Imidodisulphamide, NH₂.SO₂.NH.SO₂.NH₂

Imidodisulphamide, NH₂.SO₂.NH.SO₂.NH₂, is the first product of the action of ammonium carbamate on pyrosulphuryl chloride. It is also obtained when sulphamide is heated nearly to its melting-point. Imidodisulphamide forms needle-shaped colourless crystals, melting at 160° C., and having a distinctly acid taste, since water causes rapid decomposition into sulphamide and amidosulphonic acid:

NH(SO₂.NH₂)₂ + H₂O = SO₂(NH₂)₂ + NH₂.SO₂OH.