The electronic structure, spectra, and reactivity of nitrophenols

The all-valence-electron CNDO/2 calculations were performed for the three isomeric nitrophenols. Using the newly derived \sigma -core charges and subsequently revising the valence-state ionization potentials and one-center two-electron repulsion integrals, Pariser-Parr-Pople (PPP) CI calculations were performed on the title compounds following the Nishimoto-Forster scheme. A better agreement between theory and experiment has been observed in spectral assignments compared to the conventional PPP approach. Information from the CNDO/2 calculations was used to obtain useful electronic structural parameters and to get a quantitative insight into the chemical reactivity of these molecules. All the results were compared with the basic compounds, phenol and nitrobenzene. The electronic spectra of these isomers were recorded in both polar and nonpolar solvents