Comparison of DFT Methods for the Investigation of the Reduction Mechanisms of Aromatic Nitro- and Nitroso Compounds

The main goal of this paper is to find an adequate level of theory for the computational investigation of the reduction mechanisms of aromatic nitro- and nitroso compounds. To this end, five standard reduction potentials of nitro- and nitrosobenzene in three different solvents and four pKa values of species involved in the mechanism were compared with the values calculated at different DFT and CBS-X levels of theory. Out of fourteen tested functionals, five showed good linear correlation between calculated and experimental [[DELTA].sub.r][G.sup.[omicron]] values. However, at all explored levels of theory, the calculated [[DELTA].sub.r][G.sup.[omicron]] values systematically deviate from the experimental ones, indicating the necessity of better description of solvation effects for charged species, possibly via a cluster-continuum approach. Keywords: aromatic nitro compounds, reduction mechanism, DFT calculations, solvation.