Electronic Transitions in Sulfur-Centered Radicals by Means of MSXα Calculations

Abstract

Highly reactive sulfur-centered radicals, which play an important role in air pollution and in biological systems, are usually idientified by their UV/visible absorption and/or ESR spectra. Spectral information are sometimes insufficient for an unequivocal characterization of the transient species. Their identification could be achieved by comparing the optical absorption spectra with the energy and intensity of electronic transitions computed using quantum mechanical methods. The MSXα method¹ has proved to be a powerful tool for assigning optical transitions in radicals,² and is used to assign the spectral bands of transient sulfur-centered radical species to specific electronic transitions.³