The effect of d orbitals on the calculated ultraviolet spectra of organosulphur compounds

Abstract

The virtual orbital approximation to excited states using the results of CNDO/2-SCF–MO calculations has been used to evaluate the effect of d orbitals on the absorption spectra of thiolesters and sulphur–nitrogen compounds. In general, the predicted absorption maxima for π→π* transitions are too large; and although the inclusion of d orbitals improves the agreement with thiolesters this is not so for nitrogen–sulphur compounds. It is impossible to draw meaningful conclusions from such calculations about the necessity of d orbital participation.