Sulphimide, (SO₂NH)₃

Sulphimide, or Trisulphimide, (SO₂NH)₃, is formed together with ammonia and imidosulphonic acid when sulphamide is heated at 200° to 210° C. It is also formed in small quantity as the ammonium salt, together with sulphamide, when sulphuryl chloride is treated with ammonia in chloroform solution:

3SO₂Cl₂ + 12NH₃ = (SO₂.N.NH₄)₃ + 6NH₄Cl.

Sulphimide is described as consisting of glistening white needles, melting at about 165° C., readily soluble in water, alcohol and acetone, sparingly soluble in ether and insoluble in benzene or chloroform. It is decomposed by hydrogen chloride with formation of ammonia and sulphuric acid. Ebullioscopic determinations of the molecular weight in ethyl acetate solution point to the formula (SO₂NH)₃. Hantzsch and Stuer, however, are of opinion that trisulphimide is unknown in the solid form, and that the substance previously described as sulphimide is really imidodisulphamide, NH₂.SO₂.NH.SO₂.NH₂, produced by the action of water on trisulphimide:

+ 2H₂O = NH₂.SO₂.NH.SO₂.NH₂ + H₂SO₄.