While the world is in search of a
vaccine that can cure
COVID-19 disease,
favipiravir is the most commonly used
antiviral drug in the treatment of patients during the pandemic process. In this study, we investigated the host-guest interaction between the popular supramolecule
calix[4]arene derivatives and the
favipiravir drug by using the DFT (Density Functional Theory) method. The B3LYP hybrid method and 6-31G (d,p) basis set were utilized to determine the optimized structures of the host and guest molecules and their complexes. The negative adsorption energy (∆E) and adsorption enthalpy (∆H) calculated for the complexes formed between
calix[4]arene compounds and
favipiravir drug molecule mentioned that adsorption of
favipiravir molecule was an exothermic process on
calix[4]arene structures. On the other hand, among the
calixarene derivatives in the study, Gibbs free energy change (∆G) value for the adsorption was only negative on calix[4]arene4 molecule. The infrared spectroscopy (IR) calculations were performed by examining the C=O, O-H and NH2 vibrational frequencies to see the adsorption behavior in the
favipiravir-
calix[4]arene complex. After adsorption of the
favipiravir molecule, HOMO-LUMO gap values decreased significantly for the structures and therefore electrical conductivity increased proportionally. In addition, sensor response factors, Fermi energy levels and workfunction changes of
calix[4]arene derivatives were calculated and examined. Charge transfer between the four
calix[4]arene compounds and the
favipiravir molecule has occurred after adsorption. This attributes that
calix[4]arene derivatives can be used as a well-suited
favipiravir sensor (electronic and workfunction) and adsorbent at room temperature. Based on the calculations made to see the
solvent effect on the adsorption of
favipiravir it was determined that it did not affect the interaction between the
drug molecule and the
calix[4]arene compound too much and the adsorption energy turned into a slightly less negative value.