Molecular DFT Investigation on the Inclusion Complexation of Benzo[a]pyrene with γ-Cyclodextrin

The complexation process between benzo[a]pyrene (BaP) and -cyclodextrin (-CD) was computationally studied using DFT methodology. Several initial configurations of the interaction of BaP with -CD were explored to determine the most stable inclusion complex. According to the calculated complexation energies, the BaP/-CD complex is found to be the most favorable energetically when the BaP guest is totally entrapped into -CD cavity. The inclusion process involving the encapsulation of two guests BaP in the cavity of -CD is also thermodynamically favored. Van der Waals interactions play a determinant role in stabilizing BaP/-CD and 2BaP/-CD complexes.