Crystal structure of N-hy­droxy­picolinamide monohydrate

The crystal structure of the title compound, C6H6N2O2H2O, consists of N-hydroxypicolinamide and water molecules connected through O—HO and N—HN hydrogen bonds. The O—HO interactions and – stacking interactions between the pyridine rings [centroid–centroid distance = 3.427 (1) A˚ ] organize the components into columns extending along the b axis and the N—HN hydrogen bonds link these columns into a two-dimensional framework parallel to (100). The N-hydroxypicolinamide molecule adopts a strongly flattened conformation and only the O—H group H atom deviates significantly from the molecule best plane. The dihedral angle between the hydroxamic group and the pyridine ring is 5.6 (2). The conformation about the hydroxamic group C—N bond is Z and that about the C—C bond between the pyridine and hydroxamic groups is E.