CALCULATED AND OBSERVED IONIZATION POTENTIALS OF NITROALKANES AND OF NITROUS AND NITRIC ACIDS AND ESTERS . EXTENSION OF MINDO METHOD TO NITROGEN-OXYGEN COMPOUNDS

(a) A recently developed semiempirical SCF-MO procedure (MINDO method) has been extended to compounds containing nitrogen and oxygen. Calculations are reported for nitroalkanes and for nitrous and nitric acids and their esters, (b) The photoelectron spectra of these compounds have also been measured, using a grid-type retarding potential spectrometer; the observed first ionization potentials correlate well with the calculated energies of the highest occupied MO's. (c) The protonation of nitrous and nitric derivatives has been studied by the MINDO method; the calculations indicate that protonation should take place preferentially at the singly bound oxygen. This unexpected result is interpreted in terms of the effect of hybridization on the basicity of lone pair electrons. © 1969, American Chemical Society. All rights reserved.