Chromatographic properties of mesoporous silica gel modified with acetylacetonates of europium and copper

New mesoporous materials prepared from tetraethoxysilane, i.e., sorbents obtained with the use of surfactants, are synthesized. Their chromatographic polarity is assessed quantitatively. Their Kovats retention indices and Rohrschneider polarity coefficients are calculated. Based on physicohemical data, it is demonstrated that modifying supports with metal chelates changes the structure and properties of the initial sorbents: the differential molar Gibbs free energies rise considerably for sorbent modified with copper acetylacetonate with respect to ethanol (-ΔG′ _i = 7.09 kJ/mol) and nitromethane (-ΔG′ _i = 6.75 kJ/mol), relative to the initial silica gel (5.43 and 4.15 kJ/mol, respectively).