A DFT-D4 investigation of the complexation phenomenon between pentachlorophenol and β-cyclodextrin

Density functional theory (DFT) calculations based on the BLYP-D4 and PBEh-3c composite methods were performed for investigating encapsulation mode of pentachlorophenol (PCP) inside cavity β-cyclodextrin (β-CD). Different quantum chemical parameters such as HOMO, LUMO, HOMO–LUMO gap calculated. Complexation energies computed at molecular level to provide insight into inclusion PCP β-CD cavity. The Independent gradient model (IGM) approach was applied characterize non-covalent interactions that occurred during complex (PCP@β-CD) formation. Two modes considered in this work (modes A B). Calculated complexation well changes enthalpy, entropy, free Gibbs energy exhibit negative values both B, indicating a thermodynamically favorable process. Weak Van der Waals one strong intermolecular hydrogen bond act main driving forces behind stabilization formed most stable complex. This study carried out explore potential use host macrocycle sensing capturing pentachlorophenol.