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

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