM)(NO$$_{3}$$)$$_{3}$$(H$$_{2}$$O)], and revealed the differences in terms of the bond dissociation energy and the metal 5f-orbital participation in the covalency between the Am(III) and the Cm(III) complexes. It was suggested that the differences were key factors to understand the Am(III)/Cm(III) selectivity.

Journal Articles

Synthesis, direct formation under high pressure, structure, and electronic properties of LiNbO$$_{3}$$-type oxide PbZnO$$_{3}$$

Mori, Daisuke*; Tanaka, Kie*; Saito, Hiroyuki; Kikegawa, Takumi*; Inaguma, Yoshiyuki*

Inorganic Chemistry, 54(23), p.11405 - 11410, 2015/12

 Times Cited Count:16 Percentile:72.19(Chemistry, Inorganic & Nuclear)

Journal Articles

Synthesis, structure, and pressure-induced polymerization of Li$$_{3}$$Fe(CN)$$_{6}$$ accompanied with enhanced conductivity

Li, K.*; Zheng, H.*; Hattori, Takanori; Sano, Asami; Tulk, C. A.*; Molaison, J.*; Feygenson, M.*; Ivanov, I. N.*; Yang, W.*; Mao, H.-K.*

Inorganic Chemistry, 54(23), p.11276 - 11282, 2015/12

 Times Cited Count:5 Percentile:31.75(Chemistry, Inorganic & Nuclear)

Pressure-induced polymerization of triple bonds would produce conductive conjugated double bonds. To find a metal cyanide with a low polymerization pressure, anhydrous Li$$_{3}$$Fe(CN)$$_{6}$$ is synthesized and its crystal structure is determined. The irreversible bonding between the CN$$^{-}$$ can be realized by use of the industrial apparatus. The conductivity is enhanced by more than 3 orders of magnitude, which makes the polymerized Li$$_{3}$$Fe(CN)$$_{6}$$ a potential cathode material for rechargeable lithium batteries.

Journal Articles

Crystal structures and magnetic properties of nickel chain compounds PbM$$_2$$Ni$$_6$$Te$$_3$$O$$_{18}$$ (M = Mn, Cd)

Doi, Yoshihiro*; Suzuki, Ryo*; Hinatsu, Yukio*; Kodama, Katsuaki; Igawa, Naoki

Inorganic Chemistry, 54(22), p.10725 - 10731, 2015/11

 Times Cited Count:5 Percentile:31.75(Chemistry, Inorganic & Nuclear)

Journal Articles

Synthesis, structure, luminescence, and magnetic properties of a single-ion magnet, "$$mer$$"-[Tris($$N$$-[(imidazol-4-yl)-methylidene]-DL-phenylalaninato)terbium(III) and related "$$fac$$"-DL-alaninato derivative

Yamauchi, Suguru*; Fujinami, Takeshi*; Matsumoto, Naohide*; Mochida, Naotaka*; Ishida, Takayuki*; Sunatsuki, Yukinari*; Watanabe, Masayuki; Tsuchimoto, Masanobu*; Coletti, C.*; Re, N.*

Inorganic Chemistry, 53(12), p.5961 - 5971, 2014/06

 Times Cited Count:13 Percentile:61.14(Chemistry, Inorganic & Nuclear)

Two Tb$$^{rm III}$$ complexes with same N$$_{6}$$O$$_{3}$$ donor atoms but different coordination geometries,${it "$fac$"}$-[Tb$$^{rm III}$$(HL$$^{rm DL-ala}$$)$$_{3}$$]7H$$_{2}$$O (${bf 1}$) and ${it "$mer$"}$-[Tb$$^{rm III}$$(HL$$^{rm DL-phe}$$)$$_{3}$$]7H$$_{2}$$O (${bf 2}$), were synthesized, where H$$_{2}$$L$$^{rm DL-ala}$$ and H$$_{2}$$L$$^{rm DL-phe}$$ are ${it N}$-[(imidazol-4-yl)methylidene]-DL-alanine and -DL-phenylalanine, respectively. The magnetic data were analyzed by a spin Hamiltonian including the crystal field effect on Tb$$^{rm III}$$ ion (4f$$^{8}$$, ${it J}$ = 6, ${it S}$ = 3, ${it L}$ = 3, ${it g$_{J}$}$ = 3/2, $$^{7}$$F$$_{6}$$). The Stark splitting of the ground state $$^{7}$$F$$_{6}$$ was evaluated from the magnetic analysis, and the energy diagram pattern indicated an easy-plane and easy-axis (Ising type) magnetic anisotropies for ${bf 1}$ and ${bf 2}$, respectively. Highly efficient luminescences with $$phi$$ = 0.50 and 0.61 for ${bf 1}$ and ${bf 2}$, respectively, were observed, and the luminescence fine structure due to the $$^{5}$$D$$_{4}$$ $$rightarrow$$ $$^{7}$$F$$_{6}$$ transition is in good accordance with the energy diagram determined from the magnetic analysis.

Journal Articles

Superheavy element flerovium (element 114) is a volatile metal

Yakushev, A.*; Gates, J. M.*; T$"u$rler, A.*; Sch$"a$del, M.; D$"u$llmann, Ch. E.*; Ackermann, D.*; Andersson, L.-L.*; Block, M.*; Br$"u$chle, W.*; Dvorak, J.*; et al.

Inorganic Chemistry, 53(3), p.1624 - 1629, 2014/02

 Times Cited Count:79 Percentile:98.54(Chemistry, Inorganic & Nuclear)

We report on a gas-solid chromatography study of the adsorption of element 114 (flerovium, Fl) on a Au surface. Fl was produced in the nuclear fusion reaction $$^{244}$$Pu($$^{48}$$Ca, 3-4n)$$^{288,289}$$Fl and was isolated in-flight from the primary $$^{48}$$ beam in a physical recoil separator. The adsorption behavior of Fl, its nuclear $$alpha$$-decay product Cn, their lighter homologues in groups 14 and 12, i.e., Pb and Hg, and the noble gas Rn were studied simultaneously by isothermal gas chromatography and thermochromatography. Two Fl atoms were detected. They adsorbed on a Au surface at room temperature, but not as readily as Pb and Hg. The observed adsorption behavior of Fl points to a higher inertness compared to its nearest homologue in the group, Pb. However, the measured lower limit for the adsorption enthalpy of Fl on a Au surface points to the formation of a metal-metal bond of Fl with Au. Fl is the least reactive element in the group, but still a metal.

Journal Articles

Magnetic structure and electromagnetic properties of LnCrAsO with a ZrCuSiAs-type structure (Ln = La, Ce, Pr, and Nd)

Park, S.-W.*; Mizoguchi, Hiroshi*; Kodama, Katsuaki; Shamoto, Shinichi; Otomo, Toshiya*; Matsuishi, Satoru*; Kamiya, Toshio*; Hosono, Hideo*

Inorganic Chemistry, 52(23), p.13363 - 13368, 2013/12

 Times Cited Count:20 Percentile:73.1(Chemistry, Inorganic & Nuclear)

Journal Articles

Measurement of the Md$$^{3+}$$/Md$$^{2+}$$ reduction potential studied with flow electrolytic chromatography

Toyoshima, Atsushi; Li, Z.*; Asai, Masato; Sato, Nozomi; Sato, Tetsuya; Kikuchi, Takahiro; Kaneya, Yusuke; Kitatsuji, Yoshihiro; Tsukada, Kazuaki; Nagame, Yuichiro; et al.

Inorganic Chemistry, 52(21), p.12311 - 12313, 2013/11

 Times Cited Count:5 Percentile:26.88(Chemistry, Inorganic & Nuclear)

The reduction behavior of mendelevium (Md) was studied using a flow electrolytic chromatography apparatus. By applying appropriate potentials on the chromatography column, the more stable Md$$^{3+}$$ is reduced to Md$$^{2+}$$. The reduction potential of the Md$$^{3+}$$ + e$$^{-}$$ $$rightarrow$$ Md$$^{2+}$$ couple was determined to be -0.16$$pm$$0.05 V vs. a normal hydrogen electrode.

Journal Articles

Direct interactions between Z-DNA and alkaline earth cations, discovered in the presence of high concentrations of MgCl$$_{2}$$ and CaCl$$_{2}$$

Chatake, Toshiyuki*; Sunami, Tomoko

Journal of Inorganic Biochemistry, 124, p.15 - 25, 2013/07

 Times Cited Count:12 Percentile:54.74(Biochemistry & Molecular Biology)

Journal Articles

Rapid synthesis of radioactive transition-metal carbonyl complexes at ambient conditions

Even, J.*; Yakushev, A.*; D$"u$llmann, C. E.*; Dvorak, J.*; Eichler, R.*; Gothe, O.*; Hild, D.*; J$"a$ger, E.*; Khuyagbaatar, J.*; Kratz, J. V.*; et al.

Inorganic Chemistry, 51(12), p.6431 - 6433, 2012/06

 Times Cited Count:30 Percentile:81.21(Chemistry, Inorganic & Nuclear)

Carbonyl complexes of radioactive transition metals can be easily synthesized with high yields by stopping nuclear fission or fusion products in a gas volume containing CO. Here, we focus on Mo, W, and Os complexes. The reaction takes place at pressures of around 1 bar at room temperature, i.e., at conditions that are easy to accommodate. The formed complexes are highly volatile. They can thus be transported within a gas stream without major losses to setups for their further investigation or direct use. The rapid synthesis holds promise for radiochemical purposes and will be useful for studying, e.g., chemical properties of superheavy elements.

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