ABSTRACT
Supramolecular interactions involve bonding rearrangements that invariably produce heat effects. The measurement of the heat change (calorimetry) depending on the composition of a system thus constitutes the most direct and universal means to investigate intermolecular complexation in solution. With the advent of computer-operated highly sensitive microcalorimeters, a door was opened to investigate the energetic exchange occurring on the mutual binding of host–guest partners, as they exist in their time-averaged structural ensembles. Thus, standard thermodynamic state functions (e.g. enthalpy, entropy, free energy, and heat capacity) can be obtained on micromoles of material for the use in applications employing supramolecular equilibria or in artificial receptor design. This entry describes the physical basis, the principle of measurement, the data evaluation, and the frame for interpreting the results of one of the most convenient, fast, accurate, and non-destructive modern techniques for the determination of intermolecular interactions.
