DFT calculations towards the geometry optimization, electronic structure, infrared spectroscopy and UV-vis analyses of Favipiravir adsorption on the first-row transition metals doped fullerenes;a new strategy for COVID-19 therapy

Abstract With the global epidemic of the COVID-19 virus, extensive and rapid research on drug therapy is underway around the world. In this regard, one of the most widely studied drugs is Favipiravir. Our aim in this paper is to conduct comprehensive research based on the Density Functional Theory (DFT) on the potential of metallofullerenes as suitable drug carriers. The surface interaction of Favipiravir with organometallic compound resulted by doping of the five transition metals of the first row of the periodic table (Ti, Cr, Cr, Fe, Ni, and Zn) was examined in depth to select the most suitable metallofullerenes. First, the adsorption geometries of Favipiravir drug onto each metallofullerene were deeply investigated. It was found that Cr-, Fe-, Ni-doped fullerenes provide the excellent adsorbent property with adsorption energies of -148.2, -149.6, -146.6 kJ/mol, respectively. The Infrared spectroscopy (IR) study was conducted to survey the stretching vibration of bonds involving in the systems, specialty the C=O in the drug, C-M in the metallofullerene, and M-O in the metallofullerene-drug complex. Finally, the UV-vis analysis showed that the absorption spectra for the studied systems may be attributed to the transition from π-π * and/or n - π*.