Hierarchical aggregation in a complex fluid; The Role of isomeric interconversion

Massey, D.*; Williams, C. D.*; Mu, J.*; Masters, A. J.*; Motokawa, Ryuhei; Aoyagi, Noboru; Ueda, Yuki; Antonio, M. R.*

Journal of Physical Chemistry B, 127(9), p.2052 - 2065, 2023/03

https://doi.org/10.1021/acs.jpcb.2c07527

Development of heavy element chemistry at interfaces; Observing actinide complexes at the oil/water interface in solvent extraction by nonlinear vibrational spectroscopy

Kusaka, Ryoji; Watanabe, Masayuki

Journal of Physical Chemistry Letters (Internet), 13(30), p.7065 - 7071, 2022/08

https://doi.org/10.1021/acs.jpclett.2c01550

Application of a novel gas phase synthesis approach to carbonyl complexes of accelerator-produced 5d transition metals

Gtz, M.*; Yakushev, A.*; Gtz, S.*; Di Nitto, A.*; Dllmann, Ch. E.*; Asai, Masato; Kindler, B.*; Krier, J.*; Lommel, B.*; Nagame, Yuichiro*; et al.

Radiochimica Acta, 110(2), p.75 - 86, 2022/02

https://doi.org/10.1515/ract-2021-1028

The study of volatile superheavy element carbonyl complexes requires more efficient methods because the yield of transactinide elements decreases with increasing atomic number. This is achieved by using a newly developed double chamber system to separate the recoil chamber and the reaction one, thereby avoiding the decomposition of reactive molecules by the projectile ion beam, which hinders the synthesis of carbonyl complexes. The feasibility of this method was verified by synthesizing 5d metal short-lived isotopes as homologous element isotopes of the light transactinide elements Sg, Bh, Hs, and Mt at the Japan Atomic Energy Agency tandem accelerator and conducting model experiments.

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

https://doi.org/10.1021/acs.inorgchem.1c00106

Systematic comparison of the structure of homoleptic tetradentate NO-type Schiff base complexes of tetravalent f-elements (M(IV) = Ce, Th, U, Np, and Pu) in solid state and in solution

Radoske, T.*; Kloditz, R.*; Fichter, S.*; Mrz, J.*; Kaden, P.*; Patzschke, M.*; Schmidt, M.*; Stumpf, T.*; Walter, O.*; Ikeda, Atsushi

Dalton Transactions (Internet), 49(48), p.17559 - 17570, 2020/12

https://doi.org/10.1039/d0dt03405c

Liquid interfaces related to lanthanide and actinide chemistry studied using vibrational sum frequency generation spectroscopy

Kusaka, Ryoji

Journal of Nuclear and Radiochemical Sciences (Internet), 20, p.28 - 31, 2020/06

http://www.radiochem.org/en/paper/JN201/jn20105.pdf

Complexation of Eu(III), Pb(II), and U(VI) with a glycoprotein; Microbial transformation of heavy elements in the aquatic environment

Kozai, Naofumi; Sakamoto, Fuminori; Tanaka, Kazuya; Onuki, Toshihiko; Sato, Takahiro*; Kamiya, Tomihiro*; Grambow, B.

Chemosphere, 196, p.135 - 144, 2018/04

https://doi.org/10.1016/j.chemosphere.2017.12.154

Transformation of heavy elements by microbes such as bacteria and fungi has been an intense research subject; however, little is known about that of protozoa. This study investigated interaction of a representative protozoa, , with heavy elements (Eu(III), Pb(II), U(VI)). Non-destructive elemental analysis by micro-PIXE hardly detected those elements on living cells after sorption experiments but clearly detected on the cells that were killed with a fixative beforehand. Chromatographic analysis of aquatic species of those heavy elements after the sorption experiments revealed a fraction of those elements bound to a glycoprotein dissolved from the cell surface of living cells to form soluble pseudocolloid. These findings suggest that complexation of heavy elements with the dissolved surface glycoprotein reduced the sorption of those heavy elements on living cells.

Bonding study on trivalent europium complexes by combining Mssbauer isomer shifts with density functional calculations

Kaneko, Masashi; Watanabe, Masayuki; Miyashita, Sunao*; Nakashima, Satoru*

Radioisotopes, 66(8), p.289 - 300, 2017/08

https://doi.org/10.3769/radioisotopes.66.289

Scalar-relativistic density functional calculations applied to some trivalent europium complexes. Five Eu(III) complexes whose Eu Mssbauer isomer shifts vary from -1.8 to 0.5 mm/s are referred by previously reported results. Geometrical optimizations of their complexes reproduces the experimental coordination structures. Single-point calculations are applied to their optimized geometries at three density functionals, namely, BP86, B3LYP, and B2PLYP, to obtain their electron densities at Eu nucleus. A comparison of the linearity between the electron densities and the corresponding Eu Mssbauer isomer shifts reveals that B2PLYP functional shows the best linearity. Electron population and bond analyses indicate that d- and f-orbital electrons of Eu ion in the complexes are found to be correlated to the experimental Eu Mssbauer isomer shifts. This indicates that the d- and f-orbital electrons are involved in the covalent interaction of the coordination bond between the Eu ion and the ligands.

A Spin-crossover phenomenon depending on the environment around an iron atom for the assembled coordination polymers

Nakashima, Satoru*; Kaneko, Masashi

Advances in Chemistry Research, Vol.36, p.171 - 195, 2017/01

Spin-crossover (SCO) phenomena of the assembled coordination polymers are introduced. When the bridging ligand is flexible like 1,2-bis(4-pyridyl)ethane, 1,3-bis(4-pyridyl)propane, a variety of assembled structure can be obtained, depending on the conformer of the ligand and the guest molecules. Guest-dependent SCO phenomena of the assembled iron complexes are shown. Density functional theory is applied to know the cause of guest-dependent SCO phenomena. The validity of an iron mono-nucleus model is evaluated for the coordination polymers. It is shown that SCO occurs or not depends on the local structure around iron ion.

Sorption behavior of thorium onto montmorillonite and illite

Iida, Yoshihisa; Barr, L.; Yamaguchi, Tetsuji; Hemmi, Ko

Genshiryoku Bakkuendo Kenkyu (CD-ROM), 23(1), p.3 - 8, 2016/06

http://doi.org/10.3327/jnuce.23.1_3

Thorium (Th)-229 is one of the important radionuclides for the performance assessment calculations for high-level radioactive waste repositories. The sorption behavior of Th onto montmorillonite and illite were investigated by batch sorption experiments. Experiments were carried out under variable pH and carbonate concentrations. The sorbability of montmorillonite was higher than that of illite. Distribution coefficients, (m kg), decreased with increased carbonate concentrations and showed the minimal value at around pH 10. The sorption behaviors of Th were analyzed by the non-electrostatic surface complex model with PHREEQC computer program. The model calculations were able to explain the experimental results reasonably well. The decreases of was likely due to the stabilization of aqueous species by hydroxo-carbonate complexations in the solutions.