The heaviest element, whose chemical behavior has been studied so far is bohrium (Bh) with Z=107  behaving like a typical member of group 7 of the periodic table. The longestlived α-decaying isotope of the next heavier element hassium (Hs, Z=108) is 269 Hs (T=11.3 s) which has been identified in the decay chain of 277 112 [2,3]. Hs is supposed to be a member of group 8 of the periodic table and should thus form a very volatile tetroxide. Relativistic density functional calculations predicted the electronic structure of HsO4 to be similar to the one of OsO4 . Application of different semiempirical models of the interaction of a MeO4 molecule with quartz surface predicted the adsorption behavior of OsO4 and HsO4 to be very similar . Extrapolations of trends within group 8 of the periodic table also predicted HsO4 and OsO4 to behave similar in a gas adsorption chromatography experiment . Hs isotopes were produced directly in the reaction 248 26 269,270 Cm ( Mg;5,4n) Hs at the UNILAC at GSI Darmstadt . Hs isotopes recoiling from the target were thermalized and oxidized in a He/O2 mixture in the recoil chamber of the In-situ Volatilization and On-line detection apparatus IVO . Volatile HsO4 was transported with the carrier gas to the Cryo-On-Line-Detector (COLD), a thermochromatography device. Along a narrow channel formed of PIN-diodes registering α-decaying and spontaneously fissioning (SF) nuclides, a temperature gradient form-20 to-170 °C was established. The deposition temperature of volatile species could therefore be determined, allowing for the determination of their adsorption enthalpy. COLD is an improved version of the Cryo-Thermochromatography Separator CTS developed at Berkele
To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.