THEORETICAL-ANALYSIS OF THE INTERNAL-ROTATION, MOLECULAR-STRUCTURES AND ELECTRONIC-PROPERTIES OF THE XSSX SERIES OF MOLECULES (X=H, F, CL)

A detailed investigation of the internal rotation of hydrogen persulfi de and halogen derivatives (F, Cl) is presented. High quality torsiona l potential functions and analytic forms representing the conformation al dependence upon the internal rotation for various global and local properties have been determined. Computed equilibrium structures, barr iers to internal rotation and electronic properties reported here are in close agreement with the available experimental data. High barrier heights and the analysis of structural parameters of all molecules ind icate significant S-S pi bonding through the mechanism of hyperconjuga tion. We also analyze the nature of the barriers to internal rotation in terms of the specific through-space and through-bond interactions.