1,5-Dithia-2,4,6,8-tetrazocine: A Novel Heterocycle of Unusual Properties

Four representatives of a novel heterocycle-l,5-dithia-2,4,6,8-tetrazocine-were prepared. In the 3,7-diphenyl (3) and 3,7-bis(p-methoxyphenyl) (5) derivatives, the eight-membered ring was found to be planar by X-ray diffraction analysis; this and the bond lengths as well as the electronic spectra suggest a delocalized, aromatic system of 10 π electrons. On the other hand, 3,7-bis(dimethylamino)-1,5-dithia-2,4,6,8-tetrazocine (4) is folded along an axis drawn through the sulfur atoms; the short distance between the latter atoms is suggestive of their partial bonding in this compound.