Thermodynamic study of organic compounds in di-n-butyl ether. Enthalpy andGibbs energy of solvation

The Gibbs energies and enthalpies of solvation of some hydrocarbons (n-hexa ne, n-octane, cyclohexane), alcohols (methanol, propan-1-ol, butan-1-ol, bu tan-2-ol), ethers (diethyl ether, tetrahydrofuran), ketones (propanone, pen tan-3-one, cyclopentanone), amines (n-propylamine, n-butylamine), and aceto nitrile in di-n-butyl ether have been determined at 298.15 K from vapour-li quid equilibrium measurements and from limiting enthalpies of solution. The data obtained have been compared with the corresponding values of the solv ation functions in octan-1-ol and hexadecane. The phenomenology has been di scussed in terms of a simple group additivity scheme. The interaction effec ts of polar and non-polar groups with the solvents have been deduced from t he above group contributions combined with the cavity terms estimated throu gh the scaled particle theory. The linear solvation energy relationships (L SER) have also been used for correlating the thermodynamic solvation functi on to the structural features of the solutes. All the approaches consistent ly highlight that the hydrophobic groups exhibit interactions with the solv ent of nearly the same strength in the three media, while clearly different interactions are shown by polar groups.