Required New Experimental Data

In the meantime, the whole field of transactinoid studies, with its peculiar and nontrivial features, is still young — if not by years since birth, then by the number of experiments performed to date. The major motivation — the quest for still new elements and demands for their chemical identification — greatly stimulated the development of the experimental instruments and techniques. In the first place, these were high efficiency spectroscopic low-level measurements of the particle radioactivity of short-lived nuclides in the specific conditions of chemical experiments. Necessarily, the fundamental chemical and physicochemical problems behind the employed methods, as well as evaluation of uncertainties of the results, have not been paid adequate attention. Much more could be learned (but was not) in off-line studies of long-lived radioisotopes of common elements with good statistics. As a result, some conclusions in the literature are not well founded, and important details of the experimental conditions are not given. 

The present situation with the observed trends and with the precision of the data is better illustrated by Fig. 5.26 than by the simple linear correlations. It can be seen that the desorption energies (obtained by conventional approach) of very volatile molecular liquids tend to approach the sublimation energies (calculated for mobile adsorption), while those of more ionic liquids make only about two-thirds of AsubH. The scatter of the experimental AdesH values is very large. Evidently, if the data for less volatile and ionic liquids were not known, one would not insist on any linear correlation. The scatter of values obtained for a particular compound by different 

Pershina [103] believes that a better way to compare the volatility of analogous compounds is to take the ratio of the experimental adsorption equilibrium constants, rather than to evaluate the adsorption enthalpies. The ratio should be corrected for the involved half-lives, and the contribution from the difference in internal entropy of the compared molecules (owing to unequal masses of the metal atoms and different bond lengths) can estimated by calculations from first principles. The approach was used for analysis of the experimental data on hassium and osmium tetroxides, which were reported in [104], 

the qualitative and quantitative compositions of the carrier gas, especially as to the most chemically active components, have not been the same in different laboratories. As a result it is not known whether the surfaces were modified to a comparable degree in different studies. An even more important question is, how complete was the coverage of the surface by the grafted molecular fragments These factors critically affect the resulting surface heterogeneity and the spectrum of the desorption energies. 

While it is difficult to avoid all possible uncertainties, an obvious step forward would be a purposeful, careful conditioning of the columns before use. The data reviewed in Sects. 5.3.2 and 5.3.3 allow us to propose a tentative scheme of processing the tubes it might include the following steps  

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We have constructed the several structural hypotheses mentioned above so as to be in agreement with available experimental data (or at least our interpretation of them). Testing of these hypotheses requires new experimental data (see Section VII). For the present we turn to an examination of the consistency of the ideas advanced. 

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