Evidence for the formation of sodium hassate(VIII)

Hassium, element 108, was produced in the fusion reaction between Mg-26 and Cm-248. The hassium recoils were oxidized in-situ to a highly volatile oxide, presumably HsO(4), and were transported in a mixture of He and 02 to a deposition and detection system. The latter consisted of 16 silicon PIN-photodiodes facing a layer of NaOH, which served, in the presence of a certain partial pressure of water in the transport gas, as reactive surface for the deposition of the volatile tetroxides. Six correlated alpha-decay chains of Hs were detected in the first 5 detectors centred around detection position 3. In analogy to OsO4, which forms Na-2[OsO4(OH)(2)], an osmate(VIII), with aqueous NaOH, HsO(4) presumably was deposited as Na-2[HsO(4)(OH)(2)], a hassate(VIII).