Cyclohexane-Based Scaffold Molecules Acting as Anion Transport, Anionophores, via Noncovalent Interactions

A theoretical study of a variety of cyclohexane-based anion transporters interacting with the chloride anion has been conducted using density functional theory. The calculations have been performed in the gas phase but also, in order to describe the solvation effects on the interaction, two different solvents-chloroform and dimethylsulfoxide-have been taken into account. Gas-phase interaction energies within the complexes are found to be up to 400 kJ/mol, while, when solvent effects are considered, the interaction energy values decreased drastically concomitantly with an elongation in the interatomic distances. Atoms in molecules and natural bond analysis corroborate the trends found for the intermolecular energies and Cl···H distances, suggesting strong donations from the Cl^- anion into the σ*H-N antibonding orbitals, as well as with noncovalent interaction plots showing large areas of electron density overlap within the chloride anion surroundings.