[en] Gasothermochromatographic behaviour of volatile oxygen-containing compounds of radiorhenium (¹⁷⁷Re), formed in the atmosphere of air at different content of aqueous vapours, has been studied. Technique of continuous thermochromatographic separation of radiorhenium from the products of nuclear reactions under the effect of heavy ions is developed. It is shown that not more than 10^-5 part of ytterbium atoms-actinoid analogues, as well as of hafnium and tantalum-analogues of the elements 104 and 105 pass on thermogradient section of the column. It is found that under experimental conditions rhenium forms adsorption zone with the centre at the temperature of 100+-20 deg C. According to the evaluations of the time of atom transport from the target does not exceed 3s, and rhenium removal of the reaction column reaches 80%. The technique developed can be used for express selective separation of spontaneous fission isotopes of the element 107 as eka-rhenium from the mixture of nuclear reaction products with Z <= 107

[en] Chemical gas phase reactions of the heavier group 7 elements in the system O₂/H₂O are presumably best suited for a separation of Nielsbohrium from the lighter transactinides. We expect a higher reaction velocity using the more reactive gas system O₃/H₂O₂. For the experimental verification of this idea we prepared ¹⁸³Re/¹⁸⁴Re samples for thermochromatography experiments with both gas systems. (author) 8 refs

[en] Fully relativistic Density-Functional calculations have been performed for group 7 MO₃Cl (M = Tc, Re, and element 107, Bh), for group 8 tetroxides MO₄ (M = Ru, Os, and element 108, Hs), and for various aqueous complexes of group 6 elements Mo, W, and element 106, Sg. The electronic structure analysis has shown the transactinide compounds to be very similar to those of the lighter homologs in the respective chemical groups with the covalence increasing with increasing atomic number. Results have shown BhO₃Cl to have a trend in volatility in line with that of the lighter homologs in the group. Hydrolysis of element 106 with the formation of anionic oxo-complexes has, however, a reversed trend, so that hydrolysis decreases in the order Mo > Sg > W. (orig.)

No abstract available

[en] Certain lower oxides of radioisotopes ¹⁸⁵Os, ⁹⁷Ru, ¹⁸³Re, ⁹⁵Tc and ⁹⁶Tc were prepared using the method of gas thermochromatography. Helium served as gas carrier, while impurity oxygen in concentration at the level of 10^-7% was used as reagent. Maxima of precipitation ranges of the compounds formed, as well as their composition and chemical yield, were determined. Values of adsorption enthalpy -ΔH_a⁰ of oxidation products on the surface of quartz glass were calculated. Volatility of certain monoxides was estimated. Analysis of the obtained and literature data suggests that the values of -ΔH_a⁰ for elements of groups VII and VIII elements of the Periodic System are mainly determined by valence state of metal atom in oxide molecule. The results presented can be used in experiments on chemical isolation of elements Bh (107) and Hs (108) as volatile oxides