An MNDO study of sulfenium ions

Abstract

An MNDO study has been carried out on a variety of substituted sulfenium ions and sulfides. Relative stabilities in the gas phase have been calculated for several pairs of regioisomeric sulfenium ions. It is shown that sulfenium ions are stabilized by π-donors and that the substituent electronegativity is not an important factor. The potential implications of this result for the mechanism by which chlorosulfonium cations are converted into sulfenium ions in solution is discussed. Substituent effects on the energetics of sulfenium ion formation from sulfides have been obtained. It is shown that these effects also are related to the substituent's π-donating ability. A frontier-orbital analysis of selected sulfenium ions has been done and is discussed.