SOLUTION THERMODYNAMICS OF AMINO ACID-18 CROWN-6 AND AMINO ACID-CRYPTAND-222 COMPLEXATION REACTIONS

The thermodynamics of complexation between synthetic macrocyclic ligands (18 crown 6 and cryptand 222) and amino acids in methanol and ethanol is discussed. Attention is drawn to the enthalpy-entropy compensation effect of these ligands and amino acids in these solvents. From the thermodynamic data for these complexation reactions together with computer calculations, active sites of guest and host molecules are suggested. Transfer parameters from methanol to ethanol of amino acid-18 crown 6 complexes recently isolated, amino acids and the 18 crown 6 ligand from methanol to ethanol are discussed in relation to complexation data.