Effect of the nature of binary water-organic solvents on the thermodynamic characteristics of adsorption of certain 1,3,4-oxadiazoles and 1,2,4,5-tetrazines on phenyl-bonded silica gel

The thermodynamics of adsorption in the Henry region for certain 1,3,4-oxadiazoles and 1,2,4,5-tetrazines from water-acetonitrile, water-methanol, and water-isopropyl alcohol solutions on silica gel with grafted phenyl groups is studied according to the dynamic method under conditions close to equilibrium. The effect of the nature of the organic component of a solvent on the values of standard differential molar changes in Gibbs energy, enthalpy, and entropy is shown upon adsorption of the investigated substances from solutions. The role of intermolecular interactions occurring in bulk solutions and at the interface during the adsorption of heterocycles from diluted water-organic solutions is discussed. The compensation effect and linear Gibbs energy relationship upon the adsorption of 1,3,4-oxadiazoles and 1,2,4,5-tetrazines from the investigated water-organic solutions on silica gel with grafted phenyl groups is determined.