No abstract available

[en] We report on the characteristic anion-exchange behavior of the superheavy element dubnium (Db) with atomic number Z=105 in HF/HNO₃ solution at the fluoride ion concentration [F^-]=0.003 M. The result clearly demonstrates that the fluoro complex formation of Db is significantly different from that of the group-5 homologue Ta in the 6th period of the periodic table while the behavior of Db is similar to that of the lighter homologue Nb in the 5th period. (author)

No abstract available

[en] Several experiments have been made to study the aqueous chemistry of element 105, dubnium. Although difference of the complex formation strength among Db and its lighter homologues was deduced from some of the experiments in HF solution, enough data have not been accumulated to discuss in detail the fluoride complexations and/or relativistic effects. In the present work, we have investigated the chemical behavior of Db together with its group-5 homologues by anion-exchange chromatography in HF. (orig.)

[en] The 2013 update of the discovery of nuclide project is presented. Details of the 12 new nuclides observed for the first time in 2013 are described. In addition, the discovery of ²⁶⁶Db has been included and the previous assignments of six other nuclides were changed. Overview tables of where and how nuclides were discovered have also been updated and are discussed. (author)

[en] First investigations of chemical properties of bohrium (Z = 107) and hassium (Z = 108) showed an expected behaviour as ordinary members of groups 7 and 8 of the periodic table. Two attempts to study element 112 yielded some indication for a behaviour like a very volatile noble metal. However, a very recent experiment to confirm this preliminary observation failed. Two examples are described how chemical studies may help to support element discovery claims from purely physics experiments. The two examples are the discovery claims of the elements 112 and 115, respectively, where the progenies hassium and dubnium were chemically identified. (orig.)

[en] The radioactivity of the superheavy nuclei ^250−275Db is studied and presented using the Coulomb and proximity potentials. The half-lives corresponding to different decay modes such as α, cluster decay (¹²C, ¹⁴N, ^18,20O, ²³F, ²⁰Ne, ³⁴S, ²⁸Mg and ⁴⁰Ca) and spontaneous fission in the superheavy nuclei ^250−275Db are studied. The studied half-lives are compared with the available experiments. The decay modes and the branching ratios of isotopes of dubnium are presented. The isotopes of dubnium, ^254−263Db, are identified as α emitters, whereas isotopes such as ^250−253Db and ^264−275Db are identified as having spontaneous fission. The identified alpha emitting isotopes of dubnium have decay energies from 6 MeV to 10 MeV and half-lives 1 ms to 100 s. The possible projectile–target combinations to synthesise the superheavy nuclei ^253−263Db were predicted. The fusion of spherical projectile and target yields larger evaporation residue cross-sections. (author)

[en] Chemical studies of the heaviest elements based on an atom-at-a-time scale conducted at JAEA (Japan Atomic Energy Agency) are introduced. Chemical characterization of element 104, rutherfordium (Rf), and element 105, dubnium (Db), in liquid-phases is presented and characteristic behavior of the heaviest elements is discussed in comparison with that of respective homologues in the Periodic Table. An electrochemical approach to the heaviest elements by a flow electrolytic column chromatographic method is also given: successful oxidation of element 102, nobelium (No), with single atoms. Prospects for the future studies on chemical properties of the heaviest elements at JAEA will be briefly considered. (author)

[en] Recent experimental studies of the chemical characterization of the first two transactinide elements, rutherfordium (Rf) and dubnium (Db), conducted atom-at-a-time in aqueous phases are reviewed. A short description on experimental techniques based on partition methods, specifically automated rapid chemical separation systems, is also given. Perspectives for aqueous-phase chemistry experiments on heavier elements are briefly discussed.

No abstract available