Rubidium 3-carboxy-4-hydroxy­benzene­sulfonate monohydrate

The title compound, poly­[[rubidium-μ-5-sulfonosalicylic acid] monohydrate], Rb⁺·C₇H₅O₆S⁻·H₂O, the 5-sulfosalicylic acid anion (3-carboxy-4-hydroxy­benzene­sulfonate) has lost the proton of —SO₃H group, but retains the usual intermolecular hydrogen bond between the phenolic and carboxyl­ic O atoms. The Rb⁺ cation is surrounded by eight O atoms. The crystal packing is stabilized by intermolecular O—H...O hydrogen bonds.