DFT Investigation on the Complexation of β-Cyclodextrin and Hydroxypropyl-β-Cyclodextrin as Recognition Hosts with Trichloroethylene

Abstract

In this investigation, the potential use of native β-cyclodextrin (β-CD) and hydroxypropyl-β-cyclodextrin (HP-β-CD) as encapsulating agents for trichloroethylene (TCE) was assessed. Various quantum chemical parameters, including HOMO, LUMO, and HOMO–LUMO gap, were calculated. The docking process was examined by considering different initial configurations. The complexation energies were calculated at the molecular level using DFT/BLYP-D4 and PBEh-3c calculations to gain insight into TCE encapsulation within the β-CD and HP-β-CD cavities. We used the independent gradient model (IGM) and extended charge decomposition analysis (ECDA) approaches to examine non-covalent interactions and charge transfer within TCE@β-CD and TCE@HP-β-CD complexes. The calculated thermodynamic data and complexation energies exhibited negative values for both considered complexes, indicating a favorable complexation process. Weak Van der Waals intermolecular interactions were the main driving forces in stabilizing the formed complex. Additionally, Monte Carlo simulations were conducted for a better understanding of the inclusion process. Our results provide evidence for the use of β-CD and HP-β-CD as suitable macrocyclic hosts for complexing trichloroethylene.