The Vibrational Assignment and Rotational Isomerism of 1,2-Dithiamethyl Ethane

The infrared and Raman spectra of 1,2-dithiamethyl ethane have been measured in gaseous, liquid and solid states. Vibrational assignments have been made in relation to the rotational isomerism. The normal vibration calculation has been carried out in a modified Urey-Bradley force field. In the gaseous and liquid states, GTG′ and GGG molecular forms exist, while in the solid state the GTG′ form alone persists. The energy difference between GTG′ and GGG molecular forms has been found to be 1.1 kcal./mol. in the gaseous state and very small in the liquid state. The GTG′ form is more stable than the GGG form, in both the gaseous and liquid states.