Dithionitronium hexafloroarsenate is the inorganic compound with the formula . It is the hexafluoroarsenate salt of S=N=S+. The cation is of interest as the sulfur analogue of nitronium . Hexafloroarsenate is a weakly coordinating anion. According to X-ray crystallography, S=N=S+ is linear with S-N distances of 146 picometers.
Dithionitronium hexafluoroarsenate is prepared from thiazyl chloride using silver hexafluoroarsenate.[1] The hexachloroantimonate salt can be prepared by treating thiazyl chloride with sulfur in the presence of antimony pentachloride according to this idealized equation:
The dithionitronium cation reacts with nitriles to give dithiadiazolium salts:[2]
Addition to alkynes gives dithiazolium salts: