CONFORMATION AND STRUCTURE OF ETHANE-1,2-DITHIOL FROM ABINITIO HF AND MP3 STUDY

The structure and the conformational equilibrium of ethane-1,2-dithiol (CH2SHCH2SH) were determined by performing a geometry optimization at the HF/6-31G** level for both the anti and gauche conformers. The estimated geometries agree with the experimental values. Third-order Moller-Plesset (MP3) single-point calculations were done on the optimized geometries in order to obtain the final energies. At the Hartree-Fock (HF) level the gauche form is the most stable, while the inclusion of correlation effects reverses the stability order. Owing to the small energy difference it is possible that the two conformers coexist.