Theoretical study of host–guest interactions in complexes of cucurbit[7]uril with protonated amino acids

Abstract

The theoretical study of host–guest interactions in complexes of protonated amino acids (AA = Val, Thr, Ser, Asn) and macrocyclic cavitand cucurbit[7]uril with the focus on characterisation of non-covalent interactions between the host and the guest molecules have been carried out. Host–guest interactions have been described by means of R. Bader’s ‘Atoms in Molecules’ theory and Energy Decomposition Analysis (EDA) as it is implemented in ADF program suit. EDA shows that energies of inclusion and exclusion complexes are very close. The optimised geometries for exclusion complexes of CB[7] with protonated AA are slightly more stable than their inclusion counterparts.