1,2-dithietanes, 4-membered rings where the two sulfur atoms are adjacent, are very rare. the first stable 1,2-dithietane to be reported was the so-called dithiatopazine formed by intramolecular photodimerization of a dithiocarbonyl compound. 1,2-dithietanes are to be distinguished from 1,2-dithietes, containing two adjacent sulfur atoms and two sp-hybridized carbon centers.