Electronic Absorption Spectra of Some Highly Perturbed N-Sulfinylanilines: Molecular Orbital Treatment

摘要

The electronic absorption spectra of m- and p-chloro, m- and p-nitro-N-sulfinylanilines were investigated using different solvents. The spectral behavior indicates the planarity of the studied molecules and that the sulfinylamino (NSO) group acts as an electron acceptor. All the observed bands in the spectra correspond to delocalized #pi# -> #pi#~* transitions, and non discrete bands were observed for n -> #pi#~* transitions. Ab initio molecular orbital calculations were performed, using split-valence basis sets, on the ground state of the studied molecules and the equilibrium geometric parameters were calculated. The results indicate that the NSO group is nonlinear, the studied molecules are planar, and the syn conformer is more stable than the anti one. AM1-SCF procedure was used to calculate the wave functions as well as the energies of the excited states of the studied molecules, the correspondence between the calculated transition energies and the experimental ones is satisfactory.