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organic compounds
In the structure of the title compound, 4,8-dihydroxy-2-quinolinecarboxylic acid monohydrate, C10H7NO4.H2O, the ionized carboxyl group is located in the quinoline ring plane and the N atom of the ring is protonated so that it is positively charged, i.e. the compound may be named 4,8-dihydroxyquinolinium-2-carboxylate monohydrate. The crystal structure is stabilized by intermolecular O—HO hydrogen bonds involving the water molecule.