title: Crystal structure of N-hy-droxy-picolinamide monohydrate.
abstract: The crystal structure of the title compound, C6H6N2O2·H2O, consists of N-hy-droxy-picolinamide and water mol-ecules connected through O-H⋯O and N-H⋯N hydrogen bonds. The O-H⋯O inter-actions and π-π stacking inter-actions between the pyridine rings [centroid-centroid distance = 3.427 (1) Å] organize the components into columns extending along the b axis and the N-H⋯N hydrogen bonds link these columns into a two-dimensional framework parallel to (100). The N-hy-droxy-picolinamide mol-ecule adopts a strongly flattened conformation and only the O-H group H atom deviates significantly from the mol-ecule 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.
authors.affiliation: Department of Chemistry, National Taras Shevchenko University of Kyiv, Volodymyrska Street 64, 01601 Kiev, Ukraine.
authors.forename: Inna S
authors.initials: IS
authors.lastname: Safyanova
authors.affiliation: Department of Chemistry, National Taras Shevchenko University of Kyiv, Volodymyrska Street 64, 01601 Kiev, Ukraine.
authors.forename: Kateryna A
authors.initials: KA
authors.lastname: Ohui
authors.affiliation: SSI "Institute for Single Crystals", National Academy of Sciences of Ukraine, Lenina ave. 60, Kharkiv 61001, Ukraine.
authors.forename: Irina V
authors.initials: IV
authors.lastname: Omelchenko
keywords: crystal structure; hydrogen bonds; hydroxamic acids; π–π stacking inter­actions