The radical scavenging activity of Edaravone (3-methyl-1-phenyl-2-pyrazolin-5- one, EDA) and 26 derivatives has been studied using the density functional theory, in particular the M05-2X functional. In all cases both, the neutral and anionic forms were considered. We report for the first time their ionization potentials, proton affinities and pKas in...