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Yamagata, Kazuhito*; Ouchi, Kazuki; Marumo, Kazuki*; Tasaki-Handa, Yuiko*; Haraga, Tomoko; Saito, Shingo*
Inorganic Chemistry, 62(2), p.730 - 738, 2023/01
Times Cited Count:3 Percentile:74.01(Chemistry, Inorganic & Nuclear)The inert NpO complex with a fluorescein-modified phenanthroline-2,9-dicarboxylic acid was found by kinetic selection using polyacrylamide gel electrophoresis (PAGE) from a small chemical library. The small spontaneous dissociation rate constant of 810 s (the half-life of 23 hours) was determined. This is the singly-charged NpO complex exhibiting unusual kinetic inertness in aqueous solution, one million times slower than widely accepted fast kinetics of neptunyl complexes. Selective fluorescence detection of NpO was achieved in PAGE with a detection limit of 68 pmol dm(17 fg). This system was successfully applied to simulated spent nuclear fuel and high-level radioactive waste samples.
Eichler, R.*; Asai, Masato; Brand, H.*; Chiera, N. M.*; Di Nitto, A.*; Dressler, R.*; Dllmann, Ch. E.*; Even, J.*; Fangli, F.*; Goetz, M.*; et al.
EPJ Web of Conferences, 131, p.07005_1 - 07005_7, 2016/12
Times Cited Count:3 Percentile:72.98(Chemistry, Inorganic & Nuclear)In recent years gas-phase chemical studies assisted by physical pre-separation allowed for the productions and investigations of fragile single molecular species of superheavy elements. The latest highlight is the formation of very volatile hexacarbonyl compound of element 106, Sg(CO). Following this success, second-generation experiments were performed to measure the first bond dissociation energy between the central metal atom and the surrounding ligand. The method using a tubular decomposition reactor was developed and successfully applied to short-lived Mo(CO), W(CO), and Sg(CO).
Usoltsev, I.*; Eichler, R.*; Wang, Y.*; Even, J.*; Yakushev, A.*; Haba, Hiromitsu*; Asai, Masato; Brand, H.*; Di Nitto, A.*; Dllmann, Ch. E.*; et al.
Radiochimica Acta, 104(3), p.141 - 151, 2016/03
Times Cited Count:31 Percentile:94.91(Chemistry, Inorganic & Nuclear)Conditions of the production and decomposition of hexacarbonyl complexes of short-lived Mo and W isotopes were investigated to study thermal stability of the heaviest group 6 hexacarbonyl complex Sg(CO). A tubular flow reactor was tested to decompose the hexacarbonyl complexes and to extract the first bond dissociation energies. A silver was found to be the most appropriate reaction surface to study the decomposition of the group 6 hexacarbonyl. It was found that the surface temperature at which the decomposition occurred was correlated to the first bond dissociation energy of Mo(CO) and W(CO), indicating that the first bond dissociation energy of Sg(CO) could be determined with this technique.
Tabata, Tatsuo*; Shirai, Toshizo*; Sataka, Masao; Kubo, Hirotaka
Atomic Data and Nuclear Data Tables, 92(3), p.375 - 406, 2006/05
Times Cited Count:73 Percentile:95.12(Physics, Atomic, Molecular & Chemical)no abstracts in English
Kurosaki, Yuzuru; Yokoyama, Keiichi; Teranishi, Yoshiaki
Chemical Physics, 308(3), p.325 - 334, 2005/01
Times Cited Count:23 Percentile:60.42(Chemistry, Physical)A total of 1200 trajectories have been integrated for the two dissociation channels of formic acid, HCOOH HO + CO (1) and HCOOH CO + H (2), which occur with 248 and 193 nm photons, using the direct ab initio molecular dynamics method at the RMP2(full)/cc-pVDZ level of theory. It was found that the percentage of the energy distributed to a relative translational mode in reaction 2 is much larger than that in reaction 1. This is mainly due to the difference in the geometry of transition state (TS); the HO geometry in the TS of reaction 1 was predicted to significantly deviate from the equilibrium one, whereas the CO and H geometries in the TS of reaction 2 were found to be more similar to their equilibrium ones. It was also found that the product diatomic molecules, CO and H, are both vibrationally and rotationally excited. The calculated relative population of the vibrationally excited CO for the 248 nm photodissociation was consistent with experiment.
Kurosaki, Yuzuru; Yokoyama, Keiichi
Chemical Physics Letters, 371(5-6), p.568 - 575, 2003/04
Times Cited Count:31 Percentile:69.39(Chemistry, Physical)A total of 400 trajectories for the photodissociation, CHCHOCH+HCO, on the T potential surface have been calculated using the direct ab initio molecular dynamics method at the UB3LYP/cc-pVDZ level of theory. It was predicted that the product CH is neither vibrationally nor rotationally excited and HCO is vibrationally not excited but rotationally excited. The averaged HCO rotational energy was calculated to be 1.1 kcal/mol, which is 15.1 % of the available energy, 7.3 kcal/mol. The present result agrees with experiment within just a few percent of the observed data.
Kurosaki, Yuzuru; Yokoyama, Keiichi
Journal of Physical Chemistry A, 106(47), p.11415 - 11421, 2002/11
Times Cited Count:36 Percentile:72.97(Chemistry, Physical)A total of 100 trajectories for the photodissociation, CHCHO CH + CO, on the S0 potential surface have been calculated using the direct ab initio molecular dynamics method at the RMP2(full)/cc-pVDZ level of theory. The energy distributions for the relative translational energy, the CO internal energy, and the CH internal energy were calculated to be 28, 20, and 51 %, respectively. It was predicted that the product CO is highly rotationally excited but vibrationally almost not excited; on average, the rotational and vibrational quantum numbers were 68.2 and 0.15, respectively, which qualitatively agrees with the recent observation of Gherman et al. (J. Chem. Phys. 2001, 114, 6128.)
Yamauchi, Toshihiko; Hayakawa, Takehito; Shizuma, Toshiyuki
JAERI-Conf 2002-007, 54 Pages, 2002/08
The workshop on application of free-electron laser (FEL) and nuclear isomer study was held at Tokai Research Establishment of JAERI on September 28. The workshop was devoted to the discussions and the presentations of two thema as follows: Six papers associated with the laser compton gamma-ray, the photonuclear physics and the nuclear astrophysics using the gannma-ray produced by the T3 laser were presented in the morning session. Seven papers including an invited talk on the behavior of molecules in intense laser light fields and associated with the chemical decomposition of dioxin, the silicon isotope separetion, the infrared photoexcitation spectroscopy, the laser-tissue interaction and the single-wall carbon nanotube and nanohorn by FEL etc. were also presented in the afternoon session. The intensive discussion was exchanged among approximately 50 participants. Each performance during the first workshop was fully telecomunicated by a video conference system between Tokai and Kizu (Kansai Research Establishment) sites.
Yokoyama, Atsushi; Oba, Hironori; Shibata, Takemasa; Kawanishi, Shunichi*; Sugimoto, Shunichi*; Ishii, Takeshi*; Oya, Akio*; Miyamoto, Yoshiki*; Isomura, Shohei*; Arai, Shigeyoshi*
Journal of Nuclear Science and Technology, 39(4), p.457 - 462, 2002/04
Times Cited Count:3 Percentile:16.96(Nuclear Science & Technology)no abstracts in English
Kurosaki, Yuzuru
Journal of Molecular Structure; THEOCHEM, 545(1-3), p.225 - 232, 2001/07
The CASSCF and MRCI calculations with the cc-pVTZ basis set have been carried out for the CH + Cl CHCl + Cl reaction. It has been revealed that the reaction has a small barrier from the CHCl + Cl side at the CASSCF level of theory, but it has no barrier at the MRCI level. Namely, the CHCl + Cl CH + Cl reaction was predicted to be a spontaneous reaction. The result of the MRCI calculation strongly supports the prediction of our previous PMP4(SDTQ) calculation [J. Mol. Struct. (Theochem) 503 (2000) 231].
Ikeura, Hiromi*; Sekiguchi, Tetsuhiro; Kitajima, Yoshinori*; Baba, Yuji
Applied Surface Science, 169-170, p.282 - 286, 2001/01
Times Cited Count:8 Percentile:44.9(Chemistry, Physical)Carbon and nitrogen K-shell excitation and dissociation of condensed formamide at 96 K were studied by near edge X-ray absorption fine structure (NEXAFS) recorded by total electron yield (TEY), total ion yield (TIY) and photon-stimulated desorption (PSD) yield of H+ measurements. It was found that electronic transitions from the C1s or the N1s to the *(C-H) and/or (N-H) enhanced ion yield of H+ from the C-H and/or N-H functional group. This selective dissociation indicates that the corresponding unoccupied molecular orbital has an antibonding character of the C-H and/or N-H. To investigate the molecular orientation of condensed formamide, incidence-angle-dependent TEY-NEXAFS spectra were measured. The CNO plane of the adsorbed formamide molecule is determined to be tilted away from the surface by an averaged angle of about 42 degrees.
Yokoyama, Atsushi; Yokoyama, Keiichi; Takayanagi, Toshiyuki
Journal of Chemical Physics, 114(4), p.1617 - 1623, 2001/01
Times Cited Count:6 Percentile:18.61(Chemistry, Physical)no abstracts in English
Yamauchi, Toshihiko; Ito, Shinichi*; Minehara, Eisuke
Technical Digest on 4th Pacific Rim Conference on Lasers and Electro-Optics (CLEO/Pacific Rim 2001), p.I_148 - I_149, 2001/00
The decomposition of dioxin analogues by infrared (IR) laser irradiation includes thermal destruction and multiple-photon dissociation. It is important for the decomposition to choose the laser wavelength which is highly absorbed. The thermal decomposition takes place by the irradiation of the low IR laser power. Considering the model of thermal decomposition, it is discussed that the adjacent water vapor assists the decomposition (dechlorination) of dioxin analogues in addition to the thermal decomposition by the direct laser absorption.
Ichihara, Akira; Iwamoto, Osamu; Yokoyama, Keiichi
Atomic Collision Research in Japan, No.25, p.28 - 29, 1999/11
no abstracts in English
Yokoyama, Atsushi; Takayanagi, Toshiyuki
Chemical Physics Letters, 307(1-2), p.48 - 54, 1999/00
Times Cited Count:9 Percentile:28.09(Chemistry, Physical)no abstracts in English
Kubo, Hirotaka; Takenaga, Hidenobu; Sugie, Tatsuo; Higashijima, Satoru; *; Sakasai, Akira; Hosogane, Nobuyuki
Plasma Physics and Controlled Fusion, 40(6), p.1115 - 1126, 1998/00
Times Cited Count:64 Percentile:86.61(Physics, Fluids & Plasmas)no abstracts in English
Sato, K.*; *; Takayanagi, Toshiyuki; *; Yokoyama, Atsushi
Journal of Chemical Physics, 106(24), p.10123 - 10133, 1997/06
Times Cited Count:31 Percentile:71.5(Chemistry, Physical)no abstracts in English
; Yokoyama, Keiichi; Takayanagi, Toshiyuki
Journal of Physical Chemistry A, 101(36), p.6647 - 6652, 1997/00
Times Cited Count:15 Percentile:47.46(Chemistry, Physical)no abstracts in English
JAERI-Conf 95-022, 124 Pages, 1995/12
no abstracts in English
; Yokoyama, Keiichi;
Chemical Physics Letters, 237, p.106 - 110, 1995/05
Times Cited Count:13 Percentile:45.67(Chemistry, Physical)no abstracts in English