NH Derived Sulfonic Acids: Hydrazine Disulfonate, [(SO)HNNH(SO)], and Hydrazine Iso-disulfonate, [HNN(SO)].

The reaction of hydrazinium sulfate and chlorosulfonic acid in pyridine leads to the pyridinium salt of the hydrazine disulfonate anion, [(SO)HNNH(SO)]. The salt is the starting material for the preparation of further hydrazine disulfonates, for example of alkaline metals and barium. In all compounds, the [(SO)HNNH(SO)] anion adopts the gauche conformation.