Molecular Tweezers in Host-Guest Complexes: A Computational Study through a DFT-D Approach

The interactions of small organic molecules with a recently designed molecular tweezer have been modeled using density functional theory approaches. The weak values of the complexation constants of the different compounds make the computations particularly challenging. Nevertheless, the selected theoretical approach is shown to be able to detect several outliers that have been then reexamined by experimental means. The autoassociation, as cyclic dimers, of two carboxylic acids is shown to significantly disturb the 1:1 ligand@host equilibrium constants. Indeed, in CH2Cl2 solutions, the complexes mainly present a 2:1 ligand@host structure. This investigation is a further step toward the rational design of molecular tweezers.