Thermochemical characterization of seaborgium compounds in gas adsorption chromatography

The chemical characterization of the element seaborgium (Z = 106) requires fast experiments such as gas adsorption chromatographic separations in quar tz columns with single atoms in a clearly defined chemical state. The maxim um separation time for such experiments of only about 10 s is defined by th e relatively short half-lives of the currently known longest-lived isotopes (265)Sg and (266)Sg. To establish optimum experimental parameters, the req uired thermochemical quantities for chlorides, oxychlorides, and oxides of seaborgium were estimated by extrapolation. On the basis of these results, the stability and volatility of these compounds could be calculated. By use of empirical correlations, the thermochemical constants of the adsorption precesses were evaluated and the retention times calculated, taking into ac count the composition of the reactive carrier gas. The dioxydichloride of s eaborgium proved to be the most suitable chemical state regarding its stabi lity, volatility, and retention. Its standard sublimation enthalpy is expec ted to be between 125 and 144 kJ/mol (larger than that of WO2Cl2), resultin g in an adsorption enthalpy between -97 and -108 kJ/mol. If the chemistry o f seaborgium significantly deviates from the above predicted behavior, then this could be attributed to the possible influence of relativistic effects .