THE INTERNAL-ROTATION OF HYDROGEN THIOPEROXIDE - ENERGY, CHEMICAL-POTENTIAL, AND HARDNESS PROFILES

We present a theoretical study of the internal rotation of HSOH. Calcu lations at the ab initio HF//6-311G* level show that HSOH is a gauche molecule presenting a double-barrier torsional potential. The differe nt mechanisms associated with isomerization passing by a trans or a ci s barrier have been characterized with the use of the profiles of pote ntial energy (V), electronic chemical potential (mu), and molecular ha rdness (eta). Important results have been obtained: (a) the principle of maximum hardness is verified; (b) the profiles of mu and eta in con nection with that of local electronic populations allows one a qualita tive characterization of the nature of the two potential barriers hind ering the internal rotation.