Experimental Data for: Tuning the free energy of host–guest encapsulation by cosolvent

The data provided here correspond to the analysed THz spectra presented in the publication “Tuning the free energy of host–guest encapsulation by cosolvent”. This study experimentally and theoretically investigated the encapsulation of tetraethylammonium chloride in the supramolecular cages [Ga<sub>4</sub>L<sub>6</sub>]<sup>12−</sup> and [In<sub>4</sub>L<sub>6</sub>]<sup>12−</sup> in mixed DMSO/water solvents, demonstrating that even moderate variations in solvent composition can significantly affect entropy and guest binding.

The THz spectral data capture how the local solvent structure within hydrophobic nanocages influences host–guest interactions. The study shows that the addition of small amounts of dimethyl sulfoxide (DMSO, around 10%) leads to the preferential residence of a single DMSO molecule inside the cage cavity. This effect markedly alters the entropic contribution (ΔS) of the encapsulation process, which can be attributed to the effective reduction of the accessible cavity volume.

Overall, the dataset provides key insights into solvent-dependent modulation of supramolecular binding and illustrates the sensitivity of host–guest encapsulation to local changes in solvent composition. The THz spectra support research applications in supramolecular chemistry, catalysis and chemical separation processes.