The first diazatetrathiafulvalenes

Abstract Treatment of 1,4,2-dithiazolium salts, unsubstituted at C-5, with triethylamine yields mixed geometrical isomers of 5-(1,4,2-dithiazol-5-ylidene)- 1,4,2-dithiazoles, in 10–28% yields; X-ray analysis of the trans -3,3′-diphenyl derivative 5a shows the molecules to be planar and to stack along the b direction with close perpendicular intra-stack distances of 3.56 A.