Molecular orbital calculations on the C2H4SH+ cation

Abstract

Systematic non-empirical SCF-MO calculations were carried out on the two limiting structures of C₂H₄SH⁺. In both of these cases two different atomic orbital basis sets were used. The results indicate that the open structure (β-thioethyl cation) lacks thermodynamic stability and spontaneously interconverts into the bridged structure (thiiranium ion). The pyramidal inversion at sulphur in the thiiranium ion was computed to be 78.11 kcal mol^–1.