Density functional theories study of the interactions between host β-Cyclodextrin and guest 8-Anilinonaphthalene-1-sulfonate: Molecular structure, HOMO, LUMO, NBO, QTAIM and NMR analyses

In the present work, a quantum chemical calculation of energies, geometric parameters, frontier molecular orbitals, thermodynamic parameters, for inclusion complex of host beta-Cyclodextrin and guest 8-Anilinonaphthalene-1 -sulfonate (1,8-ANS@beta-CD) have been investigated using the following functionals, B3LYP, M06-2X and WB97X-D with the split valence double zeta 6-31G(d) basis set in both gas and aqueous phases. The results indicate that the orientation in which the guest molecule points toward the primary hydroxyls of the hydrophobic cavity of beta-CD is energetically preferred and exhibited a good agreement with the experimental results. NBO and QTAIM analysis are carried out in order to understand various second-order interactions between the filled orbital of one subsystem and vacant orbital of another subsystem. The H-1 nuclear magnetic resonance (NMR) chemical shift of the complexes was studied using the Gauge-Including Atomic Orbital (GIAO) method and compared with experimental values. (C) 2019 Published by Elsevier B.V.