Enthalpy–entropy compensation in complexation of cations with crown ethers and related ligands

Abstract

Thermodynamic parameters indicate that the enthalpy–entropy compensation effect holds in general for complexation of cations with glymes/podands, crown ethers, cryptands, and macrocyclic antibiotics in various solvents. Thus the ΔH–TΔS plots give fairly good linear relationships for each type of ligand, with different slopes (α) and intercepts (TΔS₀) characteristic of the type. The nature of the cation–ligand interaction is discussed in terms of α and TΔS₀ values.