The development of new methods of perturbation, thermodynamic integration and potential of mean force allowed us to characterize thermodynamically (delta G r, r delta H, delta S r) of the association process between a macrocycle and different types of cations in aqueous solution. Different methodologies have been developed based on the nature of non-covalent interactions involved between the macrocycle and the cation (-pi interaction, electrostatic, van der Waals). When the magnitudes of association were calculated in agreement with experiment, the appearance of complex molecular description and associated phenomena has enabled the coupling between the microscopic and macroscopic thus completing the analysis of the thermodynamic.
