DFT Prediction of Dichlorvos cyclodextrin complex

Abstract In this study, we analyzed the host-guest inclusion complexes involving Dichlorvos and β-cyclodextrin (β-CD). We used the density functional theory with the dispersion correction (DFT-D) method. The computations employed the ωB97XD functional in conjunction with the split valence double zeta 6-31G (d, p) basis set. Our main goal was to look into the molecular structure, molecular interactions, thermodynamic features, inclusion process, and stabilization energies of Dichlorvos and β-CD inclusion complexes in gaseous and aqueous environments. Our findings revealed that the B orientation, where the chlorine atoms of Dichlorvos enter the hole of β-CD on its narrow side, is more energetically stable compared to the A orientation, where the chlorine atoms of Dichlorvos enter the hole of β-CD on its broadside. Furthermore, we thoroughly characterized the hydrogen bonds involved in these inclusion complexes. The non-covalent interaction (NCI-RDG) and independent gradient model (IGM) methods were used to describe these non-covalent interactions. Our results indicate that dispersion forces play an essential role in the hydrogen bond interactions with more electrostatic contribution. Additionally, we employed the energy decomposition method (EDA) to dissect and analyze the various bonding contributions in these complexes. Our findings underscore the critical importance of dispersion forces in stabilizing these complexes while highlighting the substantial influence of electrostatic interactions.