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organic compounds
The extensive hydrogen-bonded networks of the title compounds, C7H10O6, (I), NH4+.C6H7O6-.1/2H2O, (II), 4NH4+.C8H6O84-.H2O, (III), have been analyzed. In compound (I), layers are formed by eight-membered and 16-membered hydrogen-bonded rings. In compound (II), the anions are arranged into double chains of 30-membered rings through short hydrogen bonds. These chains are cross-linked by weaker hydrogen bonds to H2O and NH4+. In compound (III), stacks of centrosymmetric anions are connected by hydrogen bonds to H2O and NH4+.