Crystal structure of -hy-droxy-quinoline-2-carboxamide monohydrate.

The title compound, CHNO·HO, consists of an -hy-droxy-quinoline-2-carboxamide mol-ecule in the keto tautomeric form and a water mol-ecule connected through an O-H⋯O hydrogen bond. The -hy-droxy-quinoline-2-carboxamide mol-ecule has a nearly planar structure [maximum deviation = 0.062 (1) Å] and only the hy-droxy H atom deviates significantly from the mol-ecule plane.

Crystal structure of bis-(μ--hy-droxy-picolin-amid-ato)bis-[bis-(-hy-droxy-picolinamide)-sodium].

The title compound, [Na(CHNO)(CHNO)], is a centrosymmetric coordination dimer based on the sodium(I) salt of -hy-droxy-picolinamide. The mol-ecule has an {NaO(μ-O)} core with two bridging carbonyl O atoms and two hydroxamate O atoms of two mono-deprotonated residues of -hy-droxy-picolinamide, while two neutral -hy-droxy-picolinamide mol-ecules are coordinated in a monodentate manner to each sodium ion the carbonyl O atoms [the Na-O distances range from 2.3044 (2) to 2.

Crystal structure of N-hy-droxy-picolinamide monohydrate.

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).

Crystal structure of 2-{[(E)-(4-anilinophen-yl)iminium-yl]meth-yl}-5-(di-ethyl-amino)-phenolate.

The title compound, C23H25N3O, crystallized with one single mol-ecule in the asymmetric unit and is present in the zwitterionic form. There is an intra-molecular N-H⋯O hydrogen bond in the mol-ecule with the phenol ring being inclined to the central benzene ring by 20.67 (14)°.

2-[(Pyridin-2-yl)amino]-pyridinium 2,4,6-tri-nitro-phenolate.

In the cation of the title salt, C10H10N3 (+)·C6H2N3O7 (-), the pyridine and pyridinium rings are linked by an intra-molecular N-H⋯N hydrogen bond and are approximately coplanar, with a dihedral angle between their planes of 4.24 (6)°. In the crystal, the cations and anions are linked through N-H⋯O hydrogen bonds, forming supra-molecular chains propagating along the c-axis direction.