Intermolecular interactions of Guanosine/β-Cyclodextrine and Guanosine-hydroxypropyl/β-Cyclodextrin inclusion complexes using DFT calculation

Abstract

In this work the study investigates intermolecular interactions in Guanosine (Guo) into β-cyclodextrin (β-CD) and their derivatives, such as hydroxypropyl-βCD (HPβCD) inclusion complexes using Density Functional Theory including dispersion correction (DFT-D3) method using the following functional, B3LYP/6-31G basis set in both gaz and aqueous phases. These complexes geometries were optimized and the final results were examined and contrasted. The global chemical reactivity descriptors, the Fukui function, and the HOMO and LUMO energies were calculated. The TD-DFT method was used to determine the complexes absorption spectra.To forecast the reactive sites for electrophilic and nucleophilic attack, the molecular electrostatic potential was computed. The interaction bonds were investigated and the formation of conventional hydrogen bonds was detected by AIM analysis. The nature of the interactions was further elucidated using the method of non-covalent   interactions (NCI). This showed that hydrogen bonds and van der Waals interactions contribute significantly to the formation of the inclusion complex. To gain more insight into the absorption and emission energies of the investigated complex, the gap energy (EHOMO-ELUMO) was calculated.