FRAGMENT CHEMISTRY OF THE HYDROGEN THIOPEROXIDE MOLECULE ENERGY, CHEMICAL-POTENTIAL AND HARDNESS

In this paper we present a complete theoretical study of the hydrogen thioperoxide molecule (HSOH). We characterize the internal rotation by studying the evolution of the energy, chemical potential and hardness along the torsional angle. We have found that hydrogen thioperoxide i n its electronic singlet state is a gauche molecule. Barrier heights, activation chemical potential and activation hardness have been obtain ed, and it has been found that the trans barrier is lower than the cis one. Good agreement of rotation barriers is obtained on the basis of comparisons with the available literature experimental data for the HO OH and HSSH parent molecules. Another important result is that the max imum hardness principle is verified for the torsional motion. On the o ther hand, we characterize the thermochemistry of chemical reactions l eading to formation of HSOH from the electronic properties associated with the free constituent fragments. The procedure, which involves the use of Sanderson's rule to estimate chemical potentials and hardnesse s, is shown to be promising and opens the possibility of rationalizing the behavior of other series of reactions.