Molecular statistical calculation of thermodynamic characteristics of adsorption of O-, S-, and Se-containing heteroadamantanes on graphitized thermal carbon black

The thermodynamic characteristics of adsorption (TCA) on the basal face of graphite have been calculated in terms of the semiempirical molecular statistical theory of adsorption for molecules of O-, S-, and Se-containing heteroadamantanes of different structure and isostructural cyclohexane derivatives. The influence of the nature, number, and position of heteroatoms in the adamantane framework on the TCA values was studied in detail, which made it possible to predict the retention of the compounds considered on the surface of graphitized thermal carbon black under the conditions of equilibrium gas adsorption chromatography. The introduction of each subsequent heteroatom into a polyheteroadamantane molecule makes a non-additive contribution to the TCA values. The contributions of various fragments to the total adsorption energy were calculated by the TCA of isostructural heterocyclohexane molecules, and the most preferential orientations of the framework molecules of the adsorbates relative to the planar graphite surface were determined.